鼠肢芽提取液及运动对坐骨神经损伤修复的比较

Effects of rat limb bud extracts versus exercise on the repair of sciatic nerve injury

目的:观察鼠肢芽提取液及运动对坐骨神经损伤修复的作用。方法:实验于2005-09/2006-09在湛江师范学院重点学科实验室完成。①实验分组:用成年Wistar怀孕大鼠肢芽制备提取液。出生3d Wistar乳鼠40只,行右侧坐骨神经切断术,按随机数字表法分为肢芽提取液非运动组、肢芽提取液运动组、生理盐水非运动组、生理盐水运动组,每组10只。肢芽提取液非运动组、肢芽提取液运动组损伤局部用鼠肢芽提取液每隔2d注射1次。肢芽提取液运动组乳鼠每天进行零坡度跑台运动训练,每周递增速度,25,30,35,40m/min。生理盐水非运动组、生理盐水运动组损伤局部注射等量的生理盐水。生理盐水运动组乳鼠运动时间和程度同上。②实验评估:术后30d肉眼观察坐骨神经失神经后有无水肿、充血、坏死,新生轴突长度、粗细等情况;光镜检查脊髓前角神经元胞体状况,尼氏染色Nissl小体状况(包括核、核仁)神经元有无浓缩、破碎、胶质细胞数量;运动神经元计数检查尼氏染色切片上双侧前角运动神经元数目,标准为能辨认出细胞核的神经元轮廓。结果:①肉眼观察坐骨神经失神经后状况:失神经后,局部有轻微水肿、充血、坏死,有新生轴突,肢芽提取液运动组新生轴突较粗较长,生理盐水非运动组局部严重水肿、充血、坏死,新生轴突,较细较短。②光镜下观察神经元情况:生理盐水非运动组神经元无浓缩、破碎不明显、胶质细胞数量稍有改变。肢芽提取液非运动组有些神经元浓缩、破碎、胶质细胞数量增多。肢芽提取液运动组神经元无浓缩、轻微破碎、胶质细胞数量增加。③运动神经元数目:术后30d肢芽提取液非运动组损伤侧神经元数目高于生理盐水非运动组,差异有显著性意义(t=2.85,P<0.005)。肢芽提取液运动组损伤侧神经元数目高于肢芽提取液非运动组,生理盐水运动组损伤侧神经元数目高于生理盐水非运动组,差异均有显著性意义(t=2.38,2.48,P<0.005)。④运动神经元存活率:乳鼠坐骨神经切断术后局部注射肢芽提取液,术后30d,运动乳鼠可维持损伤侧脊髓前角运动神经元存活率77.96%,非运动乳鼠存活率59.75%;局部注射生理盐水,运动乳鼠可维持损伤侧脊髓前角运动神经元存活率33.45%,非运动乳鼠存活率28.62%。结论:鼠肢芽提取液对坐骨神经损伤的修复作用显著,加入运动干预后恢复效果更佳。

AIM： To observe the effects of limb bud extract and exercise on the repair of sciatic nerve injury in rats. METHODS： The experiment was conducted in the Key Subject Laboratory of Zhanjiang Normal College from September 2005 to September 2006. ①The extracts were harvested from the limb buds of adult pregnant Wistar rats. Forty Wistar neonate rats of 3 days old were subjected to neurotomy of right sciatic nerve, and then randomly divided into 4 groups with 10 animals in each group. The injured sites of rats in extract alone group and extract plus exercise group were injected with limb bud extract once every three days. Besides that, the rats of extract plus exercise group performed platform training everyday, and the velocity was increased from 25 to 30, 35, and 40 m/min every week. Saline group and saline plus exercise group were given the injection of normal saline. Additionally, the saline plus exercise group did exercise with the same intensity and time as extract plus exercise group. ②Thirty days after operation, a gross observation was carried out to detect the sciatic nerve after neurotomy. Anterior cornual neuron, Nissl bodies （including nucleus and nucleoli） neuron, and gliocyte amount were examined by optical microscope. The number of bilateral anterior cemeal motoneuron （neurons with clear nucleus） in Nissl stained sections was determined. RESULTS： ①The gross observation showed that after neurotomy, there was slight edema, hyperemia, necrosis and regenerated axon, which was longer in extract plus exercise group; in saline group, severe edema, hyperemia and necrosis were found, and the regenerated axon were shorter. ②In the optical microscopic observation, the motoneurons of saline alone group did not condensed or break, only gliocyte amount changed a little; in extract alone group, there was some condensed and broken neurons, and a great amount of gliocyte, which were similar to that in extract plus exercise group. ③The number of motoneurons in extract alone group at 30 day after operation was significantly higher than that in saline alone group （t =2.85, P 〈 0.005）. The number in extract plus exercise and saline plus exercise groups was remarkably higher than that the two non-exercise groups （t =2.38, 2.48, P 〈 0.005）. ④Thirty days after neurotomy, the motoneuron survival rate of rats in extract plus exercise group was 77.96%, in extract alone group was 59.75%; in saline plus exercise group was 33.45%, and in saline alone group was 28.62%. CONCLUSION： Rat limb bud extract significantly improves the recovery of injured sciatic nerve, especially integrating with exercise.