High levels of dietary carnosine are associated with increased concentrations of carnosine and histidine in rat soleus muscle

The aims of this investigation were to: I) determine the effect of a modera tely high dose of carnosine on muscle concentrations of carnosine, histidin e and vitamin E at deficient, minimally adequate and sufficient levels of d ietary vitamin E and 2) compare the effects of moderately high and pharmaco logical doses of carnosine on muscle concentrations of carnosine, histidine and vitamin E when dietary vitamin E is minimally adequate. Muscle concent rations of carnosine, histidine and vitamin E were measured in the lateral gastrocnemius and red and white vastus lateralis; carnosine and histidine c oncentrations were also measured in soleus muscle. Male Sprague-Dawley rats (n = 12/group) were fed a basal vitamin E-deficient diet supplemented with either 0, 0.001 or 0.01% vitamin E and 0, 0.1 or 1.8% carnosine. After 8 w k, 1.8% carnosine resulted in significant fivefold increases in carnosine a nd twofold increases in histidine in the soleus muscle (P less than or equa l to 0.05). Muscle vitamin E concentrations were not significantly affected by dietary carnosine. Thus, very high levels of dietary carnosine are asso ciated with increases in carnosine and histidine concentrations in rat sole us muscle.