Vasoactive intestinal peptide stimulates rat adrenal glucocorticoid secretion, through an ACTH receptor-dependent activation of the adenylate cyclase signaling pathway.

Vasoactive intestinal peptide (VIP) concentration-dependently enhanced corticosterone and cyclic-AMP release by dispersed rat inner adrenocortical cells. A VIP-receptor antagonist and the ACTH-receptor antagonist corticotropin-inhibiting peptide annulled both adrenocortical-cell responses to VIP, while the protein kinase (PKA) inhibitor H-89 blocked only corticosterone response. Collectively, these findings suggest that VIP stimulates glucocorticoid secretion of rat adrenals, through the aspecific activation of ACTH receptors coupled with the adenylate cyclase/PKA-dependent signaling pathway.