不同间隔时间电针对佐剂性关节炎大鼠炎症局部前阿黑皮素和前脑啡肽原mRNA表达的影响

Effect of repeated electroacupuncture at different intervals on opioid peptides gene expression in tissue of rats with adjuvant arthritis

目的:观察不同间隔时间电针对佐剂性关节炎(AA)大鼠的镇痛效应,以探讨针刺镇痛的最佳间隔时间和作用机制。方法:将96只大鼠随机分为对照组、模型组和电针组,每组再分为3 h、6 h、12 h和24 h小组,以Freund’s完全佐剂造成AA大鼠模型,电针选取悬钟和昆仑穴,分别以3 h、6 h、12 h和24 h作为治疗间隔时间,连续治疗6 d,以痛阈、炎症局部前阿黑皮素(POMC)mRNA和前脑啡肽原(PENK)mRNA表达作为观察指标。结果:间隔24 h电针能显著提高AA大鼠的痛阈;不同间隔时间电针均能促进炎症局部POMC mRNA和PENK mRNA的表达。结论:间隔24 h电针可明显提高对AA大鼠的镇痛效应;不同间隔时间电针镇痛效应与促进炎症局部阿片肽基因表达有关。

Aim： To observe electroacupuncture（EA） analgesic effect on rats with adjuvant arthritis（AA） at different interval in a day so as to find the best time interval of EA for analgesia and seek for its mechanism. Methods： A total of 96 SD rats were divided randomly into control, model and EA groups which were further grouped under 3 h, 6 h, 12 h and 24 h subgroups. AA model was established by subcutaneous injection of Freund＇s Complete Adjuvant. EA was applied to the right Xuanzhong（GB39） and Kunlun（BL60） at intervals of 3 h, 6 h, 12 h and 24 h everyday and continuously for 6 days. The pain threshold of AA rats, proopiomelanocortin （ POMC ） and proenkephalin （PENK） mRNA in inflamed location after electroacupuncture analgesia were observed. Results： The pain threshold of 24 h subgroup was raised. POMC mRNA and PENK mRNA expression of the 4 subgroups were increased. Conclusions： The effect of EA analgesia at interval of 24 h is the best, and its mechanism is related to increased expression of POMC mRNA and PENK mRNA in inflamed tissue of AA rats.