Comprehensive Physiology Wiley Online Library

Mechanics of Vascular Smooth Muscle

Full Article on Wiley Online Library



ABSTRACT

Vascular smooth muscle (VSM; see Table 1 for a list of abbreviations) is a heterogeneous biomaterial comprised of cells and extracellular matrix. By surrounding tubes of endothelial cells, VSM forms a regulated network, the vasculature, through which oxygenated blood supplies specialized organs, permitting the development of large multicellular organisms. VSM cells, the engine of the vasculature, house a set of regulated nanomotors that permit rapid stress‐development, sustained stress‐maintenance and vessel constriction. Viscoelastic materials within, surrounding and attached to VSM cells, comprised largely of polymeric proteins with complex mechanical characteristics, assist the engine with countering loads imposed by the heart pump, and with control of relengthening after constriction. The complexity of this smart material can be reduced by classical mechanical studies combined with circuit modeling using spring and dashpot elements. Evaluation of the mechanical characteristics of VSM requires a more complete understanding of the mechanics and regulation of its biochemical parts, and ultimately, an understanding of how these parts work together to form the machinery of the vascular tree. Current molecular studies provide detailed mechanical data about single polymeric molecules, revealing viscoelasticity and plasticity at the protein domain level, the unique biological slip‐catch bond, and a regulated two‐step actomyosin power stroke. At the tissue level, new insight into acutely dynamic stress‐strain behavior reveals smooth muscle to exhibit adaptive plasticity. At its core, physiology aims to describe the complex interactions of molecular systems, clarifying structure‐function relationships and regulation of biological machines. The intent of this review is to provide a comprehensive presentation of one biomachine, VSM. © 2016 American Physiological Society. Compr Physiol 6:111‐168, 2016.

Comprehensive Physiology offers downloadable PowerPoint presentations of figures for non-profit, educational use, provided the content is not modified and full credit is given to the author and publication.

Download a PowerPoint presentation of all images


Figure 1. Figure 1. Diagram of vascular smooth muscle (VSM, A) and cell structural hierarchy (B‐E). VSM structure includes cells that are embedded in and mechanically attached to ECM comprised largely of elastin and collagens (Coll) I and III (A). Several models of smooth muscle cell ultrastructure have been proposed (20,274); Small's model is shown in panels B and C. An extensive cytoskeleton interconnects a filamin‐actin‐desmin filament domain (FAD) with an actomyosin (AM) domain attached to dense bodies and dense plaques (B and C). The smooth muscle sarcomere structure remains to be fully elucidated and appears to be highly dynamic. However, a general view is that the thick filaments (M) are side polar (C and D) and the thin filaments (A) and FAD attach to dense bodies (B and C). Myosin is a heterohexamer comprised of two heavy chains and two pairs of light chains (E, only a single heavy chain and single pair of light chains is shown). The light meromyosin (LMM) tail region of individual myosin heavy chains associate with other myosin heavy chain tails to form thick filaments (D). The catalytic region of the myosin S1 head extends from the α‐helical S1 neck wrapped by one essential (ELC) and one regulatory light chain (RLC), which in turn extends from the myosin S2 region, to reach actin‐binding sites. Panels A‐D adapted from, respectively (419,426,105), and (529), with permission.
Figure 2. Figure 2. Smooth muscle cell and arterial structures. 3D fluorescence micrograph of antibody‐labeled artery cross‐section revealing the alternating pattern of, respectively, caveolae (C, green) and dense plaques (D, red) within a single VSM cell digitally isolated from other cells and the ECM. Each square = 1 μ2 (A). Transmission electron micrograph of a VSM cell from rabbit renal artery shown in cross‐section (B) revealing extensive thin filaments and alternating caveolae (C) and dense plaques (D). Note that microtubules (arrow) reside adjacent to caveolae and mitochondria, supporting the notion that these structures, acting as cargo for microtubule motor proteins, are adjusted in space and time. Thin filaments occupy much of the cytosol [for examples of electron micrographs of smooth muscle revealing the relative abundance of thick and thin filaments, see (20,93,201)]. Diagram of a model of dense bodies (dots) and actomyosin filaments (lines) in a single contracted and relaxed smooth muscle cell in cut‐away lateral and cross‐sectional views (C). Electron micrograph of a rabbit femoral artery cut transverse to the long axis of the arterial tube revealing outer adventitia (A), middle media (M), and inner intima (I) (D). Fluorescence micrograph revealing the long, fusiform shapes of isolated single VSM cells (E). A single relaxed (upper panel) and contracted (lower panel) VSM cell attached at one end to a micropipette (upper right) (F). Note dramatic degree of shortening and formation of blebs (B) upon shortening. Panel A adapted from (374). Panel C adapted from (80) with permission. Panels D‐F adapted, with permission, from, respectively (191,113), and (110).
Figure 3. Figure 3. The minimum solution pO2 required to support full isometric contraction of swine carotid media stimulated with epinephrine is dependent on arterial tissue thickness such that a bathing solution bubbled with room air would suffice for tissues ≤400 μ thick (A). Arteries can be classified, according to the strength of force maintenance (tonic phase) compared to that developed during the early phasic phase of contraction, into tonic (B) and phasic (C) arteries; FA = rabbit femoral artery, SA = rabbit saphenous artery (contractile stimulus: K+‐depolarization). Compared to elastic arteries (D: abdominal aorta, AA, and E: common iliac artery, CIA), muscular arteries (D: femoral artery, FA, and E: external iliac artery, EIA) express a higher VSM/ECM ratio and therefore produce significantly stronger contractions when normalized to tissue cross‐sectional area (F). Data adapted, with permission, for panel A from (332). Solid and dashed lines in panels B‐E are, respectively, average and SE values, n = 5‐7 rabbits. * = P < 0.05 compared to AA.
Figure 4. Figure 4. Analog elements used to form mechanical circuits include a spring (A) and dashpot (B) that are fixed at one end and attached to other elements at their free end (filled circle). (C) To measure force, these elements (ele) are attached to a force transducer (FT) of known very high stiffness (kFT).
Figure 5. Figure 5. Preconditioning (B, note decline in peak force from cycle 1 to 7 and from cycle 8 to 14) of a strip of naïve rabbit bladder incubated in a Ca2+‐free solution resulting from (A) 7 sequential 1 mm ramp load‐unload cycles at 1 mm/s (1, 2, … 7), followed immediately by 7 sequential 2 mm ramp load‐unload cycles at 1 mm/s (8, 9, … 14). In this context, a naïve tissue is one mounted on a myograph that has not yet been subjected to load‐unload cycling. Clockwise force versus length work loops of data shown in panels A and B reveal a high, linear stiffness during loading for the first cycle from 0 to 1 mm (C), and during the “new” strain region (from 1 to 2 mm) of the eigth cycle (D) only. All other cycles display nonlinear length‐force curves and much smaller work loop areas. The loading curve for the first mm of cycle 8 is superimposable on the loading curve of cycle 7. Cycles 6 (not shown) and 7, and cycles 13 (not shown) and 14 are identical. Adapted, with permission, from (445).
Figure 6. Figure 6. A stepper motor controlled to stretch and compress a spring (A‐F) can reveal the linear stress (σ) versus strain (ϵ) (G) and constant stress/strain quotient (H, stiffness E) characteristic of a linear spring. The free and fixed ends of the spring are represented by, respectively, r and q. The nonstretched resting position of r is j0. Spring compression involves moving r toward j‐1 and beyond, and spring tensioning involves moving r toward j+1 and beyond. A nonlinear spring (G, dash‐dotted curve) would result in a nonconstant E (H, dash‐dotted curve). Drawings of sheets of different widths w (I) and a rectangular block of thickness h (J) showing direction of applied displacement producing measured uniaxial force, f (I), which can be normalized to calculate tension, T (I), and stress, σ (J).
Figure 7. Figure 7. Rapidly activated swine carotid media displays a linear relationship between active stiffness (dσ/dl0) and stress (σ). Adapted from (423) with permission.
Figure 8. Figure 8. A stepper motor controlled to stretch a dashpot (A‐D) can reveal the linear relationship between stress (σ) and strain‐rate (ϵ·) and constant σ/ϵ· quotient (viscosity η) characteristic of a linear dashpot (F). Stepper motor ramp stretches (E) at two different rates (ϵ vs. time: lower curves, fast and slow strains from j to j+1) induce two different levels of stress (σ: upper square‐wave curves, fast and slow). Honey has a higher viscosity than H2O (F). Thus, a slow ramp stretch of a honey‐filled dashpot will induce a higher level of stress than the same slow ramp stretch of a H2O‐filled dashpot (E, honey; slow compared to H2O; slow).
Figure 9. Figure 9. Soft tissues display stress (σ)‐relaxation (B, σ‐relaxation of rabbit renal artery, RA) over time when subjected to an imposed rapid stretch to a new tissue length [A; length (l), stretch‐ratio (λ), or strain (ϵ)‐step)] and held there for some time (l, λ, or ϵ‐clamp). Simulations of the stress responses (D, F) to a strain‐step/strain‐clamp protocol (C, E) for a spring of stiffness E = 3 (C, D) and dashpot of viscosity η = 3 (E, F). As dt approaches zero in the strain‐step rate, stress will increase toward ∞ (F).
Figure 10. Figure 10. Simulations of the stress (σ) responses (B, E, H) to a sinusoidal strain (ϵ)‐oscillation protocol (A, D, G) for a spring of stiffness E = 3 (A‐C), dashpot of viscosity η = 3 (D‐F) and 2 element Maxwell Model (G‐I). The stress‐strain (σ‐ϵ) relationships for a spring and dashpot reveal, respectively, no time dependency (C) and time dependency (F and I). The time dependency of the dashpot is revealed by a lag in the imposed length change compared to the stress response, and damping of the maximum stress value. In a Maxwell Model, the spring (s) element requires some strain to develop stress, so the dashpot (d) element dampens the stress response to the strain (i) proportionally to the spring compliance (see Fig. 11). How far the dashpot plunger is from its new equilibrium position determines stress‐strain work loop area and position on the y‐axis; the position was further from the new equilibrium during the first than the second loading. l = length, f = force.
Figure 11. Figure 11. Simulations of the stress (σ) responses (B, C, E, and F) to sinusoidal strain (ϵ)‐oscillation (A) and strain‐step/strain‐clamp (D) protocols for a two‐element Maxwell Model with spring (s) stiffness E = 3 and dashpot (d) viscosity η = 10‐fold that of Figure 10. 1, 2, … 7 identify load‐unload cycles 1, 2, … 7. In panels D‐F, segment 1 to 2 refers to the instantaneous strain‐step, and segments 2 to 3 refer to the strain‐clamp period lasting 45 s. See text for details.
Figure 12. Figure 12. Sequential loading‐unloading curves of dog femoral artery rings reveal clockwise force (F)‐length (L) loops and strain softening (force achieved during the tenth loop is less than that achieved during the first loop). Adapted, with permission, from (389).
Figure 13. Figure 13. Sequential stretch strain (ϵ)‐step/strain‐clamps applied to a viscoelastic soft tissue over time (a temporal staircase‐strain protocol) produces an instantaneous stress (σ) response due to the strain‐step and an equilibrium stress response at the end of stress‐relaxation (A, plot over time; B, stress‐strain plot). For each strain‐step, the elastic stress equals the equilibrium stress, and the viscous stress equals the difference between instantaneous and equilibrium stresses (B, C). Elastic and viscous stress‐strain plots for vena cava (VC), abdominal aorta (Ab Ao), and carotid artery (CA) reveal considerable differences for different vascular tree segments (D). Panels A‐C adapted from (406) and panel D adapted from (420), with permission.
Figure 14. Figure 14. The final viscoelastic stress‐strain (σ‐ϵ) cycle (8) from the simulation shown in Figure 11c oscillates around zero stress and is linear (A), unlike that of a swine carotid artery (B). Nonlinearity can be incorporated into a Maxwell Model stress‐strain relationship (C; for this simulation, constants for spring stress, σs, were a = 0.3, b = 0.3, and c = −0.5), but the function chosen should have some mechanistic basis. Panel B adapted, with permission, from (408).
Figure 15. Figure 15. Preconditioned soft tissues such as arteries display a passive stiffness‐stress (dσdλσ) relationship that can be modeled as a 1 (or 2) component curve consisting and a linear portion fitting the equation, dσdλ=ασ+αβ (plus a nonlinear portion at very low stress values), where σ = stress, λ = stretch ratio, and α and β are constants (459). Extrapolation of the linear portion provides a stiffness value at zero stress, E0, the product of α and β, that can be used to characterize different tissues. Compared to muscular arteries and heart (B) that display low E0 values, those for elastic arteries (A, dog aortic arch) are relatively high (356,459). The slope of the linear portion, α, is the deviation from constant stiffness. Panels A and B adapted from, respectively, (459) and (356), with permission.
Figure 16. Figure 16. Simulations of the stress (σ) response (B and C) to a sinusoidal strain (ϵ)‐oscillation protocol (A) for a two‐element Voigt Model and stress response (E and F) to a strain‐step/strain‐clamp followed by a quick‐release, small strain‐step protocol (D) for a three‐element Generalized Maxwell Model. A simulation that includes only the springs of a generalized Maxwell model is also shown (F, dash‐dotted line). See text for details.
Figure 17. Figure 17. A quick‐release small strain (ϵ)‐step protocol performed on passive (unstimulated) swine carotid artery reveals weak force redevelopment (A), adapted from (199), with permission. A three‐element generalized Voigt Model (B) and two depictions of a multielement Hill Model (C). Simulations of the stress (σ) response (E and F) to a strain (ϵ)‐step/strain‐clamp followed by a quick‐release small strain‐step protocol (D) for a three‐element Generalized Voigt Model. See text for details.
Figure 18. Figure 18. A generalized model of multiple stress‐strain (σ‐ϵ) behaviors for various types of materials (A). Examples of stress‐strain curves for elastic fibers, elastin, and resilin (B), viscoelastic biomaterials such as skeletal muscle treated to remove thin filaments and retain titin (C) and keratin fibers (D), and viscoelastic‐plastic materials such as Hagfish thread (E). The pressure‐volume (P‐Vol) relationship for femoral artery (F) reveals apparent viscoelastic‐plastic behavior. See text for details. Panels B, D, and E adapted from (315), panel C adapted from (165), and panel F adapted from (39), with permission.
Figure 19. Figure 19. A steady‐state model of the actomyosin cross‐bridge cycle showing four myosin (M) states (A) that include actin (A) plus myosin (M; 1), actin (A) + phosphorylated M (Mp; 2), a phosphorylated cross‐bridge species (AMp; 3) and a dephosphorylated cross‐bridge species, the latchbridge (AM; 4); k values represent rate constants. Rabbit femoral artery activated at time zero with a maximum KCl stimulus produces a counterclockwise [Ca2+]i‐force response revealing two phases, a rapid (∼15 s) phasic phase in which [Ca2+]i increases to its maximum level and force develops to ∼70% maximum, and a tonic phase in which force slowly (from ∼15 s to 3 min) increases further to the maximum level while [Ca2+]i declines to its steady‐state supra‐basal level (B). A comparison of the rabbit slow, tonic femoral artery (FA) and fast, phasic saphenous artery (SA) reveal that during the fast phasic phase, force (C), [Ca2+]i (D, Pk) and myosin phosphorylation (MLC‐p, E, second data point at ∼40% MLC‐p) responses are identical. With time, however, force (C) and MLC‐p (E) dissociate whereas the [Ca2+]i response does not (D, 5 and 10 min). * indicates significant difference (P < 0.05). Panel B adapted from (378) and panels C‐E adapted from (191), with permission.
Figure 20. Figure 20. Hai‐Murphy four‐state kinetic latchbridge model (L) simulation (dashed lines), a four‐state no latchbridge model (NL) simulation [dashed dotted lines (E‐H)] and empirical data (solid lines and symbols) for femoral artery (FA) and saphenous artery (SA). The simulated L model employs a very slow k7 = 0.005 compared to k4 = 0.05, whereas the NL model simulation excludes a latchbridge by assigning k7 = k4 = 0.05. The L model fits the data for the slow, tonic femoral artery (A, B, D), and the NL model fits the falling tonic phase contraction and falling intracellular free Ca2+ concentration and myosin phosphorylation (E, F, H) characteristic of the fast, phasic saphenous artery, suggesting that fast arteries lack latchbridges. Adapted, with permission, from (191).
Figure 21. Figure 21. Isolated whole rabbit femoral (A) and saphenous (B) arteries were pressurized (P) to 60 mmHg, contracted with a maximum [KCl] and allowed to constrict isobarically to measure the degree of reduction in artery lumen diameter at steady state. After recording steady‐state constriction, the arteries were fully relaxed (dilated), pressurized to the next pressure level, activated with KCl and constriction was measured at that pressure (isobaric constriction). This procedure was continued until full steady‐state pressure‐diameter curves were produced for activated femoral (A, open circles) and saphenous (B, open squares) arteries. Diameter data were normalized afterward to maximally constricted (zero) and dilated (one) values. After generation of these active pressure‐diameter curves, fully relaxed arteries were depressurizing to 60 mmHg, activated with KCl to produce full isobaric constriction at 60 mmHg (vertical down arrow), and subjected to a pressure ramp from 60 to 120 mmHg (A, femoral artery, solid circles and arrow) and 60 to 140 mmHg (B, saphenous artery, solid squares and arrow). The activated femoral artery, fully constricted at 60 mmHg, remained nearly fully constricted when subjected to the ramp pressure increase (A, solid circles). By contrast, the activated saphenous artery, also fully constricted at 60 mmHg, dilated along the isobaric constriction curve when pressurized (B, solid squares). Thus, shortened VSM of femoral artery can resist lengthening when subjected to pressures much higher than the muscle can shorten against, suggesting that latchbridges endow slow arteries with dilatation‐resistance (C). See text for additional details. Adapted, with permission, from (60).
Figure 22. Figure 22. Active stress (σ)‐strain (ϵ) (tension‐length, force‐length) curves (A‐F) and “passive” stress‐strain curves for skeletal muscle (E) and artery (F). Bottle brush cartoon illustrates the concept that the degree of overlap (solid bars) of actin (bottle wall) with myosin cross‐bridges (bristles) determines the strength of active stress on the descending limb (d.l.) of the active stress‐strain curve (A). Additional complexity is required to explain the shape of the ascending limb (a.l.). Examples of active stress‐strain curves for striated muscle sarcomere (B), carotid media (C), and small mesenteric artery displaying an initial active stress‐strain curve (D, day 0) and one produced after the tissue had been incubated in culture medium at 0.4‐fold lref for 16 h with the contractile agent endothelin (D, day 1). Also shown is the total stress‐strain curve for small mesenteric artery, which is the sum of the “passive” and active curves (F). See text for details. Panels B, C, D, and E adapted from, respectively (370,522,474) and (527), with permission. Panel F adapted, with permission, from (535).
Figure 23. Figure 23. A schematic illustrating a Maxwell Model (representing muscle) attached to a generalized apparatus designed to measure and control the degree of force and length over time (A) to assess the stress (σ)‐strain (ϵ) relationship of the series elastic component (SEC, B) and the hyperbolic relationship between force, f, or stress, σ, and velocity (v, C‐E). Asymptotes for the force‐velocity Hill equation (vertical and horizontal dashed lines) are not on the force‐velocity curve, and protocols designed to lengthen contracted muscle reveals that muscle can resist lengthening at much greater force levels than the muscle can develop isometrically (thick, curved dashed line, D). Peak power (force‐velocity product) occurs at ∼1/3 the maximum shortening velocity at zero load (V0). Assembly of additional actomyosin cross‐bridges during smooth muscle contraction may explain changes in the force‐velocity relationship known to occur over the course of a contraction (E, see text for details). wt = weight. Panels D and E adapted from, respectively (309) and (129), with permission.
Figure 24. Figure 24. Isotonic quick‐release (A‐C) and slack test (D‐F) protocols for measurement of force‐velocity and series elastic component stress‐strain curves (see text for details). In striated muscle, maximum shortening velocity (V0) is independent of muscle (sarcomere) length except at very short and long lengths (G). In smooth muscle, V0 is dependent on the level of myosin phosphorylation (MLC‐p) and not active stress (σ, H). Panels A‐F adapted from (253), with permission. Panel G adapted from (114), with permission. Panel H adapted from (375), with permission.
Figure 25. Figure 25. The mechanical contributions of the extracellular matrix components elastin and collagen can be revealed by selective digestion (A; l0 = initial unstretched muscle length). One recent model [B; nitroprusside‐relaxed artery at rest versus decellularized artery (minus VSM)] of the mechanical relationship between the three major components of an artery, VSM (diamond), elastin and collagen (labels as in panel C), derived from decellularization experiments, envisions that “passive” VSM generates considerable tone, causing compression (C) of elastin and collagen in‐parallel with VSM, and tension (T) of elastin and collagen in‐series with VSM. The “minus VSM” artery elongated by ∼12% to 20% of the nitroprusside‐relaxed (“rest”) artery. A hook‐on model used to explain the J‐shaped passive length‐tension relationship of arteries envisions longer collagen fibers in‐parallel becoming engaged at longer strain values (c.i.‐c.iv.). An alternate model envisions different in‐series collagen groups becoming stiff at different strain values (c.v.). Panels A and B adapted from, respectively (391) and (396), with permission. Panel C adapted from (491), with permission.
Figure 26. Figure 26. Arterial stiffness (estimated here as the pressure/diameter tangent at a particular diameter) is highly dependent on the level of VSM activation (A). A working model of acute adaptive plasticity of smooth muscle stress (σ)‐strain (ϵ) relationships (B) for actively contracted muscle (σa), and unstimulated muscle that includes an adjustable preload component (σap) and a purely passive component (σp). The length at which contraction is maximum (lref) and the degree of adjustable preload stress at any given strain is dependent on strain history and activation history. The degree of shift is likely greater for smooth muscle tissues that display wider physiological working length ranges (see text for details). An example of acute changes in active and passive stress values in rabbit renal artery that are dependent on activation history and strain history (C). After identification of an initial lref value by a standard stress‐strain protocol, the artery ring was released to 0.5‐fold lref and contracted twice for ∼3 min each with a maximum stimulus (black bars) and relaxed fully (“a” and “b” in c.ii.). A stretch strain‐step/strain‐clamp back to 1‐fold lref (“1a” in c.i.) produced an immediate large stiffness response reflected by the peak stress followed by considerable stress‐relaxation. After a quick release to 0.9‐fold, then 0.5‐fold lref (respectively, “1b” and “1c” in c.i.) and no contraction at 0.5‐fold lref, a subsequent stretch strain‐step/strain‐clamp (“2a” in c.i.) produced a much weaker peak stress response (0.4 × 105 N/m2) and a subsequent quick release to 0.9‐fold lref (“2b” in c.i.) produced a much weaker steady‐state adjustable preload stress (0.05 × 105 N/m2) compared to that produced by the prior release (“1b”, 0.07 × 105 N/m2). Two additional contraction‐relaxation cycles at 0.5‐fold lref (“c” and “d” in c.ii.) caused a 150% increase in the peak stress upon the subsequent third stretch strain‐step/strain‐clamp (“3a” in c.i.) compared to the second stretch (“2a” in c.i.). A subsequent release to 0.9‐fold lref (“3b” in c.i.) revealed that adjustable preload stress was also increased (by 60% to 0.08 × 105 N/m2) because of contractions “c” and “d”. Lastly, contractions at 0.5‐fold lref improved 33% over the course of four stimulations “a”‐”d”). Panel A adapted from (336), with permission, and panel B adapted from (21), with permission.


