关键词: 运动终板, 去神经支配, 方法, 神经损伤

Abstract: Objective To observe the changing rules of skeletal muscle and motor end plate of the denervated rats. Methods Fifty-four adult Wistar rats were used and separated randomly in nine groups. After established the model of denervated gastrocnemius muscle by cutting off the sciatic nerve， the muscle wet weight， diameter，cross section area of myocyte and motor end plate were measured. Results 2 weeks after denervated， the wet weight reduced to 52.1% of the normal， until 16 weeks later， it was maintained at about 25% of the normal until to 24 weeks. The diameter and the cross section decreased progres sively with prolongation of time. 2 weeks after nerve resected， the diameter wa s 64.87% of the normal， and it was only occupied 25.06% of the normal 20 week s later. The cross section changed as the changes of the diameter. The motor en d plate was normal in the first four weeks. After that， the motor end plate losed the normal shape and formed neurofilament. 16 weeks after operation， the neurofilament began to decrease. Conclusion The skeletal muscle atrophies and the motor end plate cataplasia take place after the nerve injury, the changes are getting serious with prolongation of time. The nerve repair operation should be made as early as possible.

Key words: motor end plate, denervation, metheds, nerve injury