[Involvement of purines in analgesia produced by weak electro-acupuncture].
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 A delta 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, P1-purinergic (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 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.
Liu
C
C
Institute of Acupuncture and Moxibustion, China Academy of Traditional Chinese Medicine, Beijing.
Zhao
F
F
Zhu
L
L
D015667:Acupuncture Analgesia; D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D004176:Dipyridamole / Q000494:pharmacology; D015671:Electroacupuncture; D017288:Pain Threshold / Q000187:drug effects; D058915:Purinergic P1 Receptor Antagonists; D051381:Rats; D013116:Spinal Cord / Q000502:physiology*; D013806:Theophylline / Q000494:pharmacology*
D058915:Purinergic P1 Receptor Antagonists; D002110:Caffeine; D004176:Dipyridamole; D013806:Theophylline