Figure 1. Diagram of vascular smooth muscle (VSM, A) and cell structural hierarchy (B‐E). VSM structure includes cells that are embedded in and mechanically attached to ECM comprised largely of elastin and collagens (Coll) I and III (A). Several models of smooth muscle cell ultrastructure have been proposed (20,274); Small's model is shown in panels B and C. An extensive cytoskeleton interconnects a filamin‐actin‐desmin filament domain (FAD) with an actomyosin (AM) domain attached to dense bodies and dense plaques (B and C). The smooth muscle sarcomere structure remains to be fully elucidated and appears to be highly dynamic. However, a general view is that the thick filaments (M) are side polar (C and D) and the thin filaments (A) and FAD attach to dense bodies (B and C). Myosin is a heterohexamer comprised of two heavy chains and two pairs of light chains (E, only a single heavy chain and single pair of light chains is shown). The light meromyosin (LMM) tail region of individual myosin heavy chains associate with other myosin heavy chain tails to form thick filaments (D). The catalytic region of the myosin S1 head extends from the α‐helical S1 neck wrapped by one essential (ELC) and one regulatory light chain (RLC), which in turn extends from the myosin S2 region, to reach actin‐binding sites. Panels A‐D adapted from, respectively (419,426,105), and (529), with permission.


Figure 2. Smooth muscle cell and arterial structures. 3D fluorescence micrograph of antibody‐labeled artery cross‐section revealing the alternating pattern of, respectively, caveolae (C, green) and dense plaques (D, red) within a single VSM cell digitally isolated from other cells and the ECM. Each square = 1 μ2 (A). Transmission electron micrograph of a VSM cell from rabbit renal artery shown in cross‐section (B) revealing extensive thin filaments and alternating caveolae (C) and dense plaques (D). Note that microtubules (arrow) reside adjacent to caveolae and mitochondria, supporting the notion that these structures, acting as cargo for microtubule motor proteins, are adjusted in space and time. Thin filaments occupy much of the cytosol [for examples of electron micrographs of smooth muscle revealing the relative abundance of thick and thin filaments, see (20,93,201)]. Diagram of a model of dense bodies (dots) and actomyosin filaments (lines) in a single contracted and relaxed smooth muscle cell in cut‐away lateral and cross‐sectional views (C). Electron micrograph of a rabbit femoral artery cut transverse to the long axis of the arterial tube revealing outer adventitia (A), middle media (M), and inner intima (I) (D). Fluorescence micrograph revealing the long, fusiform shapes of isolated single VSM cells (E). A single relaxed (upper panel) and contracted (lower panel) VSM cell attached at one end to a micropipette (upper right) (F). Note dramatic degree of shortening and formation of blebs (B) upon shortening. Panel A adapted from (374). Panel C adapted from (80) with permission. Panels D‐F adapted, with permission, from, respectively (191,113), and (110).


Figure 3. The minimum solution pO2 required to support full isometric contraction of swine carotid media stimulated with epinephrine is dependent on arterial tissue thickness such that a bathing solution bubbled with room air would suffice for tissues ≤400 μ thick (A). Arteries can be classified, according to the strength of force maintenance (tonic phase) compared to that developed during the early phasic phase of contraction, into tonic (B) and phasic (C) arteries; FA = rabbit femoral artery, SA = rabbit saphenous artery (contractile stimulus: K+‐depolarization). Compared to elastic arteries (D: abdominal aorta, AA, and E: common iliac artery, CIA), muscular arteries (D: femoral artery, FA, and E: external iliac artery, EIA) express a higher VSM/ECM ratio and therefore produce significantly stronger contractions when normalized to tissue cross‐sectional area (F). Data adapted, with permission, for panel A from (332). Solid and dashed lines in panels B‐E are, respectively, average and SE values, n = 5‐7 rabbits. * = P < 0.05 compared to AA.


Figure 4. Analog elements used to form mechanical circuits include a spring (A) and dashpot (B) that are fixed at one end and attached to other elements at their free end (filled circle). (C) To measure force, these elements (ele) are attached to a force transducer (FT) of known very high stiffness (kFT).


Figure 5. Preconditioning (B, note decline in peak force from cycle 1 to 7 and from cycle 8 to 14) of a strip of naïve rabbit bladder incubated in a Ca2+‐free solution resulting from (A) 7 sequential 1 mm ramp load‐unload cycles at 1 mm/s (1, 2, … 7), followed immediately by 7 sequential 2 mm ramp load‐unload cycles at 1 mm/s (8, 9, … 14). In this context, a naïve tissue is one mounted on a myograph that has not yet been subjected to load‐unload cycling. Clockwise force versus length work loops of data shown in panels A and B reveal a high, linear stiffness during loading for the first cycle from 0 to 1 mm (C), and during the “new” strain region (from 1 to 2 mm) of the eigth cycle (D) only. All other cycles display nonlinear length‐force curves and much smaller work loop areas. The loading curve for the first mm of cycle 8 is superimposable on the loading curve of cycle 7. Cycles 6 (not shown) and 7, and cycles 13 (not shown) and 14 are identical. Adapted, with permission, from (445).


Figure 6. A stepper motor controlled to stretch and compress a spring (A‐F) can reveal the linear stress (σ) versus strain (ϵ) (G) and constant stress/strain quotient (H, stiffness E) characteristic of a linear spring. The free and fixed ends of the spring are represented by, respectively, r and q. The nonstretched resting position of r is j0. Spring compression involves moving r toward j‐1 and beyond, and spring tensioning involves moving r toward j+1 and beyond. A nonlinear spring (G, dash‐dotted curve) would result in a nonconstant E (H, dash‐dotted curve). Drawings of sheets of different widths w (I) and a rectangular block of thickness h (J) showing direction of applied displacement producing measured uniaxial force, f (I), which can be normalized to calculate tension, T (I), and stress, σ (J).


Figure 7. Rapidly activated swine carotid media displays a linear relationship between active stiffness (dσ/dl0) and stress (σ). Adapted from (423) with permission.


Figure 8. A stepper motor controlled to stretch a dashpot (A‐D) can reveal the linear relationship between stress (σ) and strain‐rate (ϵ·) and constant σ/ϵ· quotient (viscosity η) characteristic of a linear dashpot (F). Stepper motor ramp stretches (E) at two different rates (ϵ vs. time: lower curves, fast and slow strains from j to j+1) induce two different levels of stress (σ: upper square‐wave curves, fast and slow). Honey has a higher viscosity than H2O (F). Thus, a slow ramp stretch of a honey‐filled dashpot will induce a higher level of stress than the same slow ramp stretch of a H2O‐filled dashpot (E, honey; slow compared to H2O; slow).


Figure 9. Soft tissues display stress (σ)‐relaxation (B, σ‐relaxation of rabbit renal artery, RA) over time when subjected to an imposed rapid stretch to a new tissue length [A; length (l), stretch‐ratio (λ), or strain (ϵ)‐step)] and held there for some time (l, λ, or ϵ‐clamp). Simulations of the stress responses (D, F) to a strain‐step/strain‐clamp protocol (C, E) for a spring of stiffness E = 3 (C, D) and dashpot of viscosity η = 3 (E, F). As dt approaches zero in the strain‐step rate, stress will increase toward ∞ (F).


Figure 10. Simulations of the stress (σ) responses (B, E, H) to a sinusoidal strain (ϵ)‐oscillation protocol (A, D, G) for a spring of stiffness E = 3 (A‐C), dashpot of viscosity η = 3 (D‐F) and 2 element Maxwell Model (G‐I). The stress‐strain (σ‐ϵ) relationships for a spring and dashpot reveal, respectively, no time dependency (C) and time dependency (F and I). The time dependency of the dashpot is revealed by a lag in the imposed length change compared to the stress response, and damping of the maximum stress value. In a Maxwell Model, the spring (s) element requires some strain to develop stress, so the dashpot (d) element dampens the stress response to the strain (i) proportionally to the spring compliance (see Fig. 11). How far the dashpot plunger is from its new equilibrium position determines stress‐strain work loop area and position on the y‐axis; the position was further from the new equilibrium during the first than the second loading. l = length, f = force.


Figure 11. Simulations of the stress (σ) responses (B, C, E, and F) to sinusoidal strain (ϵ)‐oscillation (A) and strain‐step/strain‐clamp (D) protocols for a two‐element Maxwell Model with spring (s) stiffness E = 3 and dashpot (d) viscosity η = 10‐fold that of Figure 10. 1, 2, … 7 identify load‐unload cycles 1, 2, … 7. In panels D‐F, segment 1 to 2 refers to the instantaneous strain‐step, and segments 2 to 3 refer to the strain‐clamp period lasting 45 s. See text for details.


Figure 12. Sequential loading‐unloading curves of dog femoral artery rings reveal clockwise force (F)‐length (L) loops and strain softening (force achieved during the tenth loop is less than that achieved during the first loop). Adapted, with permission, from (389).


Figure 13. Sequential stretch strain (ϵ)‐step/strain‐clamps applied to a viscoelastic soft tissue over time (a temporal staircase‐strain protocol) produces an instantaneous stress (σ) response due to the strain‐step and an equilibrium stress response at the end of stress‐relaxation (A, plot over time; B, stress‐strain plot). For each strain‐step, the elastic stress equals the equilibrium stress, and the viscous stress equals the difference between instantaneous and equilibrium stresses (B, C). Elastic and viscous stress‐strain plots for vena cava (VC), abdominal aorta (Ab Ao), and carotid artery (CA) reveal considerable differences for different vascular tree segments (D). Panels A‐C adapted from (406) and panel D adapted from (420), with permission.


Figure 14. The final viscoelastic stress‐strain (σ‐ϵ) cycle (8) from the simulation shown in Figure 11c oscillates around zero stress and is linear (A), unlike that of a swine carotid artery (B). Nonlinearity can be incorporated into a Maxwell Model stress‐strain relationship (C; for this simulation, constants for spring stress, σs, were a = 0.3, b = 0.3, and c = −0.5), but the function chosen should have some mechanistic basis. Panel B adapted, with permission, from (408).


Figure 15. Preconditioned soft tissues such as arteries display a passive stiffness‐stress (dσdλσ) relationship that can be modeled as a 1 (or 2) component curve consisting and a linear portion fitting the equation, dσdλ=ασ+αβ (plus a nonlinear portion at very low stress values), where σ = stress, λ = stretch ratio, and α and β are constants (459). Extrapolation of the linear portion provides a stiffness value at zero stress, E0, the product of α and β, that can be used to characterize different tissues. Compared to muscular arteries and heart (B) that display low E0 values, those for elastic arteries (A, dog aortic arch) are relatively high (356,459). The slope of the linear portion, α, is the deviation from constant stiffness. Panels A and B adapted from, respectively, (459) and (356), with permission.


Figure 16. Simulations of the stress (σ) response (B and C) to a sinusoidal strain (ϵ)‐oscillation protocol (A) for a two‐element Voigt Model and stress response (E and F) to a strain‐step/strain‐clamp followed by a quick‐release, small strain‐step protocol (D) for a three‐element Generalized Maxwell Model. A simulation that includes only the springs of a generalized Maxwell model is also shown (F, dash‐dotted line). See text for details.


Figure 17. A quick‐release small strain (ϵ)‐step protocol performed on passive (unstimulated) swine carotid artery reveals weak force redevelopment (A), adapted from (199), with permission. A three‐element generalized Voigt Model (B) and two depictions of a multielement Hill Model (C). Simulations of the stress (σ) response (E and F) to a strain (ϵ)‐step/strain‐clamp followed by a quick‐release small strain‐step protocol (D) for a three‐element Generalized Voigt Model. See text for details.


Figure 18. A generalized model of multiple stress‐strain (σ‐ϵ) behaviors for various types of materials (A). Examples of stress‐strain curves for elastic fibers, elastin, and resilin (B), viscoelastic biomaterials such as skeletal muscle treated to remove thin filaments and retain titin (C) and keratin fibers (D), and viscoelastic‐plastic materials such as Hagfish thread (E). The pressure‐volume (P‐Vol) relationship for femoral artery (F) reveals apparent viscoelastic‐plastic behavior. See text for details. Panels B, D, and E adapted from (315), panel C adapted from (165), and panel F adapted from (39), with permission.


Figure 19. A steady‐state model of the actomyosin cross‐bridge cycle showing four myosin (M) states (A) that include actin (A) plus myosin (M; 1), actin (A) + phosphorylated M (Mp; 2), a phosphorylated cross‐bridge species (AMp; 3) and a dephosphorylated cross‐bridge species, the latchbridge (AM; 4); k values represent rate constants. Rabbit femoral artery activated at time zero with a maximum KCl stimulus produces a counterclockwise [Ca2+]i‐force response revealing two phases, a rapid (∼15 s) phasic phase in which [Ca2+]i increases to its maximum level and force develops to ∼70% maximum, and a tonic phase in which force slowly (from ∼15 s to 3 min) increases further to the maximum level while [Ca2+]i declines to its steady‐state supra‐basal level (B). A comparison of the rabbit slow, tonic femoral artery (FA) and fast, phasic saphenous artery (SA) reveal that during the fast phasic phase, force (C), [Ca2+]i (D, Pk) and myosin phosphorylation (MLC‐p, E, second data point at ∼40% MLC‐p) responses are identical. With time, however, force (C) and MLC‐p (E) dissociate whereas the [Ca2+]i response does not (D, 5 and 10 min). * indicates significant difference (P < 0.05). Panel B adapted from (378) and panels C‐E adapted from (191), with permission.


