神经生长因子对运动终板变性与再生的研究

目的：探讨运动终板变性与再生时，神经生长因子（ＮＧＦ）对终板组织化学及超微结构变化的影响。方法：３０只Ｗｉｓｔａｒ大白鼠，切断股骨中段的坐骨神经，硅胶管桥接，两神经断端相距６ｍｍ。右侧再生室内注入ＮＧＦ，左侧注入生理盐水为对照侧。结果：终板乙酰胆碱酯酶染色，实验侧比对照侧着色深，末梢神经纤维再生丰富。术后１个月ＮＳ侧，终板区可见到雪旺氏细胞吞噬破碎的终板组织，出现典型的终板变性特征，而ＮＧＦ侧术后１个月突触裂隙内未发现雪旺氏细胞侵入。术后３个月ＮＧＦ侧再生运动终板结构接近正常，而ＮＳ侧终板结构不成熟。结论：当周围神经损伤后，损伤局部应用ＮＧＦ可减少运动终板变性的程度，促进了运动终板再生

THE STUDIES ON NGF EFFECT ON DEGENERATED AND REINNERVATED MOTOR END-PLATE HISTOCHEMICAL AND ULTRASTRCTURAL CHANGES

Objective:To evaluate the effect of exogenous NGF on denervated and reinnervated motor endplate histochemical and ultrastructural changes. Methods:Two sides sciatic nerves of 30 Wistar rats were cut and then bridged by using silicone tube to forming a regenerate chamber filled with exogenous NGF on right and normal saline(NS)on left as control. 6mm gap was left between the nerve ends 1 to 30 months after surgery,the pereoneal muscles from both sides were dissected and fixed for histochemical and ultrastructural studies Results:Histochemical analysis of MEP AChE staining showed the color of MEP on right side was deeper than that on left control side 1 to 3 months after operation Ultrastructural studies of MEP demonstrated that,1 month after operation on NS control side,the contents of the axoplasm undergo disruption and the nerve terminal breaks up into small fragments,the Schwann cell processes extend into the synaptic cleft to surround fragments of the nerve terminal. In contrast,no Schwann cell was fonud in synaptic cleft on NGF side,the structure of MEP appeared intact but the mitochondra were swollen 3mon after operation,the structure of MEP on NGF side looked near normal,while on NS side only parts of organellae could be seen in MEP,it was still unmature. Conclusion:When peripheral nerve was injured,the extent of MEP degneration could be abated by using exognous NGF in local damage,and the MEP reinnervation could be enhanced also