Effect of inhibitors and phenobarbital pretreatment upon hepatic lipid peroxidation during protein and riboflavin dietary stress in male rats.

Male young albino rats divided into three groups were maintained on the following diets. The normal group was maintained on 13% casein, 45% corn starch, 31% sucrose, 6% salt mixture, 4% peanut oil, and 1% vitamin mixture. The low protein group animals recieved only 5% casein, and the riboflavin-deficient group was fed normal diet, except that the riboflavin was absent from the vitamin mixture and ordinary casein was replaced by 13% vitamin-free casein. The effects of various inhibitors upon triphosphopyridine nucleotide, reduced form-linked lipid peroxide formation by the supernatant fraction of liver at 9000 × g from rats fed a normal diet, a low protein diet, or a riboflavin-deficient diet for 2,4, and 7 weeks were investigated. A significant decrease in triphosphoryridine nucleotide, reduced form-linked and ascorbate-induced lipid peroxidation was noticed in rats fed on low protein and riboflavin-deficient diet. Glutathione inhibited the triphosphopyridine nucleotide, reduced form-linked lipid peroxidation in rats from all three groups. However, the observed response was variable due to the nature of the diet. The magnitude of inhibition was greater in low protein-fed animals than in animals from the riboflavin-deficient and control groups. Cytochrome C inhibited peroxide formation, but the inhibition was greater in rats from the low protein and riboflavin-deficient groups than in animals from the normal group. Tocopherol exhibited the antioxidant property in all three groups of rats. Deoxycholate inhibited lipid peroxide formation in all the three groups.