Figure 20. Hai‐Murphy four‐state kinetic latchbridge model (L) simulation (dashed lines), a four‐state no latchbridge model (NL) simulation [dashed dotted lines (E‐H)] and empirical data (solid lines and symbols) for femoral artery (FA) and saphenous artery (SA). The simulated L model employs a very slow k7 = 0.005 compared to k4 = 0.05, whereas the NL model simulation excludes a latchbridge by assigning k7 = k4 = 0.05. The L model fits the data for the slow, tonic femoral artery (A, B, D), and the NL model fits the falling tonic phase contraction and falling intracellular free Ca2+ concentration and myosin phosphorylation (E, F, H) characteristic of the fast, phasic saphenous artery, suggesting that fast arteries lack latchbridges. Adapted, with permission, from (191).


Figure 21. Isolated whole rabbit femoral (A) and saphenous (B) arteries were pressurized (P) to 60 mmHg, contracted with a maximum [KCl] and allowed to constrict isobarically to measure the degree of reduction in artery lumen diameter at steady state. After recording steady‐state constriction, the arteries were fully relaxed (dilated), pressurized to the next pressure level, activated with KCl and constriction was measured at that pressure (isobaric constriction). This procedure was continued until full steady‐state pressure‐diameter curves were produced for activated femoral (A, open circles) and saphenous (B, open squares) arteries. Diameter data were normalized afterward to maximally constricted (zero) and dilated (one) values. After generation of these active pressure‐diameter curves, fully relaxed arteries were depressurizing to 60 mmHg, activated with KCl to produce full isobaric constriction at 60 mmHg (vertical down arrow), and subjected to a pressure ramp from 60 to 120 mmHg (A, femoral artery, solid circles and arrow) and 60 to 140 mmHg (B, saphenous artery, solid squares and arrow). The activated femoral artery, fully constricted at 60 mmHg, remained nearly fully constricted when subjected to the ramp pressure increase (A, solid circles). By contrast, the activated saphenous artery, also fully constricted at 60 mmHg, dilated along the isobaric constriction curve when pressurized (B, solid squares). Thus, shortened VSM of femoral artery can resist lengthening when subjected to pressures much higher than the muscle can shorten against, suggesting that latchbridges endow slow arteries with dilatation‐resistance (C). See text for additional details. Adapted, with permission, from (60).


Figure 22. Active stress (σ)‐strain (ϵ) (tension‐length, force‐length) curves (A‐F) and “passive” stress‐strain curves for skeletal muscle (E) and artery (F). Bottle brush cartoon illustrates the concept that the degree of overlap (solid bars) of actin (bottle wall) with myosin cross‐bridges (bristles) determines the strength of active stress on the descending limb (d.l.) of the active stress‐strain curve (A). Additional complexity is required to explain the shape of the ascending limb (a.l.). Examples of active stress‐strain curves for striated muscle sarcomere (B), carotid media (C), and small mesenteric artery displaying an initial active stress‐strain curve (D, day 0) and one produced after the tissue had been incubated in culture medium at 0.4‐fold lref for 16 h with the contractile agent endothelin (D, day 1). Also shown is the total stress‐strain curve for small mesenteric artery, which is the sum of the “passive” and active curves (F). See text for details. Panels B, C, D, and E adapted from, respectively (370,522,474) and (527), with permission. Panel F adapted, with permission, from (535).


Figure 23. A schematic illustrating a Maxwell Model (representing muscle) attached to a generalized apparatus designed to measure and control the degree of force and length over time (A) to assess the stress (σ)‐strain (ϵ) relationship of the series elastic component (SEC, B) and the hyperbolic relationship between force, f, or stress, σ, and velocity (v, C‐E). Asymptotes for the force‐velocity Hill equation (vertical and horizontal dashed lines) are not on the force‐velocity curve, and protocols designed to lengthen contracted muscle reveals that muscle can resist lengthening at much greater force levels than the muscle can develop isometrically (thick, curved dashed line, D). Peak power (force‐velocity product) occurs at ∼1/3 the maximum shortening velocity at zero load (V0). Assembly of additional actomyosin cross‐bridges during smooth muscle contraction may explain changes in the force‐velocity relationship known to occur over the course of a contraction (E, see text for details). wt = weight. Panels D and E adapted from, respectively (309) and (129), with permission.


Figure 24. Isotonic quick‐release (A‐C) and slack test (D‐F) protocols for measurement of force‐velocity and series elastic component stress‐strain curves (see text for details). In striated muscle, maximum shortening velocity (V0) is independent of muscle (sarcomere) length except at very short and long lengths (G). In smooth muscle, V0 is dependent on the level of myosin phosphorylation (MLC‐p) and not active stress (σ, H). Panels A‐F adapted from (253), with permission. Panel G adapted from (114), with permission. Panel H adapted from (375), with permission.


Figure 25. The mechanical contributions of the extracellular matrix components elastin and collagen can be revealed by selective digestion (A; l0 = initial unstretched muscle length). One recent model [B; nitroprusside‐relaxed artery at rest versus decellularized artery (minus VSM)] of the mechanical relationship between the three major components of an artery, VSM (diamond), elastin and collagen (labels as in panel C), derived from decellularization experiments, envisions that “passive” VSM generates considerable tone, causing compression (C) of elastin and collagen in‐parallel with VSM, and tension (T) of elastin and collagen in‐series with VSM. The “minus VSM” artery elongated by ∼12% to 20% of the nitroprusside‐relaxed (“rest”) artery. A hook‐on model used to explain the J‐shaped passive length‐tension relationship of arteries envisions longer collagen fibers in‐parallel becoming engaged at longer strain values (c.i.‐c.iv.). An alternate model envisions different in‐series collagen groups becoming stiff at different strain values (c.v.). Panels A and B adapted from, respectively (391) and (396), with permission. Panel C adapted from (491), with permission.


