Prostaglandin modulation of the mechanism of ACTH action in the human adrenal.

PGE₁ and PGE₂ significantly increased human adrenal cAMP levels $\text{in}$$\text{vitro}$; cortisol output was also increased in a dose related fashion. In contrast, PGF_1a and PGF_2a depressed adrenal cAMP (except PGF_2a at 100 μg/ml). PGF_1a and PGF_2a depressed cortisol levels at all doses. Indomethacin or 7-oxa-13-prostynoic acid did not affect these parameters. However, when applied in conjunction with ACTH they inhibited or enhanced hormonal action depending upon the temporal sequence of application. The findings indicate that prostaglandins modulate ACTH-adrenocortical cell interaction bidirectionally, initially potentiating and subsequently depressing ACTH stimulated events.