Influence of electroacupuncture on thermal changes in a soft tissue defect

This study investigated thermal changes in the skin at locations where soft tissue defects existed and acupuncture needles stimulated by using bipolar electroacupuncture (EA) had been inserted. Under general anesthesia (GA), experimental defects were made at the dorsum site of five New Zealand rabbits. Bipolar EA was used for 20 minutes to stimulate the experimental defects, and the skin temperature was monitored at the sites where the acupuncture needles had been inserted and the soft tissue defects existed. The initial thermography of those defects had the same trend as that of the negative pole of EA stimulation at the first acupoint. Skin thermography during the first 3 minutes of bipolar EA indicated a centrifugal vasoconstriction and a vasodilatation at the negative and positive poles, respectively. After that, the thermal change in soft tissue undergoing EA stimulation was not modified by a different EA polarity. The local temperature at the defect and its surroundings under both positive and negative electric loads was increased by 0.2-0.3 °C for vasodilatation. This study indicates that EA influences sympathetic modulation of soft tissue defects and that selective sympathetic modulation caused by bipolar EA is responsible for the clinical perception.