Effect of Innovar upon the autonomic control of the heart in intact dog.
This experiment compares the regulation of cardiac function in dogs before and after administration of a drug (Innovar-Vet, 0.05 ml/kg) that produces a state of 'neuroleptanalgesia'. All animals (n = 21) were chronically instrumented to measure arterial blood pressure (BP) and heart rate (HR); left ventricular pressure (LVP, n = 10) and ascending aortic flow (n = 4) were also recorded in some animals. After Innovar, the dogs became somnolent and tolerated minor surgical procedures. The paO2 decreased (95 +/- 11 vs 90 +/- 8 mm Hg, pre- vs post-Innovar, mean +/- S.D.; P less than 0.05) while paCO2 increased (33 +/- 5 vs 36 +/- 5 mm Hg; P less than 0.05) when measured (n = 6) 10 min after drug administration. The changes in HR and BP during a 5-min, left circumflex coronary artery occlusion (n = 15) were virtually identical in the awake and sedated states; likewise, no significant differences were detected in the occlusion-induced changes in BP, HR, d(LVP)/dt and stroke volume in the subset of more fully instrumented dogs. However, some significant effects were seen when the Innovar dose was increased to 5 times normal. The effects of bilateral carotid occlusion and dobutamine infusion (8, 16 and 30 mg/kg) were tested in another 7 dogs. Once again, the analysis of variance interaction terms testing the reflex or drug-induced changes in HR, BP and d(LVP)/dt before vs after sedation were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)
Vallance
S R
SR
Department of Physiology and Biophysics, University of Kentucky College of Medicine, Lexington 40536.
Fitzovich
D E
DE
Billman
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GE
Randall
D C
DC
D000818:Animals; D001157:Arterial Occlusive Diseases / Q000503:physiopathology; D001341:Autonomic Nervous System / Q000187:drug effects*; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002340:Carotid Artery Diseases / Q000503:physiopathology; D003327:Coronary Disease / Q000503:physiopathology; D004280:Dobutamine / Q000494:pharmacology; D004285:Dogs; D004329:Droperidol / Q000494:pharmacology*; D004338:Drug Combinations / Q000494:pharmacology; D005283:Fentanyl / Q000494:pharmacology*; D006329:Heart Conduction System / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects
D004338:Drug Combinations; D004280:Dobutamine; C001451:Innovar; D004329:Droperidol; D005283:Fentanyl