Characterization of dopamine receptors associated with aldosterone secretion in rat adrenal glomerulosa

Dopamine (DA) may participate in the control of aldosterone secretion. We report that two different receptors for DA are present in rat adrenal glomerulosa: D-1, associated with stimulation of adenylate cyclase, and D-2, whose action inhibits adenylate cyclase. The adenylate cyclase system was stimulated by DA (EC50, 7.2 microM) and different DA agonists. When the D-1 receptor blocker SCH 23390 was added to the incubation medium, DA elicited a dose-dependent inhibition of adenylate cyclase (IC50, 10 microM); (-)sulpiride specifically blocked this effect. Furthermore, DA blocked angiotensin II-induced aldosterone release from glomerulosa slices in vitro. This effect was prevented by (-)sulpiride, but not by SCH 23390. The results suggest that the D-2 receptor acts to inhibit the cAMP-generating system and may be physiologically involved in the regulation of aldosterone secretion.