Abstract:

Objective　To studythe degeneration and regeneration of skeletal muscle after denervation.Methods　Denervation was carried out in gastrocnemius muscles in 30 adult BALB/C mice by cutting the sciatic nerve. The gastrocnemius muscles were removed at 1,2,4,8,12,16 weeks after denervation, respectively. Specimens were processed for histological study and immuno- histochemical technique.Results　Muscle fiber atrophy followed by degerneration and regenerationwas observed in the early peri- od of denervation. Fusion of the regenerated muscle cellswith each other followed by degeneration of the cells and growth of fibro- connective tissue were observed in the later stage. The expression of myoglobin and actin decreased in 1~4 weeks after denerva- tion. The postive expression of the proteins was observed in some 8 weeks′cells and in many degenerated 12~14 weeks′muscle cells.Conclusion　Degeneration and regeneration may coexisted in the denervated muscles. The regenerated muscle cells can′t fully develop due to the deficit of nerve regulation and degenerate again. The regenerated muscle cells will melt each other and can′t develop to mature muscle fiber in the later stage.

Key words: muscles, denervation, regeneration, immunohistochemical technique