Relationship between dietary retinol and α‐tocopherol and lipid peroxidation in rat liver cytosol

The effects of retinol and α‐tocopherol‐deficient and supplemented diets on the cytosolic concentration of thiobarbituric acid reactive substances (TBARS) in rat liver have been studied. Physiological lipoperoxidation (LPO) was observed in liver cytosol of control rats (TBARS = 0.315 ± 0.034 nmol of MDA equivalents/mg of liver cytosolic proteins). In retinol‐deficient diets there was a decrease in retinolaemia and the absence of retinol in liver cytosol while cytosolic TBARS increased significantly (P < 0.001). Vitamin E was not found in cytosolic fractions, except in α‐tocopherol‐supplemented diet rats. α‐Tocopherol‐deficient diets induced an absence of vitamin E in the serum and cytosolic TBARS were increased compared to controls (P < 0.001). Supplementation of the diet with retinol and α‐tocopherol or both in combination induced a significant decrease in liver cytosolic TBARS (P < 0.001). Finally the combination of low dietary supplementation with retinol and α‐tocopherol (ten times the normal diet eac...