Sex-related differences in desaturation and chain elongation of essential fatty acids studied in isolated rat...

When [14C]linoleic acid (18:2(n-6)) or [14C]dihomogammalinolenic acid (20:3(n-6)) was incubated with isolated liver cells from rats fed an essential fatty acid deficient diet, delta 6- and delta 5-desaturation, chain elongation and synthesis of 14C-labelled C14-C18 fatty acids (from [14C]acetate) were enhanced in female cells compared with male ones. No sex difference in total secretion of very low density lipoproteins (VLDL) was observed. However, VLDL secreted from female cells contained significantly more C16-C18 fatty acids than male cells. It is suggested that the observed sex differences, at least in part, may be related to the different content of fatty acid binding proteins in female cells compared with males.