title: Activation of protein kinase C potentiates isoprenaline-induced cyclic AMP accumulation in rat pinealocytes.
abstract: The pineal gland has proven to be an excellent model for the study of adrenergic control systems. Noradrenaline, released from sympathetic nerve terminals in the pineal gland, regulates a large nocturnal increase in melatonin synthesis by stimulating the activity of arylalkylamine N-acetyltransferase (NAT, EC 2.3.1.87) 30-70-fold. An essential step in both the induction and maintenance of high NAT activity is an increase in intracellular cyclic AMP. Noradrenaline acts via beta-adrenoceptors to increase pineal cyclic AMP by activating adenylate cyclase, and the activation of pineal alpha 1-adrenoceptors potentiates beta-adrenergic stimulation not only of NAT but of both cyclic AMP and cyclic GMP. Here we describe investigations designed to test whether alpha 1-adrenergic potentiation of beta-adrenergic stimulation of pineal cyclic AMP involves protein kinase C. Our results suggest that kinase activation is involved and the data provide the first demonstration of a synergistic interaction between Ca2+-phospholipid-dependent protein kinase (protein kinase C) and neurotransmitter-dependent stimulation of cyclic AMP.
authors.forename: D
authors.initials: D
authors.lastname: Sugden
authors.forename: J
authors.initials: J
authors.lastname: Vanecek
authors.forename: D C
authors.initials: DC
authors.lastname: Klein
authors.forename: T P
authors.initials: TP
authors.lastname: Thomas
authors.forename: W B
authors.initials: WB
authors.lastname: Anderson
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology; D000242:Cyclic AMP / Q000378:metabolism*; D004075:Diglycerides / Q000494:pharmacology; D004357:Drug Synergism; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010703:Phorbol Esters / Q000494:pharmacology; D010870:Pineal Gland / Q000378:metabolism*; D011493:Protein Kinase C; D011494:Protein Kinases / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004075:Diglycerides; D010703:Phorbol Esters; D010656:Phenylephrine; D000242:Cyclic AMP; D011494:Protein Kinases; D011493:Protein Kinase C; D007545:Isoproterenol; D002118:Calcium