Figure 26. Arterial stiffness (estimated here as the pressure/diameter tangent at a particular diameter) is highly dependent on the level of VSM activation (A). A working model of acute adaptive plasticity of smooth muscle stress (σ)‐strain (ϵ) relationships (B) for actively contracted muscle (σa), and unstimulated muscle that includes an adjustable preload component (σap) and a purely passive component (σp). The length at which contraction is maximum (lref) and the degree of adjustable preload stress at any given strain is dependent on strain history and activation history. The degree of shift is likely greater for smooth muscle tissues that display wider physiological working length ranges (see text for details). An example of acute changes in active and passive stress values in rabbit renal artery that are dependent on activation history and strain history (C). After identification of an initial lref value by a standard stress‐strain protocol, the artery ring was released to 0.5‐fold lref and contracted twice for ∼3 min each with a maximum stimulus (black bars) and relaxed fully (“a” and “b” in c.ii.). A stretch strain‐step/strain‐clamp back to 1‐fold lref (“1a” in c.i.) produced an immediate large stiffness response reflected by the peak stress followed by considerable stress‐relaxation. After a quick release to 0.9‐fold, then 0.5‐fold lref (respectively, “1b” and “1c” in c.i.) and no contraction at 0.5‐fold lref, a subsequent stretch strain‐step/strain‐clamp (“2a” in c.i.) produced a much weaker peak stress response (0.4 × 105 N/m2) and a subsequent quick release to 0.9‐fold lref (“2b” in c.i.) produced a much weaker steady‐state adjustable preload stress (0.05 × 105 N/m2) compared to that produced by the prior release (“1b”, 0.07 × 105 N/m2). Two additional contraction‐relaxation cycles at 0.5‐fold lref (“c” and “d” in c.ii.) caused a 150% increase in the peak stress upon the subsequent third stretch strain‐step/strain‐clamp (“3a” in c.i.) compared to the second stretch (“2a” in c.i.). A subsequent release to 0.9‐fold lref (“3b” in c.i.) revealed that adjustable preload stress was also increased (by 60% to 0.08 × 105 N/m2) because of contractions “c” and “d”. Lastly, contractions at 0.5‐fold lref improved 33% over the course of four stimulations “a”‐”d”). Panel A adapted from (336), with permission, and panel B adapted from (21), with permission.
References
 1. Abbott BC , Lowy J . Stress relaxation in muscle. Proc R Soc Lond B Biol Sci 146: 281‐288, 1957.
 2. Adamovic I , Mijailovich SM , Karplus M . The elastic properties of the structurally characterized myosin II S2 subdomain: A molecular dynamics and normal mode analysis. Biophys J 94: 3779‐3789, 2008.
 3. Adelstein RS . Regulation of contractile proteins by phosphorylation. J Clin Invest 72: 1863‐1866, 1983.
 4. Aidley DJ. The Physiology of Excitable Cells. Cambridge; New York: Cambridge University Press, 1978.
 5. Aksoy MO , Murphy RA , Kamm KE . Role of Ca2+ and myosin light chain phosphorylation in regulation of smooth muscle. Am J Physiol 242: C109‐C116, 1982.
 6. Alexander MR , Owens GK . Epigenetic control of smooth muscle cell differentiation and phenotypic switching in vascular development and disease. Annu Rev Physiol 74: 13‐40, 2012.
 7. Alexander RS . Viscoplasticity of smooth muscle of urinary bladder. Am J Physiol 224: 618‐622, 1973.
 8. Alexander RS . Series elasticity of urinary bladder smooth muscle. Am J Physiol 231: 1337‐1342, 1976.
 9. Ali F , Pare PD , Seow CY . Models of contractile units and their assembly in smooth muscle. Can J Physiol Pharmacol 83: 825‐831, 2005.
 10. Allen DG , Kentish JC . The cellular basis of the length‐tension relation in cardiac muscle. J Mol Cell Cardiol 17: 821‐840, 1985.
 11. Almasri AM , Ratz PH , Speich JE . Length adaptation of the passive‐to‐active tension ratio in rabbit detrusor. Ann Biomed Eng 38: 2594‐2604, 2010.
 12. Alvarez SM , Miner AS , Browne BM , Ratz PH . Failure of Bay K 8644 to induce RhoA kinase‐dependent calcium sensitization in rabbit blood vessels. Br J Pharmacol 160: 1326‐1337, 2010.
 13. Apter JT . Models in medical research. “Muscles are motors”. JAMA 195: 931‐934, 1966.
 14. Apter JT . Correlation of visco‐elastic properties with microscopic structure of large arteries. IV. Thermal responses of collagen, elastin, smooth muscle, and intact arteries. Circ Res 21: 901‐918, 1967.
 15. Armentano RL , Barra JG , Pessana FM , Craiem DO , Graf S , Santana DB , Sanchez RA . Smart smooth muscle spring‐dampers. Smooth muscle smart filtering helps to more efficiently protect the arterial wall. IEEE Eng Med Biol Mag 26: 62‐70, 2007.
 16. Arner A , Lofgren M , Morano I . Smooth, slow and smart muscle motors. J Muscle Res Cell Motil 24: 165‐173, 2003.
 17. Arner A , Uvelius B . Force‐velocity characteristics and active tension in relation to content and orientation of smooth muscle cells in aortas from normotensive and spontaneous hypertensive rats. Circ Res 50: 812‐821, 1982.
 18. Ashton FT , Somlyo AV , Somlyo AP . The contractile apparatus of vascular smooth muscle: Intermediate high voltage stereo electron microscopy. J Mol Biol 98: 17‐29, 1975.
 19. Azuma T , Hasegawa M . Distensibility of the vein: From the architectural point of view. Biorheology 10: 469‐479, 1973.
 20. Bagby RM , Fisher BA . Graded contractions in muscle strips and single cells from Bufo marinus stomach. Am J Physiol 225: 105‐109, 1973.
 21. Bagby RM . Organization of contractile/cytoskeletal elements. In: Stephens NL , editor. Biochemistry of Smooth Muscle. Boca Raton, Florida: CRC Press, 1983, pp. 1‐84.
 22. Bai TR , Bates JH , Brusasco V , Camoretti‐Mercado B , Chitano P , Deng LH , Dowell M , Fabry B , Ford LE , Fredberg JJ , Gerthoffer WT , Gilbert SH , Gunst SJ , Hai CM , Halayko AJ , Hirst SJ , James AL , Janssen LJ , Jones KA , King GG , Lakser OJ , Lambert RK , Lauzon AM , Lutchen KR , Maksym GN , Meiss RA , Mijailovich SM , Mitchell HW , Mitchell RW , Mitzner W , Murphy TM , Pare PD , Schellenberg RR , Seow CY , Sieck GC , Smith PG , Smolensky AV , Solway J , Stephens NL , Stewart AG , Tang DD , Wang L . On the terminology for describing the length‐force relationship and its changes in airway smooth muscle. J Appl Physiol 97: 2029‐2034, 2004.
 23. Baker JE , Brosseau C , Fagnant P , Warshaw DM . The unique properties of tonic smooth muscle emerge from intrinsic as well as intermolecular behaviors of Myosin molecules. J Biol Chem 278: 28533‐28539, 2003.
 24. Baldock C , Oberhauser AF , Ma L , Lammie D , Siegler V , Mithieux SM , Tu Y , Chow JY , Suleman F , Malfois M , Rogers S , Guo L , Irving TC , Wess TJ , Weiss AS . Shape of tropoelastin, the highly extensible protein that controls human tissue elasticity. Proc Natl Acad Sci U S A 108: 4322‐4327, 2011.
 25. Bank AJ , Kaiser DR . Smooth muscle relaxation: Effects on arterial compliance, distensibility, elastic modulus, and pulse wave velocity. Hypertension 32: 356‐359, 1998.
 26. Bank AJ , Wang H , Holte JE , Mullen K , Shammas R , Kubo SH . Contribution of collagen, elastin, and smooth muscle to in vivo human brachial artery wall stress and elastic modulus. Circulation 94: 3263‐3270, 1996.
 27. Barany M . ATPase activity of myosin correlated with speed of muscle contraction. J Gen Physiol 50: 197‐218, 1967.
 28. Barnes HA . Thixotropy ‐ a review. J Non‐Newton Fluid 70: 1‐33, 1997.
 29. Barr L , Headings VE , Bohr DF . Potassium and the recovery of arterial smooth muscle after cold storage. J Gen Physiol 46: 19‐33, 1962.
 30. Barra JG , Armentano RL , Levenson J , Fischer EI , Pichel RH , Simon A . Assessment of smooth muscle contribution to descending thoracic aortic elastic mechanics in conscious dogs. Circ Res 73: 1040‐1050, 1993.
 31. Barsotti RJ , Dantzig JA , Goldman YE . Myosin isoforms show different strokes for different blokes. Nat Struct Biol 3: 737‐739, 1996.
 32. Bartoo ML , Popov VI , Fearn LA , Pollack GH . Active tension generation in isolated skeletal myofibrils. J Muscle Res Cell Motil 14: 498‐510, 1993.
 33. Bassett DR, Jr . Scientific contributions of A. V. Hill: Exercise physiology pioneer. J Appl Physiol 93: 1567‐1582, 2002.
 34. Bauer RD . Rheological approaches of arteries. Biorheology Suppl 1: 159‐167, 1984.
 35. Bausch AR , Moller W , Sackmann E . Measurement of local viscoelasticity and forces in living cells by magnetic tweezers. Biophys J 76: 573‐579, 1999.
 36. Bausch AR , Ziemann F , Boulbitch AA , Jacobson K , Sackmann E . Local measurements of viscoelastic parameters of adherent cell surfaces by magnetic bead microrheometry. Biophys J 75: 2038‐2049, 1998.
 37. Bednarek ML , Speich JE , Miner AS , Ratz PH . Active tension adaptation at a shortened arterial muscle length: Inhibition by cytochalasin‐D. Am J Physiol Heart Circ Physiol 300: H1166‐H1173, 2011.
 38. Bellini C , Ferruzzi J , Roccabianca S , Di Martino ES , Humphrey JD . A microstructurally motivated model of arterial wall mechanics with mechanobiological implications. Ann Biomed Eng 42: 488‐502, 2014.
 39. Bergel DH . The dynamic elastic properties of the arterial wall. J Physiol 156: 458‐469, 1961.
 40. Bergel DH . The static elastic properties of the arterial wall. J Physiol 156: 445‐457, 1961.
 41. Berro J , Michelot A , Blanchoin L , Kovar DR , Martiel JL . Attachment conditions control actin filament buckling and the production of forces. Biophys J 92: 2546‐2558, 2007.
 42. Besser A , Schwarz US . Coupling biochemistry and mechanics in cell adhesion: A model for inhomogeneous stress fiber contraction. New J Phys 9: 425‐452, 2007.
 43. Bevan JA , Osher JV . A direct method for recording tension changes in the wall of small blood vessels in vitro. Agents Actions 2: 257‐260, 1972.
 44. Bevan JA , Purdy RE . Variations in adrenergic innervation and contractile responses of the rabbit saphenous artery. Circ Res 32: 746‐751, 1973.
 45. Blanchoin L , Boujemaa‐Paterski R , Sykes C , Plastino J . Actin dynamics, architecture, and mechanics in cell motility. Physiol Rev 94: 235‐263, 2014.
 46. Bloemink MJ , Geeves MA . Shaking the myosin family tree: Biochemical kinetics defines four types of myosin motor. Semin Cell Dev Biol 22: 961‐967, 2011.
 47. Bois RM . The organization of the contractile apparatus of vertebrate smooth muscle. Anat Rec 177: 61‐77, 1973.
 48. Bosse Y , Sobieszek A , Pare PD , Seow CY . Length adaptation of airway smooth muscle. Proc Am Thorac Soc 5: 62‐67, 2008.
 49. Bozler E . The heat production of smooth muscle. J Physiol 69: 442‐462, 1930.
 50. Bozler E . Plasticity of contractile elements of muscle as studies in extracted muscle fibers. Am J Physiol 171: 359‐364, 1952.
 51. Bozler E . Mechanical properties of contractile elements of smooth muscle. In: Bulbring E , Shuba MF , editors. Physiology of Smooth Muscle. New York: Raven Press, 1976, pp. 217‐221.
 52. Brady AJ . Mechanical properties of isolated cardiac myocytes. Physiol Rev 71: 413‐428, 1991.
 53. Broedersz CP , Depken M , Yao NY , Pollak MR , Weitz DA , MacKintosh FC . Cross‐link‐governed dynamics of biopolymer networks. Phys Rev Lett 105: 238101, 2010.
 54. Brook BS , Jensen OE . The role of contractile unit reorganization in force generation in airway smooth muscle. Math Med Biol 31: 99‐124, 2014.
 55. Brown MC , Turner CE . Paxillin: Adapting to change. Physiol Rev 84: 1315‐1339, 2004.
 56. Brutsaert DL , Claes VA , Sonnenblick EH . Velocity of shortening of unloaded heart muscle and the length‐tension relation. Circ Res 29: 63‐75, 1971.
 57. Burnstock G , Prosser CL . Responses of smooth muscles to quick stretch: Relation of stretch to conduction. Am J Physiol 198: 921‐925, 1960.
 58. Bursac P , Fabry B , Trepat X , Lenormand G , Butler JP , Wang N , Fredberg JJ , An SS . Cytoskeleton dynamics: Fluctuations within the network. Biochem Biophys Res Commun 355: 324‐330, 2007.
 59. Bursac P , Lenormand G , Fabry B , Oliver M , Weitz DA , Viasnoff V , Butler JP , Fredberg JJ . Cytoskeletal remodelling and slow dynamics in the living cell. Nat Mater 4: 557‐561, 2005.
 60. Buus NH , VanBavel E , Mulvany MJ . Differences in sensitivity of rat mesenteric small arteries to agonists when studied as ring preparations or as cannulated preparations. Br J Pharmacol 112: 579‐587, 1994.
 61. Call C , Han S , Speich JE , Eddinger TJ , Ratz PH . Resistance to pressure‐induced dilatation in femoral but not saphenous artery: Physiological role of latch? Am J Physiol Heart Circ Physiol 291: H1513‐H1520, 2006.
 62. Campbell KS . Interactions between connected half‐sarcomeres produce emergent mechanical behavior in a mathematical model of muscle. PLoS Comput Biol 5: e1000560, 2009.
 63. Campbell KS , Lakie M . A cross‐bridge mechanism can explain the thixotropic short‐range elastic component of relaxed frog skeletal muscle. J Physiol 510(Pt 3): 941‐962, 1998.
 64. Cantournet S , Desmorat R , Besson J . Mullins effect and cyclic stress softening of filled elastomers by internal sliding and friction thermodynamics model. Int J Solids Struct 46: 2255‐2264, 2009.
 65. Capitanio M , Pavone FS . Interrogating biology with force: Single molecule high‐resolution measurements with optical tweezers. Biophys J 105: 1293‐1303, 2013.
 66. Carrier O, Jr. , Murphy JC , Tenner TE, Jr . Effect of cold storage on calcium‐related responses and electrolyte content of rabbit aortic strips. Eur J Pharmacol 24: 225‐233, 1973.
 67. Carton RW , Dainauskas J , Clark JW . Elastic properties of single elastic fibers. J Appl Physiol 17: 547‐551, 1962.
 68. Chase PB , Denkinger TM , Kushmerick MJ . Effect of viscosity on mechanics of single, skinned fibers from rabbit psoas muscle. Biophys J 74: 1428‐1438, 1998.
 69. Chi RJ , Olenych SG , Kim K , Keller TC, III . Smooth muscle alpha‐actinin interaction with smitin. Int J Biochem Cell Biol 37: 1470‐1482, 2005.
 70. Chi RJ , Simon AR , Bienkiewicz EA , Felix A , Keller TC, III . Smooth muscle titin Zq domain interaction with the smooth muscle alpha‐actinin central rod. J Biol Chem 283: 20959‐20967, 2008.
 71. Chin L , Yue P , Feng JJ , Seow CY . Mathematical simulation of muscle cross‐bridge cycle and force‐velocity relationship. Biophys J 91: 3653‐3663, 2006.
 72. Chow MJ , Mondonedo JR , Johnson VM , Zhang Y . Progressive structural and biomechanical changes in elastin degraded aorta. Biomech Model Mechanobiol 12: 361‐372, 2013.
 73. Chow MJ , Turcotte R , Lin CP , Zhang Y . Arterial extracellular matrix: A mechanobiological study of the contributions and interactions of elastin and collagen. Biophys J 106: 2684‐2692, 2014.
 74. Chrzanowski W , Khademhosseini A . Biologically inspired ‘smart’ materials. Adv Drug Deliv Rev 65: 403‐404, 2013.
 75. Cipolla MJ , Gokina NI , Osol G . Pressure‐induced actin polymerization in vascular smooth muscle as a mechanism underlying myogenic behavior. Faseb J 16: 72‐76, 2002.
 76. Clobes AM , Guilford WH . Loop 2 of myosin is a force‐dependent inhibitor of the rigor bond. J Muscle Res Cell Motil 35: 143‐152, 2014.
 77. Close RI . Dynamic properties of mammalian skeletal muscles. Physiol Rev 52: 129‐197, 1972.
 78. Cohen DM , Murphy RA . Differences in cellular contractile protein contents among porcine smooth muscles: Evidence for variation in the contractile system. J Gen Physiol 72: 369‐380, 1978.
 79. Cohen DM , Murphy RA . Cellular thin filament protein contents and force generation in porcine arteries and veins. Circ Res 45: 661‐665, 1979.
 80. Colombelli J , Besser A , Kress H , Reynaud EG , Girard P , Caussinus E , Haselmann U , Small JV , Schwarz US , Stelzer EH . Mechanosensing in actin stress fibers revealed by a close correlation between force and protein localization. J Cell Sci 122: 1665‐1679, 2009.
 81. Cooke PH , Fay FS . Correlation between fiber length, ultrastructure, and the length‐tension relationship of mammalian smooth muscle. J Cell Biol 52: 105‐116, 1972.
 82. Craig R , Megerman J . Assembly of smooth muscle myosin into side‐polar filaments. J Cell Biol 75: 990‐996, 1977.
 83. Craig R , Woodhead JL . Structure and function of myosin filaments. Curr Opin Struct Biol 16: 204‐212, 2006.
 84. Cremo CR , Geeves MA . Interaction of actin and ADP with the head domain of smooth muscle myosin: Implications for strain‐dependent ADP release in smooth muscle. Biochemistry 37: 1969‐1978, 1998.
 85. Curtin NA , Edman KA . Force‐velocity relation for frog muscle fibres: Effects of moderate fatigue and of intracellular acidification. J Physiol 475: 483‐494, 1994.
 86. Cyron CJ , Muller KW , Bausch AR , Wall WA . Micromechanical simulations of biopolymer networks with finite elements. J Comput Phys 244: 236‐251, 2013.
 87. Dagenais F , Buluran J , Cartier R . [In vitro endothelial dysfunction after cold storage: Comparison with various preservative solutions]. Ann Chir 49: 700‐705, 1995.
 88. Dantzig JA , Barsotti RJ , Manz S , Sweeney HL , Goldman YE . The ADP release step of the smooth muscle cross‐bridge cycle is not directly associated with force generation. Biophys J 77: 386‐397, 1999.
 89. Dargazany R , Itskov M . Constitutive modeling of the Mullins effect and cyclic stress softening in filled elastomers. Phys Rev E Stat Nonlin Soft Matter Phys 88: 012602, 2013.
 90. Davis MJ , Gore RW . Length‐tension relationship of vascular smooth muscle in single arterioles. Am J Physiol 256: H630‐H640, 1989.
 91. De La Cruz EM , Ostap EM . Relating biochemistry and function in the myosin superfamily. Curr Opin Cell Biol 16: 61‐67, 2004.
 92. de Tombe PP , ter Keurs HE . An internal viscous element limits unloaded velocity of sarcomere shortening in rat myocardium. J Physiol 454: 619‐642, 1992.
 93. DeFuria RR , Kushmerick MJ . ATP utilization associated with recovery metabolism in anaerobic frog muscle. Am J Physiol 232: C30‐C36, 1977.
 94. Devine CE , Somlyo AP . Thick filaments in vascular smooth muscle. J Cell Biol 49: 636‐649, 1971.
