title: GRF is a highly potent activator of adenylate cyclase in the normal human, bovine and rat pituitary: interaction with somatostatin.
abstract: The effect of GRF adenylate cyclase activation was studied in normal human, bovine and rat pituitary tissues. Human GRF (hGRF) activates adenylate cyclase in normal human pituitary membrane preparations in a concentration dependent manner (ED5 0 = 10(-11) M). In bovine pituitary cells hGRF stimulates GH secretion into the medium (ED5 0 = 7 X 10(-12) M) and activates adenylate cyclase (ED5 0 = 10(-11) M). In normal rat pituitary cells in monolayer culture, rat GRF (rGRF) stimulates adenylate cyclase (ED5 0 = 3 X 10(-11) M). In normal human pituitary membrane preparations and in normal rat pituitary cells in culture, somatostatin inhibits GRF-stimulated adenylate cyclase in a non-competitive manner, while it does not affect basal (i.e. non-stimulated) adenylate cyclase levels. VIP, a peptide which is structurally homologous to hGRF and rGRF is a weak GRF-agonist and activates adenylate cyclase in human and rat pituitary preparations at concentrations greater than 10 nM.
authors.forename: F
authors.initials: F
authors.lastname: Reyl-Desmars
authors.forename: A
authors.initials: A
authors.lastname: Baird
authors.forename: F N
authors.initials: FN
authors.lastname: Zeytin
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D013006:Growth Hormone / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D010902:Pituitary Gland / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D013004:Somatostatin / Q000494:pharmacology*; D013045:Species Specificity; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D000262:Adenylyl Cyclases