Effects of Hypoxia on the Myocardial Metabolism of Intact Dogs

Coronary blood flow and myocardial oxygen and carbohydrate metabolism were studied in normal intact dogs subjected to different Degreess of hypoxia. Total left ventricular oxygen consumption was maintained during administration of 10 per cent and 5 per cent oxygen owing to increase in coronary flow and myocardial oxygen extraction. Ten per cent oxygen administration had little effect on carbohydrate uptake by the heart. Five per cent oxygen resulted in decreased coefficients of extraction for glucose, lactate and pyruvate, but total utilization was maintained. Complete anoxia resulted in negative arteriovenous differences for lactate and markedly decreased or negative values for pyruvate.