Prostaglandin effects upon cyclic AMP levels, corticosterone output, and aldosterone output in the adrenal of the frog, Rana berlandieri forreri.

The mechanism of prostaglandin action in the adrenal of the frog (Rana berlandieri forreri) was evaluated in vitro. The prostaglandins evoked transient (PGA₂, PGB₁, PGE₂), continued (PGA₁, PGB₂, PGF_1α, PGF_2α), or no effects (PGE₁) upon cyclic AMP (cAMP) levels. Further, the cAMP levels were depressed (PGA₁, PGB₁, PGB₂), elevated (PGA₂, PGE₂, PGF_1α, PGF_2α), or unchanged (PGE₁) compared to the controls. Prostaglandins regulate cAMP levels in the frog adrenal. In addition, specific prostaglandins evoke specific effects in this regard. The frog adrenal corticosterone and aldosterone outputs are modulated by the prostaglandins. The modulations produced differ with the prostaglandins tested. The greatest adrenocortical sensitivity is to PGB₂ which evoked about a 13-fold increase in corticosterone output and a 5-fold increase in aldosterone output at 16 min. Only PGF_1α inhibited steroid output; the other prostaglandins stimulated steroid outputs to varying degrees. A close correlation of the prostaglandin-evoked corticosterone and aldosterone output responses with the cAMP changes was not present in the frog adrenal. The prostaglandins differentially affected cAMP levels and when compared to adrenocorticoid outputs, different prostaglandins produce different effects. The responses of the frog adrenal indicate that the mechanisms controlling adrenocortical function are more complex than originally visualized. In this regard, the site(s) of action (plasma membrane, mitochondrion, etc.) of a given factor must also be considered. Thus, the current concepts must be broadened to include a number of interacting factors among which are the cyclic nucleotides and the prostaglandins.