Metabolism of glucose by the ischemic dog heart

Publisher Website
Google Scholar
Abstract
In order to determine if increased glucose utilization, which occurs during hypoxia in the isolated heart, also occurs in vivo in the ischemic heart, the left coronary artery was perfused at ischemic flow rates in the open-chest dog. Arterial and coronary sinus blood was analyzed for O2 content, lactate, pyruvate, and glucose. Myocardial ischemia occurred with a mean reduction in coronary flow of 63% from control levels. There was a 400% increase in atrial pressure, a 43% decrease in mean aortic pressure and a 38% decrease in pressure time/min. Myocardial Og consumption declined 45%. Percent myocardial glucose extraction increased 504% and glucose consumption increased 91%. Myocardial lactate extraction was present during the control period and lactate production occurred with ischemia in all experiments. There was a 210% increase in the coronary sinus lactate-pyruvate ratio. Myocardial lactate production averaged 39 [mu]moles/100 g per min. during ischemia, which was equivalent to 50% of the glucose consumed. These experiments demonstrate that myocardial ischemia is accompanied by accelerated glycolysis as evidenced by increased glucose consumption and lactate production by the myocardium.