Effects of Electroacupuncture on Expression of COX-2 in the Dorsal Horn of Spinal Cord of Arthritic Rats

Objective： The present study was to observe the expression of COX-2 protein in the dorsal horn of the spinal cord in rats with chronic inflammatory pain to investigate whether COX-2 is involved in the mechanism of electroacupuncture （EA） analgesia. Methods： After EA treatment, the pain score and expression of COX-2 protein in the dorsal horn of spinal cord in rats with complete Freund＇s adjuvant （CFA）-induced arthritis were measured by the behavioral test and immunohistochemistry technique, and compared with those of the normal group, model group and medicine group. Results： EA could decrease the pain score significantly and repeated EA treatments had the remarkable cumulative analgesic effect; and with the increase in EA treatments, the number of COX-2 immunoreactive cells was obviously decreased. Conclusion： EA at acupoints Yanglingquan （GB 34） and Kunlun （BL 60） had remarkable analgesic effect on adjuvant arthritis rats; and in the meantime, could inhibit the expression of COX-2 protein in the dorsal horn of spinal cord.

目的:本工作试图通过观察慢性炎症痛大鼠脊髓背角环氧合酶(COX-2)蛋白表达的变化,探讨脊髓背角 COX-2是否与电针镇痛的作用机制有关。方法:在佐剂性关节炎大鼠的模型上,采用行为学和免疫组化技术两种方法,观察电针治疗后不同时相关节炎大鼠的痛敏评分及脊髓背角 COX-2蛋白的表达,并与正常组、模型组和药物组加以对照。结果:电针能明显减小关节炎大鼠痛敏评分的绝对值。多次电针具有显著的累积效应;并且随着电针治疗次数的增加,大鼠脊髓背角 COX-2免疫阳性细胞数显著下降。结论:电针阳陵泉和昆仑两穴对佐剂性关节炎大鼠有明显的镇痛作用,并同时抑制其脊髓背角 COX-2蛋白的表达。