电针对神经痛大鼠治疗作用的研究

Effect of electroacupuncture on neuropathic pain rats

目的观察神经痛大鼠电针治疗前后脊髓背角与痛觉相关的孤啡肽受体mRNA表达的变化，探讨电针对神经痛的治疗作用。方法30只SD大鼠随机分为3组，每组10只，对照组为正常大鼠，自由生长；神经痛组为大鼠坐骨神经慢性限制性损伤致神经痛模型；电针组为术后第7天给予神经痛大鼠电针治疗30min。各组动物处死后，取脊髓背角组织，冰冻切片，采用原位杂交的方法，观察各组脊髓背角Ⅰ～Ⅵ层内与痛觉相关孤啡肽受体mRNA的变化。结果大鼠坐骨神经结扎后出现痛敏，电针能明显抑制大鼠痛敏，与神经痛组比较缩爪潜伏期（PWL）明显延长（P〈0．01）；对照组脊髓背角Ⅰ～Ⅵ层有少量孤啡肽mRNA阳性细胞，神经痛组大鼠术后第7天时脊髓背角孤啡肽mRNA阳性细胞数明显多于对照组，2组比较差异具有显著性（P〈0．001）；电针组脊髓背角Ⅰ～Ⅱ层、Ⅴ～Ⅵ层孤啡肽mRNA阳性细胞数与神经痛组比较，差异具有显著性（P〈0．05）。Ⅲ～Ⅳ层孤啡肽mRNA阳性细胞数与神经痛组比较无显著性差异（P〉0．05）。结论电针对神经痛的治疗作用可能与脊髓背角内孤啡肽受体有关。

Objective To observe the changes of orphanin receptor mRNA which was related with algesia in cornu dorsale medullae spinalis pre- and post- electroacupuncture and to investigate the therapeutical effect of electroacupuncture on neuralgia rats. Methods Thirty rats were divided into three groups, ten in each group. The control group was normal rats and growth freely. The rats in neuralgia group received the operation of chronic constriction injury on sciatic nerve. And electroacupuncture group were given electroacupuncture to treat for 30min at the seventh day after operation. Then sacrificed the rats in every group to get cornu dorsale medullae spinalis and to make frozen section. The changes of orphanin receptor mRNA which was related with algesia in cornu dorsale medullae spinalis were observed by hybridization in situ. Results Hyperalgesia appeared after ligating sciatic nerve of rats. Electroacupuncture could depress the hyperalgesia, and compared with neuralgia group, paw withdrawal latency of electroaeupuncture group was significantly longer（ P 〈 0.01 ）. There were little positive cells of orphanin receptor mRNA in Ⅰ - Ⅵ layer of cornu dorsale medullae spinalis. The positive cells of orphanin receptor mRNA in neuralgia group on the seventh day after operation were more than those in control group （ P 〈 0.001 ）. There was significant difference between neuralgia group and electroacupuncture group in tbe number of positive ceils of orphanin receptor mRNA in Ⅰ - Ⅱlayer and Ⅴ - Ⅵ layer （P 〈 0.05）, but there was no difference between two groups in the number of positive cells of orphanin receptor mRNA in Ⅲ-Ⅳ layer （ P 〉 0.05 ）. Conclusion Therapeutical effect of electroacupuncture on neuralgia may be related with orphanin receptor in cornu dorsale medullae spinalis.