神经生长因子对神经损伤后运动终板再生影响的研究——酶组织化学和超微结构观察

THE EFFECT OF NROWTH FACTOR ON REGENERATION OF MOTOR END PLATES AFTER NERVE INJURY--HISTOCHMICAL AND ULTRASTRUCTURAL STUDY

本研究采用定位、定量方式钳夹兔右侧坐骨神经，ＮＧＦ组动物于神经损伤处局部喷布蛇毒神经生长因子（ｎｅｒｖｅｇｒｏｗｔｈｆａｃｔｏｒ，ＮＧＦ），对照组动物于同部位给予等量生理盐水。对胫骨前肌中的红肌、白肌和中间型肌纤维运动终板乙酰胆碱酯酶（ＡＣｈＥ）活性和超微结构改变进行观察。结果表明，神经损伤早期，ＡＣｈＥ活性持续下降，超微结构显示逐渐变性。第４周末，ＮＧＦ组运动终板ＡＣｈＥ活性和超微结构恢复正常。第８周末，对照组运动终板酶活性和超微结构才基本恢复正常。本研究结果提示，周围神经损伤后，外源性ＮＧＦ能促进运动神经元轴突再生。

After crushing the right sciatic nerve quantitatively, rabbits of NGF group were sprayed with nerve growth factor (NGF) in the position of crushed nerve daily and the control group were sprayed with normal saline in the same position. Using histochemical and electron microscopic technique, the AChE activity and ultrastructure of three types of motor end plates in the right tibialis anterior muscle were detected. Two weeks after nerve injury, the enzyme activity reduced gradually in NGF group and control group. From 3rd to 8th week, the AChE activity in NGF group became stronger than that in control group (P<0 05～0 01). The changes of ultrastructure were coincident with the enzyme activity. The results suggested that NGF might play an important role in protecting the motor neurons and promoting their biologic synthesis, meanwhile some essential materials of axon regenration were transported to the injured region to accelerate the recovery of injured axon and motor end plate.