Anaerobic heat production by the heart.

Open Access
Publisher Website
Google Scholar
Abstract
Anaerobic heat production by the isolated perfused dog heart was determined by heat appearing in excess of the heat attributable to its O2 consumption. External work by the heart was prevented. During a control period, the heart consumed lactate, and the caloric equivalent of its O2 consumption was 4.4 cal/ml O2. Reduction in O2 supply to the heart led to signs of myocardial nypoxia and, in some instances, caused a reversal from lactate uptake by the heart to lactate output. Lactate output was accompanied by the development of anaerobic heat production. The anaerobic heat comprised 5 - 60% of the total metabolic rate. Anaerobic heat was dependent upon lactate production, not upon myocardial hypoxia. Lactate output by the heart induced by alkalization in the absence of hypoxia also was accompanied by myocardial anaerobic heat production.