Single voltage-dependent chloride-selective channels of large conductance in cultured rat muscle

Biophys J. 1983 Aug;43(2):237-41. doi: 10.1016/S0006-3495(83)84344-6.

Abstract

Single-channel currents of an anion-selective channel in the plasma membrane of cultured rat muscle cells (myotubes) were recorded with the patch-clamp technique (Hamill, O.P., A. Marty, E. Neher, B. Sakmann, and F.J. Sigworth, 1981. Pfluegers Arch. Eur. J. Physiol., 391:85-100). The channel is selective for Cl- over cations, and has an unusually large single-channel conductance of approximately 430 pS in symmetrical 143 mM KCl. The channel is often active at 0 mV, opening and closing spontaneously. When active, steps from 0 mV to either negative or positive membrane potentials close the channel to an apparent inactivated state. The mean effective time that a channel is open before it inactivates is approximately 1.19 s for steps to -30 mV and 0.48 s for steps to +30 mV. Returning the membrane potential to 0 mV results in recovery from inactivation. Calcium ions are not required for channel activity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium / physiology
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Chlorides / metabolism*
  • Ion Channels / metabolism*
  • Muscles / metabolism*
  • Potassium Chloride / pharmacology
  • Rats

Substances

  • Chlorides
  • Ion Channels
  • Potassium Chloride
  • Calcium