大鼠坐骨神经损伤修复后近端轴突再生的初步研究

目的 采用生长相关蛋白-43(GAP-43)对SD大鼠坐骨神经近端新生轴突进行标记,观察坐骨神经损伤修复后近端轴突再生过程.方法 64只SPF级SD大鼠于右侧坐骨神经分叉以上5mm处切断坐骨神经,分别采用原位缝合以及生物可溶性甲壳质套管小间隙(2 mm)缝合方法进行修复,分别于术后1、3、7及14 d取材.观察神经缝合处组织大体形态;套管内坐骨神经生长状态;近端新生轴突形态,并应用图像分析方法对新生轴突数目进行定量分析.结果 套管小间隙缝合组大鼠神经缝合处粘连情况较轻.免疫荧光染色显示:术后14 d,新生纤维神经干形成圆锥形向前生长.形态规则均一.原位缝合组大鼠缝合处粘连较重,新生轴突于7 d左右长过缝合点,坐骨神经远端新生轴突散在分布,形态不规则.免疫荧光染色图像分析结果显示:大鼠坐骨神经损伤修复后,术后3 d原位缝合组新生轴突数目较套管缝合组多.差异有统计学意义(P<0.01);术后7 d套管小间隙缝合组大鼠坐骨神经开始大量再生;术后14 d左右,套管小间隙缝合组新生轴突数目显著高于原位缝合组(P<0.05).结论 甲壳质套管具有良好的生物相容性,套管内新生轴突前沿以圆锥形向前生长,新生轴突形态较原位缝合组好,套管小间隙修复7 d后新生轴突数目开始较原位缝合组多.本实验主要观察了两种术式修复后大鼠坐骨神经新生轴突的生长规律,也从组织学角度解释了生物套管小间隙套接方法的再生效果比原位缝合效果好的可能原因所在.

A preliminary experimental study of proximal regeneration process of sciatic nerve after injury

Objective GAP-43 protein is a marker of peripheral nerve regeneration,To report the regeneration of rat proximal sciatic nerve were observed labeled by GAP-43 in two types of surgical repair model. Methods Right side of sciatic nerves of 64 SPF-class healthy adult male SD rats were cut at 5cm above the branch,32 rats were subjected to small gap(2mm)bridging repair with chitin conduit;others were subjected to traditionary epineurium suture.The general conditions of local tissue,sciatic nerve growth state and regenerative patterns of peripheral nerve fiber were observed at 1 d,3 d,7 d and 14 d respectively.Results The small gap bridging group had less local adhesion,immunofluorescencc staining showed that new axons Was in conic-sharp and homogeneously tidy.Local adhesion of traditionary epineurium suture group was more serious,distal new regenerated axons were irregular compared to the small gap bridging group.Immunofluorescence image analysis results showed that: early after the repair of rat sciatic nerve injury.the number of new axons of traditionary epineurium suture group was more compared with small gap bridging group(P<0.01);around 14 days after operation,the number of small gap bridging group was significantly higher than the traditionary epineurium suture group(P<0.05). Conclusion The small gap bridging group has less focal adhesion, better shape of nerve fibers and more regenerating axons than the traditionary epineurium suture group.The regenerative law of peripheral nerve fibers may further give us an explanation why regeneration results of small gap bridging group is better than traditionary epineurium suture group.