[Vagal influence in experimental arrhythmias caused by dopamine].
Dopamine induced cardiac arrhythmias in control and reserpine-treated rats which was successfully++ prevented by functional inhibition of the parasympathetic system. Both EKG and intracarotid mean blood pressure were recorded through a polygraph. Animals were anesthetized with urethane, intravenously heparinized and enhanced its spontaneous pulmonary ventilation with a tracheal cannula. Dopamine (50, 100, 200 and 400 micrograms/100 g,) produced cardiac arrhythmias characterized by atrioventricular block, ventricular premature depolarization and ventricular tachycardia. The parasympathetic inhibition resulting from bilateral vagotomy or atropine injection (1 mg/kg i.v.) induced a significant reduction in the arrhythmia frequency. A vagal reflex originating in great vessel baroreceptors is postulated as the ensuing mechanism. Vagal inhibition seems to be efficacious to prevent cardiac arrhythmias and lowering mortality rate.
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000503:physiopathology*; D001285:Atropine / Q000494:pharmacology; D004298:Dopamine; D004562:Electrocardiography; D005260:Female; D008297:Male; D051381:Rats; D012110:Reserpine / Q000494:pharmacology; D014628:Vagotomy; D014630:Vagus Nerve / Q000503:physiopathology*
D001285:Atropine; D012110:Reserpine; D004298:Dopamine
Influencia vagal en las arritmias experimentales por dopamina.