Effect of inhibition of lipolysis on myocardial oxygen consumption in the presence of isoproterenol.
The effect of intravenous infusion of isoproterenol on myocardial oxygen consumption (MVo(2)) was studied in 10 intact and anesthetized dogs before and after inhibition of lipolysis. In five dogs lipolysis was inhibited by nicotinic acid or beta pyridyl carbinol and in five other dogs by high plasma glucose concentrations. In spite of similar mechanical responses to isoproterenol, as evidenced by left ventricular pressure, maximal rate of rise of left ventricular pressure (dP/dt), heart rate and cardiac output, augmentation of MVo(2) was larger before (on average 7.6 ml/min.100 g) than after inhibition of lipolysis either by antilipolytic drugs (on average 4.5 ml/min.100 g) (P < 0.005), or by high plasma glucose concentrations (on average 4.3 ml/min.100 g) (P < 0.02). As mechanical responses to isoproterenol were similar before and after inhibition of lipolysis, it is concluded that the additional rise in MVo(2) with intact lipolysis was caused by a metabolic stimulation by high concentrations of free fatty acids.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D003864:Depression, Chemical; D004285:Dogs; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology*; D050356:Lipid Metabolism; D008297:Male; D000432:Methanol; D009206:Myocardium / Q000378:metabolism*; D009539:Nicotinic Acids / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects*; D011725:Pyridines / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology; D016276:Ventricular Function
D005230:Fatty Acids, Nonesterified; D009539:Nicotinic Acids; D011725:Pyridines; D014665:Vasodilator Agents; D007545:Isoproterenol; D000432:Methanol