The Metabolism of Fatty Acids in the Rat IV. Stearic acid

Abstract 1‐C 14 ‐Stearic acid and H 3 ‐palmitic acid in rat serum were injected i. v. into fasted and refed male rats and the disappearance of radioactivity from the blood, its tissue distribution and recirculation into the blood were studied. Stearic acid was taken up at a lower rate than palmitic acid. Five minutes after the injection about the same total amount of C 14 ‐as of H 3 ‐label was recovered from the fasted rats. At 320 min more C 14 ‐label was left. This may be due to the less rapid turnover of the Stearic acid‐containing phospholipids compared to the glycerides. In the liver there was a marked preferential incorporation of stearic acid into the phospholipids, whereas the ratio of incorporated stearic acid to palmitic acid in the glycerides was low. This skewed distribution was also seen in the blood phospholipids and the blood glycerides.