电针治疗大鼠神经痛后脑内孤啡肽受体mRNA表达的变化

Effect of Electroacupuncture on Expression of ORL_1 Receptor mRNA in Some Brain Nuclei of the Neuropathic Pain Rats

目的 观察电针治疗大鼠神经痛前后脑内一些与痛觉相关的核团孤啡肽受体 m RNA表达的变化。方法 实验分为3组 ,对照组为正常大鼠 ,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日给予神经痛大鼠电针治疗 30 m in。各组动物处死后 ,取脑组织 ,冰冻切片 ,采用原位杂交的方法 ,观察电针后脑内与痛觉相关的中脑导水管周围灰质腹外侧 (vl PAG)、中缝背核 (DRN)、中缝大核 (NRM)核团孤啡肽受体 m RNA表达的变化。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 ;神经痛大鼠给予电针后脑内 vl PAG、DRN、NRM中孤啡肽受体 m RNA表达明显降低。结论 实验提示脑内孤啡肽受体可能参与电针镇痛过程。

Objective To investigate the effect of electroacupuncture (EA) on the expression of ORL 1 receptor mRNA in some brain nuclei of the neuropathic pain rats. Methods Rats were divided into three groups: control group, neuropathic pain group and EA group. Rats were given four loose ligation to sciatic nerve. On day 7 after operation, rats with hyperalgesia to radiant heat were selected as neuropathic pain rats and one group was administered with EA for 30 min. Expression of ORL 1 receptor mRNA in nucleus raphe magnus (NRM), ventrolateral periaqueductal gray (vlPAG) and dorsal raphe nucleus (DRN) of the neuropathic pain rats was investigated using in situ hybridization technique. Results The results showed that hyperalgesia appeared after sciatic nerve chronic constriction injury to rats and EA could depress the hyperalgesia. A significant decrease in ORL 1 receptor mRNA expression was observed in the nuclei of vlPAG, DRN, NRM after EA. Conclusion Our results suggested that ORL 1 receptor was involved in EA analgesia.