title: Catecholamine infusion in vagotomized dogs during thiamylal-halothane and pentobarbital anesthesia.
abstract: The cardiac arrhythmogenic infusion rate of epinephrine, dopamine, and dobutamine in vagotomized dogs was determined during thiamylal-halothane and pentobarbital anesthesia. Epinephrine, dopamine, and dobutamine were administered until 4 or more ventricular arrhythmias on duplicated trials were produced or until a predetermined maximum infusion rate was attained. The mean ventricular arrhythmogenic infusion rates (micrograms X kg-1 X min-1) during thiamylal-halothane anesthesia were: epinephrine, 0.57 +/- 0.24; dopamine, 23.7 +/- 8.26; and dobutamine, 10.21 +/- 3.54. Few arrhythmias were produced at the maximum administered infusion rate during pentobarbital anesthesia (2 of 6 with epinephrine, 3 of 6 with dopamine, and 0 of 6 administered dobutamine). Heart rate and blood pressure increased progressively with increasing infusion rates for all 3 catecholamines during thiamylal-halothane anesthesia. Heart rate and blood pressure changes were similar during pentobarbital anesthesia except for blood pressure changes during dobutamine infusion.
mesh_terms: D000768:Anesthesia, General; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000494:pharmacology*; D004280:Dobutamine / Q000494:pharmacology; D004285:Dogs; D004298:Dopamine / Q000494:pharmacology; D004837:Epinephrine / Q000494:pharmacology; D006221:Halothane; D006339:Heart Rate / Q000187:drug effects; D010424:Pentobarbital; D013840:Thiamylal; D014628:Vagotomy
chemical_list: D002395:Catecholamines; D013840:Thiamylal; D004280:Dobutamine; D010424:Pentobarbital; D006221:Halothane; D004298:Dopamine; D004837:Epinephrine