Figure 2. Rat RA model was successfully constructed.

(A) Rats of model group exhibited much higher secondary foot swelling degree than the Normal group. (B) Significantly increased polyarthritis index was found in rats of model group when compared with Normal group. (C) The spleen and thymus index of rats of model group was much higher than that of Normal group. (D) HE staining indicated that the synovial tissues of rats in Normal group were much thinner with one to two layers of synovial cells, whereas the synovial tissues of rats in Model group occurred severe inflammatory cell infiltration with three to five layers of synovial cells. **P<0.01 when compared with Normal group.