川芎嗪对P2X_3受体介导的神经病理痛的作用研究

目的探讨川芎嗪(tetramethylpyrazine,TMP)对P2X3受体介导的神经病理痛的作用。方法建立大鼠坐骨神经慢性压迫性损伤(CCI)神经病理痛模型,应用vonFrey细丝法和热辐射法测定机械缩足反射阈值(mechanical withdrawal threshold,MWT)和热缩足反射潜伏期(thermal withdrawal latency,TWL),观察川芎嗪对CCI大鼠MWT和TWL的影响。结合免疫组织化学方法观察大鼠L4/L5段脊髓P2X3受体的表达变化。结果术后14d,Ⅴ组(CCI模型组)和Ⅰ组(生理盐水对照组)、Ⅱ组(TMP对照组)、Ⅲ组(假手术组)、Ⅳ组(CCI模型+TMP治疗组)相比较大鼠后爪的机械和热痛敏阈值明显降低(P<0.05),大鼠脊髓P2X3受体表达明显升高(P<0.05);Ⅰ、Ⅱ、Ⅲ、Ⅳ组之间相比大鼠后爪的机械和热痛敏阈值差异没有显著性(P>0.05),大鼠脊髓P2X3受体表达差异没有显著性(P>0.05);Ⅳ组脊髓P2X3受体的表达较Ⅴ组低(P<0.05)。结论川芎嗪对P2X3受体介导的神经病理痛有抑制作用。

Effect of TMP on neuropathic pain mediated by P2X_3 receptor

Aim To investigate effects of tetramethylpyrazine (TMP) on neuropathic pain induced by P2X_3 receptor. Methods Chronic constriction injury (CCI) model was adopted. Mechanical withdrawal threshold and thermal withdrawal latency were measured and P2X_3 immunoreactivity in L_4/L_5 spinal cord was detected by immunohistochemistry. Results At day 14 after operation, the mechanical withdrawal threshold and thermal withdrawal latency in group Ⅴ(CCI group) were lower than those in groupⅠ(NS group),Ⅱ(TMP group),Ⅲ(sham group) and Ⅳ (CCI+ TMP group)(P<0.05), while the expression of P2X_3 receptor in L_4/L_5 spinal cord of group Ⅴ was higher than that in groupⅠ, Ⅱ, Ⅳ and Ⅲ (P<0.01). The mechanical withdrawal threshold, thermal withdrawal latency and the expression of P2X_3 receptor in L_4/L_5 spinal cord showed no significant difference among groupⅠ ,Ⅱ ,Ⅲ and Ⅳ (P>0.05). The expression of P2X_3 receptor in L_4/L_5 spinal cord of group Ⅳ was lower than that of group Ⅴ (P<0.05). Conclusion TMP may alleviate neuropathic pain induced by P2X_3 receptor.