EFFECT OF DIETARY CARNOSINE ON PLASMA AND TISSUE ANTIOXIDANT CONCENTRATIONS AND ON LIPID OXIDATION IN RAT SKELETAL-MUSCLE

The effect of dietary carnosine supplementation on plasma and tissue c arnosine and alpha-tocopherol concentrations and on the formation of t hiobarbituric acid reactive substances (TBARS) in rat skeletal muscle homo-genates was evaluated. Plasma, heart, liver and hind leg muscle w as obtained from rats fed basal semipurified diets or basal diets cont aining carnosine (0.0875%), alpha-tocopheryl acetate (50 ppm), or carn osine (0.0875%) plus alpha-tocopheryl acetate (50 ppm). Dietary carnos ine supplementation did not increase carnosine concentrations in heart , Liver and skeletal muscle. Dietary supplementation with both carnosi ne and alpha-tocopherol increased carnosine concentrations in liver 1. 56-, 1.51- and 1.51-fold as compared with diets lacking carnosine, alp ha-tocopherol or both carnosine and alpha-tocopherol, respectively. Di etary supplementation with both carnosine and alpha-tocopherol also in creased a-tocopherol concentrations in heart and liver 1.38-fold and 1 .68-fold, respectively, as compared to supplementation with alpha-toco pherol alone. Dietary supplementation with carnosine, alpha-tocopherol or both car-nosine and alpha-tocopherol was effective in decreasing t he formation of TBARS in rat skeletal muscle homogenate, with dietary alpha-tocopherol and alpha-tocopherol plus carnosine being more effect ive than dietary carnosine alone. The data suggest that dietary supple mentation with carnosine and alpha-tocopherol modulates some tissue ca rnosine and alpha-tocopherol concentrations and the formation of TBARS in rat skeletal muscle homogenates.