[Observation on the analgesic effect of heat-reinforcing needling manipulation for acute arthritis and the concomitant changes of beta-EP and PGE2 contents in the local joint tissue in rabbits].

Objective To observe the analgesic effect of heat-reinforcing needling manipulation for acute inflammatory arthritis and its underlying mechanism in experimental rheumatoid arthritis rabbits.Methods A total of 60 rabbits were randomized into control(n=6),model(n=6),needle-twirling(n=24) and heat-reinforcing(n=24) groups,and the later 2 groups were further divided into 0 h,0.5 h,1 h and 2 h subgroups,with 6 cases in each.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).Fourteen days later,the injection was repeated once again,and another 6 days later,egg-albumin(0.4 ml,20 mg/ml) solution was injected into the bilateral knee-joints."Zusanli"(ST 36) and "Hegu"(LI 4) were punctured and stimulated by needle-twirling or by heat-reinforcing needling technique for 1 min,with the needle retained for 30 min.The pain threshold of the paw was detected with K+import stimulation method.β-EP and PGE2 contents of the joint tissue were assayed with radioimmunoassay.Results Compared with model group,the pain threshold of needle-twirling group and heat-reinforcing group at each time-point increased significantly(P0.01,P0.05).Compared with needle-twirling group,the pain threshold of heat-reinforcing group at 0.5 h,1 h and 2 h subgroups increased significantly(P0.05,P0.01).Both β-EP and PGE2 contents of model group were significantly higher than those of control group(P0.01,P0.05).In comparison with model group,β-EP contents of needle-twirling group and heat-reinforcing group at each time-point increased significantly(P0.01,P0.05),and PGE2 contents of needle-twirling group and heat-reinforcing group at each time-point decreased significantly(P0.01,P0.05).The β-EP content of heat-reinforcing group was significantly higher than that of needle-twirling group at 2 h(P0.05),while PGE2 content of the former group was significantly lower than that of needle-twirling group at 0 h(P0.01).Conclusion Both needle-twirling and heat-reinforcing needling can effectively raise the pain threshold in acute arthritis rabbits,which my be closely associated with their effects in upregulating β-EP content and lowering PGE2 level in the local joint tissue.The analgesic effect of heat-reinforcing needling manipulation is superior to that of needle-twirling.