Analgesic effect of buccal acupuncture on acute arthritis in rabbits and underlying mechanisms / 中南大学学报(医学版)

ABSTRACT

Objective:To observe the analgesic effect of acupuncture and to explore its central analgesic mechanism in rheumatoid arthritis rabbits.Methods:A total of 60 flap-eared white rabbits were randomly assigned into a normal control group (n=6),a model group (n=6),a body-acupuncture group (n=24),and a buccal acupuncture group (n=24).The later 2 groups were further randomly assigned into 0,0.5,1,and 2 h subgroups,with 6 cases in each group.The rheumatoid arthritis model was established by induction of eggalbumin.In the body acupuncture group,bilateral Xiyan and Zusanli were punctured for 15 s while in the buccal acupuncture group,acupuncture was applied to Xi for 15 s,with the needle retaining for 30 min.The pain threshold was detected with PL-200,taking struggle movements of rabbits as a measurement index,response latency from irradiation to struggling movements as the rabbit's pain threshold.The contents of β-endorplhin (β-EP) and cholecystokinin-8 (CCK-8) in cerebrospinal fluid were examined by radioimmunoassay.Results:Compared with the control group,pain threshold and CCK-8 levels decreased significantly (P＜0.01) and the concentration of β-EP significantly increased (P＜0.05) in the model group.The pain threshold in the body-acupuncture group and the buccal acupuncture group at 0 and 1 h (P＜0.05 or P＜0.01) increased significantly,while the β-EP and CCK-8 contents in the bodyacupuncture group and the buccal acupuncture group were significantly higher than those in the model group (P＜0.01 or P＜0.05).Both β-EP and CCK-8 contents in the buccal acupuncture group at 0 h were significantly higher than those in the body-acupuncture group (P＜0.05).Conclusion:The analgesic effect of buccal acupuncture is superior to that of body-acupuncture.Both buccal acupuncture and body-acupuncture can effectively raise the pain threshold in acute arthritis rabbits,which is closely associated with their effects in the up-regulation of β-EP and CCK-8 contents in cerebrospinal fluid.