神经再生素促进大鼠坐骨神经损伤后再生

Nerve regeneration factor promotes nerve regeneration after sciatic nerve injury in rats

目的：探讨神经再生素（NRF）对大鼠坐骨神经损伤后再生的影响。方法：SD大鼠30只，雌雄各半，随机分为3组：NRF低、高剂量组和空白对照组。分别于坐骨神经夹伤术后10、15、20d测定大鼠坐骨神经功能指数（SFI），分离出大鼠双侧坐骨神经行电生理学检测，计算神经干动作电位恢复率；各组随机选取2只大鼠，应用透射电镜观察再生坐骨神经超微结构；其余大鼠行光镜下观察脊髓腰膨大（k～k）、夹伤远端处坐骨神经、损伤侧腓肠肌组织，并测定脊髓前角运动神经元数、再生有髓神经纤维数、腓肠肌肌细胞截面积等指标。结果：术后10d各组SFI无显著差异，术后15d仅仅高剂量组SFI明显优于对照组（P〈0．01），术后20d高、低剂量组SFI均优于对照组（P〈0．01，P〈0．05）；术后20d高、低剂量组及对照组大鼠坐骨神经干动作电位的恢复率分别为（57±26）％、（44±15）％、（31±9）％，其中高剂量组与对照组相比有显著差异（P〈0．05）；高剂量NRF组的有髓神经纤维成熟度优于对照组，而变性纤维少于对照组；光镜下NRF高剂量组再生神经纤维排列致密整齐、结构均匀，腓肠肌肌细胞饱满、排列整齐，双侧脊髓前角运动神经元更接近；NRF高剂量组脊髓前角运动神经元计数、有髓神经纤维计数均显著高于对照组（P〈0．05，P〈0．01），NRF高、低剂量组腓肠肌肌细胞截面积显著高于对照组（P〈0．01，P〈0．05）。结论：NRF能促进坐骨神经再生及其功能恢复。

Objective： To investigate the promoting effect of nerve regeneration factor （NRF） on nerve regeneration after sciatic nerve injury in rats. Methods： Thirty Sprague-Dawely rats, including 15 females and 15 males, were equally randomized into 3 groups： low dose NRF group, high dose NRF group and control group. Rats＇ sciatic nerves were injured by crushing and sciatic function index （SFI） was determined by walking tract analysis at days 10, 15 and 20 after crushing. Then sciatic nerves on both sides were dissociated for electrophysiology study and the recovery rate of nerve conduction velocity （NCV） was calculated. Then, 2 rats were randomly selected from each group and the ultrastructure of regenerated sciatic nerves was observed by electron microscope. Meanwhile, the spinal cord segments （L4-L6）, the distal site of injured sciatic nerve and the injured gastrocnemius muscle in other rats were observed by light microscope. The count of motor neurons of anterior hom, the number of myelinated fibers, the transverse section area of gastrocnemius muscle cells and other parameters were determined. Results： At day 10 after crushing, SFI scores had no significant difference between 3 groups; at day 15 after crushing, SFI score of high dose NRF group was significantly higher than that of the control group （P〈0.01）; at day 20 after crushing, SFI scores of 2 NRF groups were significantly higher than those of the control group （P〈0. 01, P〈0. 05）. At day 20 after crushing, the recovery rates of NCV in the high dose group, the low dose group and the control group were （57±26） %, （44±15） % and （31±9）%, respectively, with significant difference between the high dose group and the control group （P〈0. 05）. Compared with the control group, the high dose group had more mature myelinated nerve fibers and less degenerated nerve fibers. In the high dose group, the layout of regenerated nerve fibers was dense and well-arranged, the gastrocnemius muscle cells was well alive and neatly arranged, and the bilateral motor neurons of anterior hom was more close to each other. The numbers of motor neurons of anterior hom and myelinated nerve fibers in high dose group were significantly higher than those in control group （P〈0.05, P〈0. 01 ） ; the transverse section areas of gastrocnemius muscle cells in both NRF groups were significantly higher than those in the control group （P〈0.01 ,P〈0.05）. Conclusion： NRF can promote the regeneration of peripheral nerves and improve the recovery of their function.