神经病理性痛大鼠背根神经节P2X3受体表达及电生理学特性的改变

目的 观察坐骨神经缩窄性损伤(CCI)致神经病理性痛后大鼠背根节神经元P2X3受体的表达和电生理学特性的变化.方法 应用免疫组化技术观察CCI后不同时间相应节段(L4、L5、L6)脊髓及背根神经节P2X3受体表达的变化;全细胞膜片钳技术观察CCI后不同时间L4、L5、L6节段背根节神经元ATP反应电流的变化.结果 CCI后7、14 d,损伤同侧L4、L5、L6节段背根节P2X3免疫阳性神经元数量明显增加,而且染色加深,相应节段的脊髓背角浅层P2X3免疫反应性亦明显增加.CCI后7、14 d,损伤同侧相应节段背根节产生ATP快反应电流的细胞数量明显增加,电流幅度亦增强.应用非选择性P2X受体拮抗剂Suramin能明显抑制ATP反应电流.结论 坐骨神经缩窄性损伤致神经痛后同侧对应节段的背根节神经元P2X3受体表达明显增加,ATP快反应电流明显增强.

Dorsal root ganglion P2X3 receptor expression and electrophysiological characteristics in rats with neuropathic pain

Objective To investigate the P2X3 receptor expression and electrophysiological characteristics in dorsal root ganglion (DRG) in rat with neuropathic pain caused by chronic constriction injury of sciatic nerve (CCI) Methods P2X3 receptor expressions in L4,L5 and L6 DRG following CCI were observed by using a polyclonal antibody to label the P2X3 receptor ATP-activated currents in corresponding DRG neurons following CCI were observed by using electrophysiological technique Results A significant increase in P2X3 immunoreactivity was observed in the ipsilateral (injured) L4,L5 and L6 DRG and spinal cord on 7,14 d after CCI In small diameter neurons,a significant increase in the number of cells exhibiting a transient current to ATP was observed on 7,14 d after CCI Moreover,amplitude of these currents was increased Conclusion After CCI,the expression and function of P2X3 receptor in corresponding DRG are increased