川芎嗪对大鼠坐骨神经慢性压迫性损伤L4/L5段背根神经节P2X3受体表达的影响

目的 探讨川芎嗪抑制P2X₃受体介导慢性神经病理痛的作用途径。方法 制备大鼠坐骨神经慢性压迫性损伤(CCI)神经病理痛模型，于d 2起ip川芎嗪100 mg·kg^-1，每天1次，共14 d。免疫组织化学法观察CCI大鼠L₄/L₅段背根神经节P2X₃受体的表达，全细胞膜片钳技术测定新鲜分离的L₄/L₅段背根神经节三磷酸腺苷（ATP）和α,β-亚甲基三磷酸腺苷（α,β-meATP）激活的电流。结果 与正常对照组比较，正常大鼠ip川芎嗪14 d，L₄/L₅段背根神经节P2X₃受体表达、ATP激活电流和α,β-meATP激活电流无明显变化，假手术组亦无明显变化。与假手术组比较，CCI模型组大鼠L₄/L₅段背根神经节P2X₃受体的表达、ATP和α,β-meATP激活电流明显增强。CCI大鼠ip川芎嗪14 d，L₄/L₅段背根神经节P2X₃受体表达、ATP和α,β-meATP激活电流较CCI模型组明显降低。结论 川芎嗪可抑制CCI大鼠L₄/L₅段背根神经节P2X₃受体的表达，从而对P2X₃受体介导的神经病理痛产生抑制作用。

Effect of ligustrazine on expression of P2X3 receptors in L4/L5 dorsal root ganglion of rats with chronic constriction injury

AIM To investigate the pathway of ligustrazine to alleviate neuropathic pain induced by P2X₃ receptor. METHODS Chronic constriction injury (CCI) rat model with neuropathic pain was prepared. From d 2, ligustrazine 100 mg·kg^-1 was given ip once daily for 14 d. The P2X₃ receptor expression in L₄/L₅ dorsal root ganglion (DRG) neurons was detected with immunohistochemistry assay. Whole-cell patch-clamp technique was used to measure adenosine triphospate(ATP) and α,β-methylene-ATP(α,β-meATP) activated currents in freshly isolated DRG neurons of CCI rats. RESULTS Compared with normal control, the expression of P2X₃ receptors and ATP-activated currents (I_ATP) and α,β-meATP-activated currents(I_α,β-meATP) in L₄/L₅ DRG neurons did not change after ligustrazine was given to normal rats for 14 d. There was also no significant difference between sham and normal control groups. The expression of P2X₃ receptor, I_ATP and I_α,β-meATP in L₄/L₅ DRG neurons of CCI model rats significantly increased compared with sham group. After ligustrazine was given ip to CCI model rats for 14 d, the expression of P2X₃ receptor, I_ATP and I_α,β-meATP in L₄/L₅ DRG neurons decreased significantly. CONCLUSION Ligustrazine can alleviate neuropathic pain induced by P2X₃ receptor, which may be related to its inhibitory effect on the expression of P2X₃ receptor in L₄/L₅ DRG of CCI rats.