[Influence of capsaicin treating sciatic nerve on the pain threshold and the effect of acupuncture analgesia of rats].

The model of local application of 1.5% Capsaicin (Cap) on the right sciatic nerve and control of Vehicle (Veh) on the left were used. The influence of Cap on pain threshold, electroacupuncture (EA) analgesia and Fluoride-resistant acid phosphatase (FRAP) activity in the dorsal horn of spinal cord were observed. The results showed, the pain threshold of Cap treatment side rose significantly compared with the control side, FRAP in dorsal horn of spinal cord vanished, and the analgesic effect of EA at "Huantiao" of the Cap treatment side markedly decreased, compared with not only that EA at the control side but also that EA before Cap treatment. It is indicated that the C fibers of the primary afferent participate in the input of pain and EA analgesic information.