Dissociation of aldosterone and prostaglandin biosynthesis in the rat adrenal glomerulosa

Abstract The relationship between aldosterone production and prostaglandin E 2 synthesis was evaluated using the responses of isolated rat adrenal glomerulosa cells to angiotensin II, ACTH and potassium. Simultaneous PGE 2 and aldosterone measurements were made during timed incubations with these stimuli, and in incubations with arachidonic acid, meclofenamate, indomethacin, and aminoglutethamide. PGE 2 and aldosterone production were assessed by radioimmunoassay. We were not able to demonstrate stimulation of PGE 2 by angiotensin II, ACTH, or potassium despite significant increments in aldosterone production with these stimuli. Arachidonic acid enhanced PGE 2 synthesis, but had no effect on aldosterone release. Indomethacin and meclofenamate inhibited aldosterone secretion. Aminoglutethimide depressed aldosterone production, but had little effect on PGE 2 levels in the media. These studies demonstrate that dienoic prostaglandins play no direct role in aldosterone production stimulated by angiotensin II, ACTH, or potassium in rat adrenal glomerulosa cells. Since inhibitors of cyclo-oxygenase decreased aldosterone synthesis, it is possible that fatty acids other than arachidonic acid may be cyclo-oxygenated to products which regulate aldosterone production.