传统“热补”针法对实验性关节炎家兔的镇痛效应及脑脊液中-βEP、CCK-8含量的影响

Effect of Heat-reinforcing Needling on Inflammatory Pain and β-EP and CCK-8 Contents in Cerebrospinal Fluid in Rheumatoid Arthritis Rabbits

目的:观察传统“热补”针法对实验性关节炎家兔的镇痛效应和探求其中枢作用机制。方法:以卵蛋白诱导的关节炎家兔为疼痛模型,连续治疗6 d后比较药物组、捻针组、电针组和热补组关节炎家兔关节局部痛阈和脑脊液中-βEP和CCK-8的含量。结果:治疗后各治疗组痛阈和-βEP含量均升高,热补组-βEP含量明显高于药物组和捻针组(P<0.01),但不及电针明显(P<0.05);各治疗组CCK-8含量均向正常水平恢复,热补组CCK-8含量比药物组和捻针组恢复明显(P<0.01),但不及电针组恢复显著(P<0.01)。结论:“热补”针法的镇痛效应和捻转针法、药物(痹冲剂)相同,但不及电针的镇痛效应;升高脑脊液中-βEP含量和促使CCK-8含量向正常水平恢复,可能是其镇痛的中枢机制之一。

Objective： To observe the effect of heat-reinforcing needling manipulation on inflammatory pain and explore its analgesic mechanism in experimental rheumatoid arthritis rabbits. Methods： Fifty-two rabbits were randomized into control （n=9）, model （n=9）, medication （n=9）, needle-twirling （n=9）, electroacupuncture （EA, n=9） and heat-reinforcing （n= 9） groups. Rheumatoid arthritis model was established by injecting mixed solution of egg-albumin （4 mg/mL） and equal volume of complete Freund＇s adjuvant （CFA） into the subcutaneous tissue （6 points around the shoulder, 0.2 mL/point）, 14 days later, the injection was repeated once again, another 6 days later, egg-albumin （0.4 mL, 20 mg/mL） solution was injected into the bilateral knee.joints. Rabbits of medication group was fed with ＂Wangbi Granule＂ （尪痹冲剂） 0.56 g/time （t. i. d. ）. ＂Zusanli＂ （ST 36） and＂Hegu＂ （LI 4） were punctured and stimulated by twirling the needle leftward and rightward for 1 min （needle retention 30 min）, or electrically （4/20 Hz, 0.5 ms pulse-duration, 2.4-3.1 mA and duration of 30 min） or by manipulating the needle with heat-reinforcing method for 1 min （needle-retention 30 min）. The treatment was conducted once daily and continuously for 6 days. The pain threshold （leg-withdrawal latency） was detected, and β-EP and CCK-8 contents in cerebrospinal fluid were assayedwith radioimmunoassay. Results： Compared with control group, the pain threshold and CCK-8 contents of model group lowered significantly （ P〈 0.01 ）, and β-EP of model group increased significantly （ P 〈 0.05） ; while in comparison with model group, the pain threshold and CCK-8 contents of medication, needle-twirling, EA and heat-reinforcing groups increased significantly （P〈 0.05, 0.01 ）, and β-EP contents of the 4 treatment groups increased further considerably （P 〈 0.05, 0.01 ）; and the effects of EA group were significantly superior to those of the other 3 treatment groups in raising pain threshold, and the contents of β-EP and CCK-8 （P〈 0.05, 0.01 ）. The effects of heat-reinforcing group were significantly superior to those of needle-twirling and medication groups in raising β-EP and CCK-8 levels （ P〈 0.01 ）. Conclusion： Heat-reinforcing needling manipulation, Chinese herbal medicine, EA and needle-twirling method all have an analgesic effect in rheumatoid arthritis rats, which is probably related to their effects in raising cerebral β-EP and CCK-8 contents.