细胞外ATP对周围神经导管中再生轴突诱导作用的实验研究

Guidance of regenerating axon by extracellular ATP at peripheral nerve conduit : an experimental study

目的 证实细胞外ATP对坐骨神经损伤后再生轴突的吸引性诱导作用。方法 将SD雌性大鼠制成 5mm长坐骨神经缺损的模型 ,用长双臂“Y”形硅胶管桥接神经。硅胶管单臂端与坐骨神经近端作套入缝合 ,与左侧坐骨神经缝接的硅胶管两端缝合封闭 ,硅胶管两臂内注入ATP的为实验组 ,注入生理盐水的为对照组。与右侧坐骨神经缝接的硅胶管两远端管中注入ATP的硅胶管与远端坐骨神经缝接。术后 4周、8周取材 ,肉眼观察神经纤维生长情况 ;并作光镜、电镜观察及病理图像分析 ,观察再生神经纤维的数目和形成髓鞘的厚度。结果 再生的神经轴突均长入含ATP的硅胶管内 ,生理盐水对照组内未见任何神经纤维长入。远端与坐骨神经缝合能增强ATP的轴突诱导作用 ,并具有促进再生神经轴突成熟的作用。结论 细胞外ATP具有很强的再生神经轴突诱导作用 。

Objective To confirm the effect of extracellular ATP on the attractive guidance of the regenerating axon after injuries of the sciatic nerve in rats. Methods The model of the sciatic nerve defect (5 mm in length) was set up in SD female rats. A 'Y shaped' silicone tube was used to bridge the defect. The single arm of the silicone tube was sutured to the proximal side of the sciatic nerve. At the left side, the distal two arms of the silicone tube were ligated, with injection of ATP into the left chamber (served as experimental group) and of physiological saline into another tube(control group).The model of the right side was similar to the left side except that the distal tube with injection of ATP was sutured with the distal side the sciatic nerve. After 4 and 8 weeks general observation of the regenerating nerve was made. Light and electron microscopy examination were checked, and image analysis was done accordingly. The number of the regenerating nerve fiber and the myelin thickness was examined. Results The regenerating axons were found only at the silicone tube containing the ATP. The sciatic nerve sutured with the distal arm of the Y tube can enhance the guidance of ATP and maturation of the regenerating axon.Conclusions Extracellular ATP has a powerful attraction to the regenerating axon of peripheral nerve. It can also promote maturation of the regenerating axon.