单双侧取穴电针对CCI模型大鼠镇痛效果及脊髓背角P2X3受体表达的影响

目的：观察单侧、双侧取穴电针对坐骨神经慢性挤压伤模型大鼠痛阈和脊髓背角中P2X3受体表达的影响。方法：通过测定造模后第15天及第5天大鼠足底热痛阈，比较各组间电针治疗后与电针治疗前痛阈的差值；采用免疫组织化学技术检测脊髓背角中P2X3受体的表达。结果：①与模型对照组比较，各电针治疗组大鼠痛阈差值均显著升高（P〈0．01）；双侧取穴电针组分别与健侧取穴电针组及患侧取穴电针组比较，痛阈差值均有显著升高（P〈0．01）；健侧取穴电针组与患侧取穴电针组之间痛阈差值没有显著差异（P〉0．05）。②与模型对照组比较，各电针治疗组大鼠脊髓背角中P2X3受体表达均有不同程度减少（P〈0．01）；各电针治疗组之间比较，大鼠脊髓背角中P2X3受体表达没有显著差异（P〉0．05）。结论：电针可能通过抑制大鼠脊髓背角中P2X3受体的表达，产生镇痛作用；电针治疗坐骨神经慢性挤压伤引起的疼痛时，双侧取穴较单侧取穴镇痛效果更明显。

Effect of Unilateral and Bilateral Acupoints Electroacupuncture on Pain Thresholds and Expression of P2X3 Receptor in Spinal Cord of Rats with CCI

Objective：To observe the changes of pain thresholds and P2X3 receptor expression in spinal cord of chronic constriction injury of the sciatic nerve model rats by unilateral and bilateral acupoints electroacupuncture treatment. Methods ：The difference value of.pain threshold was compared before and after the electroacupuncture by determining the 15th and fifth day pain threshold of rats after the model was successfully made. And the expressing of P2X3 receptor in spinal dorsal horn was detected by using immnnohistochemistry. Results ： （1）In electroacupuncture groups, difference values of the pain threshold of rats were significantly increased compared with those of the model control group （ P 〈 0.01 ）. In bilateral acupoints electroacupuncture group,rats＇ difference values of pain threshold all had significant differences compared separately with that of contralateral and ipsilateral acupoints electroacupuncture groups （P 〈 0.01 ）. Rats＇ difference values of pain threshold between contralateral and ipsilateral acupoints electroacnpuncture groups had no significant difference （P 〉 0.05 ）. （2）In electroacupuncture groups, P2X3 receptor positive material expression in spinal dorsal horn of rats was decreased in different levels compared with that of model control group （P 〈 0.01 ）. Compared among electroacupuncture groups, P2X3 receptor expression in spinal dorsal horn of rats had no significant difference （P 〉0. 05 ）. Conclusion：Electroacupuncture therapy may produce analgesia by suppressing P2X3 receptor expression in the spinal dorsal horn of CCI rats. When using electroacupuncture to treat chronic constriction injury pain of the sciatic nerve, bilateral acupoints have a stronger analgesic effect than unilateral acupoints.