Anterior pituitary control of active sodium transport across frog skin

¹ Department of Biology, University of Oregon, Eugene, Oregon

Removal of the anterior lobe of the pituitary from the frog Rana pipiens is followed by an increase in the outflux of Na²² across the skin, which persists at least 4 months, and by a decrease in resting potential and sodium (‘short-circuit’) current, which persists no more than 3 weeks. The increased outflux is interpreted as resulting from increased permeability of the skin to sodium ion, and the decreased sodium current is interpreted as a decreased rate of active sodium transport. Either change is opposed by treatment with mammalian ACTH or with aldosterone. Effects of other hormones could not be established with certainty. The increased permeability of the skin to sodium appears to be associated with a decrease in the amount of a mucopolysaccharide in the dermis. The evidence suggests that the pituitary effects involve the interrenal bodies.