Effects of Ethanol on Electrophysiological Properties of Rat Skeletal Myotubes in Culture1

Ethanol was studied for its effects on electrophysiological prop-erties of cultured skeletal myotubes prepared from fetal or neo-natal rats. Intracellular recordings were made with KCI-filled (3 M) glass micropipettes from cells 7 to 9 days after plating. Ethanol produced a temperature-dependent, dose-related de-polarization of the myotubes. Maximum depolarization of 1 5 mV was reached at a concentration of 21 7 mM at 37#{176}C;at 25#{176}C, ethanol caused hyperpolanzation at low concentration (21.7 mM) and was without effect at higher concentrations (up to 435 mM). Of other alcohols examined, only propanol had a significant effect on transmembrane resting potential (Em). In the presence of ouabain, a specific Na-K pump inhibitor, ethanol had no effect on Em. Ethanol decreased the relation between Em and [K]0. At 37#{176}C,spontaneously occurring action potentials were abol