Background: This study aimed to elucidate mechanism of analgesic effect of warming acupuncture on Knee Osteoarthritis (KOA).
Methods: A total of 40 SD rats were randomly divided into control group, KOA group, Pharmacotherapy (PT) group and Warming Acupuncture (WA) group. Rats in PT and WA groups received intra-articular injection of papain into bilateral knees. In PT group, rats were intragastrically treated with meloxicam; in WA group, rats received warming acupuncture. Then, Tetrodotoxin Resistance (TTX-R) sodium channel current of Dorsal Root Ganglion (DRG) and serum PGE2 were measured.
Results: TTX-R sodium channel current was significantly different among groups (P<0.01). When compared with control group, TTX-R sodium channel current increased significantly in KOA group (P<0.01). When compared with KOA group, TTX-R sodium channel current reduced markedly in PT group and WA group (P<0.01). It was suggested that WA and PT were able to reduce TTX-R sodium channel current to exert certain analgesic effects. In addition, WA and PT also reduced peripheral serum PGE2 to a certain extent in rats with KOA.
Conclusions: Warming acupuncture may reduce TTX-R sodium channel current of DRG and decrease inflammatory PGE2 to improve inflammatory hyperalgesia, exerting analgesic effect.