 95. Diani J , Fayolle B , Gilormini P . A review on the Mullins effect. Eur Polym J 45: 601‐612, 2009.
 96. Dillon PF , Aksoy MO , Driska SP , Murphy RA . Myosin phosphorylation and the cross‐bridge cycle in arterial smooth muscle. Science 211: 495‐497, 1981.
 97. Dillon PF , Murphy RA . High force development and crossbridge attachment in smooth muscle from swine carotid arteries. Circ Res 50: 799‐804, 1982.
 98. Dillon PF , Murphy RA . Tonic force maintenance with reduced shortening velocity in arterial smooth muscle. Am J Physiol 242: C102‐C108, 1982.
 99. Dobbie I , Linari M , Piazzesi G , Reconditi M , Koubassova N , Ferenczi MA , Lombardi V , Irving M . Elastic bending and active tilting of myosin heads during muscle contraction. Nature 396: 383‐387, 1998.
 100. Dobrin PB . Influence of initial length on length‐tension relationship of vascular smooth muscle. Am J Physiol 225: 664‐670, 1973.
 101. Dobrin PB . Mechanical properties of arteries. Physiol Rev 58: 397‐460, 1978.
 102. Dobrin PB , Rovick AA . Influence of vascular smooth muscle on contractile mechanics and elasticity of arteries. Am J Physiol 217: 1644‐1651, 1969.
 103. Dorfmann A , Ogden RW . A constitutive model for the Mullins effect with permanent set in particle‐reinforced rubber. Int J Solids Struct 41: 1855‐1878, 2004.
 104. dos Remedios CG , Chhabra D , Kekic M , Dedova IV , Tsubakihara M , Berry DA , Nosworthy NJ . Actin binding proteins: Regulation of cytoskeletal microfilaments. Physiol Rev 83: 433‐473, 2003.
 105. Doyle JM , Dobrin PB . Stress gradients in the walls of large arteries. J Biomech 6: 631‐639, 1973.
 106. Draeger A , Amos WB , Ikebe M , Small JV . The cytoskeletal and contractile apparatus of smooth muscle: Contraction bands and segmentation of the contractile elements. J Cell Biol 111: 2463‐2473, 1990.
 107. Driska SP , Aksoy MO , Murphy RA . Myosin light chain phosphorylation associated with contraction in arterial smooth muscle. Am J Physiol 240: C222‐C233, 1981.
 108. Driska SP , Damon DN , Murphy RA . Estimates of cellular mechanics in an arterial smooth muscle. Biophys J 24: 525‐540, 1978.
 109. Duling BR , Gore RW , Dacey RG, Jr. , Damon DN . Methods for isolation, cannulation, and in vitro study of single microvessels. Am J Physiol 241: H108‐H116, 1981.
 110. Dupuis DE , Guilford WH , Wu J , Warshaw DM . Actin filament mechanics in the laser trap. J Muscle Res Cell Motil 18: 17‐30, 1997.
 111. Eddinger TJ , Korwek AA , Meer DP , Sherwood JJ . Expression of smooth muscle myosin light chain 17 and unloaded shortening in single smooth muscle cells. Am J Physiol 278: C1133‐C1142, 2000.
 112. Eddinger TJ , Meer DP . Myosin II isoforms in smooth muscle: Heterogeneity and function. Am J Physiol Cell Physiol 293: C493‐C508, 2007.
 113. Eddinger TJ , Meer DP , Miner AS , Meehl J , Rovner AS , Ratz PH . Potent inhibition of arterial smooth muscle tonic contractions by the selective myosin II inhibitor, blebbistatin. J Pharmacol Exp Ther 320: 865‐870, 2007.
 114. Eddinger TJ , Schiebout JD , Swartz DR . Adherens junction‐associated protein distribution differs in smooth muscle tissue and acutely isolated cells. Am J Physiol Gastrointest Liver Physiol 292: G684‐G697, 2007.
 115. Edman KA . The velocity of unloaded shortening and its relation to sarcomere length and isometric force in vertebrate muscle fibres. J Physiol 291: 143‐159, 1979.
 116. Edman KA . Double‐hyperbolic force‐velocity relation in frog muscle fibres. J Physiol 404: 301‐321, 1988.
 117. Edman KA , Reggiani C , Schiaffino S , te Kronnie G . Maximum velocity of shortening related to myosin isoform composition in frog skeletal muscle fibres. J Physiol 395: 679‐694, 1988.
 118. Emery JL , Omens JH , McCulloch AD . Strain softening in rat left ventricular myocardium. J Biomech Eng 119: 6‐12, 1997.
 119. Fabry B , Fredberg JJ . Remodeling of the airway smooth muscle cell: Are we built of glass? Respir Physiol Neurobiol 137: 109‐124, 2003.
 120. Faury G . Function‐structure relationship of elastic arteries in evolution: From microfibrils to elastin and elastic fibres. Pathologie‐biologie 49: 310‐325, 2001.
 121. Fay FS , Cooke PH , Canaday PG . Contractile properties of isolated smooth muscle cells. In: Bulbring E , Shuba MF , editors. Physiology of Smooth Muscle. New York: Raven Press, 1976, p. 249‐264.
 122. Fenn WO . A quantitative comparison between the energy liberated and the work performed by the isolated sartorius muscle of the frog. J Physiol 58: 175‐203, 1923.
 123. Fenn WO , Latchford WB . The effect of muscle length on the energy for maintenance of tension. J Physiol 80: 213‐219, 1933.
 124. Fenn WO , Marsh BS . Muscular force at different speeds of shortening. J Physiol 85: 277‐297, 1935.
 125. Ferrer JM , Lee H , Chen J , Pelz B , Nakamura F , Kamm RD , Lang MJ . Measuring molecular rupture forces between single actin filaments and actin‐binding proteins. Proc Natl Acad Sci U S A 105: 9221‐9226, 2008.
 126. Feughelman M . Natural protein fibers. J Appl Polym Sci 83: 489‐507, 2002.
 127. Finer JT , Simmons RM , Spudich JA . Single myosin molecule mechanics: Piconewton forces and nanometre steps. Nature 368: 113‐119, 1994.
 128. Flavahan NA , Bailey SR , Flavahan WA , Mitra S , Flavahan S . Imaging remodeling of the actin cytoskeleton in vascular smooth muscle cells after mechanosensitive arteriolar constriction. Am J Physiol Heart Circ Physiol 288: H660‐H669, 2005.
 129. Folkow B , Grimby G , Thulesius O . Adaptive structural changes of the vascular walls in hypertension and their relation to the control of the peripheral resistance. Acta Physiol Scand 44: 255‐272, 1958.
 130. Ford LE . Plasticity in airway smooth muscle: An update. Can J Physiol Pharmacol 83: 841‐850, 2005.
 131. Ford LE , Gilbert SH . The significance of variable passive compliance in smooth muscle. J Appl Physiol 102: 1735‐1736, 2007.
 132. Ford LE , Huxley AF , Simmons RM . Tension responses to sudden length change in stimulated frog muscle fibres near slack length. J Physiol 269: 441‐515, 1977.
 133. Fuchs F , Martyn DA . Length‐dependent Ca(2+) activation in cardiac muscle: Some remaining questions. J Muscle Res Cell Motil 26: 199‐212, 2005.
 134. Fuglsang A , Khromov A , Torok K , Somlyo AV , Somlyo AP . Flash photolysis studies of relaxation and cross‐bridge detachment: Higher sensitivity of tonic than phasic smooth muscle to MgADP. J Muscle Res Cell Motil 14: 666‐677, 1993.
 135. Fukuda N , Granzier HL . Titin/connectin‐based modulation of the Frank‐Starling mechanism of the heart. J Muscle Res Cell Motil 26: 319‐323, 2005.
 136. Fukuda N , Granzier HL , Ishiwata S , Kurihara S . Physiological functions of the giant elastic protein titin in Mammalian striated muscle. J Physiol Sci 58: 151‐159, 2008.
 137. Fung YC . Elasticity of soft tissues in simple elongation. Am J Physiol 213: 1532‐1544, 1967.
 138. Fung YC . What are the residual stresses doing in our blood vessels? Ann Biomed Eng 19: 237‐249, 1991.
 139. Fung YC. Biomechanics. New York: Springer‐Verlag, 1993.
 140. Furchgott RF . The pharmacology of vascular smooth muscle. Pharmacol Rev 7: 183‐265, 1955.
 141. Furuike S , Ito T , Yamazaki M . Mechanical unfolding of single filamin A (ABP‐280) molecules detected by atomic force microscopy. FEBS Lett 498: 72‐75, 2001.
 142. Gabella G . Structural apparatus for force transmission in smooth muscles. Physiol Rev 64: 455‐477, 1984.
 143. Gasser TC . An irreversible constitutive model for fibrous soft biological tissue: A 3‐D microfiber approach with demonstrative application to abdominal aortic aneurysms. Acta Biomater 7: 2457‐2466, 2011.
 144. Gasser TC , Ogden RW , Holzapfel GA . Hyperelastic modelling of arterial layers with distributed collagen fibre orientations. J Roy Soc Interface 3: 15‐35, 2006.
 145. Geeves MA , Fedorov R , Manstein DJ . Molecular mechanism of actomyosin‐based motility. Cell Mol Life Sci 62: 1462‐1477, 2005.
 146. Gestrelius S , Borgstrom P . A dynamic model of smooth muscle contraction. Biophys J 50: 157‐169, 1986.
 147. Glantz SA . A constitutive equation for the passive properties of muscle. J Biomech 7: 137‐145, 1974.
 148. Glantz SA . A three‐element model describes excised cat papillary muscle elasticity. Am J Physiol 228: 284‐294, 1975.
 149. Glantz SA . A three‐element description for muscle with viscoelastic passive elements. J Biomech 10: 5‐20, 1977.
 150. Glasser SP , Arnett DK , McVeigh GE , Finkelstein SM , Bank AJ , Morgan DJ , Cohn JN . Vascular compliance and cardiovascular disease: A risk factor or a marker? Am J Hypertens 10: 1175‐1189, 1997.
 151. Gluck E , Paul RJ . The aerobic metabolism of porcine carotid artery and its relationship to isometric force. Energy cost of isometric contraction. Pflugers Arch 370: 9‐18, 1977.
 152. Goldman YE , Hibberd MG , Trentham DR . Initiation of active contraction by photogeneration of adenosine‐5′‐triphosphate in rabbit psoas muscle fibres. J Physiol 354: 605‐624, 1984.
 153. Goldman YE , Hibberd MG , Trentham DR . Relaxation of rabbit psoas muscle fibres from rigor by photochemical generation of adenosine‐5′‐triphosphate. J Physiol 354: 577‐604, 1984.
 154. Gollub J , Cremo CR , Cooke R . Phosphorylation regulates the ADP‐induced rotation of the light chain domain of smooth muscle myosin. Biochemistry 38: 10107‐10118, 1999.
 155. Gordon AM , Homsher E , Regnier M . Regulation of contraction in striated muscle. Physiol Rev 80: 853‐924, 2000.
 156. Gordon AM , Huxley AF , Julian FJ . The variation in isometric tension with sarcomere length in vertebrate muscle fibres. J Physiol 184: 170‐192, 1966.
 157. Gordon AR , Siegman MJ . Mechanical properties of smooth muscle. I. Length‐tension and force‐velocity relations. Am J Physiol 221: 1243‐1249, 1971.
 158. Gordon AR , Siegman MJ . Mechanical properties of smooth muscle. II. Active state. Am J Physiol 221: 1250‐1254, 1971.
 159. Gore RW , Davis MJ . Mechanics of smooth muscle in isolated single microvessels. Ann Biomed Eng 12: 511‐520, 1984.
 160. Gosline J , Lillie M , Carrington E , Guerette P , Ortlepp C , Savage K . Elastic proteins: Biological roles and mechanical properties. Philos Trans R Soc Lond B Biol Sci 357: 121‐132, 2002.
 161. Gosling RG , Budge MM . Terminology for describing the elastic behavior of arteries. Hypertension 41: 1180‐1182, 2003.
 162. Gow BS , Taylor MG . Measurement of viscoelastic properties of arteries in the living dog. Circ Res 23: 111‐122, 1968.
 163. Graceffa P , Mazurkie A . Effect of caldesmon on the position and myosin‐induced movement of smooth muscle tropomyosin bound to actin. J Biol Chem 280: 4135‐4143, 2005.
 164. Granzier H , Labeit S . Structure‐function relations of the giant elastic protein titin in striated and smooth muscle cells. Muscle Nerve 36: 740‐755, 2007.
 165. Granzier HL , Irving TC . Passive tension in cardiac muscle: Contribution of collagen, titin, microtubules, and intermediate filaments. Biophys J 68: 1027‐1044, 1995.
 166. Granzier HL , Wang K . Passive tension and stiffness of vertebrate skeletal and insect flight muscles: The contribution of weak cross‐bridges and elastic filaments. Biophys J 65: 2141‐2159, 1993.
 167. Greenberg MJ , Mealy TR , Watt JD , Jones M , Szczesna‐Cordary D , Moore JR . The molecular effects of skeletal muscle myosin regulatory light chain phosphorylation. Am J Physiol Regul Integr Comp Physiol 297: R265‐R274, 2009.
 168. Greenberg MJ , Wang CL , Lehman W , Moore JR . Modulation of actin mechanics by caldesmon and tropomyosin. Cell Motil Cytoskeleton 65: 156‐164, 2008.
 169. Greensmith JE , Duling BR . Morphology of the constricted arteriolar wall: Physiological implications. Am J Physiol 247: H687‐H698, 1984.
 170. Gregersen H , Emery JL , McCulloch AD . History‐dependent mechanical behavior of guinea‐pig small intestine. Ann Biomed Eng 26: 850‐858, 1998.
 171. Greven K . Plastic properties of vertebrate smooth muscle (taenia coli of the guinea pig). Pflugers Arch 362: 289‐290, 1976.
 172. Greven K . Viscoelastic and plastic properties of visceral smooth muscles in vertebrates. J Biomech 11: 49‐55, 1978.
 173. Greven K , Hohorst B . Creep after loading in relaxed and contracted (KC1 or K2SO4 depolarized) smooth muscle (taenia coli of the guinea pig). Pflugers Arch 359: 111‐125, 1975.
 174. Greven K , Rudolph KH , Hohorst B . Creep after loading in the relaxed and contracted smooth muscle (taenia coli of the guinea pig) under various osmotic conditions. Pflugers Arch 362: 255‐260, 1976.
 175. Guilford WH , Dupuis DE , Kennedy G , Wu J , Patlak JB , Warshaw DM . Smooth muscle and skeletal muscle myosins produce similar unitary forces and displacements in the laser trap. Biophys J 72: 1006‐1021, 1997.
 176. Gundiah N , B Ratcliffe M , A Pruitt L . Determination of strain energy function for arterial elastin: Experiments using histology and mechanical tests. J Biomech 40: 586‐594, 2007.
 177. Gunning P , O'Neill G , Hardeman E . Tropomyosin‐based regulation of the actin cytoskeleton in time and space. Physiol Rev 88: 1‐35, 2008.
 178. Gunst SJ , Fredberg JJ . The first three minutes: Smooth muscle contraction, cytoskeletal events, and soft glasses. J Appl Physiol 95: 413‐425, 2003.
 179. Gunst SJ , Meiss RA , Wu MF , Rowe M . Mechanisms for the mechanical plasticity of tracheal smooth muscle. Am J Physiol 268: C1267‐C1276, 1995.
 180. Gunst SJ , Wu MF . Selected contribution: Plasticity of airway smooth muscle stiffness and extensibility: Role of length‐adaptive mechanisms. J Appl Physiol 90: 741‐749, 2001.
 181. Gunst SJ , Zhang W . Actin cytoskeletal dynamics in smooth muscle: A new paradigm for the regulation of smooth muscle contraction. Am J Physiol Cell Physiol 295: C576‐C587, 2008.
 182. Guo B , Guilford WH . Mechanics of actomyosin bonds in different nucleotide states are tuned to muscle contraction. Proc Natl Acad Sci U S A 103: 9844‐9849, 2006.
 183. Gusev NB . Some properties of caldesmon and calponin and the participation of these proteins in regulation of smooth muscle contraction and cytoskeleton formation. Biochemistry (Mosc) 66: 1112‐1121, 2001.
 184. Guth K , Junge J . Low Ca2+ impedes cross‐bridge detachment in chemically skinned Taenia coli. Nature 300: 775‐776, 1982.
 185. Hadjiantoniou S , Guolla L , Pelling AE . Mechanically induced deformation and strain dynamics in actin stress fibers. Commun Integr Biol 5: 627‐630, 2012.
 186. Haeberle JR , Hott JW , Hathaway DR . Regulation of isometric force and isotonic shortening velocity by phosphorylation of the 20,000 dalton myosin light chain of rat uterine smooth muscle. Pflugers Arch 403: 215‐219, 1985.
 187. Hai CM , Kim HR . An expanded latchbridge model of protein kinase C‐mediated smooth muscle contraction. J Appl Physiol 98: 1356‐1365, 2004.
 188. Hai CM , Murphy RA . Cross‐bridge phosphorylation and regulation of latch state in smooth muscle. Am J Physiol 254: C99‐C106, 1988.
 189. Hai CM , Murphy RA . Regulation of shortening velocity by cross‐bridge phosphorylation in smooth muscle. Am J Physiol 255: C86‐C94, 1988.
 190. Halayko AJ , Solway J . Molecular mechanisms of phenotypic plasticity in smooth muscle cells. J Appl Physiol [1985] 90: 358‐368, 2001.
 191. Halpern W , Mulvany MJ , Warshaw DM . Mechanical properties of smooth muscle cells in the walls of arterial resistance vessels. J Physiol 275: 85‐101, 1978.
 192. Han SJ , Speich JE , Eddinger TJ , Berg KM , Miner AS , Call C , Ratz PH . Evidence for absence of latch‐bridge formation in muscular saphenous arteries. Am J Physiol Heart Circ Physiol 291: H138‐H146, 2006.
 193. Hansen TR , Dineen DX , Pullen GL . Orientation of arterial smooth muscle and strength of contraction of aortic strips from DOCA‐hypertensive rats. Blood Vessels 17: 302‐311, 1980.
 194. Hartshorne DJ , Siemankowski RF . Regulation of smooth‐muscle actomyosin. Annu Rev Physiol 43: 519‐530, 1981.
 195. Hayashi K . Mechanical properties of soft tissues and arterial walls. In: Holzapfel GA , Ogden RW , editors. Biomechanics of Soft Tissue in Cardiovascular Systems. Wien and New York: Springer‐Verlag, 2003, pp. 15‐63.
 196. Hayden MR , Sowers JR , Tyagi SC . The central role of vascular extracellular matrix and basement membrane remodeling in metabolic syndrome and type 2 diabetes: The matrix preloaded. Cardiovasc Diabetol 4: 9, 2005.
 197. Hearle JWS . A critical review of the structural mechanics of wool and hair fibres. Int J Biol Macromol 27: 123‐138, 2000.
 198. Hellstrand P . Oxygen consumption and lactate production of the rat portal vein in relation to its contractile activity. Acta Physiol Scand 100: 91‐106, 1977.
 199. Hellstrand P , Johansson B . Analysis of the length response to a force step in smooth muscle from rabbit urinary bladder. Acta Physiol Scand 106: 221‐238, 1979.
 200. Herlihy JT , Murphy RA . Length‐tension relationship of smooth muscle of the hog carotid artery. Circ Res 33: 257‐283, 1973.
 201. Herlihy JT , Murphy RA . Force‐velocity and series elastic characteristics of smooth muscle from the hog carotid artery. Circ Res 34: 461‐466, 1974.
 202. Herrera AM , McParland BE , Bienkowska A , Tait R , Pare PD , Seow CY . ‘Sarcomeres’ of smooth muscle: Functional characteristics and ultrastructural evidence. J Cell Sci 118: 2381‐2392, 2005.
 203. Herzog W , Ait‐Haddou R . Considerations on muscle contraction. J Electromyogr Kinesiol 12: 425‐433, 2002.
 204. Herzog W , Lee EJ , Rassier DE . Residual force enhancement in skeletal muscle. J Physiol 574: 635‐642, 2006.
 205. Herzog W , Leonard TR , Joumaa V , Mehta A . Mysteries of muscle contraction. J Appl Biomech 24: 1‐13, 2008.
 206. Hidalgo C , Granzier H . Tuning the molecular giant titin through phosphorylation: Role in health and disease. Trends Cardiovasc Med 23: 165‐171, 2013.
 207. Hill AV . The viscous elastic properties of smooth muscle. Proc R Soc Lond Ser B 100: 108‐115, 1926.
 208. Hill AV . The heat of shortening and the dynamic constants of muscle. Proc R Soc Lond B 126: 136‐195, 1938.
