Nature and Localization of the Sodium Pool during Active Transport in the Isolated Frog Skin

Abstract

Abstract In the frog skin epithelium the amount of radio‐sodium originating from the outside solution has been determined under different experimental conditions. It has been found that this sodium‐pool behaves largely as a pool in which the sodium has passed the transport mechanism. It has not been possible under any of the conditions used to demonstrate the existence of epithelial radio‐sodium awaiting active transport. This finding leads to the conclusion that the mechanism for active transport of sodium is effective at the outer surface of the frog skin.