Influence of denervation and reinnervation on autolytic activity and on protein composition of skeletal muscle in rat.

Changes in the proteolytic activity and in the relative content of protein in soluble, myofibrillar and insoluble fractions were investigated following denervation and reinnervation of the soleus and tibialis anterior muscles of the rat. After denervation an increase of autolysis in the acid and neutral pH range, but not in the alkaline one, was found in both muscles. An increased autolysis at the acid and neutral pH range was also observed in both muscles after reinnervation, when the weight of the muscles increased. The results indicate the lack of inverse relationship between the changes of proteolytic activity and the decrease or increase of the amount of muscle protein in the course of muscle atrophy and regeneration.