 209. Hill AV . Mechanics of the contractile element of muscle. Nature 166: 415‐419, 1950.
 210. Hill AV . The transition from rest to full activity in muscle: The velocity of shortening. Proc R Soc Lond B Biol Sci 138: 329‐338, 1951.
 211. Hill AV. Trails and Trials in Physiology: A Bibliography, 1909‐1964; with Reviews of Certain Topics and Methods and A Reconnaissance for Further Research. Williams & Wilkins, 1965.
 212. Hill AV. First and Last Experiments in Muscle Mechanics. Cambridge: Cambridge University Press, 1970.
 213. Hill DK . Tension due to interaction between the sliding filaments in resting striated muscle. The effect of stimulation. J Physiol 199: 637‐684, 1968.
 214. Hill TL , Eisenberg E , Chen YD , Podolsky RJ . Some self‐consistent two‐state sliding filament models of muscle contraction. Biophys J 15: 335‐372, 1975.
 215. Hoffman BD , Crocker JC . Cell mechanics: Dissecting the physical responses of cells to force. Annu Rev Biomed Eng 11: 259‐288, 2009.
 216. Hoffman BD , Grashoff C , Schwartz MA . Dynamic molecular processes mediate cellular mechanotransduction. Nature 475: 316‐323, 2011.
 217. Hoffman BF , Bassett AL , Bartelst Hj . Some Mechanical Properties of Isolated Mammalian Cardiac Muscle. Circ Res 23: 291‐&, 1968.
 218. Holzapfel GA , Gasser TC . Computational stress‐deformation analysis of arterial walls including high‐pressure response. Int J Cardiol 116: 78‐85, 2007.
 219. Holzapfel GA , Gasser TC , Ogden RW . A new constitutive framework for arterial wall mechanics and a comparative study of material models. J Elasticity 61: 1‐48, 2000.
 220. Holzapfel GA , Gasser TC , Stadler M . A structural model for the viscoelastic behavior of arterial walls: Continuum formulation and finite element analysis. Eur J Mech a‐Solid 21: 441‐463, 2002.
 221. Holzapfel GA , Ogden RW . Constitutive modelling of arteries. P Roy Soc a‐Math Phy 466: 1551‐1596, 2010.
 222. Holzapfel GA , Ogden RW . Modelling the layer‐specific three‐dimensional residual stresses in arteries, with an application to the human aorta. J Roy Soc Interface 7: 787‐799, 2010.
 223. Hong F , Haldeman BD , Jackson D , Carter M , Baker JE , Cremo CR . Biochemistry of smooth muscle myosin light chain kinase. Arch Biochem Biophys 510: 135‐146, 2011.
 224. Hooft AM , Maki EJ , Cox KK , Baker JE . An accelerated state of myosin‐based actin motility. Biochemistry 46: 3513‐3520, 2007.
 225. Horiuti K , Somlyo AV , Goldman YE , Somlyo AP . Kinetics of contraction initiated by flash photolysis of caged adenosine triphosphate in tonic and phasic smooth muscles. J Gen Physiol 94: 769‐781, 1989.
 226. Hoshijima M . Mechanical stress‐strain sensors embedded in cardiac cytoskeleton: Z disk, titin, and associated structures. Am J Physiol Heart Circ Physiol 290: H1313‐H1325, 2006.
 227. Howard J , Spudich JA . Is the lever arm of myosin a molecular elastic element? Proc Natl Acad Sci U S A 93: 4462‐4464, 1996.
 228. Hsin J , Strumpfer J , Lee EH , Schulten K . Molecular origin of the hierarchical elasticity of titin: Simulation, experiment, and theory. Annu Rev Biophys 40: 187‐203, 2011.
 229. Hudson SD , Zhurov V , Grbic V , Grbic M , Hutter JL . Measurement of the elastic modulus of spider mite silk fibers using atomic force microscopy. J Appl Phys 113: 154307‐154314, 2013.
 230. Humphrey JD . Continuum biomechanics of soft biological tissues. P Roy Soc a‐Math Phy 459: 3‐46, 2003.
 231. Humphrey JD . Vascular mechanics, mechanobiology, and remodeling. J Mech Med Biol 9: 243‐257, 2009.
 232. Humphrey JD , Na S . Elastodynamics and arterial wall stress. Ann Biomed Eng 30: 509‐523, 2002.
 233. Huxley AF . Muscle structure and theories of contraction. Prog Biophys Biophys Chem 7: 255‐318, 1957.
 234. Huxley AF . Muscular contraction. J Physiol 243: 1‐43, 1974.
 235. Huxley AF . Mechanics and models of the myosin motor. Philos Trans R Soc Lond B Biol Sci 355: 433‐440, 2000.
 236. Huxley AF , Simmons RM . Proposed mechanism of force generation in striated muscle. Nature 233: 533‐538, 1971.
 237. Huxley HE . The structural basis of muscular contraction. Proc R Soc Lond Ser B 178: 131‐149, 1971.
 238. Huxley HE . Fifty years of muscle and the sliding filament hypothesis. Eur J Biochem 271: 1403‐1415, 2004.
 239. Huxley HE . Past, present and future experiments on muscle. Philos Trans R Soc Lond B Biol Sci 355: 539‐543, 2000.
 240. Huxley HE . Evidence about the structural behaviour of myosin crossbridges during muscle contraction. Adv Exp Med Biol 592: 315‐326, 2007.
 241. Ingber DE . Tensegrity I. Cell structure and hierarchical systems biology. J Cell Sci 116: 1157‐1173, 2003.
 242. Iorga B , Adamek N , Geeves MA . The slow skeletal muscle isoform of myosin shows kinetic features common to smooth and non‐muscle myosins. J Biol Chem 282: 3559‐3570, 2007.
 243. Ito M , Nakano T , Erdodi F , Hartshorne DJ . Myosin phosphatase: Structure, regulation and function. Mol Cell Biochem 259: 197‐209, 2004.
 244. Iwamoto H , Sugaya R , Sugi H . Force‐velocity relation of frog skeletal muscle fibres shortening under continuously changing load. J Physiol 422: 185‐202, 1990.
 245. Jacobsen JC , Mulvany MJ , Holstein‐Rathlou NH . A mechanism for arteriolar remodeling based on maintenance of smooth muscle cell activation. Am J Physiol Regul Integr Comp Physiol 294: R1379‐R1389, 2008.
 246. Janmey PA , Euteneuer U , Traub P , Schliwa M . Viscoelastic properties of vimentin compared with other filamentous biopolymer networks. J Cell Biol 113: 155‐160, 1991.
 247. Janmey PA , Hvidt S , Lamb J , Stossel TP . Resemblance of actin‐binding protein/actin gels to covalently crosslinked networks. Nature 345: 89‐92, 1990.
 248. Janmey PA , Miller RT . Mechanisms of mechanical signaling in development and disease. J Cell Sci 124: 9‐18, 2011.
 249. Jiang H , Liao D , Zhao J , Wang G , Gregersen H . Contractions reverse stress softening in rat esophagus. Ann Biomed Eng 42: 1717‐1728, 2014.
 250. Johansson B . The contractile machinery and mechanics of contraction. J Cardiovasc Pharmacol 6(Suppl 2): S313‐319, 1984.
 251. Johnson PC . The myogenic response. In: D.F. Bohr APS, Harvey V. Sparks, Jr, editors. Handbook of Physiology: The Cardiovascular System; Vascular Smooth Muscle. Bethesda: American Physiological Society, 1980, pp. 409‐442.
 252. Jones AW , Somlyo AP , Somlyo AV . Potassium accumulation in smooth muscle and associated ultrastructural changes. J Physiol 232: 247‐273, 1973.
 253. Julian FJ , Moss RL . Effects of calcium and ionic strength on shortening velocity and tension development in frog skinned muscle fibres. J Physiol 311: 179‐199, 1981.
 254. Julian FJ , Rome LC , Stephenson DG , Striz S . The maximum speed of shortening in living and skinned frog muscle fibres. J Physiol 370: 181‐199, 1986.
 255. Julian FJ , Sollins MR . Sarcomere length‐tension relations in living rat papillary muscle. Circ Res 37: 299‐308, 1975.
 256. Kamm KE , Stull JT . Activation of smooth muscle contraction: Relation between myosin phosphorylation and stiffness. Science 232: 80‐82, 1986.
 257. Kasza KE , Rowat AC , Liu J , Angelini TE , Brangwynne CP , Koenderink GH , Weitz DA . The cell as a material. Curr Opin Cell Biol 19: 101‐107, 2007.
 258. Katz B . Archibald Vivian Hill. 26 September 1886‐3 June 1977. Biogr Mem Fellows R Soc 24: 71‐149, 1978.
 259. Kawasaki H , Nuki C , Saito A , Takasaki K . NPY modulates neurotransmission of CGRP‐containing vasodilator nerves in rat mesenteric arteries. Am J Physiol 261: H683‐H690, 1991.
 260. Kellermayer MS , Grama L . Stretching and visualizing titin molecules: Combining structure, dynamics and mechanics. J Muscle Res Cell Motil 23: 499‐511, 2002.
 261. Khamdaeng T , Luo J , Vappou J , Terdtoon P , Konofagou EE . Arterial stiffness identification of the human carotid artery using the stress‐strain relationship in vivo. Ultrasonics 52: 402‐411, 2012.
 262. Khromov A , Somlyo AV , Trentham DR , Zimmermann B , Somlyo AP . The role of MgADP in force maintenance by dephosphorylated cross‐bridges in smooth muscle: A flash photolysis study. Biophys J 69: 2611‐2622, 1995.
 263. Kim HR , Appel S , Vetterkind S , Gangopadhyay SS , Morgan KG . Smooth muscle signalling pathways in health and disease. J Cell Mol Med 12: 2165‐2180, 2008.
 264. Kim K , Keller TC, III . Smitin, a novel smooth muscle titin‐like protein, interacts with myosin filaments in vivo and in vitro. J Cell Biol 156: 101‐111, 2002.
 265. Kim T . Determinants of contractile forces generated in disorganized actomyosin bundles. Biomech Model Mechanobiol 14: 345‐355, 2014.
 266. Kim T , Gardel ML , Munro E . Determinants of fluidlike behavior and effective viscosity in cross‐linked actin networks. Biophys J 106: 526‐534, 2014.
 267. Kirton RS , Taberner AJ , Young AA , Nielsen PM , Loiselle DS . Strain softening is not present during axial extensions of rat intact right ventricular trabeculae in the presence or absence of 2,3‐butanedione monoxime. Am J Physiol Heart Circ Physiol 286: H708‐H715, 2004.
 268. Kishino A , Yanagida T . Force measurements by micromanipulation of a single actin filament by glass needles. Nature 334: 74‐76, 1988.
 269. Kochova P , Kuncova J , Sviglerova J , Cimrman R , Miklikova M , Liska V , Tonar Z . The contribution of vascular smooth muscle, elastin and collagen on the passive mechanics of porcine carotid arteries. Physiol Meas 33: 1335‐1351, 2012.
 270. Kojima H , Ishijima A , Yanagida T . Direct measurement of stiffness of single actin filaments with and without tropomyosin by in vitro nanomanipulation. Proc Natl Acad Sci U S A 91: 12962‐12966, 1994.
 271. Komuro T , Desaki J , Uehara Y . Three‐dimensional organization of smooth muscle cells in blood vessels of laboratory rodents. Cell Tissue Res 227: 429‐437, 1982.
 272. Korn ED . Coevolution of head, neck, and tail domains of myosin heavy chains. Proc Natl Acad Sci U S A 97: 12559‐12564, 2000.
 273. Kreplak L , Doucet J , Dumas P , Briki F . New aspects of the alpha‐helix to beta‐sheet transition in stretched hard alpha‐keratin fibers. Biophys J 87: 640‐647, 2004.
 274. Kulke M , Fujita‐Becker S , Rostkova E , Neagoe C , Labeit D , Manstein DJ , Gautel M , Linke WA . Interaction between PEVK‐titin and actin filaments: Origin of a viscous force component in cardiac myofibrils. Circ Res 89: 874‐881, 2001.
 275. Kuo KH , Seow CY . Contractile filament architecture and force transmission in swine airway smooth muscle. J Cell Sci 117: 1503‐1511, 2004.
 276. Kushmerick MJ , Paul RJ . Chemical energetics in repeated contractions of frog sartorius muscles at 0 degrees C. J Physiol 267: 249‐260, 1977.
 277. Kushmerick MJ , Podolsky RJ . Ionic mobility in muscle cells. Science 166: 1297‐1298, 1969.
 278. Labeit S , Lahmers S , Burkart C , Fong C , McNabb M , Witt S , Witt C , Labeit D , Granzier H . Expression of distinct classes of titin isoforms in striated and smooth muscles by alternative splicing, and their conserved interaction with filamins. J Mol Biol 362: 664‐681, 2006.
 279. Lannoy M , Slove S , Jacob MP . The function of elastic fibers in the arteries: Beyond elasticity. Pathologie‐biologie 62: 79‐83, 2014.
 280. Laudadio RE , Millet EJ , Fabry B , An SS , Butler JP , Fredberg JJ . Rat airway smooth muscle cell during actin modulation: Rheology and glassy dynamics. Am J Physiol Cell Physiol 289: C1388‐C1395, 2005.
 281. Lawton RW . Measurements on the elasticity and damping of isolated aortic strips of the dog. Circ Res 3: 403‐408, 1955.
 282. Lefkowitz RJ , Whalen EJ . beta‐arrestins: Traffic cops of cell signaling. Curr Opin Cell Biol 16: 162‐168, 2004.
 283. Levayer R , Lecuit T . Biomechanical regulation of contractility: Spatial control and dynamics. Trends Cell Biol 22: 61‐81, 2012.
 284. Levin A , Wyman J . The viscous elastic properties of muscle. Proc R Soc Lond Ser B 101: 218‐243, 1927.
 285. Lewalle A , Steffen W , Stevenson O , Ouyang Z , Sleep J . Single‐molecule measurement of the stiffness of the rigor myosin head. Biophys J 94: 2160‐2169, 2008.
 286. Liao D , Zhao J , Kunwald P , Gregersen H . Tissue softening of guinea pig oesophagus tested by the tri‐axial test machine. J Biomech 42: 804‐810, 2009.
 287. Lide DR . CRC Handbook of Chemistry and Physics, Internet Version 2005. Boca Raton: CRC Press, 2005.
 288. Linari M , Caremani M , Piperio C , Brandt P , Lombardi V . Stiffness and fraction of Myosin motors responsible for active force in permeabilized muscle fibers from rabbit psoas. Biophys J 92: 2476‐2490, 2007.
 289. Linke WA , Grutzner A . Pulling single molecules of titin by AFM–recent advances and physiological implications. Pflugers Arch 456: 101‐115, 2008.
 290. Linke WA , Hamdani N . Gigantic business: Titin properties and function through thick and thin. Circ Res 114: 1052‐1068, 2014.
 291. Linke WA , Popov VI , Pollack GH . Passive and active tension in single cardiac myofibrils. Biophys J 67: 782‐792, 1994.
 292. Lionne C , Iorga B , Candau R , Travers F . Why choose myofibrils to study muscle myosin ATPase? J Muscle Res Cell Motil 24: 139‐148, 2003.
 293. Liou YM , Watanabe M , Yumoto M , Ishiwata S . Regulatory mechanism of smooth muscle contraction studied with gelsolin‐treated strips of taenia caeci in guinea pig. Am J Physiol Cell Physiol 296: C1024‐C1033, 2009.
 294. Lokshin O , Lanir Y . Viscoelasticity and preconditioning of rat skin under uniaxial stretch: Microstructural constitutive characterization. J Biomech Eng 131: 031009, 2009.
 295. Lowey S , Trybus KM . Common structural motifs for the regulation of divergent class II myosins. J Biol Chem 285: 16403‐16407, 2010.
 296. Lynch RM , Paul RJ . Compartmentation of glycolytic and glycogenolytic metabolism in vascular smooth muscle. Science 222: 1344‐1346, 1983.
 297. Mahadevan L , Riera CS , Shin JH . Structural Dynamics of an Actin Spring. Biophys J 100: 839‐844, 2011.
 298. Malmqvist U , Arner A . Correlation between isoform composition of the 17 kDa myosin light chain and maximal shortening velocity in smooth muscle. Pflugers Arch 418: 523‐530, 1991.
 299. Malmqvist U , Trybus KM , Yagi S , Carmichael J , Fay FS . Slow cycling of unphosphorylated myosin is inhibited by calponin, thus keeping smooth muscle relaxed. Proc Natl Acad Sci U S A 94: 7655‐7660, 1997.
 300. Marey EJ. Animal Mechanism: A Treatise on Terrestrial and Aerial Locomotion. New York: D. Appleton and Company, 1874.
 301. Marshall BT , Long M , Piper JW , Yago T , McEver RP , Zhu C . Direct observation of catch bonds involving cell‐adhesion molecules. Nature 423: 190‐193, 2003.
 302. Marston SB . The regulation of smooth‐muscle contractile proteins. Prog Biophys Mol Bio 41: 1‐41, 1983.
 303. Martinez‐Lemus LA , Hill MA , Meininger GA . The plastic nature of the vascular wall: A continuum of remodeling events contributing to control of arteriolar diameter and structure. Physiology (Bethesda) 24: 45‐57, 2009.
 304. Martinez‐Lemus LA , Wu X , Wilson E , Hill MA , Davis GE , Davis MJ , Meininger GA . Integrins as unique receptors for vascular control. J Vasc Res 40: 211‐233, 2003.
 305.Martins JAC, Pires EB , Salvado R , Dinis PB . A numerical model of passive and active behavior of skeletal muscles. Comp Methods Appl Mech Eng 151: 419‐433, 1998.
 306. Matsumoto T , Nagayama K . Tensile properties of vascular smooth muscle cells: Bridging vascular and cellular biomechanics. J Biomech 45: 745‐755, 2012.
 307. Matthew JD , Khromov AS , Trybus KM , Somlyo AP , Somlyo AV . Myosin essential light chain isoforms modulate the velocity of shortening propelled by nonphosphorylated cross‐bridges. J Biol Chem 273: 31289‐31296, 1998.
 308. Mayans O , Benian GM , Simkovic F , Rigden DJ . Mechanistic and functional diversity in the mechanosensory kinases of the titin‐like family. Biochem Soc Trans 41: 1066‐1071, 2013.
 309. McKillop DF , Geeves MA . Regulation of the interaction between actin and myosin subfragment 1: Evidence for three states of the thin filament. Biophys J 65: 693‐701, 1993.
 310. McMahon TA. Muscles, Reflexes and Locomotion. Princeton, NJ: Princeton University Press, 1984.
 311. Mederos y Schnitzler M , Storch U , Meibers S , Nurwakagari P , Breit A , Essin K , Gollasch M , Gudermann T . Gq‐coupled receptors as mechanosensors mediating myogenic vasoconstriction. EMBO J 27: 3092‐3103, 2008.
 312. Meiss RA . Dynamic stiffness of rabbit mesotubarium smooth muscle: Effect of isometric length. Am J Physiol 234: C14‐C26, 1978.
 313. Meiss RA . Limits to shortening in smooth muscle tissues. J Muscle Res Cell Motil 13: 190‐198, 1992.
 314. Meiss RA , Pidaparti RM . Mechanical state of airway smooth muscle at very short lengths. J Appl Physiol 96: 655‐667, 2004.
 315. Merkel L , Gerthoffer WT , Torphy TJ . Dissociation between myosin phosphorylation and shortening velocity in canine trachea. Am J Physiol 258: C524‐C532, 1990.
 316. Miserez A , Guerette PA . Phase transition‐induced elasticity of alpha‐helical bioelastomeric fibres and networks. Chem Soc Rev 42: 1973‐1995, 2013.
 317. Mithieux SM , Wise SG , Weiss AS . Tropoelastin–a multifaceted naturally smart material. Adv Drug Deliv Rev 65: 421‐428, 2013.
 318. Miyata H , Yasuda R , Kinosita K, Jr . Strength and lifetime of the bond between actin and skeletal muscle alpha‐actinin studied with an optical trapping technique. Biochim Biophys Acta 1290: 83‐88, 1996.
 319. Molloy JE , Burns JE , Kendrick‐Jones J , Tregear RT , White DC . Movement and force produced by a single myosin head. Nature 378: 209‐212, 1995.
 320. Morano I . Tuning smooth muscle contraction by molecular motors. J Mol Med 81: 481‐487, 2003.
 321. Morgan DL , Proske U . Vertebrate slow muscle: Its structure, pattern of innervation, and mechanical properties. Physiol Rev 64: 103‐169, 1984.
 322. Mullins L . Effect of stretching on the properties of rubber. J Rubber Res 16: 275‐289, 1947.
