Effects of corn oil- and fish oil-supplemented diets on phospholipid fatty acid composition of rat liver nuclei.

The effects of dietary fat on fatty acid compositions of phospholipids in liver nuclei were investigated. By feeding a diet containing 5% corn oil or fish oil to rats, the proportions of n -6 or n -3 polyunsaturated fatty acids (PUFA), respectively, were increased in phospholipids of the liver nuclei. By feeding a fat-free diet, endogenous PUFA were increased. Even after feeding the fat-free diet for 40 weeks, the n - 6 still remained at about 10% in both phosphatidylcholine (PC) and phosphatidylethanolamine (PE), while the n -3 PUFA remained at about 5 and 16% in PC and PE, respectively. The fatty acid compositions of phospholipids in the liver nuclei were influenced by dietary fat and were roughly similar to those in the microsomes. The proportion of n - 3 PUFA was high in PE of both the nuclear membrane and matrix. The proportion of n - 6 was higher in both PC and PE of the nuclear matrix than in those of the membrane.