Abstract
Voltage-clamp experiments on single freshly dissociated (i.e. uncultured) vertebrate smooth muscle cells were carried out under conditions where the inital inward current, as well as various phases of outward current, could be studied. Current-voltage relationships were obtained for the initial current, the peak outward current, and a later, steady-state outward current, over a potential range of approximately −130 mV to +50 mV. Evidence is presented that the initial current is carried by Ca++ ions and is responsible for the rising phase of the action potential and that the peak in the outward current is due to Ca++ activation of K+ conductance.
Similar content being viewed by others
References
Aldrich, R.W. Jr., Getting, P.A., Thompson, S.H.: Inactivation of delayed outward current in molluscan neurone somata. J. Physiol. 291:507–530 (1979).
Anderson, N.C., Jr.: Limitations and possibilities in smooth muscle voltage-clamp. In: Casteels, R., Godfraind, T., Ruegg, J.C. (eds.)Excitation-Contraction Coupling in Smooth Muscle. Elsevier, New York, pp. 81–89 (1977).
Bagby, R.M., Young, A.M., Dotson, R.S., Fisher, B.A., and McKinnon, K.: Contraction of single smooth muscle cells fromBufo marinus stomach. Nature London 234:351–352 (1971).
Bennett, M.R.:Autonomic Neuromuscular Transmission. London: Cambridge (1972).
Caffrey, J.M., Anderson, N.C., Jr., and Moore, J.W.: Voltage clamp of single isolated smooth muscle cells. Federation Proc. 39:2077 (1980).
Coburn, R.F., Ohba, M., Tomita, T.: Recording of intracellular electrical activity with the voltage-clamp technique with double sucrose gap. In: Daniel, E.E., Paton, D.M., (eds.)Methods In Pharmacology. Vol. 3 Smooth Muscle, Plenum, New York p. 247–260 (1975).
Colatsky, T.J., Tsien, R.W.: Sodium channels in rabbit cardiac Purkinje fibres. Nature 278:265–268 (1979).
Eckert, R., Tillotson, D.: Potassium activation associated with intraneuronal free calcium. Science 200:437–439 (1978).
Inomata, H., Kao, C.Y.: Ionic mechanisms of repolarization in the guinea-pig taenia coli as revealed by the actions of strontium. J. Physiol. 297:443–462 (1979).
Johnson, E.A., Lieberman, M.: Heart: excitation and contraction. Ann. Rev. Physiol. 33:479–532 (1971).
Meech, R.W., Standen, N.B.: Potassium activation inHelix aspersa neurones under voltage clamp: a component mediated by calcium influx. J. Physiol. 249:211–239 (1975).
Mironneau, J., Savineau, J.P., Rahety, A.: Evidence for a component of the outward current mediated by calcium influx in uterine smooth muscle. In: Casteels, R., Godfraind, T., Ruegg, J.C. (eds.)Excitation-Contraction Coupling in Smooth Muscle, Elsevier, New York, pp. 117–122 (1977).
Singer, J.J., Fay, F.S.: Detection of contraction of isolated smooth muscle cells in suspension. Am. J. Physiol. 232 (Cell Physiol. 1): C138-C143 (1977).
Singer, J.J., Walsh, J.V., Jr.: Passive properties of the membrane of single freshly isolated smooth muscle cells. Am. J. Physiol. 239 (Cell Physiol. 8): C153-C161 (1980).
Singer, J.J., Walsh, J.V., Jr.: Rectifying properties of the membrane of single freshly isolated smooth muscle cells. Am. J. Physiol. 239 (Cell Physiol. 8): C175-C181 (1980).
Singer, J.J., Walsh, J.V., Jr.: Membrane currents of single, freshly isolated smooth muscle cells studied with voltage clamp. Soc. Neurosci. Abstr. 6:837 (1980).
Singer, J.J., Walsh, J.V., Jr.: Four ionic currents in single freshly isolated smooth muscle cells studied with voltage clamp and microperfusion. Biophys. J. 33:37a (1981).
Tomita, T.: Electrical properties of mammalian smooth muscle. In: Bulbring, E., Brading, A.F., Jones, A.W., Tomita, T. (eds)Smooth Muscle. Williams and Wilkins, Baltimore pp. 197–243. (1970).
Tomita, T.: Electrophysiology of mammalian smooth muscle. Prog. Biophys. Mol. Biol. 30:185–203 (1975).
Walsh, J.V., Jr., Singer, J.J.: Calcium action potentials in single freshly isolated smooth muscle cells. Am. J. Physiol. 239 (Cell Physiol. 8): C162-C174 (1980).
Walsh, J.V., Jr., Singer, J.J.: 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).
Walsh, J.V. Jr., Singer, J.J.: Voltage clamp of single freshly-isolated smooth muscle cells. Federation Proc. 39:2078 (1980).
Weigel, R.J., Connor, J.A., Prosser, C.L.: Two roles of calcium during the spike in circular muscle of small intestine in cat. Am. J. Physiol. 237 (Cell Physiol. 6): C247-C256 (1979).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Walsh, J.V., Singer, J.J. Voltage clamp of single freshly dissociated smooth muscle cells: Current-voltage relationship for three currents. Pflugers Arch. 390, 207–210 (1981). https://doi.org/10.1007/BF00590209
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00590209