Schwann细胞对大鼠坐骨神经缺损后脊髓前角运动神经元保护作用观察

摘要

目的 观察Schwann 细胞(SC)脊髓内移植对大鼠坐骨神经缺损后脊髓前角运动神经元的保护作用并探讨机制.方法 取2 d龄SD 大鼠坐骨神经培养、纯化、传代SC,并行纯度鉴定.另取48只SD大鼠制作坐骨神经缺损模型,随机均分为实验组和对照组.实验组大鼠于脊髓腹角注射SC;对照组给予等量生理盐水.两组分别于术后1、4、8周各取8只大鼠,取L4～6段脊髓,观察运动神经元数目并计算存活百分率,电子显微镜下观察神经元的超微结构.结果 SC经培养纯化后纯度为95.6%±2.5%.实验组伤侧神经元数目较对照组明显增加,运动神经元存活率为87.2%±4.6%,高于对照组的58.4%±5.4%(P＜0.01).实验组神经元细胞器及大部分神经纤维的髓鞘结构较对照组清晰完整.结论 SC对大鼠坐骨神经缺损后的脊髓前角运动神经元具有保护作用,其机制可能是促进脊髓运动神经元的存活和再生.%Objective To observe the protective effect of Schawann cells(SC) spinal transplant on the regeneration of motoneurons in ventral horn after sciatic nerve defect and discuss its action mechanism.Methods The primary SC were cultured, purified and passaged from sciatic nerves of 2 d young SD rat, and their purity were calculated.48 adult rats of sciatic nerve defect model were randomly divided into experimental group and control group.After 1,4, 8 week, the 8 rats were removed L4-6 spinal cord and surveyed the numbers of regeneration motoneurons and survival percentage respectively.Neuron ultrastructure was observed by electron microscopy.Results The SC of degree of purity was 95.6％ ± 2.5％ after cultured and purified.The numbers of regenerating motoneurons in experimental group was higher than that in control group.The motoneurons survival percentage was 87.2％ ±4.6％ in experimental group, which was higher than 58.4％ ±5.4％ in control group( P ＜0.01).The organelle and myelin sheath of nerve fibers of the spinal cord neurons by electron microscopy in experimental group were more clear and onder than control group.Conclusions SC transplantion can protect motoneurons in ventral horn of the spinal cord after sciatic nerve defect.The mechanism maybe promoting the survival and regeneration ability of motoneurons.