Abstract
Using the isolated frog skin, the effects of ouabain on active as well as on passive ion transport were investigated under short-circuit conditions. The drug decreased the short-circuit current and the electrical conductance, but it enhanced the Na and SO4 outfluxes. When the concentration of Na in the fluid outside the skin was low, the electrical conductance did not change by application of the drug. In some skins it was observed that before the addition of ouabain, the conductance for the passive Na transport was negligibly small compared with the total electrical conductance. These facts were explained by assuming that the electrical conductance of the frog skin depended on the active Na transport process as well as on the passive diffusion of ions.
