Effects of chronic ethanol treatment on membrane potential, its electrogenic pump component and Na-K pump activity of cultured rat skeletal myotubes.
Effects of chronic ethanol treatment were examined on transmembrane resting potential (Em), electrogenic pump component of Em and on Na-K pump activity of cultured rat skeletal myotubes. Properties of Na-K pump activity were determined by measurement of [3H]ouabain binding and 86Rb uptake by myotubes after incubation of myotubes in ethanol (217 mM) for up to 9 days. Chronic ethanol exposure caused an increase in Em, an increase in electrogenic pump component of Em and a decrease in depolarizing response to addition of ethanol to the myotubes. Chronic ethanol also produced increases in Na-K pump sites and in Na-K pump activity. Thus, chronic ethanol treatment causes a compensatory increase in amount and activity of the Na-K pump, and this results in an increased expression of the electrogenic pump component of Em. These effects may represent the membrane expression of tolerance to the depressant effects of ethanol.
D000818:Animals; D002478:Cells, Cultured; D000431:Ethanol / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D009132:Muscles / Q000187:drug effects* / Q000502:physiology; D010042:Ouabain / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000378:metabolism*
D007473:Ion Channels; D000431:Ethanol; D010042:Ouabain; D012964:Sodium; D011188:Potassium