Adenylate cyclase inhibition is not involved in the adrenal steroidogenic response to angiotensin II.

Angiotensin II (AII) receptors in adrenal glomerulosa cells are coupled to adenylate cyclase inhibition. We investigated the importance of cyclase inhibition in adrenal steroidogenesis by treating adrenal glomerulosa cells with the toxin of Bordetella pertussis (20 ng/ml) for 3 and 18 h. This treatment prevented inhibition of forskolin-stimulated adenylate cyclase by AII. However, the aldosterone response to AII was not altered by toxin treatment. These results strongly suggest that adenylate cyclase inhibition is not directly involved in mediating the adrenal actions of AII. In addition, ACTH-induced steroidogenesis also was unaffected by toxin treatment demonstrating that cyclase inhibition is not involved in suppressing steroidogenesis via the cAMP pathway.