title: The responsiveness of M2-muscarinic receptors in the posterior hypothalamus and brain stem of vasopressin hypertensive rats.
abstract: The response of an endogenous inhibitor of cAMP-dependent protein kinase (type I inhibitor) to tremorine was used as an index of sensitivity of control muscarinic M2-receptors. Tremorine induced a dose-dependent increase in type I inhibitor activity in the posterior hypothalamus and brain stem. The action of the compound was blocked by pretreatment with aminophylline and atropine. Prolonged, 28 days treatment with lysine vasopressin (1 U/kg/day ip) induced hypertension and modified the dose-response curve for tremorine. Five times higher doses of tremorine than in normotensive rats were necessary to induce statistically significant increase in type I inhibitor activity in the posterior hypothalamus and brain stem suggesting subsensitivity of M2-muscarinic receptors in the brain areas responsible for the regulation of blood pressure.
authors.affiliation: Department of Pharmacodynamics, Medical Academy, Lódź, Poland.
authors.forename: H
authors.initials: H
authors.lastname: Szmigielska
authors.forename: A
authors.initials: A
authors.lastname: Szmigielski
authors.forename: A
authors.initials: A
authors.lastname: Szadowska
mesh_terms: D000628:Aminophylline / Q000494:pharmacology; D000818:Animals; D001933:Brain Stem / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism*; D007034:Hypothalamus, Posterior / Q000187:drug effects / Q000378:metabolism*; D007274:Injections, Intraperitoneal; D008236:Lypressin; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000378:metabolism*; D014203:Tremorine / Q000037:antagonists & inhibitors / Q000494:pharmacology
chemical_list: D011976:Receptors, Muscarinic; D000628:Aminophylline; D008236:Lypressin; D014203:Tremorine