Altered rat skeletal muscle carnitine with age and after denervation.

We investigated the effect of denervation on the concentration of total free, and acyl carnitine in the soleus (S), extensor digitorum longus (EDL), and anterior tibial (AT) muscles of the rat. Soon after denervation there was a marked decrease in total carnitine in all three muscles. Acyl carnitine levels decreased concomitantly with changes in total carnitine. In control but not in denervated muscle, the carnitine concentration was age-dependent during the period of rapid growth of the animals. The highest carnitine concentration was observed at 14 weeks of age. The results of this study suggest that normal innervation significantly influences carnitine-mediated lipid metabolism in skeletal muscle.