[Histochemical study on the denervated and reinnervated muscle of the rat (author's transl)]

Distribution of white and red muscle fiber is well demonstrated by means of enzyme histochemistry as a mosaic pattern. Nervous control on both different type of fibers is still obscure. In order to elucidate this problem, an experiment of denervation was carried out on the rat. The sciatic nerve was resected at sciatic notch for a distance of one cm. The extensors of lower leg were examined on histochemical preparation using succinate dehydrogenase activity staining at intervals following denervation. A tendency of faster atrophy of white fibers in the relatively superficial layer than red fibers was noted. Enzyme activity decreased gradually in both fibers. At about eight weeks reinnervation began to occur at the deeper layer near the motor point. Reinnervated large fibers appeared with a tendency of cluster formation with the enzyme as red fibers. It is suggested that fiber type is dependent on the nervous control.