title: Effect of selective stimulation of muscarinic M3 cholinoceptors on electrical and contractile activity of rat ventricular myocardium.
abstract: We studied the effect of selective activation of muscarinic M3receptors on electrical activity in the isolated preparation of rat ventricular myocardium as well as contractile activity of the left ventricle of Langendorff-perfused isolated heart. Application of muscarinic agonist pilocarpine (10(-5)M) against the background of selective blockade of subtype 2 muscarinic receptors with methoctramine (10(-7)M) markedly shortened the duration of action potentials in the isolated ventricular myocardium and reduced the amplitude and maximum rates of left-ventricular pressure rise and decay in the isolated heart paced at a fixed rate. All these effects were significantly suppressed by selective M3receptor blocker 4-DAMP (10(-8)M), which attested to the involvement of M3muscarinic receptors.
authors.affiliation: Department of Human and Animal Physiology, M. V. Lomonosov Moscow State University, Russia. abram340@mail.ru
authors.forename: D V
authors.initials: DV
authors.lastname: Abramochkin
authors.forename: S V
authors.initials: SV
authors.lastname: Tapilina
authors.forename: G S
authors.initials: GS
authors.lastname: Sukhova
mesh_terms: D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D003959:Diamines / Q000494:pharmacology; D006321:Heart / Q000187:drug effects; D018721:Muscarinic Agonists / Q000494:pharmacology*; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism*; D010276:Parasympatholytics / Q000494:pharmacology; D010862:Pilocarpine / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D043585:Receptor, Muscarinic M2 / Q000037:antagonists & inhibitors; D043587:Receptor, Muscarinic M3 / Q000819:agonists* / Q000378:metabolism; D016276:Ventricular Function
chemical_list: D003959:Diamines; D018721:Muscarinic Agonists; D018727:Muscarinic Antagonists; D010276:Parasympatholytics; D010880:Piperidines; D043585:Receptor, Muscarinic M2; D043587:Receptor, Muscarinic M3; D010862:Pilocarpine; C042375:4-diphenylacetoxy-1,1-dimethylpiperidinium; C054938:methoctramine