Abstract: Objective To investigate the effect of electroacupuncture with low frequency on pain sensitization of neuropathic pain rats,and the possible mechanism of regulating peripheral pain sensitization. Methods Rat neuropathic pain model was established with the right L5 spinal nerve ligation. Zusanli (ST36) and Kunlun (BL60) were selected for electroacupuncture intervention. Mechanical allodynia, and the levels of stransient receptor potential vanilloid type 1 (TRPV1) and substance P (SP) in ipsilateral L5 and L4 dorsal root ganglion (DRG) were tested. A further validation experiment with TRPV1 agonist 6'-IRTX was carried out. Results Rats suffered from L5 spinal nerve ligation showed obvious pain sensitization. The levels of TRPV1 in ipsilateral L4 DRG and SP in ipsilateral L5 DRG were significantly elevated.Electroacupuncture with low frequency significantly relieved pain sensitization, and suppressed TRPV1 and SP increase. 6'-IRTX intraperitoneally administered significantly counteracted the anti-pain sensitization action of electroacupuncture with low frequency. Conclusion Electroacupuncture with low frequency is effective on neuropathic pain by intervening pain sensitization, which may be related to the regulation
of DRG TRPV1 and SP.

Key words: neuropathic pain, electroacupuncture, dorsal root ganglion, transient receptor potential vanilloid type l, substance P