神经生长因子及远侧神经残端诱导神经侧枝生长的研究

Experimental Studies on Collateral Sprouting from Intact Peripheral Nerve Inducted by Nerve Growth Factor and Distal Nerve Stump

目的：研究神经生长因子（ＮＧＦ）及远侧神经残端诱导神经干侧枝的生长。方法：１０只大白兔，于两侧胫神经、腓总神经分叉处切断腓总神经，分叉上１ｃｍ坐骨神经外膜“开窗”，硅胶管桥接“开窗”处和腓总神经远侧断端，中间留６ｍｍ间隙。右侧管内注入ＮＧＦ，左侧注入生理盐水（ＮＳ）为对照侧。结果：大体观察ＮＧＦ侧比ＮＳ侧神经侧枝再生快，直径粗。超微结构显示ＮＧＦ侧比ＮＳ侧神经轴突数目多、髓鞘厚、组织排列整齐。电生理检测，ＮＧＦ侧的诱发动作电位峰值（ＡＭＰ）（２．５９００±０．８５６８ｍＶ）、神经传导速度（ＣＶ）（７６．００００±２．３４５７ｍ／ｓ）均优于ＮＳ侧的ＡＭＰ（０．７０８９±０．１２３１ｍＶ）、ＣＶ（２０．００００±１．５８１１ｍ／ｓ），ｔ检验Ｐ均＜０．０１。

bjective: To evaluate the possibility that collateral sprouting could occur from intact axons in an undamaged sciatic nerve. Methods: Bilateral sciatic nerves were exposed in the lower part of thigh, and the peroneal nerve was sectioned at the site of branch from sciatic nerve proper. The sciatic epineural window was created 10 mm above breaching. One end of silicone tube (60° slope) was sutured to epineural window, and other end to distal peroneal nerve stump. 6 mm gap was left within silicone tubing. The right silicone tubing was filled with NGF, the left with normal saline (NS) as control side. Results: (1) There was a fine tissue bridging sciatic nerve to distal peroneal nerve stump in silicone tubing on NGF side 1.5 months after operation. In contrast, there was no tissue on NS side. The diameter of regeneration nerve on NGF side was equal to that of distal peroneal nerve 3 months after operation, the regeneration nerve was smooth without any scar formation. The diameter of regeneration nerve on NS side was thinner than that on NGF side. (2) Ultrastructural studies of collatreal sprouting nerve showed that there were more axons wrapped by thicker myelin shealth on NGF side, the tissue arranged in regularity. (3) Electrophysiological studies demonstrated that electrical impulses could conduct through the collateral sprouting nerve to made muscle contraction. The results of electrical stimulation on NGF side were better than that on NS control side. Conclusion: Collateral sprouting may occur from intact axons, perhaps induced by some actors emanating from the distal nerve segment, enhanced by exogenous nerve growth factor, and subsequently make functional peripheral connections.