Tone of sympathetic nerves and regulation of heart activity.
Tone of sympathetic nerves to the heart was studied in rats and guinea pigs. Experiments with pharmacological blockade of the sympathetic nervous system and vagotomy confirmed the general notion on the absence of tonic effects of sympathetic nerves on the heart. Reduction of the heart rate reported previously probably attests to various experimental designs (type and depth of anesthesia, possible hypothermia, duration of observations, and pharmacological preparations). As differentiated from the vascular tone, the heart rate under rest conditions depends on the vagal tone and circulating humoral substances.
Smirnov
V M
VM
Department of Physiology, Russian State Medical University. vms@doctor.com
D018686:Anesthetics, Intravenous / Q000494:pharmacology; D000818:Animals; D001340:Autonomic Nerve Block; D001950:Bretylium Tosylate / Q000494:pharmacology; D004562:Electrocardiography; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000294:innervation*; D006339:Heart Rate / Q000187:drug effects; D051381:Rats; D013233:Stellate Ganglion / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D014520:Urethane / Q000494:pharmacology; D014628:Vagotomy; D014630:Vagus Nerve / Q000187:drug effects / Q000502:physiology / Q000601:surgery
D018686:Anesthetics, Intravenous; D014520:Urethane; D001950:Bretylium Tosylate