Effects of renin and ACTH on adrenal steroid secretion in the American bullfrog

Abstract

Aldosterone and corticosterone were measured in peripheral and postcaval vein plasma of the bullfrog, Rana catesbeiana, by the double-isotope derivative method. Concentrations of both steroids were higher in postcaval vein plasma than in peripheral venous plasma; these observations indicate that the adrenal gland of the frog secretes these steroids. Cortisol was not detected in postcaval vein plasma. Intravenous infusion of mammalian ACTH and renin preparations produced an increase in the plasma concentration and adrenal output of aldosterone and corticosterone. Hypophysectomy was followed by a significant fall in the postcaval vein plasma level of corticosterone, and infusion of the frog renin preparation into these hypophysectomized animals increased aldosterone production. Hemorrhage was also associated with a significant increase in the concentration of aldosterone in postcaval vein plasma. The extract of frog kidneys produced a prolonged blood pressure response as well as a steroidogenic action in the frog. The active agent in the kidney extract, similar to mammalian renin, was stable at pH 2.6 and nondialyzable, was destroyed by heat, and was digested by trypsin.