 323. Mulvany MJ . The undamped and damped series elastic components of a vascular smooth muscle. Biophys J 26: 401‐413, 1979.
 324. Mulvany MJ . Vascular remodelling of resistance vessels: Can we define this? Cardiovasc Res 41: 9‐13, 1999.
 325. Mulvany MJ , Aalkjaer C . Structure and function of small arteries. Physiol Rev 70: 921‐961, 1990.
 326. Mulvany MJ , Halpern W . Mechanical properties of vascular smooth muscle cells in situ. Nature 260: 617‐619, 1976.
 327. Mulvany MJ , Halpern W . Contractile properties of small arterial resistance vessels in spontaneously hypertensive and normotensive rats. Circ Res 41: 19‐26, 1977.
 328. Mulvany MJ , Hansen OK , Aalkjaer C . Direct evidence that the greater contractility of resistance vessels in spontaneously hypertensive rats is associated with a narrowed lumen, a thickened media, and an increased number of smooth muscle cell layers. Circ Res 43: 854‐864, 1978.
 329. Mulvany MJ , Warshaw DM . The active tension‐length curve of vascular smooth muscle related to its cellular components. J Gen Physiol 74: 85‐104, 1979.
 330. Munro JA . The viscosity and thixotropy of honey. J Econ Entomol 36: 769‐ 777, 1943.
 331. Murphy CT , Spudich JA . Variable surface loops and myosin activity: Accessories to a motor. J Muscle Res Cell Motil 21: 139‐151, 2000.
 332. Murphy RA . Filament organization and contractile function in vertebrate smooth muscle. Annu Rev Physiol 41: 737‐748, 1979.
 333. Murphy RA . Mechanics of vascular smooth muscle. In: D.F. Bohr APS, Harvey V. Sparks, Jr, editors. Handbook of Physiology: The Cardiovascular System. Bethesda, MD: American Physiological Society, 1980, pp. 325‐351.
 334. Murphy RA . Muscle cells of hollow organs. News Physiol Sci 3: 124‐128, 1988.
 335. Murphy RA . What is special about smooth muscle? The significance of covalent crossbridge regulation. FASEB J 8: 311‐318, 1994.
 336. Murtada SC , Arner A , Holzapfel GA . Experiments and mechanochemical modeling of smooth muscle contraction: Significance of filament overlap. J Theor Biol 297: 176‐186, 2012.
 337. Nagasawa S , Handa H , Okumura A , Naruo Y , Okamoto S , Moritake K , Hayashi K . Mechanical properties of human cerebral arteries: Part 2. Vasospasm. Surg Neurol 14: 285‐290, 1980.
 338. Nielsen‐Kudsk F , Poulsen B , Ryom C , Nielsen‐Kudsk JE . A strain‐gauge myograph for isometric measurements of tension in isolated small blood vessels and other muscle preparations. J Pharmacol Methods 16: 215‐225, 1986.
 339. Nikooyan AA , Zadpoor AA . Mass‐spring‐damper modelling of the human body to study running and hopping–an overview. Proc Inst Mech Eng [H] 225: 1121‐1135, 2011.
 340. Nishiye E , Somlyo AV , Torok K , Somlyo AP . The effects of MgADP on cross‐bridge kinetics: A laser flash photolysis study of guinea‐pig smooth muscle. J Physiol 460: 247‐271, 1993.
 341. Nyitrai M , Geeves MA . Adenosine diphosphate and strain sensitivity in myosin motors. Philos Trans R Soc Lond B Biol Sci 359: 1867‐1877, 2004.
 342. Nyitrai M , Rossi R , Adamek N , Pellegrino MA , Bottinelli R , Geeves MA . What limits the velocity of fast‐skeletal muscle contraction in mammals? J Mol Biol 355: 432‐442, 2006.
 343. O'Connell MK , Murthy S , Phan S , Xu C , Buchanan J , Spilker R , Dalman RL , Zarins CK , Denk W , Taylor CA . The three‐dimensional micro‐ and nanostructure of the aortic medial lamellar unit measured using 3D confocal and electron microscopy imaging. Matrix Biol 27: 171‐181, 2008.
 344. Ogden RW , Roxburgh DG . A pseudo–elastic model for the Mullins effect in filled rubber. Proc R Soc A 455: 2861‐2877, 1999.
 345. Ohki T , Mikhailenko SV , Morales MF , Onishi H , Mochizuki N . Transmission of force and displacement within the myosin molecule. Biochemistry 43: 13707‐13714, 2004.
 346. Pant K , Watt J , Greenberg M , Jones M , Szczesna‐Cordary D , Moore JR . Removal of the cardiac myosin regulatory light chain increases isometric force production. FASEB J 23: 3571‐3580, 2009.
 347. Pardo JV , Siliciano JD , Craig SW . A vinculin‐containing cortical lattice in skeletal muscle: Transverse lattice elements (“costameres”) mark sites of attachment between myofibrils and sarcolemma. Proc Natl Acad Sci U S A 80: 1008‐1012, 1983.
 348. Patel DJ , De Freitas FM , Greenfield JC, Jr. , Fry DL . Relationship of Radius to Pressure Along the Aorta in Living Dogs. J Appl Physiol 18: 1111‐1117, 1963.
 349. Paul RJ . Chemical energetics of vascular smooth muscle. In: D.F. Bohr APS , Harvey V. Sparks, Jr , editors. Handbook of Physiology, Section 2: The Cardiovascular System. Bethesda, MD: American Physiological Society, 1980, pp. 201‐235.
 350. Paul RJ , Bowman PS , Kolodney MS . Effects of microtubule disruption on force, velocity, stiffness and [Ca(2+)](i) in porcine coronary arteries. Am J Physiol Heart Circ Physiol 279: H2493‐H2501, 2000.
 351. Paul RJ , Peterson JW . Relation between length, isometric force, and O2 consumption rate in vascular smooth muscle. Am J Physiol 228: 915‐922, 1975.
 352. Pereverzev YV , Prezhdo OV , Forero M , Sokurenko EV , Thomas WE . The two‐pathway model for the catch‐slip transition in biological adhesion. Biophys J 89: 1446‐1454, 2005.
 353. Peterson JW , Paul RJ . Effects of initial length and active shortening on vascular smooth muscle contractility. Am J Physiol 227: 1019‐1024, 1974.
 354. Piazzesi G , Reconditi M , Linari M , Lucii L , Bianco P , Brunello E , Decostre V , Stewart A , Gore DB , Irving TC , Irving M , Lombardi V . Skeletal muscle performance determined by modulation of number of myosin motors rather than motor force or stroke size. Cell 131: 784‐795, 2007.
 355. Piazzesi G , Reconditi M , Linari M , Lucii L , Sun YB , Narayanan T , Boesecke P , Lombardi V , Irving M . Mechanism of force generation by myosin heads in skeletal muscle. Nature 415: 659‐662, 2002.
 356. Pinniger GJ , Ranatunga KW , Offer GW . Crossbridge and non‐crossbridge contributions to tension in lengthening rat muscle: Force‐induced reversal of the power stroke. J Physiol 573: 627‐643, 2006.
 357. Pinto JG , Fung YC . Mechanical properties of the heart muscle in the passive state. J Biomech 6: 597‐616, 1973.
 358. Pinto JG , Price JM , Fung YC , Mead EH . A device for testing mechanical properties of biological materials–the “Biodyne”. J Appl Physiol 39: 863‐867, 1975.
 359. Pittman RN , Duling BR . Oxygen sensitivity of vascular smooth muscle. I. In vitro studies. Microvasc Res 6: 202‐211, 1973.
 360. Podolin RA , Ford LE . Influence of partial activation on force‐velocity properties of frog skinned muscle fibers in millimolar magnesium ion. J Gen Physiol 87: 607‐631, 1986.
 361. Prado LG , Makarenko I , Andresen C , Kruger M , Opitz CA , Linke WA . Isoform diversity of giant proteins in relation to passive and active contractile properties of rabbit skeletal muscles. J Gen Physiol 126: 461‐480, 2005.
 362. Prezhdo OV , Pereverzev YV . Theoretical aspects of the biological catch bond. Acc Chem Res 42: 693‐703, 2009.
 363. Proske U , Morgan DL . Do cross‐bridges contribute to the tension during stretch of passive muscle? J Muscle Res Cell Motil 20: 433‐442, 1999.
 364. Puetz S , Lubomirov LT , Pfitzer G . Regulation of smooth muscle contraction by small GTPases. Physiology (Bethesda) 24: 342‐356, 2009.
 365. Qi HJ , Boyce MC . Constitutive model for stretch‐induced softening of the stress‐stretch behavior of elastomeric materials. J Mech Phys Solids 52: 2187‐2205, 2004.
 366. Qiu J , Zheng Y , Hu J , Liao D , Gregersen H , Deng X , Fan Y , Wang G . Biomechanical regulation of vascular smooth muscle cell functions: From in vitro to in vivo understanding. J R Soc Interface 11: 20130852, 2014.
 367. Rachev A , Greenwald SE . Residual strains in conduit arteries. J Biomech 36: 661‐670, 2003.
 368. Rall JA. Mechanism of Muscular Contraction. New York: Springer, 2014.
 369. Rao VS , Clobes AM , Guilford WH . Force spectroscopy reveals multiple “closed states” of the muscle thin filament. J Biol Chem 286: 24135‐24141, 2011.
 370. Rasmussen H , Takuwa Y , Park S . Protein kinase C in the regulation of smooth muscle contraction. Faseb J 1: 177‐185, 1987.
 371. Rassier DE . Residual force enhancement in skeletal muscles: One sarcomere after the other. J Muscle Res Cell Motil 33: 155‐165, 2012.
 372. Ratz PH . Dependence of Ca2+ sensitivity of arterial contractions on history of receptor activation. Am J Physiol 277: H1661‐H1668, 1999.
 373. Ratz PH . High α1‐adrenergic receptor occupancy decreases relaxing potency of nifedipine by increasing myosin light chain phosphorylation. Circ Res 72: 1308‐1316, 1993.
 374. Ratz PH . Receptor activation induces short‐term modulation of arterial contractions: Memory in vascular smooth muscle. Am J Physiol 269: C417‐C423, 1995.
 375. Ratz PH , Berg KM , Urban NH , Miner AS . Regulation of smooth muscle calcium sensitivity: KCl as a calcium‐sensitizing stimulus. Am J Physiol Cell Physiol 288: C769‐C783, 2005.
 376. Ratz PH , Hai C‐M , Murphy RA . Dependence of stress on cross‐bridge phosphorylation in vascular smooth muscle. Am J Physiol 256: C96‐C100, 1989.
 377. Ratz PH , Lattanzio FA, Jr , Salomonsky P‐M . Memory of arterial receptor activation involves reduced [Ca2+]i and desensitization of cross bridges to [Ca2+]i . Am J Physiol 269: C1402‐C1407, 1995.
 378. Ratz PH , Miner AS . Role of protein kinase Czeta and calcium entry in KCl‐induced vascular smooth muscle calcium sensitization and feedback control of cellular calcium levels. J Pharmacol Exp Ther 328: 399‐408, 2009.
 379. Ratz PH , Miner AS , Barbour SE . Calcium‐independent phospholipase A2 participates in KCl‐induced calcium sensitization of vascular smooth muscle. Cell Calcium 46: 65‐72, 2009.
 380. Ratz PH , Murphy RA . Contributions of intracellular and extracellular Ca2+ pools to activation of myosin phosphorylation and stress in swine carotid media. Circ Res 60: 410‐421, 1987.
 381. Ratz PH , Salomonsky PM , Lattanzio FA, Jr . Memory of previous receptor activation induces a delay in Ca2+ mobilization and decreases the [Ca2+]i sensitivity of arterial contractions. J Vasc Res 33: 489‐498, 1996.
 382. Ratz PH , Speich JE . Evidence that actomyosin cross bridges contribute to “passive” tension in detrusor smooth muscle. Am J Physiol Renal Physiol 298: F1424‐F1435, 2010.
 383. Rayment I , Rypniewski WR , Schmidt‐Base K , Smith R , Tomhick DR , Benning MM , Winklemann DA , Wesenberg G , Holden HM . Three dimensional structure of myosin subfragment 1: A molecular motor. Science 261: 50‐58, 1993.
 384. Reedy MC . Visualizing myosin's power stroke in muscle contraction. J Cell Sci 113(Pt 20): 3551‐3562, 2000.
 385. Reho JJ , Zheng X , Fisher SA . Smooth muscle contractile diversity in the control of regional circulations. Am J Physiol Heart Circ Physiol 306: H163‐H172, 2014.
 386. Rembold CM , Murphy RA . Myoplasmic calcium, myosin phosphorylation, and regulation of the crossbridge cycle in swine arterial smooth muscle. Circ Res 58: 803‐815, 1986.
 387. Rembold CM , Murphy RA . Myoplasmic [Ca2+] determines myosin phosphorylation in agonist‐stimulated swine arterial smooth muscle. Circ Res 63: 593‐603, 1988.
 388. Rembold CM , Tejani AD , Ripley ML , Han S . Paxillin phosphorylation, actin polymerization, noise temperature, and the sustained phase of swine carotid artery contraction. Am J Physiol Cell Physiol 293: C993‐C1002, 2007.
 389. Rembold CM , Wardle RL , Wingard CJ , Batts TW , Etter EF , Murphy RA . Cooperative attachment of cross bridges predicts regulation of smooth muscle force by myosin phosphorylation. Am J Physiol Cell Physiol 287: C594‐C602, 2004.
 390. Remington JW . Hysteresis loop behavior of the aorta and other extensible tissues. Am J Physiol 180: 83‐95, 1955.
 391. Rhodin JAG . Architecture of the vessel wall. In: D.F. Bohr ASHS, editors. Handbook of Physiology: The Cardiovascular System. Bethesda: American Physiological Society, 1980, pp. 1‐31.
 392. Roach MR , Burton AC . The reason for the shape of the distensibility curves of arteries. Can J Med Sci 35: 681‐690, 1957.
 393. Robinson MS , Rigby BJ . Thiol differences along keratin fibers ‐ stress‐strain and stress‐relaxation behavior as a function of temperature and extension. Text Res J 55: 597‐600, 1985.
 394. Rognoni L , Stigler J , Pelz B , Ylanne J , Rief M . Dynamic force sensing of filamin revealed in single‐molecule experiments. Proc Natl Acad Sci U S A 109: 19679‐19684, 2012.
 395. Roy CS , Brown JG . The blood‐pressure and its variations in the arterioles, capillaries and smaller veins. J Physiol 2: 323‐446, 321, 1880.
 396. Roy S , Silacci P , Stergiopulos N . Biomechanical properties of decellularized porcine common carotid arteries. Am J Physiol Heart Circ Physiol 289: H1567‐H1576, 2005.
 397. Roy S , Thacher T , Silacci P , Stergiopulos N . Arterial biomechanics after destruction of cytoskeleton by Cytochalasin D. J Biomech 42: 2562‐2568, 2009.
 398. Roy S , Tsamis A , Prod'hom G , Stergiopulos N . On the in‐series and in‐parallel contribution of elastin assessed by a structure‐based biomechanical model of the arterial wall. J Biomech 41: 737‐743, 2008.
 399. Ruegg C , Veigel C , Molloy JE , Schmitz S , Sparrow JC , Fink RH . Molecular motors: Force and movement generated by single myosin II molecules. News Physiol Sci 17: 213‐218, 2002.
 400. Ruegg JC . Smooth muscle tone. Physiol Rev 51: 201‐248, 1971.
 401. Sachs F , Latorre R . Cytoplasmic solvent structure of single barnacle muscle cells studied by electron spin resonance. Biophys J 14: 316‐326, 1974.
 402. Sacks MS , Sun W . Multiaxial mechanical behavior of biological materials. Annu Rev Biomed Eng 5: 251‐284, 2003.
 403. Saito SY , Hori M , Ozaki H , Karaki H . Cytochalasin D inhibits smooth muscle contraction by directly inhibiting contractile apparatus. J Smooth Muscle Res 32: 51‐60, 1996.
 404. Sanjeevi R , Somanathan N , Ramaswamy D . A viscoelastic model for collagen fibres. J Biomech 15: 181‐183, 1982.
 405. Sato M , Schwarz WH , Pollard TD . Dependence of the mechanical properties of actin/alpha‐actinin gels on deformation rate. Nature 325: 828‐830, 1987.
 406. Scott RS , Li Z , Paulin D , Uvelius B , Small JV , Arner A . Role of desmin in active force transmission and maintenance of structure during growth of urinary bladder. Am J Physiol Cell Physiol 295: C324‐C331, 2008.
 407. Seehra GP , Silver FH . Viscoelastic properties of acid‐ and alkaline‐treated human dermis: A correlation between total surface charge and elastic modulus. Skin Res Technol 12: 190‐198, 2006.
 408. Seidel CL , Murphy RA . Stress relaxation in hog carotid artery as related to contractile activity. Blood Vessels 13: 78‐91, 1976.
 409. Seow CY . Response of arterial smooth muscle to length perturbation. J Appl Physiol 89: 2065‐2072, 2000.
 410. Seow CY . Myosin filament assembly in an ever‐changing myofilament lattice of smooth muscle. Am J Physiol Cell Physiol 289: C1363‐C1368, 2005.
 411. Seow CY . Hill's equation of muscle performance and its hidden insight on molecular mechanisms. J Gen Physiol 142: 561‐573, 2013.
 412. Seow CY , Pare PD . Ultrastructural basis of airway smooth muscle contraction. Can J Physiol Pharmacol 85: 659‐665, 2007.
 413. Shadwick RE . Mechanical design in arteries. J Exp Biol 202: 3305‐3313, 1999.
 414. Shibata S . Effect of prolonged cold storage on the contractile response of strips of rabbit aorta to various agents. Circ Res 24: 179‐187, 1969.
 415. Siegman MJ , Butler TM , Mooers SU , Davies RE . Calcium‐dependent resistance to stretch and stress relaxation in resting smooth muscles. Am J Physiol 231: 1501‐1508, 1976.
 416. Siegman MJ , Butler TM , Mooers SU , Davies RE . Crossbridge attachment, resistance to stretch, and viscoelasticity in resting mammalian smooth muscle. Science 191: 383‐385, 1976.
 417. Siegman MJ , Butler TM , Mooers SU , Davies RE . Chemical energetics of force development, force maintenance, and relaxation in mammalian smooth muscle. J Gen Physiol 76: 609‐629, 1980.
 418. Siegman MJ , Davidheiser S , Mooers SU , Butler TM . Structural limits on force production and shortening of smooth muscle. J Muscle Res Cell Motil 34: 43‐60, 2013.
 419. Siemankowski RF , Wiseman MO , White HD . ADP dissociation from actomyosin subfragment 1 is sufficiently slow to limit the unloaded shortening velocity in vertebrate muscle. Proc Natl Acad Sci 82: 658‐662, 1985.
 420. Silver FH , Horvath I , Foran DJ . Viscoelasticity of the vessel wall: The role of collagen and elastic fibers. Crit Rev Biomed Eng 29: 279‐301, 2001.
 421. Silver FH , Snowhill PB , Foran DJ . Mechanical behavior of vessel wall: A comparative study of aorta, vena cava, and carotid artery. Ann Biomed Eng 31: 793‐803, 2003.
 422. Simmons RM , Jewell BR . Mechanics and models of muscular contraction. In: Linden RJ , editor. Recent Advances in Physiology. Edinburgh and London: Churchill Livingstone, 1974, pp. 87‐147.
 423. Singer HA , Kamm KE , Murphy RA . Estimates of activation in arterial smooth muscle. Am J Physiol 251: C465‐C473, 1986.
 424. Singer HA , Murphy RA . Maximal rates of activation in electrically stimulated swine carotid media. Circ Res 60: 438‐445, 1987.
 425. Sjuve R , Arner A , Li Z , Mies B , Paulin D , Schmittner M , Small JV . Mechanical alterations in smooth muscle from mice lacking desmin. J Muscle Res Cell Motil 19: 415‐429, 1998.
 426. Sleek GE , Duling BR . Coordination of mural elements and myofilaments during arteriolar constriction. Circ Res 59: 620‐627, 1986.
 427. Small JV . Studies on isolated smooth muscle cells: The contractile apparatus. J Cell Sci 24: 327‐349, 1977.
 428. Small JV , Furst DO , De Mey J . Localization of filamin in smooth muscle. J Cell Biol 102: 210‐220, 1986.
 429. Small JV , Gimona M . The cytoskeleton of the vertebrate smooth muscle cell. Acta Physiol Scand 164: 341‐348, 1998.
 430. Small JV , Herzog M , Barth M , Draeger A . Supercontracted state of vertebrate smooth muscle cell fragments reveals myofilament lengths. J Cell Biol 111: 2451‐2461, 1990.
