大黄素对P2X_(2/3)受体介导的三叉神经痛的作用研究

目的探究大黄素(emodin)对P2X2/3受体介导的三叉神经痛的作用影响。方法慢性压迫性损伤大鼠眶下神经(CCI-ION)建立大鼠三叉神经痛动物模型,应用von Frey细丝法测试机械痛敏阈值,观察大黄素对三叉神经痛(TN)大鼠机械痛敏阈值的影响。结合原位杂交、PT-PCR、免疫组织化学、免疫荧光、蛋白印迹等方法观察大鼠三叉神经节(TG)中P2X2/3受体的表达变化。结果术后14 d,Ⅲ组(TN模型组)和Ⅰ组(生理盐水对照组)、Ⅱ组(假手术组)、Ⅳ组(TN模型+大黄素干预组)相比较,大鼠手术侧眶下神经面部感觉区域机械痛敏阈值明显降低(P<0.01),大鼠TG中P2X2/3受体表达明显升高(P<0.01);Ⅰ、Ⅱ、Ⅳ组之间相比,大鼠手术侧眶下神经面部感觉区域机械痛敏阈值差异没有显著性(P>0.05);Ⅳ组TG中P2X2/3受体的表达较Ⅲ组低(P<0.01)。结论 P2X2/3受体涉及到三叉神经痛,大黄素对P2X2/3受体介导的三叉神经痛有一定抑制作用。

The role of emodin in trigeminal neuralgia mediated by P2X2/3 receptor

Aim To explore the role of emodin in trigeminal neuralgia mediated by P2X2/3 receptor.Methods The trigeminal neuralgia rat model(a chronic constriction injury of the infraorbital branch of the trigeminal nerve,ION-CCI) was established.The mechanical hyperalgesia threshold of trigeminal neuralgia(TN) rats was tested by the von Frey filaments.The change of the expression of P2X2/3 receptors in rat trigeminal ganglion(TG) was detected with in situ hybridization,RT-PCR,immunohistochemical staining,immunofluorescence,and Western Blot.Results 14 days after operation,compared withⅠ group(saline control group),Ⅱ group(sham operation group) or Ⅳ group(TN model+emodin intervention group),Ⅲ group(TN model group) had a significant decrease of mechanical hyperalgesia threshold in the territory of ligated infraorbital nerve(P<0.01),and an obvious increase in expression of P2X2/3 receptor in rat TG(P<0.01);there was no significant differences of mechanical hyperalgesia threshold amongⅠ,Ⅱ and Ⅳ group(P>0.05);the expression of P2X2/3 receptor of TG in Ⅳ group was lower than that in Ⅲ group(P<0.01).Conclusion P2X2/3 receptor may play a key role in the pain transmitting of trigeminal neuralgia,and emodin has inhibitory effect on trigeminal neuralgia.