Pain-relieving effects of acupuncture and electroacupuncture in an animal model of arthritic pain.

The effects of acupuncture and electroacupuncture on an animal model of arthritic pain were examined. Under halothane anesthesia, arthritic pain was induced by the injection of carrageenan into the knee joint cavity of male Sprague-Dawley rats. Behavioral performance was tested before and after the termination of acupuncture or electroacupuncture. Electrophysiologically, the responses of afferents to a movement cycle were recorded before and after acupuncture or electroacupuncture. After the acupuncture procedure, the weight-bearing force of the rats was significantly improved and the neural responses to noxious movement stimulation were reduced. Electroacupuncture significantly improved weight-bearing behavior and inhibited neural responses of articular afferents to noxious stimulation. These results indicate that acupuncture and electroacupuncture may provide a potent strategy in relieving arthritic pain.