大鼠坐骨神经切断后VEGF及其受体flk-1在脊髓与脊神经节中的表达

Expression of VEGF and flk-1 receptor in spinal cord and dorsal root ganglia after neurotomy of rat sciatic nerve

目的观察大鼠坐骨神经切断后脊髓与神经节组织中血管内皮生长因子(VEGF)及其胎肝激酶-1(flk-1)受体的表达变化规律. 方法取成年雄性Wistar大鼠45只,对照组5只,实验组切断双侧坐骨神经后,在术后8 h、24 h、72 h、5 d、7 d、10 d、14 d、21 d取L4～L6段脊髓与相应脊神经节组织,采用免疫组织化学方法和图像分析技术,对VEGF及其flk-1受体的表达进行检测与分析. 结果大鼠正常脊髓与神经节组织中均存在VEGF及flk-1的表达,坐骨神经切断后其表达可反应性地增强,持续一段时间后迅速回落至正常水平.并且flk-1在胶质细胞及白质中的神经纤维也有所表达. 结论本实验从中枢神经元的角度揭示VEGF促周围神经再生机制,为今后进一步应用VEGF治疗外周神经损伤奠定基础.

Objective To investigate the expression and the pattern of vascular endothelial growth factor (VEGF) and flk-1 receptor in spinal cord and dorsal root ganglia after neurotomy of rat sciatic nerve. Methods Forty-five male adult Wistar rats were divided randomly into control group (n=5) and experimental group (n=40).The rats of experimental group were received a neurotomy to bilateral sciatic nerve and L_4~L_6 spinal cord and dorsal root ganglia were harvested respectively at 8h,24h,72h,5d,7d,10d,14d,21d postoperatively.Immunohistochemical method and image analysis were used to study the expression of VEGF and flk-1 receptor. Results Both VEGF and flk-1 receptor were expressed in normal rat spinal cord and dorsal root ganglia.In response to the neurotomy,the expression of them reached a higher level,persisted for a short period of time and declined to normal level rapidly.Besides,immunoreactivities of flk-1 were also can be seen in glial cells and nerve fibers that located in the white matter of spinal cord. Conclusion The results reveal the favorable effects of VEGF on nerve regeneration from the angles of central neurons,which establishes the experimental and theoretical foundation in the further treating peripheral nerve injuries with VEGF.