title: [Age-dependent peculiarities of the rat's heart cholinergic regulation].
abstract: In vitro and in vivo studies were performed to investigate the effects of M1-, M2-, M3-cholinoreceptors (M-AChR) blockade on the chronotropic and inotropic cardiac function in the rats of 1, 3, 6, 8 and 20 weeks old. These age groups were selected according to the development level of the autonomic regulation of the heart. It was found that the prior blockade of all three subtypes M-AChR did not prevent inhibitory effect of carbacholin on contractility of the atria and ventricles the animals of all studied age groups. The presence of the positive chronotropic response was found after blockade of M3-cholinoreceptor in 20 weeks-old rats. The absence of cardiac chronotropic response to the blockade of M2-receptor was revealed. In 3, 6, 8 weeks-old rats the selective blockade of M-AChR does not change of the heart chronotrope. At the same time, the effect of the M1- and M2-AChR blockade on myocardial contractility was revealed.
authors.forename: T L
authors.initials: TL
authors.lastname: Zefirov
authors.forename: N I
authors.initials: NI
authors.lastname: Ziatdinova
authors.forename: I I
authors.initials: II
authors.lastname: Khabibrakhmanov
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004562:Electrocardiography; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011976:Receptors, Muscarinic / Q000378:metabolism*; D012815:Signal Processing, Computer-Assisted
chemical_list: D018727:Muscarinic Antagonists; D011976:Receptors, Muscarinic