Cardiac activity and blood pressure in rats during selective blockade of various subtypes of muscarinic cholinoceptors.
Cardiac activity and blood pressure in adult rats were recorded during selective blockade of cholinoceptors. Blockade of muscarinic M1 and M2-cholinoceptors had little effect on cardiac activity. Blockade of muscarinic M3-cholinoceptors was followed by heart acceleration. The data suggest that the tonic inhibitory influence of the vagus nerve is mediated via cardiac muscarinic M3-cholinoceptors. Electrostimulation of the right vagus nerve during selective blockade of various subtypes of muscarinic cholinoceptors was followed by the decrease in heart rate. Our results indicate that muscarinic cholinoceptors play a role in the immediate inhibition of cardiac activity upon vagus nerve stimulation.
Zefirov
T L
TL
Department of Anatomy, Physiology, and Human Health Care, Tatar State Humanitarian-and-Pedagogical University; Department of Normal Physiology, Kazan State Medical University. nafisaz@mail.ru.
Ziyatdinova
N I
NI
Saifutdinova
L R
LR
Zefirov
A L
AL
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004558:Electric Stimulation; D004562:Electrocardiography; D005703:Gallamine Triethiodide / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology*; D010890:Pirenzepine / Q000494:pharmacology*; D051381:Rats; D013997:Time Factors; D014630:Vagus Nerve / Q000502:physiology
D018727:Muscarinic Antagonists; D010880:Piperidines; D010890:Pirenzepine; C042375:4-diphenylacetoxy-1,1-dimethylpiperidinium; D005703:Gallamine Triethiodide