RESUMEN
Objective To compare the analgesic effects of fire needling, conventional acupuncture and acupoint catgut embedding in rats with rheumatoid arthritis.Methods Fifty healthy male SD rats were randomized into control, model, acupuncture, fire needling and catgut embedding groups, 10 rats each. A SD rat model of rheumatoid arthritis was made by intracutaneous injection of complete Freund’s adjuvant into the right hind foot pad. Right Kunlun and Zusanli were selected as therapeutic points in the three groups and given fire needling, acupuncture or catgut embedding. The right paw mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were used as observation indices and measured in every group of rats at one day before and four days after model making and at one, seven and fourteen days after the beginning of treatment. Rat paw inflammatory tissues were separated after the completion of treatment. The IL-1 and TNF-α contents of them were measured. Results There were statistically significant differences in MWT and TWL between the model, acupuncture, fire needling or catgut embedding group and the control group after model making, and one, seven and fourteen days of treatment (P<0.01). There were statistically significant differences in MWT and TWL between the fire needling group and the model, acupuncture or catgut embedding group after one, seven and fourteen days of treatment (P<0.01,P<0.05). There was a statistically significant difference in MWT between the acupuncture or catgut embedding group and the model group after one, seven and fourteen days of treatment (P<0.01). There was a statistically significant difference in TWL between the acupuncture or catgut embedding group and the model group after seven and fourteen days of treatment (P<0.01,P<0.05). There were statistically significant differences in IL-1 and TNF-α contents between the model, acupuncture, catgut embedding or fire needling group and the control group after model making (P<0.01). after treatment, there were statistically significant differences in IL-1 and TNF-α contents between the acupuncture, catgut embedding or fire needling group and the model group and between the acupuncture or catgut embedding group and the fire needling group (P<0.05).Conclusions Fire needling can raise pain threshold in rats with rheumatoid arthritis. It alleviates rheumatoid arthritis-induced chronic pain by reducing the inflammatory factor content of affected muscular tissues.