Evidence for a possible prostaglandin link in ACTH-induced steroidogenesis

Abstract

The steroidogenic response to ACTH and prostaglandin E 2 (PGE 2) was studied in cat adrenocortical cells dispersed with trypsin. The dose-response curves of both agents were qualitatively and quantitatively similar. Exposure to PGE 2 or ACTH in the presence of labeled steroid precursor (acetate) resulted in the accumulation of comparable levels of steroid intermediates and end-product. Submaximal or maximal concentrations of ACTH and PGE 2 given simultaneously elicited a response which was no greater than that obtained with either stimulant alone. Although calcium was required for optimal PGE 2 stimulation of steroid production, this requirement for calcium was less than the requirement with ACTH as the stimulant, but greater than with butyryl cyclic AMP. PGE 2-induced increase in the adrenal cyclic AMP was not statistically significant and was small in relation to that found with equipotent steroidogenic ACTH concentrations. The possible relationship between prostaglandins, cyclic AMP, and calcium in the action of ACTH is discussed.