Comprehensive Physiology Wiley Online Library

Electrophysiology of dissociated gastrointestinal muscle cells

Full Article on Wiley Online Library



Abstract

The sections in this article are:

1 Dispersion Techniques
1.1 Comparison of Approaches
1.2 Evaluation of Dispersed Cells
2 Rhythmicity In Cellular Preparations
3 Voltage Recordings From Isolated Cells
3.1 Agonist Effects on Voltage
3.2 Other Voltage Recordings in Isolated Cells
4 Voltage‐Clamp Studies Of Isolated Cells
4.1 Microelectrode Voltage‐Clamp Studies
4.2 Whole‐Cell Current and Voltage Clamp by Patch‐Clamp Technique
4.3 Properties of Potassium Channels
4.4 Properties of Calcium Channels
4.5 Properties of Chloride Channels
5 Effects of Physiological Agonists on Channels
5.1 Cholinergic Regulation of Potassium Channels
5.2 Cholinergic Effects on Calcium Channels
5.3 Effects of Other Agonists
6 Relating Studies of Ionic Channels to Electrical Events of the Gut
7 Implications of Single‐Channel Studies on Models of Electrical Activity
Figure 1. Figure 1.

Freshly dispersed circular muscle cells from canine proximal colon. Cells average 400 μm in length and have a relaxed, smooth appearance. They appear bright when visualized with phase‐contrast optics. Most cells with this appearance are Ca2+ tolerant, contract to a variety of agonists , maintain a resting membrane potential, and express Ca2+‐ and K+‐channel activities. Cells in this condition have been maintained for up to 36 h after dispersion.

Figure 2. Figure 2.

Spontaneous electrical activity recorded from longitudinal cells dispersed from rabbit jejunum. Cells demonstrated rhythmic depolarizations, some of which led to fast action potential transients. Under current clamp, application of hyperpolarizing currents caused cessation of spontaneous activity. Second hyperpolarization was not maintained by the constant current pulse, suggesting that membrane conductance increases during pulse, which is evidence for presence of inward rectifier channels in these cells.

From Benham et al.
Figure 3. Figure 3.

Membrane potentials and currents recorded from isolated longitudinal muscle cell of rabbit jejunum using current‐ and voltage‐clamp conditions. Pipette contained K+ (126 mM), EGTA (0.77 mM), and no Ca2+. A and B, top traces: in normal physiological solution (2.5 mM Ca2+, 6 mM K+, 137 mM Na+), depolarizing current evoked overshooting action potentials. A and B, bottom traces: hyperpolarizing current yielded an electrotonic response. B: in Ca2+‐free solution that contained 20 mM Ba2+, amplitude and duration of action potentials were increased. Increase in input resistance was also noted; amplitude of electrotonic response increased. C, top traces: under voltage‐clamp conditions, depolarizing test pulses evoked 2 current phases: transient inward current followed by sustained outward current. C, bottom traces: in Ba2+‐containing solution, amplitude and duration of inward current increased and outward current was essentially blocked.

Adapted from Bolton et al.
Figure 4. Figure 4.

Current‐voltage relationship for gastric muscle cell from Bufo marinus. Inset: voltage‐clamp step from holding potential (VH) of −78 to +10 mV. Symbols, 3 current phases recognized from these traces: 1) inward (circles), 2) transient outward (triangles), and 3) steady‐state outward (squares). Amplitudes of these 3 current phases are plotted as function of a series of test pulses to several levels. Note voltages at which currents appear to activate and reversal potentials of currents. Inward current was carried by Ca2+ ions; outward currents were carried by K+ currents. Transient outward current (triangles) activates steeply in range where inward current (circles) is greatest in amplitude. Transient outward current depended on magnitude of inward Ca2+ current and was thought to result from opening of Ca2+‐activated K+ currents. As Ca2+ is removed from the cytoplasm, this current decays.

Adapted from Walsh and Singer
Figure 5. Figure 5.

Schematic showing procedures for obtaining several membrane preparations that can be studied with patch‐clamp technique. Top, blunt pipette tip pressed against cell membrane. With suction a gigaseal can be formed that isolates interior of pipette and surface of membrane patch from bath solution. Therefore majority of current flowing through pipette must pass through membrane patch. In this cell‐attached configuration, single‐channel openings in membrane patch can be monitored without losing cellular regulation by second messengers. The drawback is that unless cell membrane potential is monitored independently, one cannot be sure of the potential across the isolated patch. From cell‐attached configuration, patch can be excised by withdrawing pipette from cell surface. In these inside‐out patches one can control ionic gradients and transmembrane potential precisely. By passing a small pulse of current or suction, it is also possible to break the isolated patch in the cell‐attached configuration while maintaining the gigaohm seal. This provides low‐resistance access to cell interior. Contents of pipette rapidly exchange with cellular contents (dialyze). In this configuration one has control over ionic gradients and transmembrane potential. Whole‐cell or macroscopic currents can be quantitated. Disadvantage is that important second messengers that regulate channels can be lost by dialysis. Finally it is also possible to withdraw the pipette after whole‐cell conditions have been obtained, which results in an excised patch that forms with exterior of membrane facing the bath. This configuration is particularly useful in studies of receptor‐activated channels, because exterior surface can be easily exposed to agonists and blockers.

