Objective To observe the effect of electroacupuncture(EA)intervention on inflammatory reactions and articular synovial nuclear factor kappa B(NF-κB)and TNF-αconverting enzyme(TACE)protein expression in rheumatoid arthritis(RA)rats

so as to elucidate its anti-inflammatory mechanism.Methods Forty Sprague-Dawley(SD)rats were randomly divided into normal control

model

EA

and non-acupoint groups

with 10 rats in each group.The RA model was established by intradermal injection of bovine type II collagen emulsified in incomplete Freund's adjuvant for 21 days.EA(2Hz

1mA)was applied to bilateral"Zusanli"(ST 36)

"Xuanzhong"(GB 39)and"Shenshu"(BL 23)for 15 min

once daily for 19 days

starting from the third day on after modeling.The sham acupoints(5mm lateral to the above-mentioned acupoints)received the same stimulation to EA group.Paw swelling volume was detected using a water-filled glass mug

the serum C-reactive protein(CRP)and rheumatoid factor(RF)contents were assayed using velocity scatter turbidimetric method

and the plasma erythrocyte sedimentation rate(ESR)was assayed with Westergren method and VES-MATIC 20 ESR auto-analyzer and the expression levels of TACE and NF-κB proteins in the synovial tissue of knee joint were detected by Western blot.Results After RA modeling

the hind-paw volume was significantly bigger in the RA rats than in the normal rats(P<0.01)

and remarkably lower in the EA group(not in the non-acupoint group)than in the model group(P<0.05).In addition

the plasma ESR

serum CRP and RF contents and the expression levels of NF-κB and TACE proteins in the synovial tissues were significantly increased in the model group compared with those in the normal group(P<0.01)

and were obviously down-regulated in the EA group(P<0.05)

but not in the non-acupoint group(P>0.05).Conclusion EA can effectively improve the severity of articular inflammatory swelling and lower ESR

serum CRP and RF contents and suppress synovial TACE/NF-κB protein signaling in RA rats.