title: Induction and superinduction of serotonin N-acetyltransferase by adrenergic drugs and denervation in rat pineal organ.
abstract: Activity of serotonin N-acetyltransferase (EC 2.3.1.5) in rat pineal organ is rapidly and markedly elevated in vivo after administration of beta-(3,4-dihydroxyphenyl)-L-alanine (L-DOPA), norepinephrine, epinephrine, isoproterenol, monoamine oxidase inhibitors, or theophylline. Serotonin or 5-hydroxytryptophan has no effect on the increase in activity of this enzyme. Inhibitors of protein synthesis or propranolol, a beta-adrenergic blocking agent completely inhibit(s) the increase in activity of serotonin N-acetyltransferase induced by drugs, indicating that new enzyme molecules are formed via stimulation of beta-receptors of pineal cells and adenosine 3':5'-cyclic monophosphate. When rat pineal organ is denervated by ganglionectomy, beta-(3,4-dihydroxyphenyl)-L-alanine induces much more serotonin N-acetyltransferase than in the innervated gland. This superinduction by denervation appears to be due to changes of the postsynaptic site, probably the beta-adrenergic receptor on the pineal cell.
mesh_terms: D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000217:Acyltransferases / Q000032:analysis* / Q000037:antagonists & inhibitors; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D003714:Denervation; D004295:Dihydroxyphenylalanine / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects*; D004837:Epinephrine / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D010643:Phenoxybenzamine / Q000494:pharmacology; D010870:Pineal Gland / Q000187:drug effects / Q000201:enzymology*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology
chemical_list: D000319:Adrenergic beta-Antagonists; D008996:Monoamine Oxidase Inhibitors; D011941:Receptors, Adrenergic; D010643:Phenoxybenzamine; D003609:Dactinomycin; D012701:Serotonin; D004295:Dihydroxyphenylalanine; D003513:Cycloheximide; D011433:Propranolol; D013806:Theophylline; D006916:5-Hydroxytryptophan; D000217:Acyltransferases; D007545:Isoproterenol; D009638:Norepinephrine; D004837:Epinephrine