Adapted from Hamill et al.
Figure 6. Figure 6.

Voltage dependence of K+ channels in isolated membrane patch from gastric cell of Bufo marinus (C, closed; O, open). Pipette and bath contained equivalent concentrations of K+. In symmetrical K+ concentrations, current flowing through channel should reverse direction at 0 mV. Bath contained 10−6 M Ca2+; pipette was Ca2+ free with 2 mM EGTA. Top trace, membrane was held at +28 mV. At this potential channel was frequently open; probability of being open was 0.43. At −14 mV channel was open infrequently; probability was only 0.07. Amplitude of current is voltage dependent, and direction of current is opposite at 2 test potentials.

From Singer and Walsh
Figure 7. Figure 7.

Permeability of K+ channels to Rb+ in excised patch from rabbit jejunal muscle cell. Pipette and bath contained symmetrical K+ concentrations. Top, current records at several test potentials. At positive potentials current was outward with respect to inner surface of membrane (current flowed from bath into pipette). At negative potentials current direction reversed, but K+ ions passed through the channel equally well. Data are plotted in graph (solid circles). When K+ was replaced in bath solution with 126 mM Rb+, outward current was greatly decreased. Current still passed easily out of pipette. Data are plotted in graph (crosses). Data can be interpreted as follows. Channel passed K+ in either direction (no rectification). Rb+ does not pass through channel as well as K+. When Rb+ served as current carrier (current flowing from bath into pipette), current was diminished, but at potentials favoring inward current, K+ in pipette served as current carrier and effects of Rb+ were not apparent.

From Benham et al.
Figure 8. Figure 8.

Calcium dependence of K+ channels in isolated patch from circular muscle cell of canine gastric antrum. Data from excised inside‐out patch in symmetrical K+ gradient. Patch held at −70 mV. A: transition in activity when concentration of Ca2+ bathing inner surface of membrane was increased from 10−7 to 10−6 M. This caused a large increase in the probability of opening and revealed that the patch contained at least 6 channels. B: reduction in Ca2+ (from 10−6 to 10−7 M) rapidly decreased probability of opening. Changes in intracellular Ca2+ concentration in submicromolar range shift activation voltage for these K+ channels into physiological range.

Data from A. Carl
Figure 9. Figure 9.

Voltage and Ca2+ dependence of K+ channels from mesenteric artery cell. A: channel activity in 10−6 M Ca2+ at several voltages. Channel is highly active at 10−6 M Ca2+. B: when Ca2+ was reduced to 10‐7 M, channel rarely opened at negative potentials, but opening was increased by depolarization. C and D: probability of opening of channels from mesenteric and jejunal cells, respectively; Ca2+ concentration given next to curves. Data describe Ca2+ and voltage dependence of channel. When Ca2+ increases from 10−7 to 10−6 M, channel becomes highly activable at potentials achieved physiologically (negative to 0 mV). During excitation‐contraction coupling in situ when cytoplasmic Ca2+ increases, activation range of Ca2+‐activated K+ channels can shift to more negative, physiological potentials.

From Benham et al.
Figure 10. Figure 10.

Effects of cholinergic stimulation on electrical activity of isolated gastric cells of Bufo marinus. A: intracellular recording of membrane potential (top trace) in response to ionophoretic application of acetylcholine (ACh) (bottom trace). ACh depolarized membrane potential and caused spiking. Magnitude of response was related to amplitude and duration of ionophoretic pulse (pulses a‐e). B and C: current‐clamp records; top traces, application of square pulses of hyperpolarizing current; lower traces, voltage responses. Bars, muscarine was applied. Muscarine depolarized the membrane and increased amplitude of voltage responses to injected current. C: offset current was applied to hold membrane potential fairly constant during muscarine application. This further increased the amplitude of voltage responses during muscarine application. Data suggest that cholinergic stimulation decreases membrane conductance. A: extracellular [Ca2+] ([Ca2+]o) = 50 mM, [Na+]o = 39 mM, and extracellular tetraethylammonium ion ([TEA+]o) = 18 mM. B and C: [Ca2+]0 = 20 M, [Na+]o = 97 mM, and [TEA+]o = 5 mM.

From Sims et al.
Figure 11. Figure 11.

Cholinergic responses of gastric muscle cell from Bufo marinus studied with voltage clamp. Traces, time (sweep speed is varied during trace, but tics denote seconds), voltage (stepped between −36 and −65 mV), and current responses. Expanded pulse at beginning of record shows control responses. Stepping to −65 mV revealed relaxation of outward current (outward tail current); stepping back to −36 mV shows development of outward current. Bar, muscarine was added to bath. This caused development of sustained inward current (departure from dashed line) and blockade of current relaxations upon hyperpolarization and development of outward current upon depolarization. Data suggest that cholinergic agonists act to block K+ current. Vh, holding potential; Iss steady‐state current.

From Sims et al.
Figure 12. Figure 12.

Current records under whole‐cell voltage clamp of guinea pig ileum. Pipette contained 140 mM Cs+ to block outward currents. Traces, voltage dependence of inward current. Graph, I‐ V relationship at peak inward current. Current activated at about −40 mV, reached a maximum at −10 mV, and reversed at approximately −40 mV. Tests showed that inward current was carried by Ca2+ ions.

