Baroreceptor mechanisms in rat.
Baroreflex control of cardiovascular parameters was studied in control, atropine- and guanethidine-treated rats. Baroreceptor activity was tested by the relationship between the increase in blood pressure produced by a phenylephrine administration (bolus ov infusion) and the induced bradycardia. No differences were observed in basal arterial blood pressure and heart rate between treated- and control rats. Baroreceptor sensitivity was lower in atropine- or guanethidine-treated rats than in control animals. Baroreceptor activity has two components: a first, rapid, predominantly parasympathetic and a second, slower, that is mediated by both parasympathetic and sympathetic efferent pathways.
D000818:Animals; D001286:Atropine Derivatives / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D006145:Guanethidine / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D011311:Pressoreceptors / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D014630:Vagus Nerve / Q000187:drug effects
D001286:Atropine Derivatives; D010656:Phenylephrine; C006649:methylatropine; D006145:Guanethidine