1,8-桉叶素对背根神经节内P2X3受体介导神经病理痛的作用

摘要

目的:探讨1,8-桉叶素对大鼠背根神经节(DRG)神经元P2X3受体介导神经病理痛的作用.方法:建立大鼠坐骨神经慢性压迫性损伤模型(CCI).SD大鼠随机分为假手术(Sham)组,坐骨神经慢性压迫性损伤(模型组,CCI)组、低剂量1,8-桉叶素治疗组、高剂量1,8-桉叶素治疗组、二甲亚砜对照组.检测大鼠术后7、14d机械缩足反射(MWT)及热缩足反射潜伏期(TWL),观察大鼠行为学变化.免疫组织化学和原位杂交观察神经病理痛大鼠第4~5腰(L4-5)DRG神经元P2X3受体表达变化.结果:术后第7和14天,模型组大鼠MWT和TWL明显低于假手术组,低、高剂量治疗组较模型组明显升高,二甲亚砜组与模型组比较无差别;L4-5DRG内P2X3受体表达模型组明显高于假手术组,低、高剂量治疗组较模型组均明显降低,二甲亚砜组与模型组比较无明显区别.结论:1,8-桉叶素抑制CCI大鼠L4-5DRG神经元P2X3受体过表达,从而缓解神经病理性疼痛症状.%Objective: To explore the effect of 1,8-cineole on P2X3 receptors in isolated dorsal root ganglion (DRG) regulating neuropathic pain in rats.Methods: The sciatic nerve chronic constrictive injury model(CCI) of rats was established.Sprague-Dawley rats were randomly divided into sham group,chronic constriction injury (CCI) group,1,8-cineole(50mg/kg/d) treated group,1,8-cineole(100mg/kg/d) treated group and CCI+DMSO group.The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) at the 7th and 14th day after the operation were measured.P2X3 receptor expression changes in L4-5 DRG of the rats were observed by immunohistochemistry and in situ hybridization techniques.Results: 7 and 14 days after the operation,the MWT and TWL of rats in CCI group were significantly higher than that in sham group but lower significantly than that in low and high dose treatmant group.and has no difference with DMSO group.Expression of P2X3 receptor in L4-5 DRG in CCI group was significantly higher than that in sham group.Low and high dose treatment goups showed an apparent decrease compared with the CCI group,and the high dose treatment group was lower than that in low-dose treatment group.DMSO group had no difference with CCI group.Conclusion: 1,8-cineole can alleviate neuropathic pain through inhibiting the overexpression of P2X3 receptor in L4-5 DRG of CCI rats.