From Droogmans and Callewaert
Figure 13. Figure 13.

Steady‐state activation (solid circles) and inactivation (open circles) of inward current as function of membrane potential. Data taken from isolated cell from guinea pig ileum. Curves, fit of data with Boltzmann equation. Activation and inactivation curves overlap, indicating that at approximately −40 mV a fraction of the Ca2+ may be open, producing a small sustained inward current (window current).

From Droogmans and Callewaert
Figure 14. Figure 14.

Effect of acetylcholine (AcCho) on voltage‐activated Ca2+ current in gastric muscle cell of Bufo marinus. Current response under voltage clamp from a holding potential of −78 mV to a test potential of 9 mV. Acetylcholine increased the magnitude of inward current.

From Clapp et al.
Figure 15. Figure 15.

Effects of acetylcholine (ACh) on electrical activity of gastric muscle of Bufo marinus. Record, continuous intracellular recording from circular muscle cell of corpus region. Arrow, ACh (10−5 M) was applied by superfusion. This caused a significant increase in slow‐wave frequency, a small tonic depolarization, and changed the waveforms of slow waves by reducing upstroke velocity and amplitude. Insets, specific portions of record enlarged to display effects of ACh on waveform. None of these effects on electrical activity are easily reconcilable on basis of suppression of an M current (see ref. .

Data from P. Shonnard


Figure 1.

Freshly dispersed circular muscle cells from canine proximal colon. Cells average 400 μm in length and have a relaxed, smooth appearance. They appear bright when visualized with phase‐contrast optics. Most cells with this appearance are Ca2+ tolerant, contract to a variety of agonists , maintain a resting membrane potential, and express Ca2+‐ and K+‐channel activities. Cells in this condition have been maintained for up to 36 h after dispersion.



Figure 2.

Spontaneous electrical activity recorded from longitudinal cells dispersed from rabbit jejunum. Cells demonstrated rhythmic depolarizations, some of which led to fast action potential transients. Under current clamp, application of hyperpolarizing currents caused cessation of spontaneous activity. Second hyperpolarization was not maintained by the constant current pulse, suggesting that membrane conductance increases during pulse, which is evidence for presence of inward rectifier channels in these cells.

From Benham et al.


Figure 3.

Membrane potentials and currents recorded from isolated longitudinal muscle cell of rabbit jejunum using current‐ and voltage‐clamp conditions. Pipette contained K+ (126 mM), EGTA (0.77 mM), and no Ca2+. A and B, top traces: in normal physiological solution (2.5 mM Ca2+, 6 mM K+, 137 mM Na+), depolarizing current evoked overshooting action potentials. A and B, bottom traces: hyperpolarizing current yielded an electrotonic response. B: in Ca2+‐free solution that contained 20 mM Ba2+, amplitude and duration of action potentials were increased. Increase in input resistance was also noted; amplitude of electrotonic response increased. C, top traces: under voltage‐clamp conditions, depolarizing test pulses evoked 2 current phases: transient inward current followed by sustained outward current. C, bottom traces: in Ba2+‐containing solution, amplitude and duration of inward current increased and outward current was essentially blocked.

Adapted from Bolton et al.


Figure 4.

Current‐voltage relationship for gastric muscle cell from Bufo marinus. Inset: voltage‐clamp step from holding potential (VH) of −78 to +10 mV. Symbols, 3 current phases recognized from these traces: 1) inward (circles), 2) transient outward (triangles), and 3) steady‐state outward (squares). Amplitudes of these 3 current phases are plotted as function of a series of test pulses to several levels. Note voltages at which currents appear to activate and reversal potentials of currents. Inward current was carried by Ca2+ ions; outward currents were carried by K+ currents. Transient outward current (triangles) activates steeply in range where inward current (circles) is greatest in amplitude. Transient outward current depended on magnitude of inward Ca2+ current and was thought to result from opening of Ca2+‐activated K+ currents. As Ca2+ is removed from the cytoplasm, this current decays.

Adapted from Walsh and Singer


Figure 5.

Schematic showing procedures for obtaining several membrane preparations that can be studied with patch‐clamp technique. Top, blunt pipette tip pressed against cell membrane. With suction a gigaseal can be formed that isolates interior of pipette and surface of membrane patch from bath solution. Therefore majority of current flowing through pipette must pass through membrane patch. In this cell‐attached configuration, single‐channel openings in membrane patch can be monitored without losing cellular regulation by second messengers. The drawback is that unless cell membrane potential is monitored independently, one cannot be sure of the potential across the isolated patch. From cell‐attached configuration, patch can be excised by withdrawing pipette from cell surface. In these inside‐out patches one can control ionic gradients and transmembrane potential precisely. By passing a small pulse of current or suction, it is also possible to break the isolated patch in the cell‐attached configuration while maintaining the gigaohm seal. This provides low‐resistance access to cell interior. Contents of pipette rapidly exchange with cellular contents (dialyze). In this configuration one has control over ionic gradients and transmembrane potential. Whole‐cell or macroscopic currents can be quantitated. Disadvantage is that important second messengers that regulate channels can be lost by dialysis. Finally it is also possible to withdraw the pipette after whole‐cell conditions have been obtained, which results in an excised patch that forms with exterior of membrane facing the bath. This configuration is particularly useful in studies of receptor‐activated channels, because exterior surface can be easily exposed to agonists and blockers.

