The Metabolism of Fatty Acids in the Rat

Abstract Göransson, G. and T. Olivecrona. The metabolism of fatty acids in the rat. I. Palmitic acid . Acta physiol. scand. 1964. 62 . 224–239. — Data on the concentration and the fatty acid composition of neutral lipid fatty acids and of phospholipid fatty acids in blood, liver, heart, kidney, lung, spleen and muscle from fasted and refed male rats are reported. Data are also given on the radioactivity in these tissue lipid fractions at several time intervals after the intrevenous injection of 9–10‐H 3 ‐labeled palmitic acid in rat serum. These data are intended as a reference for further studies on the metabolism of other long‐chain fatty acids. The data are discussed with reference to a general picture of the metabolism of the plasma FFA after their removal from the plasma. After entering the tissues the FFA are oxidized, converted to other long‐chain fatty acids, esterified or transferred back to the plasma. The fractions diverted into the different pathways depend upon the nutritional state. The fraction oxidized is larger in the fasted than in the refed rats. The diversion into one or the other of the possible pathways occurs almost immediately after the FFA have entered the tissue. Subsequently, the remaining labeled fatty acids are metabolized at considerably lower fractional rates since they have entered larger fatty acid pools, than the plasma FFA pool.