大鼠坐骨神经切断后相应脊髓节段中GAP-43表达的变化

目的 探讨成年Wister大鼠在坐骨神经切断后GAP-43于相应脊髓节段前角运动神经元内的表达变化。方法 选取健康成年雄性Wister大鼠60只,随机分为坐骨神经切断组和对照组,分别于术后1、2、4、8、12、16周处死后取其L4～L6脊髓,利用免疫组织化学技术检测GAP-43在相应脊髓节段中的表达变化,并利用影像分析系统进行统计学分析。结果 在对照组中GAP-43表达呈阴性,随着时间的变化无明显改变。坐骨神经切断组与对照组在不同时相中的变化:1周时对照组中胞体内GAP-43有明显表达,2周达到高峰,4～8周时呈下调趋势,9～16周时GAP-43在神经元中仍有表达。结论 坐骨神经切断可导致成年大鼠相应脊髓阶段中前角运动神经元GAP-43表达明显增加,表明周围神经损伤后,神经元的再生能力增强,但并不能长时间持续。

Objective To investigate the expression of GAP-43 at the motor neuron of the comu anterius medullae spinalis after the sciatic nerve dissection in adult Wister rats. Methods Sixty adult male Wister rats were used in the experiment. Animals were randomly divided into 2 groups： sham-operated group and nerve dissection group. The rats were sacrificed at 1,2,4,8,12and 16 weeks postoperative and the spinal cord L4-L6 of every rat was harvested. Then we observed the altering expression of GAP-43 in the corresponding segments of spinal cord using immuno-histochemical technology and image analysis system. The results were analyzed statistically. Results GAP-43 showed negative expression in the sham-operated group and had no obvious changes in different phases. Compared with the nerve dissection group, from the first week, GAP-43expression of the nerve dissection grouop was observed remarkably in the cytoplasm of motor neuron. It reached the peak in the 4th week and gradually descended fi＇om the 6th week. There was still small amount of GAP-43 expression in the nucleus at the 8th week. we found that there was no significant difference between the sham-operated group and the nerve dissection group in the first week. Conclusion The upregulated expression of GAP-43 in the motor neuron of comu anterius medullae spinalis by the sciatic nerve dissection, to explain regeneration ability of mortor neuron was potentiation but no long-time course to keep. The procedure takes part in the protection of the injured motor neuron.