Adapted from Hamill et al.


Figure 6.

Voltage dependence of K+ channels in isolated membrane patch from gastric cell of Bufo marinus (C, closed; O, open). Pipette and bath contained equivalent concentrations of K+. In symmetrical K+ concentrations, current flowing through channel should reverse direction at 0 mV. Bath contained 10−6 M Ca2+; pipette was Ca2+ free with 2 mM EGTA. Top trace, membrane was held at +28 mV. At this potential channel was frequently open; probability of being open was 0.43. At −14 mV channel was open infrequently; probability was only 0.07. Amplitude of current is voltage dependent, and direction of current is opposite at 2 test potentials.

From Singer and Walsh


Figure 7.

Permeability of K+ channels to Rb+ in excised patch from rabbit jejunal muscle cell. Pipette and bath contained symmetrical K+ concentrations. Top, current records at several test potentials. At positive potentials current was outward with respect to inner surface of membrane (current flowed from bath into pipette). At negative potentials current direction reversed, but K+ ions passed through the channel equally well. Data are plotted in graph (solid circles). When K+ was replaced in bath solution with 126 mM Rb+, outward current was greatly decreased. Current still passed easily out of pipette. Data are plotted in graph (crosses). Data can be interpreted as follows. Channel passed K+ in either direction (no rectification). Rb+ does not pass through channel as well as K+. When Rb+ served as current carrier (current flowing from bath into pipette), current was diminished, but at potentials favoring inward current, K+ in pipette served as current carrier and effects of Rb+ were not apparent.

From Benham et al.


Figure 8.

Calcium dependence of K+ channels in isolated patch from circular muscle cell of canine gastric antrum. Data from excised inside‐out patch in symmetrical K+ gradient. Patch held at −70 mV. A: transition in activity when concentration of Ca2+ bathing inner surface of membrane was increased from 10−7 to 10−6 M. This caused a large increase in the probability of opening and revealed that the patch contained at least 6 channels. B: reduction in Ca2+ (from 10−6 to 10−7 M) rapidly decreased probability of opening. Changes in intracellular Ca2+ concentration in submicromolar range shift activation voltage for these K+ channels into physiological range.

Data from A. Carl


Figure 9.

Voltage and Ca2+ dependence of K+ channels from mesenteric artery cell. A: channel activity in 10−6 M Ca2+ at several voltages. Channel is highly active at 10−6 M Ca2+. B: when Ca2+ was reduced to 10‐7 M, channel rarely opened at negative potentials, but opening was increased by depolarization. C and D: probability of opening of channels from mesenteric and jejunal cells, respectively; Ca2+ concentration given next to curves. Data describe Ca2+ and voltage dependence of channel. When Ca2+ increases from 10−7 to 10−6 M, channel becomes highly activable at potentials achieved physiologically (negative to 0 mV). During excitation‐contraction coupling in situ when cytoplasmic Ca2+ increases, activation range of Ca2+‐activated K+ channels can shift to more negative, physiological potentials.

From Benham et al.


Figure 10.

Effects of cholinergic stimulation on electrical activity of isolated gastric cells of Bufo marinus. A: intracellular recording of membrane potential (top trace) in response to ionophoretic application of acetylcholine (ACh) (bottom trace). ACh depolarized membrane potential and caused spiking. Magnitude of response was related to amplitude and duration of ionophoretic pulse (pulses a‐e). B and C: current‐clamp records; top traces, application of square pulses of hyperpolarizing current; lower traces, voltage responses. Bars, muscarine was applied. Muscarine depolarized the membrane and increased amplitude of voltage responses to injected current. C: offset current was applied to hold membrane potential fairly constant during muscarine application. This further increased the amplitude of voltage responses during muscarine application. Data suggest that cholinergic stimulation decreases membrane conductance. A: extracellular [Ca2+] ([Ca2+]o) = 50 mM, [Na+]o = 39 mM, and extracellular tetraethylammonium ion ([TEA+]o) = 18 mM. B and C: [Ca2+]0 = 20 M, [Na+]o = 97 mM, and [TEA+]o = 5 mM.

From Sims et al.


Figure 11.

Cholinergic responses of gastric muscle cell from Bufo marinus studied with voltage clamp. Traces, time (sweep speed is varied during trace, but tics denote seconds), voltage (stepped between −36 and −65 mV), and current responses. Expanded pulse at beginning of record shows control responses. Stepping to −65 mV revealed relaxation of outward current (outward tail current); stepping back to −36 mV shows development of outward current. Bar, muscarine was added to bath. This caused development of sustained inward current (departure from dashed line) and blockade of current relaxations upon hyperpolarization and development of outward current upon depolarization. Data suggest that cholinergic agonists act to block K+ current. Vh, holding potential; Iss steady‐state current.

From Sims et al.


Figure 12.

