兔坐骨神经损伤后内源性生长因子含量的变化及意义

Changes of endogenous growth factors and their significance after sciatic nerve injury in rabbits

目的探讨兔坐骨神经损伤后内源性bFGF、NGF及脑源性神经营养因子（brain—derivedneurotrophicfactor，BDNF）的变化规律及干细胞移植治疗周围神经损伤的最佳时机。方法新西兰大白兔16只，采用钳夹法制作坐骨神经损伤模型，按随机数字表法分为正常对照组、损伤3，7，14d组，每组4只。病理切片HE染色观察钳夹损伤后神经组织的结构变化，采用ELISA方法检测各组坐骨神经匀浆上清液中bFGF、NGF及BDNF的含量。结果损伤坐骨神经组织中bFGF的含量伤后缓慢上升，至伤后7d达到峰值（P〈0．05），之后下降并于14d降至正常水平（P〉0．05）；BDNF的含量伤后迅速上升，至伤后7d达到峰值（P〈0．05），之后逐渐下降并于14d降至正常神经水平（P〉0．05）；NGF的含量伤后迅速上升，至伤后3d达到峰值（P〈0．05），之后迅速下降并于7d降至正常水平（P〉0．05）。结论在周围神经损伤后的早期修复过程中，神经组织能够迅速调节NGF、bFGF及BDNF的分泌，各因子的分泌调节与损伤时间有关，呈峰值效应；伤后早期（3～7d）是进行神经吻合修复、神经移植及干细胞移植治疗的最佳时间。

Objective To investigate variations in bFGF, NGF, and brain-derived neurotrophic factor（BDNF） following sciatic nerve injury in rabbits and the optimum time to perform stem cell trans- plantation. Methods Sixteen New Zealand rabbits were divided into control group and groups at 3, 7, and 14 days postinjury according to the random number table, with 4 rabbits per group. Rabbit models of the sciatic nerve injury were induced by forceps. Structural change of the injured nerve tissues were ob- served with HE staining. Contents of NGF, bFGF, and BDNF in supernatants of homogenated sciatic nerves were detected by ELISA test. Results Level of bFGF increased slowly postinjury, reached the peak at day 7 （P 〈 0. 05 ）, and then restored to the normal level at day 14 （P 〉 0.05 ）. Level of BDNF raised quickly postinjury, reached the peak at day 7 （P 〈 0.05）, and then restored to the normal level at day 14 （P 〉 0. 05 ）. Level of NGF increased rapidly postinjury, reached the peak at day 3 （P 〈0. 05 ）, and then restored to the normal level at day 7 （P 〉 0.05）. Conclusions In the early recovery process after peripheral nerve injury, the nerve tissues regulate the secretion of NGF, bFGF, and BDNF immediately and secretions of these growth factors correlate with the time of injury. Early period （3-7 days ） after injury is the best time to perform nerve repairing, nerve transplantation, and stem cell transplantation.