title: Pineal hyperactivity in spontaneously hypertensive rats: muscarinic regulation of indole metabolism.
abstract: 1. Choline acetyltransferase activity and [3H]quinuclidinyl benzylate-binding sites were detected in the pineal gland of normotensive Wistar-Kyoto rats and of spontaneously hypertensive rats. 2. In vitro, muscarinic activation by pilocarpine increased the pineal metabolic production of hydroxyindole derivatives up to 5-hydroxytryptamine and produced a less marked stimulation of melatonin biosynthesis. 3. Electrical field stimulation of pineal gland slices caused similar metabolic effects. 4. Muscarinic blockade with atropine inhibited the effects on hydroxyindole metabolism. 5. [3H]Quinuclidinyl benzylate-binding sites, indicative of muscarinic receptors, were more numerous, and basal 5-hydroxytryptamine and melatonin levels were higher, in the pineal gland of spontaneously hypertensive rats compared with Wistar-Kyoto rats. 6. The atropine-sensitive metabolic effects of pilocarpine and electrical field stimulation on the pineal gland were increased in spontaneously hypertensive rats compared with Wistar-Kyoto rats.
authors.affiliation: Laboratorio de Sustancias Vasoactivas, Universidad de Buenos Aires, Argentina.
authors.forename: L M
authors.initials: LM
authors.lastname: Finocchiaro
authors.forename: A
authors.initials: A
authors.lastname: Scheucher
authors.forename: A L
authors.initials: AL
authors.lastname: Alvarez
authors.forename: S
authors.initials: S
authors.lastname: Finkielman
authors.forename: V E
authors.initials: VE
authors.lastname: Nahmod
authors.forename: C J
authors.initials: CJ
authors.lastname: Pirola
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D006973:Hypertension / Q000503:physiopathology*; D007211:Indoles / Q000378:metabolism*; D008297:Male; D008550:Melatonin / Q000096:biosynthesis; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology*; D010862:Pilocarpine / Q000494:pharmacology; D010870:Pineal Gland / Q000503:physiopathology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D011976:Receptors, Muscarinic / Q000378:metabolism; D012701:Serotonin / Q000096:biosynthesis
chemical_list: D007211:Indoles; D011976:Receptors, Muscarinic; D010862:Pilocarpine; D012701:Serotonin; D008550:Melatonin