Background: Electroacupuncture (EA) has been observed to exerts in inflammatory pain. However, the invasiveness of EA may bring risk of infection. Transcutaneous electrical acupoint stimulation (TEAS)with similar parameters as EA without the risk of infection. Previous studies have shown that TEAS treatment can alleviate postoperative pain. However, its analgesic role in inflammatory pain has not been investigated. Methods: Complete Freund’s adjuvant (CFA)was injected into the male Sprague‐Dawley of rats to generate an inflammatory model. EA or TEAS treatment at the Zusanli (ST36) and Sanyinjiao (SP6) acupoints was given 4 days of CFA injection of mechanical and thermal sensitivity were determined. Microdialysis was performed before and after EA or TEAS. Adenosine concentration of dialysates as measured by high performance liquid chromatography. Results: TEAS treatment showed similar analgesic effects to EA treatment as assessed of rat’s paw withdrawal latency in response to mechanical and thermal stimulation. EA treatment significantly elevated adenosine concentration for at least 30 minutes, while TEAS induced a significant adenosine increase with similar amplitude over 60 minutes. Conclusion: TEAS may be a more convenient and more effective substitute for EA in inflammatory pain treatment.

Objective:To explore electrical acupuncture (EA) therapy effects on complete freund's adjuvant (CFA) induced inflammatory pain model rats. Methods:A total of 30 SD male rats were randomly divided into normal saline + Sham Electroacupuncture (NS+SE) group, CFA+Sham EA (CFA+SE) group and CFA+ Electroacupuncture (CFA+EA) group, with 10 rats in each group.Mechanical and thermal allodynia were assessed before and after EA treatment at Day 4 after CFA injection. Dialysate of the rats was collected from the right tibialis anterior muscle by microdialysis at Day 5 from 1.5 hours before the treatment until 1.5 hours after treatment. Adenosine concentration in the dialysate was analyzed by HPLC. Results:At Day 4 after injection of paclitaxel, EA treatment can obviously increase the pain threshold of CFA-induced inflammatory pain rat model. The mechanical allodynia showed that the Von Frey result of the CFA+EA group was significantly decreased (P＜0.05) after treatment, and the PWL results also significantly prolonged (P＜0.05) compared with the NS+SE group and the CFA+SE group. Conclusion:EA can increase rats pain threshold of CFA-induced inflammatory pain, and alleviate inflammatory pain. The alleviate of inflammatory pain might through adenosine increasment in the local tissue fluid around the acupoints.