Effects of Electroacupuncture on the Rats with Neuropathic Pain and EAAs in Spinal Cord / 针灸推拿医学（英文版）

ABSTRACT

Objective: To observe the impact of electroacupuncture on the pain threshold and the content of excitatory amino acids in the spinal cord of the rats with neuropathic pain to discuss the mechanism of electroacupuncture in treating neuropathic pain. Methods: The rats were randomly divided into a control group (n=10), a sham surgery group (n=10) and a surgery group (n=30) to take spared nerve injury (SNI) surgery of sciatic nerve. The successful SNI model rats in the surgery group were randomly divided into a model group (n=10), an electroacupuncture group (n=10) and a sham electroacupuncture group (n=10). The mechanical pain threshold (MPT) and heat pain threshold (HPT) were measured on the preoperative day, postoperative day 7, postoperative day 9 and the day after the sixth acupuncture treatment. The electroacupuncture was carried out at Huantiao (GB 30) and Weizhong (BL 40) starting from the postoperative day 10 to reflect the impact on the mechanical pain threshold and heat pain threshold. The pre-column deriverization and HPLC fluorescence detection as well as microdialysis method were adopted to test the content of EAAs in spinal cord of rats. Results: The SNI surgery decreased the mechanical pain threshold of rats significantly. The glutamate (Glu) and aspartic acid (Asp) in the microdialysis solution of rats in the model group were higher than in the control group and sham surgery group at the same time point (P<0.05). The contents of Glu and Asp in the microdialysis solution of rats in the electroacupuncture group and sham electroacupuncture group decreased significantly (P<0.05), comparing with model group at the same time point (except the Glu of the sham electroacupuncture group at the second time point). The electroacupuncture reduced the mechanical allodynia markedly. Conclusion: The mechanism of electroacupuncture treating neuropathic pain may relate with the decrease of excitatory amino acids in spinal cord.