The effect of antioxidant deficiency on tissue lipid composition in the rat. II. Liver.

The hepatic phospholipids of the antioxidant-deficient rat fed a source of both linoleate and linolenate showed a progressive net decrease in eicosapentaenoate, a progressive net increase in arachidonate, and there was a concomitant accumulation of fluorescent pigment of the lipofuscin or ceroid type in the tissue. An increased incorporation of isotopically labeled acetate into both the tetraenoic and pentaplus hexaenoic acid fractions was also noted, indicating that the disappearance of polyunsaturated fatty acids was partially countered by increased synthesis. Comparable results were obtained on diets containing either suboptimum or adequate levels of biologically available selenium. Vesicular dilation of the endoplasmic reticulum was noted in animals fed the tocopherol-deficient diet. In separate experiments using a necrogenic diet containing torula yeast, these subcellular alterations were found to be prevented by tocopherol but not by selenium, although selenium supplementation did prevent macroscopically observable damage.