Current records under whole‐cell voltage clamp of guinea pig ileum. Pipette contained 140 mM Cs+ to block outward currents. Traces, voltage dependence of inward current. Graph, I‐ V relationship at peak inward current. Current activated at about −40 mV, reached a maximum at −10 mV, and reversed at approximately −40 mV. Tests showed that inward current was carried by Ca2+ ions.

From Droogmans and Callewaert


Figure 13.

Steady‐state activation (solid circles) and inactivation (open circles) of inward current as function of membrane potential. Data taken from isolated cell from guinea pig ileum. Curves, fit of data with Boltzmann equation. Activation and inactivation curves overlap, indicating that at approximately −40 mV a fraction of the Ca2+ may be open, producing a small sustained inward current (window current).

From Droogmans and Callewaert


Figure 14.

Effect of acetylcholine (AcCho) on voltage‐activated Ca2+ current in gastric muscle cell of Bufo marinus. Current response under voltage clamp from a holding potential of −78 mV to a test potential of 9 mV. Acetylcholine increased the magnitude of inward current.

From Clapp et al.


Figure 15.

Effects of acetylcholine (ACh) on electrical activity of gastric muscle of Bufo marinus. Record, continuous intracellular recording from circular muscle cell of corpus region. Arrow, ACh (10−5 M) was applied by superfusion. This caused a significant increase in slow‐wave frequency, a small tonic depolarization, and changed the waveforms of slow waves by reducing upstroke velocity and amplitude. Insets, specific portions of record enlarged to display effects of ACh on waveform. None of these effects on electrical activity are easily reconcilable on basis of suppression of an M current (see ref. .

