Forskolin stimulates adenylate cyclase activity, adenosine 3',5'-monophosphate production and peptide release from the intermediate lobe of the rat pituitary gland.
Forskolin stimulates adenylate cyclase activity in a cell-free homogenate of the intermediate lobe (IL) of the rat pituitary gland. L-Isoproterenol, a beta-adrenergic agonist, enhances and apomorphine, a D-2 agonist, inhibits the forskolin-stimulated adenylate cyclase activity. Guanosine triphosphate is obligatory for the dopaminergic attenuation of the forskolin-enhanced enzyme activity. When tested upon enzymatically dispersed IL cells, forskolin enhances the release of both cAMP and immunoreactive alpha MSH-like peptides. These effects of forskolin upon the IL are discussed within the context of a previously published working hypothesis that cAMP in some way triggers the calcium-dependent release of hormones from the IL.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001058:Apomorphine / Q000494:pharmacology; D005576:Colforsin; D000242:Cyclic AMP / Q000378:metabolism*; D004224:Diterpenes / Q000494:pharmacology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism*; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D051381:Rats
D000959:Antihypertensive Agents; D004224:Diterpenes; D005576:Colforsin; D006160:Guanosine Triphosphate; D009074:Melanocyte-Stimulating Hormones; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D001058:Apomorphine