大鼠脊髓损伤后神经生长因子BDNF／轴突导向因子slit-2的表达变化

Expression changes of BDNF\slit-2 during the spinal cord injury of rats

目的:研究脊髓损伤后神经生长因子BDNF和轴突导向因子slit-2的表达变化,同时观察大鼠行为学、脊髓形态学及体感诱发电位(SEP)的变化特点。方法:雄性SD大鼠45只,随机分成正常组,假手术组和手术后1、3、5、7、14、21、28天组,每组各5只。免疫组化法观察神经生长因子BDNF\slit-2的表达变化,计算阳性细胞灰度值,并进行统计学分析。BBB法进行功能评分。HE染色观察脊髓损伤后不同时期的形态学变化。结果:大鼠脊髓损伤后,肢体瘫痪从第7天开始明显恢复直至28天。免疫组化结果正常组和假手术组脊髓前角BDNF\slit-2的表达较低。脊髓损伤24h后,损伤位点前角神经元中,BDNF\slit-2表达活跃,3天表达达高峰。形态学显示了损伤后脊髓出血吸收、变性的过程。结论:成年大鼠脊髓损伤后,神经生长因子BDNF和轴突导向因子slit-2随之上调,呈一定规律性,提示两者与脊髓损伤后神经再生相关。且BDNF、slit-2主要表达于脊髓前角,提示与脊髓损伤后肢体运动功能恢复密切相关。

Objectiye：To investigate the expression of BDNF and axon guidanc cue slit-2 after the spinal cord injury,simuhaneously observe the ethology, morphology and SEP changes of rats. Methods：Male Sprague-Dawley rats were randomly divided into normal group, the sham-operation group and the operation group （1,3,5, 7,14,21,28 days sub groups）, each group with 5 rats, The exprbssion of BDNF and slit-2 were detected through immunohistochemistry methods. The positive cells were analyzed by a computer image analysis system. Function changes were evaluated by BBB method, the morphological changes were obsered by HE staining, and the SEP change was also analyzed. Results：The limb function of experimental rats significantly recovered from 7 d to 28 d. The immunohisto- chemistry results indicated that expression of BDNF／slit-2 in the angulus anterior was low in either normal or sham operation group,while BDNF／slit-2 expressed actively at 24 h in the operation group,reached the peak at 3 days after operation. The morphology gradually changed from local hematoma to tissue degeneration. Conclusion：With the spinal cord injury of adult rats, BDNF and slit-2 increased with regularity, indicating the correlation between the two factors and the neuranagenesis. BDNF and sllt-2 were mainly expressed in the ventricolumna, implying they might be correlated with the limb movement function restore.