Data from P. Shonnard
References
 1. Abe, Y., and T. Tomita. Cable properties of smooth muscle. J. Physiol. Lond. 196: 87–100, 1968.
 2. Adams, P. R., D. A. Brown, and A. Constanti. M‐currents and other potassium currents in bullfrog sympathetic neurones. J. Physiol. Lond. 330: 537–572, 1982.
 3. Adams, P. R., D. A. Brown, and A. Constanti. Pharmacological inhibition of the M‐current. J. Physiol. Lond. 332: 223–262, 1982.
 4. Bagby, R. M., A. M. Young, R. S. Dotson, B. A. Fisher, and K. Mcklnnon. Contraction of single smooth muscle cells from Bufo marinus stomach. Nature Lond. 234: 351–352, 1971.
 5. Barrett, J. N., K. L. Magleby, and B. S. Pallotta. Properties of single calcium‐activated potassium channels in cultured rat muscle. J. Physiol. Lond. 331: 211–230, 1982.
 6. Bauer, A. J., N. G. Publicover, and K. M. Sanders. Origin and spread of slow waves in canine gastric antral circular muscle. Am. J. Physiol. 249 (Gastrointest. Liver Physiol. 12): G800–G806, 1985.
 7. Benham, C. D., and T. B. Bolton. Patch‐clamp studies of slow potential‐sensitive potassium channels in longitudinal smooth muscle cells of rabbit jejunum. J. Physiol. Lond. 340: 469–486, 1983.
 8. Benham, C. D., and T. B. Bolton. Spontaneous transient outward currents in single visceral and vascular smooth muscle cells of the rabbit. J. Physiol. Lond. 381: 385–406, 1986.
 9. Benham, C. D., T. B. Bolton, J. S. Denbigh, and R. J. Lang. Inward rectification in freshly isolated single smooth muscle cells of the rabbit jejunum. J. Physiol. Lond. 383: 461–476, 1987.
 10. Benham, C. D., T. B. Bolton, and R. J. Lang. Acetylcholine activates an inward current in single mammalian smooth muscle cells. Nature Lond. 316: 345–346, 1985.
 11. Benham, C. D., T. B. Bolton, R. J. Lang, and T. Takewaki. The mechanism of action of Ba2+ and TEA on single Ca2+‐activated K+ channels in arterial and intestinal smooth muscle cell membranes. Pfluegers Arch. 403: 120–127, 1985.
 12. Benham, C. D., T. B. Bolton, R. J. Lang, and T. Takewaki. Calcium‐activated potassium channels in single smooth muscle cells of rabbit jejunum and guinea‐pig mesenteric artery. J. Physiol. Lond. 371: 45–67, 1986.
 13. Benham, C. D., P. Hess, and R. W. Tsien. TWO types of calcium channels in single smooth muscle cells from rabbit ear artery studied with whole‐cell and single‐channel recordings. Circ. Res. 61: 10–16, 1987.
 14. Bitar, K. N., and G. M. Makhlouf. Receptors on smooth muscle cells: characterization by contraction and specific antagonists. Am. J. Physiol. 242 (Gastrointest. Liver Physiol. 5): G400–G407, 1982.
 15. Bitar, K. N., and G. M. Makhlouf. Measurement of function in isolated single smooth muscle cells. Am. J. Physiol. 250 (Gastrointest. Liver Physiol. 13): G357–G360, 1986.
 16. Bitar, K. N., A. M. Zfass, and G. M. Makhlouf. Interaction of acetylcholine and cholecystokinin with dispersed smooth muscle cells. Am. J. Physiol. 237 (Endocrinol. Metab. Gastrointest. Physiol. 6): E172–E176, 1979.
 17. Bolton, T. B., R. J. Lang, T. Takewaki, and C. D. Benham. Patch and whole‐cell voltage clamp of single mammalian visceral and vascular smooth muscle cells. Experientia Basel 41: 887–894, 1985.
 18. Brown, A. M., D. L. Kunze, and A. Yatani. The agonist effect of dihydropyridine on Ca channels. Nature Lond. 311: 570–572, 1984.
 19. Brown, D. A., and P. R. Adams. Muscarinic suppression of a novel voltage‐sensitive K+ current in a vertebrate neurone. Nature Lond. 283: 673–676, 1980.
 20. Brown, H. F., J. Kimura, D. Noble, S. J. Noble, and A. Taupignon. The ionic currents underlying pacemaker activity in rabbit sino‐atrial node: experimental results and computer simulations. Proc. R. Soc. Lond. B Biol. Sci. 222: 329–347, 1984.
 21. Byrne, N. G., and W. A. Large. Action of noradrenaline on single smooth muscle cells freshly dispersed from the rat anococcygeous muscle. J. Physiol. Lond. 389: 513–525, 1987.
 22. Carl, A., and K. M. Sanders. Calcium‐Activated Potassium Channels In Dog Colon (Abstract). Biophys. J. 53: 548a, 1988.
 23. Clapp, L. H., M. B. Vivadou, J. V. Walsh, Jr., and J. J. Singer. Acetylcholine increases voltage‐activated Ca2+ current in freshly dissociated smooth muscle cells. Proc. Natl. Acad. Sci. USA 84: 2092–2096, 1987.
 24. Connor, J. A., C. L. Prosser, and W. A. Weems. A study of pace‐maker activity in intestinal smooth muscle. J. Physiol. Lond. 240: 671–701, 1974.
 25. Constanti, A., and M. Galvan. Fast inward‐rectifying current accounts for anomalous rectification in olfactory cortex neurones. J. Physiol. Lond. 335: 153–178, 1983.
 26. Difrancesco, D. The cardiac hyperpolarizing‐activated current. Origins and development. Prog. Biophys. Mol. Biol. 46: 163–183, 1985.
 27. Droogmans, G., and G. Callewaert. Ca2+‐channel current and its modification by the dihydropyridine agonist BAY k 8644 in isolated smooth muscle cells. Pfluegers Arch. 406: 259–265, 1986.
 28. Eckert, R., and D. L. Tillotson. Calcium‐mediated inactivation of the calcium conductance in caesium‐loaded giant neurones of Aplysia californica. J. Physiol. Lond. 314: 265–280, 1981.
 29. El‐Sharkawy, T. Y., K. G. Morgan, and J. H. Szurszewski. Intracellular electrical activity of canine and human gastric smooth muscle. J. Physiol. Lond. 279: 291–307, 1978.
