Somatostatin inhibits the isoproterenol-stimulated adenylate cyclase in the intermediate lobe of the male rat pituitary gland.
Somatostatin-14 inhibited the isoproterenol-stimulated adenylate cyclase in cell-free homogenates of pituitary intermediate lobe of the male rat with a Ki of 7.25 +/- 0.31 X 10(-7) M. Somatostatin-28 was found to be a partial agonist. Other neuropeptides (met- and leu-enkephalin, beta-endorphin, alpha-melanocyte-stimulating hormone, ACTH, neurotensin, substance P, vasoactive intestinal polypeptide, and vasopressin) were without effect. Our results suggest a role for pituitary and/or brain somatostatin in the physiological regulation of the intermediate pituitary lobe, and the possibility of an interaction between somatostatins and catecholamines on the regulation of intermediate lobe adenylate cyclase.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D010455:Peptides / Q000502:physiology; D010902:Pituitary Gland / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000502:physiology*; D013268:Stimulation, Chemical
D010455:Peptides; D013004:Somatostatin; D000262:Adenylyl Cyclases; D007545:Isoproterenol