[Effect of forskolin and VIP on the release of somatostatin and the cAMP content of cultured rat diencephalon neurons].

Forskolin, a direct activator of adenylate cyclase, stimulates somatostatin release in dispersed fetal diencephalic cells in culture (10 j). It was found that concentrations ranging from 10(-8) M to 10(-4) M increase the release of somatostatin in a dose-dependent manner, as well as the formation of intracellular cyclic AMP. Furthermore, VIP (10(-6) M) which produces a significant (p less than 0.03) elevation of SRIF release at 30 min of incubation, also induces a prompt increase of intracellular cyclic AMP (10 min). These results suggest that VIP could stimulate the somatostatin release through a cyclic AMP-dependent mechanism.