 30. Fay, F. S., and C. M. Delise. Contraction of isolated smooth‐muscle cells‐structural changes. Proc. Natl. Acad. Sci. USA 70: 641–645, 1973.
 31. Fay, F. S., R. Hoffmann, S. Leclair, and P. Merriam. Preparation of individual smooth muscle cells from the stomach of Bufo marinus. Methods Enzymol. 85: 284–292, 1982.
 32. Fay, F. S., and J. J. Singer. Characteristics of response of isolated smooth muscle cells to cholinergic drugs. Am. J. Physiol 232 (Cell Physiol. 1): C144–C154, 1977.
 33. Fenwick, E. M., A. Marty, and E. Neher. Sodium and calcium channels in bovine chromaffin cells. J. Physiol. Lond. 331: 599–635, 1982.
 34. Ganitkevich, V. Y., M. F. Shuba, and S. V. Smirnov. Potential‐dependent calcium inward current in a single isolated smooth muscle cell of the guinea‐pig taenia caeci. J. Physiol. Lond. 380: 1–16, 1986.
 35. Hagiwara, S., and K. Takahashi. The anomalous rectification and cation selectivity of the membrane of a starfish egg cell. J. Membr. Biol. 18: 61–80, 1974.
 36. Hamill, O. P., A. Marty, E. Neher, B. Sakmann, and F. J. Slgworth. Improved patch‐clamp techniques for high‐resolution current recording from cells and cell‐free membrane patches. Pfluegers Arch. 391: 85–100, 1981.
 37. Hescheler, J., D. Pelzer, G. Trube, and W. Trautwein. Does the organic calcium channel blocker D600 act from inside or outside on the cardiac cell membrane? Pfluegers Arch. 393: 287–291, 1982.
 38. Hess, P., J. B. Lansman, and R. W. Tsien. Different modes of Ca channel gating behaviour favoured by dihydropyridine Ca agonists and antagonists. Nature Lond. 311: 538–544, 1984.
 39. Hille, B. Ionic selectivity of Na and K channels of nerve membranes. In: Membranes. A Series of Advances, edited by G. Eisenman. New York: Dekker, 1975, p. 256–323.
 40. Honeyman, T., P. Merriam, and F. S. Fay. The effects of isoproterenol on adenosine cyclic 3′,5′‐monophosphate and contractility in isolated smooth muscle cells. Mol. Pharmacol. 14: 86–98, 1978.
 41. Irisawa, H., and S. Kokubun. Modulation by intracellular ATP and cyclic AMP of the slow inward current in isolated single ventricular cells of the guinea‐pig. J. Physiol. Lond. 338: 321–337, 1983.
 42. Langton, P. D., and K. M. Sanders. Colonic muscle cells do not all respond to cholinergic and adrenergic agonists (Abstract). FASEB J. 2: A757, 1988.
 43. Lassignal, N. L., J. J. Singer, and J. V. Walsh, Jr. Multiple neuropeptides exert a direct effect on the same isolated single smooth muscle cell. Am. J. Physiol. 250 (Cell Physiol. 19): C792–C798, 1986.
 44. Lee, K. S., and R. W. Tsien. High selectivity of calcium channels in single dialysed heart cells of the guinea‐pig. J. Physiol. Lond. 354: 253–272, 1984.
 45. Lieberman, M., S. D. Hauschka, Z. W. Hall, B. R. Eisenberg, R. Horn, J. V. Walsh, R. W. Tsien, A. W. Jones, J. L. Walker, M. Poenie, F. Fay, F. Fabiato, and C. C. Ashley. Isolated muscle cells as a physiological model. Am. J. Physiol. 253 (Cell Physiol. 22): C349–C363, 1987.
 46. Marty, A., Y. P. Tan, and A. Trautmann. Three types of calcium‐dependent channel in rat lacrimal glands. J. Physiol. Lond. 357: 293–325, 1984.
 47. Mayer, M., and G. L. Westbrook. A voltage clamp analysis of inward (anomalous) rectification in mouse spinal sensory ganglion neurones. J. Physiol. Lond. 340: 19–45, 1983.
 48. Mitra, R., and M. Morad. Ca2+ and Ca2+‐activated K+ currents in mammalian gastric smooth muscle cells. Science Wash. DC 229: 269–272, 1985.
 49. Momose, K., and Y. Gomi. Studies on isolated smooth muscle cells. IV. Isolation and acetylcholine‐contraction of single smooth muscle cells from taenia coli of guinea pig. J. Pharmacobio‐Dyn. 1: 184–191, 1978.
 50. Momose, K., and Y. Gomi. Studies on isolated smooth muscle cells. VI. Dispersion procedures for acetylcholine‐sensitive smooth muscle cells of guinea‐pig. Jpn. J. Smooth Muscle Res. 16: 29–36, 1980.
 51. Nilius, B., P. Hess, J. B. Lansman, and R. W. Tsien. A novel type of cardiac calcium channel in ventricular cells. Nature Lond. 316: 443–446, 1985.
 52. North, R. A., and T. Tokimasa. Depression of calcium‐dependent potassium conductance of guinea‐pig myenteric neurones by muscarinic agonists. J. Physiol. Lond. 342: 253–266, 1983.
 53. Nowycky, M. C., A. P. Fox, and R. W. Tsien. Three types of neuronal calcium channels with different calcium agonist sensitivity. Nature Lond. 316: 440–443, 1985.
 54. Ohya, Y., K. Terada, K. Kitamura, and H. Kuriyama. Membrane currents recorded from a fragment of rabbit intestinal smooth muscle cell. Am. J. Physiol. 251 (Cell Physiol. 20): C335–C346, 1986.
 55. Ohya, Y., K. Terada, K. Kitamura, and H. Kuriyama. D600 blocks the Ca2+ channel from the outer surface of smooth muscle cell membrane of the rabbit intestine and portal vein. Pfluegers Arch. 408: 80–82, 1987.
 56. Piper, H. M., and P. G. Spieckermann (Editors). Adult Heart Muscle Cells: Isolation, Properties and Applications. New York: Springer‐Verlag, 1984.
 57. Publicover, N. G., and K. M. Sanders. A technique to locate the pacemaker in smooth muscles. J. Appl. Physiol. 57: 1586–1590, 1984.
 58. Sarna, S. K. Models of smooth muscle electrical activity. In: Methods in Pharmacology. Smooth Muscle, edited by E. E. Daniel and D. M. Paton. New York: Plenum, 1975, vol. 3, p. 519–540.
