The effect of ethanol on ion transport in frog skin.
Frog skin has been used as a model epithelial sodium-transporting system to study the effect of ethanol on ion transport. Treatment of the outside of frog skin with ethanol decreased the net sodium transport due to inhibition of 22Na+ influx. Ethanol did not alter sodium outflux when bathin the outside of the skin. The inhibition was in proportion to the concentration of ethanol, 0.25 M resulting in 50% inhibition. The chloride permeability of the skin was increased several-fold when the skin was exposed to ethanol in either bathing solution. With 0.4 M ethanol in the inner bathing solution, all the unidirectional fluxes of Na+ and C1- were increased. The movement of C1- was evaluated by comparison of C1- flux with urea flux, since urea is thought to move passively across frog skin via an extracellular (shunt) pathway. Chloride flux was increased to a greater extent than urea flux. These experiments indicate that ethanol affects chloride permeability beyond an increase in extracellular ion flow and independent of its effect of Na+ transport.
D000818:Animals; D001692:Biological Transport; D001693:Biological Transport, Active; D002712:Chlorides / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology*; D011894:Rana pipiens; D012413:Rubidium / Q000378:metabolism*; D012867:Skin / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D014508:Urea / Q000378:metabolism
D002712:Chlorides; D000431:Ethanol; D014508:Urea; D012964:Sodium; D012413:Rubidium