Effects of exogenous ATP on short-circuit current and potential difference of the isolated frog skin

The addition of ATP (10(-3) M = final concentration) to the bathing medium of either side of the isolated frog skin resulted in parallel increases in potential difference and short-circuit current. Reductions in these electrical parameters induced by anaerobic conditions and sodium azide could be partially reversed by exogenous ATP. The response is apparently not mediated by cyclic adenylic acid, as it was not enhanced by theophylline. Ouabain failed to reduce rates of phosphate liberation induced by ATP, although potential difference and short-circuit current were reduced.