 59. Sarna, S. K., E. E. Daniel, and Y. J. Kingma. Simulation of slow‐wave electrical activity of small intestine. Am. J. Physiol. 221: 166–175, 1971.
 60. Scheid, C. R., T. W. Honeyman, and F. S. Fay. Mechanism of beta‐adrenergic relaxation in smooth muscle. Nature Lond. 277: 32–36, 1979.
 61. Shonnard, P., and K. M. Sanders. Influence of prostaglandins on electrical and mechanical activities of gastric muscles of Bufo marinus. Comp. Biochem. Physiol. C Comp. Pharmacol. 90: 325–333, 1988.
 62. Shonnard, P., and K. M. Sanders. Excitation of toad gastric muscles by ACh and substance P cannot be explained by decreased “M‐current” (Abstract). FASEB J. 2: A758, 1988.
 63. Sims, S. M., J. J. Singer, and J. V. Walsh, Jr. Cholinergic Agonists Suppress A Potassium Current In Freshly Dissociated Smooth Muscle Cells Of The Toad. J. Physiol. Lond. 367: 503–529, 1985.
 64. Sims, S. M., J. J. Singer, and J. V. Walsh, Jr. Antagonistic adrenergic‐muscarinic regulation of M current in smooth muscle cells. Science Wash. DC 239: 190–193, 1988.
 65. Sims, S. M. J. V. Walsh, Jr., and J. J. Singer. Substance P and acetylcholine both suppress the same K+ current in dissociated smooth muscle cells. Am. J. Physiol. 251: (Cell Physiol. 20): C580–C587, 1986.
 66. Singer, J. J., and J. V. Walsh, Jr. Passive properties of the membrane of single freshly isolated smooth muscle cells. Am. J. Physiol. 239 (Cell Physiol. 8): C153–C161, 1980.
 67. Singer, J. J., and J. V. Walsh, Jr. Rectifying properties of the membrane of single freshly isolated smooth muscle cells. Am. J. Physiol. 239 (Cell Physiol. 8): C175–C181, 1980.
 68. Singer, J. J., and J. V. Walsh, Jr. Large conductance Ca2+‐activated K+ channels in smooth muscle cell membrane. Biophys. J. 45: 68–70, 1984.
 69. Singer, J. J., and J. V. Walsh, Jr. Characterization of calcium‐activated potassium channels in single smooth muscle cells using the patch‐clamp technique. Pfluegers Arch. 408: 98–111, 1987.
 70. Smith, T. K., J. B. Reed, and K. M. Sanders. Origin and propagation of electrical slow waves in circular muscle of canine proximal colon. Am. J. Physiol. 252 (Cell Physiol. 21): C215–C224, 1987.
 71. Smith, T. K., J. B. Reed, and K. M. Sanders. Interaction of two electrical pacemakers in muscularis of canine proximal colon. Am. J. Physiol. 252 (Cell Physiol. 21): C290–C299, 1987.
 72. Standen, N. B. Ca Channel Inactivation By Intracellular Ca Injection Into Helix Neurones. Nature Lond. 293: 158–159, 1981.
 73. Standen, N. B., and P. R. Stanfield. A potential‐ and time‐dependent blockade of inward rectification of frog skeletal muscle fibres of barium and strontium ions. J. Physiol. Lond. 280: 169–191, 1978.
 74. Suzuki, N., C. L. Prosser, and V. Dahms. Boundary cells between longitudinal and circular layers: essential for electrical slow waves in cat intestine. Am. J. Physiol. 250 (Gastrointest. Liver Physiol. 13): G287–G294, 1986.
 75. Terada, K., K. Kitamura, and H. Kuriyama. Blocking actions of Ca2+ antagonists on the Ca2+ channels in the smooth muscle cell membrane of rabbit small intestine. Pfluegers Arch. 408: 552–557, 1987.
 76. Thuneberg, L. Interstitial cells of Cajal: intestinal pacemaker cells. Adv. Anat. Embryol. Cell Biol. 71: 1–130, 1982.
 77. Walsh, J. V., Jr., and J. J. Singer. Calcium action potentials in single freshly isolated smooth muscle cells. Am. J. Physiol. 239 (Cell Physiol. 8): C162–C174, 1980.
 78. Walsh, J. V., Jr., and J. J. Singer. Penetration‐induced hyperpolarization as evidence for Ca2+ activation of K+ conductance in isolated smooth muscle cells. Am. J. Physiol. 239 (Cell Physiol. 8): C182–C189, 1980.
 79. Walsh, J. V., Jr., and J. J. Singer. Voltage clamp of single freshly dissociated smooth muscle cells: current‐voltage relationships for three currents. Pfluegers Arch. 390: 207–210, 1981.
 80. Walsh, J. V., Jr., and J. J. Singer. Identification and characterization of major ionic currents in isolated smooth muscle cells using the voltage‐clamp technique. Pfluegers Arch. 408: 83–97, 1987.
 81. Williams, D. A., K. E. Fogarty, R. Y. Tsien, and F. S. Fay. Calcium gradient in single smooth muscle cells revealed by the digital imaging microscope using Fura‐2. Nature Lond. 318: 558–561, 1985.
 82. Yamaguchi, H. Recording of intracellular Ca2+ from smooth muscle cells by sub‐micron tip, double‐barrelled Ca2+‐selective microelectrodes. Cell Calcium 7: 203–219, 1986.
 83. Yamaguchi, H., T. W. Honeyman, and F. S. Fay. β‐Adrenergic actions on membrane electrical properties of dissociated smooth muscle cells. Am. J. Physiol. 254 (Cell Physiol. 23): C423–C431, 1988.
 84. Yoshino, M., T. Someya, A. Nlshio, and H. Yabu. Wholecell and unitary Ca channel currents in mammalian intestinal smooth muscle cells: evidence for the existence of two types of Ca channels. Pfluegers Arch. 411: 229–231, 1988.
 85. Yoshino, M., and H. Yabu. Single Ca channel currents in mammalian visceral smooth muscle cells. Pfluegers Arch. 404: 285–286, 1985.

Contact Editor

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

* Required Field

How to Cite

Kenton M. Sanders. Electrophysiology of dissociated gastrointestinal muscle cells. Compr Physiol 2011, Supplement 16: Handbook of Physiology, The Gastrointestinal System, Motility and Circulation: 163-185. First published in print 1989. doi: 10.1002/cphy.cp060104