Oxidative status of plasma and muscle in rabbits supplemented with dietaryvitamin E

Thirty New Zealand white rabbits, mean weight 2 kg, were divided into three equal groups balanced for body weight and randomly assigned to a diet cont aining 60 (C), 150 (T1) or 375 (T2) mg/kg of all-rac-alpha -tocopheryl acet ate. After 29 days, the animals were slaughtered, alpha -Tocopherol was ass ayed in muscle (longissimus dorsi) and plasma; triglycerides and cholestero l (total, high density lipoprotein, low density lipoprotein) were analysed in plasma; reactive oxygen metabolites (ROMs) were analysed in serum; and t hiobarbituric acid-reactive substances (TBARS) were analysed in muscle, The re were no body weight and food intake differences between the groups. The plasma vitamin E and vitamin E:lipid ratio were significantly higher in gro ups T1 and T2 than in C, but increases were not linearly related to dietary levels. Muscle alpha -tocopherol concentrations in the treated groups were significantly higher than in C, and linearly related (R = .67) to the vita min E:lipid ratio. ROM and vitamin E levels in blood were inversely related (R = .74), with ROMs significantly lower in the treated groups than in C. The 60-mg/kg dose of C recommended by the National Research Council was una ble to control ROM production. Lipid oxidation in muscle was significantly lower in T2 than in the other groups, and TBARS correlated significantly wi th muscle vitamin E (R = .61) and serum ROM (R = .73). These data suggest t hat vitamin E supplemented at 375 mg/kg diet can effectively control ROM pr oduction and improve muscle lipostability. ROM assay provides a useful indi rect estimate of the oxidative status of muscle in vivo. (C) 2001 Elsevier Science Inc. All rights reserved.