嘌呤类参与大鼠弱电针镇痛

Involvement of Purines in Analgesia Produced by Weak Electro-acupuncture

本文用电生理学逆向碰撞方法测定了兴奋穴位Aδ类传入神经纤维的模拟电针强度。用弱于此强度的脉冲（50Hz，1～1．5mA），电针大鼠“阳陵泉”和“悬钟”穴，可引起大鼠缩腿痛阈升高，但不引起甩尾痛阈升高。腹腔给予腺苷受体阻断剂茶碱和咖啡因可阻断电针效应，并呈一定的量效关系；腹腔注射腺苷释放抑制剂潘生丁可缩短电针的后效应，减弱电针效应。结果提示：弱强度电针可引起节段性的镇痛效应，其中可能有嘌呤类参与。

In the present investigation the intensity of stimulated electro-acupuncture (EA) was measured by electrophysiological collision technique. In the behavioral experiments, by applying the weak electro-acupuncture pulses (50 Hz, 1~1. 5mA), not enough to activated Aδ afferent fibers, to Yanglingquan and Xuanzhong points, the latency of nociceptive hind limb withdrawal reflex, but not tail -flick latency was prolonged. Administered intraperitoneally, both theophylline and caffeine, P1purinergic (adenosine) receptor antagonists, could block the electroacupuncture-induced elevation of the nociceptive thresholds in a dose-effect related manner, whereas dipyridamole, an inhibitor of adenosine release, could shorten the after effect of electro-acupuncture in a dose dependent way.These results suggest that weak electro-acupuncture may induce analgesia and purines appear to be involved in this process