Effect of chronic consumption of ethanol and vitamin E on fatty acid composition and lipid peroxidation in rat heart tissue

Lipid peroxidation products and the fatty acid composition of phospholipids were studied in the hearts of rats chronically consuming ethanol supplemented with large amounts of vitamin E. Ethanol representing 36% of the total calories was ingested for 7 weeks in a modified Lieber-DeCarli liquid diet that contained vitamin E at 30 IU/L in the control or 172 IU/L in the supplemental dietary group. Ethanol and/or vitamin E did not change the absolute content (μg per mg of phospholipids) of the main fatty acids (C_18:0, C_18:2, and C_20:4) of heart phospholipids but increased the amount of the minor C₂₀-C₂₂ fatty acids. Cardiac phospholipid levels increased in rats chronically consuming excess vitamin E and/or alcohol. Chronic ethanol consumption caused elevations of the relative content (percent of total fatty acids) of tri-, tetra-, and hexaenoic acids and peroxidizability index (PI) of the cardiac phospholipids. Supplementation with vitamin E blocked this ethanol-induced shift in the fatty acid profile toward unsaturation and decreased the PI. Ethanol enhanced accumulation of vitamin E in heart tissue by 30% irrespective of the vitamin E content in the diet. Enrichment of the diet with vitamin E coincided with the low levels of fluorescent products in heart lipids. A positive correlation (r = 0.36; p = 2%) was found between vitamin E and diene conjugates in the heart cells. Thus, vitamin E has a stabilizing effect on heart phospholipids by preventing changes in their fatty acid composition and peroxidative deterioration.