The action of progesterone on sodium transport of isolated toad skin. Further evidences of a metabolic action.

To understand the mechanism of progesterone inhibition of the sodium influx in the toad skin, the effects of the hormone on the active sodium transport and oxidative metabolism of the transporting cells were examined. A direct relationship was observed between the initial value of the short circuit current and the sensitivity of a given skin toad preparation to progesterone. Progesterone had a higher effect on the sodium potential than on any other parameter of an equivalent electrical circuit of toad skin. Direct measurement of oxygen consumption indicated that progesterone can act as a blocking agent of the respiratory chain of the sodium transporting cells of toad skin.