MYOCARDIAL METABOLISM OF FATTY ACIDS*

Abstract

The myocardial extraction and usage of total and free fatty acids (FFA) have been determined in patients and in dogs. In the postabsorptive state significant amounts of both esterified and free fatty acids were extracted by the myocardium. The determination of the I numbers in plasma revealed that there was proportionately greater usage of saturated than of unsaturated fatty acids by the heart. The ingestion of a fat meal increased both plasma concentration and myocardial extraction of FFA. Heparin induced in man and in fasting dogs a fall in the plasma concentration of total fatty acids and an increase in the concentration of FFA. Esterified fatty acids account for more than 1/2 of the total fats extracted by the myocardium. Under the experimental conditions reported here, the myocardial extraction of free fatty acids in any given patient and animal is usually dependent upon their respective arterial concentrations.