 431. Small JV , Squire JM . Structural basis of contraction in vertebrate smooth muscle. J Mol Biol 67: 117‐149, 1972.
 432. Smith BA , Tolloczko B , Martin JG , Grutter P . Probing the viscoelastic behavior of cultured airway smooth muscle cells with atomic force microscopy: Stiffening induced by contractile agonist. Biophys J 88: 2994‐3007, 2005.
 433. Smith DA , Geeves MA , Sleep J , Mijailovich SM . Towards a unified theory of muscle contraction. I: Foundations. Ann Biomed Eng 36: 1624‐1640, 2008.
 434. Smith JB , Zhao JB , Dou YL , Gregersen H . Time‐dependent viscoelastic properties along rat small intestine. World J Gastroenterol 11: 4974‐4978, 2005.
 435. Smolensky AV , Ragozzino J , Gilbert SH , Seow CY , Ford LE . Length‐dependent filament formation assessed from birefringence increases during activation of porcine tracheal muscle. J Physiol 563: 517‐527, 2005.
 436. Sollich P . Rheological constitutive equation for a model of soft glassy materials. Phys Rev E 58: 738‐759, 1998.
 437. Somlyo AP , Devine CE , Somlyo AV , Rice RV . Filament organization in vertebrate smooth muscle. Philos Trans R Soc Lond B Biol Sci 265: 223‐229, 1973.
 438. Somlyo AP , Somlyo AV . Signal transduction by G‐proteins, Rho‐kinase and protein phosphatase to smooth muscle and non‐muscle myosin II. J Physiol 522.2: 177‐185, 2000.
 439. Somlyo AV , Goldman YE , Fujimori T , Bond M , Trentham DR , Somlyo AP . Cross‐bridge kinetics, cooperativity, and negatively strained cross‐bridges in vertebrate smooth muscle. A laser‐flash photolysis study. J Gen Physiol 91: 165‐192, 1988.
 440. Somlyo AV , Khromov AS , Webb MR , Ferenczi MA , Trentham DR , He ZH , Sheng S , Shao Z , Somlyo AP . Smooth muscle myosin: Regulation and properties. Philos Trans R Soc Lond B Biol Sci 359: 1921‐1930, 2004.
 441. Sotomayor M , Schulten K . Single‐molecule experiments in vitro and in silico. Science 316: 1144‐1148, 2007.
 442. Southern JB , Frazier JR , Miner AS , Speich JE , Klausner AP , Ratz PH . Elevated steady‐state bladder preload activates myosin phosphorylation: Detrusor smooth muscle is a preload tension sensor. Am J Physiol Renal Physiol 303: F1517‐F1526, 2012.
 443. Sparks HV, Jr. , Bohr DF . Effect of stretch on passive tension and contractility of isolated vascular smooth muscle. Am J Physiol 202: 835‐840, 1962.
 444. Speden RN . The effect of initial strip length on the noradrenaline‐induced contraction of arterial strips. J Physiol 154: 15‐25, 1960.
 445. Speich JE , Almasri AM , Bhatia H , Klausner AP , Ratz PH . Adaptation of the length‐active tension relationship in rabbit detrusor. Am J Physiol Renal Physiol 297: F1119‐F1128, 2009.
 446. Speich JE , Borgsmiller L , Call C , Mohr R , Ratz PH . ROK‐induced cross‐link formation stiffens passive muscle: Reversible strain‐induced stress softening in rabbit detrusor. Am J Physiol Cell Physiol 289: C12‐C21, 2005.
 447. Speich JE , Dosier C , Borgsmiller L , Quintero K , Koo HP , Ratz PH . Adjustable passive length‐tension curve in rabbit detrusor smooth muscle. J Appl Physiol 102: 1746‐1755, 2007.
 448. Speich JE , Quintero K , Dosier C , Borgsmiller L , Koo HP , Ratz PH . A mechanical model for adjustable passive stiffness in rabbit detrusor. J Appl Physiol 101: 1189‐1198, 2006.
 449. Speich JE , Southern JB , Henderson S , Wilson CW , Klausner AP , Ratz PH . Adjustable passive stiffness in mouse bladder: Regulated by Rho kinase and elevated following partial bladder outlet obstruction. Am J Physiol Renal Physiol 302: F967‐F976, 2012.
 450. Stamenovic D . Rheological behavior of mammalian cells. Cell Mol Life Sci 65: 3592‐3605, 2008.
 451. Stephens NL , Cardinal R , Simmons B . Mechanical properties of tracheal smooth muscle: Effects of temperature. Am J Physiol 233: C92‐C98, 1977.
 452. Stephens NL , Kroeger E , Mehta JA . Force‐velocity characteristics of respiratory airway smooth muscle. J Appl Physiol 26: 685‐692, 1969.
 453. Stossel TP . Contribution of actin to the structure of the cytoplasmic matrix. J Cell Biol 99: 15s‐21s, 1984.
 454. Stossel TP . On the crawling of animal cells. Science 260: 1086‐1094, 1993.
 455. Stromer MH . The cytoskeleton in skeletal, cardiac and smooth muscle cells. Histol Histopathol 13: 283‐291, 1998.
 456. Szent‐Gyorgyi AG . The early history of the biochemistry of muscle contraction. J Gen Physiol 123: 631‐641, 2004.
 457. Takagi Y , Homsher EE , Goldman YE , Shuman H . Force generation in single conventional actomyosin complexes under high dynamic load. Biophys J 90: 1295‐1307, 2006.
 458. Takamizawa K , Hayashi K . Strain energy density function and uniform strain hypothesis for arterial mechanics. J Biomech 20: 7‐17, 1987.
 459. Tanaka E , van Eijden T . Biomechanical behavior of the temporomandibular joint disc. Crit Rev Oral Biol Med 14: 138‐150, 2003.
 460. Tanaka TT , Fung YC . Elastic and inelastic properties of the canine aorta and their variation along the aortic tree. J Biomech 7: 357‐370, 1974.
 461. Tang DD . Intermediate filaments in smooth muscle. Am J Physiol Cell Physiol 294: C869‐C878, 2008.
 462. Tang DD , Anfinogenova Y . Physiologic properties and regulation of the actin cytoskeleton in vascular smooth muscle. J Cardiovasc Pharmacol Ther 13: 130‐140, 2008.
 463. Tanpichai S , Quero F , Nogi M , Yano H , Young RJ , Lindstrom T , Sampson WW , Eichhorn SJ . Effective Young's Modulus of Bacterial and Microfibrillated Cellulose Fibrils in Fibrous Networks. Biomacromolecules 13: 1340‐1349, 2012.
 464. Tatham AS , Shewry PR . Elastomeric proteins: Biological roles, structures and mechanisms. Trends Biochem Sci 25: 567‐571, 2000.
 465. Telley IA , Denoth J . Sarcomere dynamics during muscular contraction and their implications to muscle function. J Muscle Res Cell Motil 28: 89‐104, 2007.
 466. Thomas WE , Vogel V , Sokurenko E . Biophysics of catch bonds. Annu Rev Biophys 37: 399‐416, 2008.
 467. Thoresen T , Lenz M , Gardel ML . Thick filament length and isoform composition determine self‐organized contractile units in actomyosin bundles. Biophys J 104: 655‐665, 2013.
 468. Toyama BH , Hetzer MW . Protein homeostasis: Live long, won't prosper. Nat Rev Mol Cell Biol 14: 55‐61, 2013.
 469. Trepat X , Deng L , An SS , Navajas D , Tschumperlin DJ , Gerthoffer WT , Butler JP , Fredberg JJ . Universal physical responses to stretch in the living cell. Nature 447: 592‐595, 2007.
 470. Trybus KM . Assembly of cytoplasmic and smooth muscle myosins. Curr Opin Cell Biol 3: 105‐111, 1991.
 471. Tskhovrebova L , Trinick J . Role of titin in vertebrate striated muscle. Philos Trans R Soc Lond B Biol Sci 357: 199‐206, 2002.
 472. Tskhovrebova L , Trinick J , Sleep JA , Simmons RM . Elasticity and unfolding of single molecules of the giant muscle protein titin. Nature 387: 308‐312, 1997.
 473. Tuna BG , Bakker EN , VanBavel E . Smooth muscle biomechanics and plasticity: Relevance for vascular calibre and remodelling. Basic Clin Pharmacol Toxicol 110: 35‐41, 2012.
 474. Tuna BG , Bakker EN , VanBavel E . Relation between active and passive biomechanics of small mesenteric arteries during remodeling. J Biomech 46: 1420‐1426, 2013.
 475. Tuna BG , Schoorl MJ , Bakker EN , de Vos J , VanBavel E . Smooth muscle contractile plasticity in rat mesenteric small arteries: Sensitivity to specific vasoconstrictors, distension and inflammatory cytokines. J Vasc Res 50: 249‐262, 2013.
 476. Tyska MJ , Dupuis DE , Guilford WH , Patlak JB , Waller GS , Trybus KM , Warshaw DM , Lowey S . Two heads of myosin are better than one for generating force and motion. Proc Natl Acad Sci U S A 96: 4402‐4407, 1999.
 477. Tyska MJ , Warshaw DM . The myosin power stroke. Cell Motil Cytoskeleton 51: 1‐15, 2002.
 478. Urban NH , Berg KM , Ratz PH . K+ depolarization induces RhoA kinase translocation to caveolae and Ca2+ sensitization of arterial muscle. Am J Physiol Cell Physiol 285: C1377‐C1385, 2003.
 479. Uvelius B . Isometric and isotonic length‐tension relations and variations in longitudinal smooth muscle from rabbit urinary bladder. Acta Physiol Scand 97: 1‐12, 1976.
 480. Uvelius B . Shortening velocity, active force and homogeneity of contraction during electrically evoked twitches in smooth muscle from rabbit urinary bladder. Acta Physiol Scand 106: 481‐486, 1979.
 481. Vale RD . Switches, latches, and amplifiers: Common themes of G proteins and molecular motors. J Cell Biol 135: 291‐302, 1996.
 482. van den Akker J , Schoorl MJ , Bakker EN , Vanbavel E . Small artery remodeling: Current concepts and questions. J Vasc Res 47: 183‐202, 2010.
 483. van Duyl WA . A model for both the passive and active properties of urinary bladder tissue related to bladder function. Neurourol Urodyn 4: 275‐283, 1985.
 484. Van Heijst BG , Blange T , Jongsma HJ , De Beer EL . The length dependency of calcium activated contractions in the femoral artery smooth muscle studied with different methods of skinning. J Muscle Res Cell Motil 21: 59‐66, 2000.
 485. Van Heijst BG , De Wit E , Van der Heide UA , Blange T , Jongsma HJ , De Beer EL . The effect of length on the sensitivity to phenylephrine and calcium in intact and skinned vascular smooth muscle. J Muscle Res Cell Motil 20: 11‐18, 1999.
 486. Van Koeveringe GA , Van Mastrigt R . Excitatory pathways in smooth muscle investigated by phase‐plot analysis of isometric force development. Am J Physiol 261: R138‐R144, 1991.
 487. van Mastrigt R . The force recovery following repeated quick releases applied to pig urinary bladder smooth muscle. J Muscle Res Cell Motil 12: 45‐52, 1991.
 488. van Mastrigt R . Mechanical properties of (urinary bladder) smooth muscle. J Muscle Res Cell Motil 23: 53‐57, 2002.
 489. Van Vliet KJ , Bao G , Suresh S . The biomechanics toolbox: Experimental approaches for living cells and biomolecules. Acta Mater 51: 5881‐5905, 2003.
 490. VanBavel E , Mooij T , Giezeman MJ , Spaan JA . Cannulation and continuous cross‐sectional area measurement of small blood vessels. J Pharmacol Methods 24: 219‐227, 1990.
 491. VanBavel E , Mulvany MJ . Role of wall tension in the vasoconstrictor response of cannulated rat mesenteric small arteries. J Physiol 477(Pt 1): 103‐115, 1994.
 492. VanBavel E , Siersma P , Spaan JA . Elasticity of passive blood vessels: A new concept. Am J Physiol Heart Circ Physiol 285: H1986‐H2000, 2003.
 493. VanBavel E , Wesselman JPM , Spaan JAE . Myogenic activation and calcium sensitivity of cannulated rat mesenteric small arteries. Circ Res 82: 210‐220, 1998.
 494. Veigel C , Molloy JE , Schmitz S , Kendrick‐Jones J . Load‐dependent kinetics of force production by smooth muscle myosin measured with optical tweezers. Nat Cell Biol 5: 980‐986, 2003.
 495. Veigel C , Schmidt CF . Moving into the cell: Single‐molecule studies of molecular motors in complex environments. Nat Rev Mol Cell Biol 12: 163‐176, 2011.
 496. Vito RP , Dixon SA . Blood vessel constitutive models‐1995‐2002. Annu Rev Biomed Eng 5: 413‐439, 2003.
 497. Vogel S. Comparative Biomechanics: Life's Physical World. Princeton University Press, 2003.
 498. Vogel S. Prime Mover : A Natural History Of Muscle. New York: Norton, 2001.
 499. Vogel S . The emergence of comparative biomechanics. Integr Comp Biol 47: 13‐15, 2007.
 500. Wagenseil JE , Mecham RP . Vascular extracellular matrix and arterial mechanics. Physiol Rev 89: 957‐989, 2009.
 501. Walker JS , Walker LA , Etter EF , Murphy RA . A dilution immunoassay to measure myosin regulatory light chain phosphorylation. Anal Biochem 284: 173‐182, 2000.
 502. Walker JS , Wingard CJ , Murphy RA . Energetics of crossbridge phosphorylation and contraction in vascular smooth muscle. Hypertension 23: 1106‐1112, 1994.
 503. Walmsley JG , Gore RW , Dacey RG, Jr. , Damon DN , Duling BR . Quantitative morphology of arterioles from the hamster cheek pouch related to mechanical analysis. Microvasc Res 24: 249‐271, 1982.
 504. Walmsley JG , Murphy RA . Force‐length dependence of arterial lamellar, smooth muscle, and myofilament orientations. Am J Physiol 253: H1141‐H1147, 1987.
 505. Walmsley JG , Owen MP , Bevan JA . Medial morphometry and mechanics of sequential rabbit ear arteries and myograph ring segments. Am J Physiol 245: H840‐H848, 1983.
 506. Wang C , Zhang W , Kassab GS . The validation of a generalized Hooke's law for coronary arteries. Am J Physiol Heart Circ Physiol 294: H66‐H73, 2008.
 507. Wang CL . Caldesmon and smooth‐muscle regulation. Cell Biochem Biophys 35: 275‐288, 2001.
 508. Wang CL . Caldesmon and the regulation of cytoskeletal functions. Adv Exp Med Biol 644: 250‐272, 2008.
 509. Wang JH , Thampatty BP . An introductory review of cell mechanobiology. Biomech Model Mechanobiol 5: 1‐16, 2006.
 510. Wang K , Forbes JG , Jin AJ . Single molecule measurements of titin elasticity. Prog Biophys Mol Biol 77: 1‐44, 2001.
 511. Wang K , McCarter R , Wright J , Beverly J , Ramirez‐Mitchell R . Viscoelasticity of the sarcomere matrix of skeletal muscles. The titin‐myosin composite filament is a dual‐stage molecular spring. Biophys J 64: 1161‐1177, 1993.
 512. Wang L , Pare PD , Seow CY . Plasticity in skeletal, cardiac, and smooth muscle: Selected contribution: Effect of chronic passive length change on airway smooth muscle length‐tension relationship. J Appl Physiol 90: 734‐740, 2001.
 513. Wang R , Li Q , Tang DD . Role of vimentin in smooth muscle force development. Am J Physiol Cell Physiol 291: C483‐C489, 2006.
 514. Wang Y , Zocchi G . Viscoelastic transition and yield strain of the folded protein. PLoS One 6: e28097, 2011.
 515. Warshaw DM , Fay FS . Cross‐bridge elasticity in single smooth muscle cells. J Gen Physiol 82: 157‐199, 1983.
 516. Warshaw DM , Guilford WH , Freyzon Y , Krementsova E , Palmiter KA , Tyska MJ , Baker JE , Trybus KM . The light chain binding domain of expressed smooth muscle heavy meromyosin acts as a mechanical lever. J Biol Chem 275: 37167‐37172, 2000.
 517. Warshaw DM , Mulvany MJ , Halpern W . Mechanical and morphological properties of arterial resistance vessels in young and old spontaneously hypertensive rats. Circ Res 45: 250‐259, 1979.
 518. Warshaw DM , Yamakawa M , Harris D . Evidence for an internal load in single smooth muscle cells. Prog Clin Biol Res 315: 329‐345, 1989.
 519. Wede OK , Lofgren M , Li Z , Paulin D , Arner A . Mechanical function of intermediate filaments in arteries of different size examined using desmin deficient mice. J Physiol 540: 941‐949, 2002.
 520. Weihs D , Mason TG , Teitell MA . Bio‐microrheology: A frontier in microrheology. Biophys J 91: 4296‐4305, 2006.
 521. Weisbrodt NW , Murphy RA . Myosin phosphorylation and contraction of feline esophageal smooth muscle. Am J Physiol 249: C9‐C14, 1985.
 522. Winegard T , Herr J , Mena C , Lee B , Dinov I , Bird D , Bernards M, Jr. , Hobel S , Van Valkenburgh B , Toga A , Fudge D . Coiling and maturation of a high‐performance fibre in hagfish slime gland thread cells. Nat Commun 5: 3534, 2014.
 523. Wingard CJ , Browne AK , Murphy RA . Dependence of force on length at constant cross‐bridge phosphorylation in the swine carotid media. J Physiol 488(Pt 3): 729‐739, 1995.
 524. Wingard CJ , Paul RJ , Murphy RA . Dependence of ATP consumption on cross‐bridge phosphorylation in swine carotid smooth muscle. J Physiol 481(Pt 1): 111‐117, 1994.
 525. Wingard CJ , Paul RJ , Murphy RA . Energetic cost of activation processes during contraction of swine arterial smooth muscle. J Physiol 501(Pt 1): 213‐223, 1997.
 526. Winters JM . A framework for mapping between “living” muscle model parameters and systems biology data for muscle tissue. Conf Proc IEEE Eng Med Biol Soc 2011: 162‐165, 2011.
 527. Winters JM , Woo SL‐Y . Multiple Muscle Systems: Biomechanics and Movement Organization. New York: Springer‐Verlag, 1990.
 528. Winters TM , Takahashi M , Lieber RL , Ward SR . Whole muscle length‐tension relationships are accurately modeled as scaled sarcomeres in rabbit hindlimb muscles. J Biomech 44: 109‐115, 2011.
 529. Wright G , Hurn E . Cytochalasin inhibition of slow tension increase in rat aortic rings. Am J Physiol 267: H1437‐H1446, 1994.
 530. Xu JQ , Harder BA , Uman P , Craig R . Myosin filament structure in vertebrate smooth muscle. J Cell Biol 134: 53‐66, 1996.
 531. Yamin R , Morgan KG . Deciphering actin cytoskeletal function in the contractile vascular smooth muscle cell. J Physiol 590: 4145‐4154, 2012.
 532. Yao NY , Broedersz CP , Depken M , Becker DJ , Pollak MR , Mackintosh FC , Weitz DA . Stress‐enhanced gelation: A dynamic nonlinearity of elasticity. Phys Rev Lett 110: 018103, 2013.
 533. Yoshinaga N , Marcq P . Contraction of cross‐linked actomyosin bundles. Phys Biol 9: 046004, 2012.
 534. Zeinali‐Davarani S , Chow MJ , Turcotte R , Zhang Y . Characterization of biaxial mechanical behavior of porcine aorta under gradual elastin degradation. Ann Biomed Eng 41: 1528‐1538, 2013.
 535. Zhang D , Sherwood J , Li L , Swartz DR . Unloaded shortening velocity in single permeabilized vascular smooth muscle cells is independent of microtubule status. J Muscle Res Cell Motil 25: 167‐175, 2004.
 536. Zhang R , Gashev AA , Zawieja DC , Davis MJ . Length‐tension relationships of small arteries, veins, and lymphatics from the rat mesenteric microcirculation. Am J Physiol Heart Circ Physiol 292: H1943‐H1952, 2006.
 537. Zulliger MA , Rachev A , Stergiopulos N . A constitutive formulation of arterial mechanics including vascular smooth muscle tone. Am J Physiol Heart Circ Physiol 287: H1335‐H1343, 2004.

Related Articles:

Biochemistry of the Contractile Proteins of Smooth Muscle
Mechanics of Vascular Smooth Muscle
Mechanotransduction
Mechanical and Structural Plasticity
Energetics of Contraction

Contact Editor

Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite

Paul H. Ratz. Mechanics of Vascular Smooth Muscle. Compr Physiol 2015, 6: 111-168. doi: 10.1002/cphy.c140072