大鼠坐骨神经受压和解压后背根节和脊髓内神经元nNOS表达的变化

目的 :观察坐骨神经受压及解压后大鼠腰段背根节和脊髓内神经元型一氧化氮合酶 (nNOS)表达的变化 ,借以探讨外周神经源性痛的发病和影响机制。方法 :大鼠随机分为压迫组、解压组和对照组 ,采用聚乙烯管压迫坐骨神经的动物模型 ,用免疫细胞化学方法并结合计算机图像分析进行研究。结果 :与对照组比较 ,压迫组和解压组腰4～ 6背根节中nNOS的表达显著增加 ,相应节段脊髓背角的表达则明显降低 ;解压组与压迫组比较 ,背根节中nNOS的表达明显减少 ,而脊髓背角的已经下调的nNOS表达则回升 ,但仍然低于对照组水平。结论 :NO可能与神经源性痛时在中枢和外周的痛觉敏感性形成和神经系统长时程改变有关。

Neuronal nitric oxide synthase expression in lumbar dorsal root ganglia and spinal cord following sciatic nerve compression and decompression in rats

Objective: To investigate the changes of neuronal nitric oxide synthase (nNOS) expression in lumbar dorsal root ganglia (DRG) and spinal cord following sciatic nerve compression and decompression in rats,and to explore the neurochemical events underlying mechanisms of neuropathic pain.Methods:Adult male rats were randomly divided into 3 groups:sciatic nerve compression group,decompression group and control group.Polyethyene cuffs were applied to the rat sciatic nerve to induce a rat model of neuropathic pain.Immunocytochemistry combined with the image quantitative analysis were performed.Results:In both the compression group and the decompression group,the expression of nNOS-positive neurons in DRG was significantly increased and that in spinal dorsal horn was significantly decreased compared with those in the control group.In the decompression group,the expression of nNOS-positive neurons in DRG was significantly decreased and that in spinal dorsal horn was significantly increased compared with that in the compression group.Conclusion:NO may contribute to the development of peripheral,central sensitization and long-term changes in nerve system during the process of neuropathic pain.