脱细胞异体神经基质移植物对脊髓前角运动神经元的保护作用

目的探讨脱细胞神经基质移植物异体移植对脊髓前角运动神经元的保护作用。方法W ist-ar大鼠30只,10只用化学提取法制备坐骨神经脱细胞基质移植物;另20只分为实验组(坐骨神经缺损移植物桥接组)和对照组(坐骨神经缺损组),每组10只。动物饲养3到4个月后取移植物、脊髓腰6-骶1节段和术侧腓肠肌,做HE、尼氏和AchE结合镀银染色以及电镜标本,进行组织学和超微结构观察,并对脊髓前角细胞的数量做统计学分析。结果实验组动物移植术后3到4个月术侧下肢行走时,后蹬动作有力,足趾能分开,步态趋于正常;针刺足底有逃避动作。对照组动物术侧下肢的运动和感觉功能未见恢复。实验组动物的移植物内见有大量再生的神经纤维,髓鞘结构清晰,腓肠肌内见有再生的神经纤维束和运动终板。实验组移植侧和对照组缺损侧脊髓腰6到骶1节段前角外侧群细胞的数量比正常侧减少,尤以对照组为甚。实验组移植侧前角细胞比正常侧的前角细胞数减少而移植侧前角细胞数比对照组缺损侧明显减少(P<0.01)。结论脱细胞异体神经基质移植物桥接周围神经缺损对运动神经元胞体的存活具有良好的保护作用。

The Protective Effects of the Acellular Nerve Matrix Allografts on the Motor Neurons of the Anterior Horn of Spinal Cord

Objective To explore the protective effects of the acellular nerve matrix allografts on the motor neurons of the spinal cord. Methods Ten rats were prepared for the acellular matrix grafts of sciatic nerves by chemical extraction, the other rats were divided into the experimental group (sciatic nerve injury bridged by grafts, 10 rats) and the control group (sciatic nerve injury, 10 rats). After three to four months survival, the grafts, L_6~S_1 spinal cord seqments and the gastrocnemius of the operative side of the rats were taken out. All the samples were stained by HE, Nissl and AchE combining silver staining, and were processed for electronic microscopy. The number of the neurons in anterior horn was analyzed statistically. Results Three to four months after transplantation, the operated leg of the experimental group stepped backward powerfully, the toe could separate and walk to normal gradually, the bottom of the operated paw escaped when it was punctured by a needle. The operated leg of the control group didn′t recover in the functions of motor and sense. A large quantity of regenerated nerve fibers with myelin sheath was observed in the graft of the experimental group. The regenerated nerve fiber bunches and motor endplates in the operative gastrocnemius of the experimental group were observed. The number of the anterior lateral group cells of the L_6~S_1 spinal cord in the transplated side of the experimental group and the defect side of the control group was less than that of the normal side, especially the control group. The number of the neurons in the anterior horn of the transplated side of the experimental group was less than that of the normal side and was much more than that of the defect side of the control group (P<0.01). Conclusions The acellular nerve matrix allografts had well protective effects on the motor neurons by bridging the defect of the peripheral nerve.