Effects of prolonged starvation on plasma free fatty acid levels and fatty acid composition of myocardial total lipids in the rat.

Experiments were carried out on male rat fed ad libitum or starved for a period of 7 days. Plasma levels of free fatty acids (FFA) and the quantity and composition of fatty acids in total lipids of heart ventricular tissue in vivo were analyzed by gas liquid chromatography (GLC). In addition, FFA extraction ratios and uptake rates were determined in isolated perfused hearts using the classical Langendorff technique. After 7 days of starvation, distribution and concentrations obtained for total lipid fatty acids from heart ventricles of starved animals were substantially different from those of controls. In particular, 20:5 and 22:6 carbon polyunsaturated fatty acids were significantly elevated. Also, total plasma FFA level was elevated and FFA extraction ratios were increased as a result of prolonged starvation. Accumulation of 20- and 22-carbon polyunsaturated fatty acids observed in ventricles of starved rats may have resulted from increased availability and extraction of FFA.