Modulation of C-reactive protein and tumour necrosis factor-alpha in collagen-induced arthritis in Dark Agouti rats: Impact of collagen concentration on severity of arthritis

Objectives The study investigated the effect of collageninduced arthritis in Dark Agouti (DA) rats on the level of C-reactive protein and inflammatory cytokine tumour necrosis factor-alpha (TNF-TNF-α). Subjects Female Dark Agouti (DA) rats. Methods Three different dosages of (2 mg/kg of body weight, 3 mg/kg of body weight and 4 mg/kg of body weight) collagen and complete Freund's adjuvant suspension were tested. After 45 days, serum C-reactive protein, TNF-TNF-α, superoxide dismutase and total glutathione assays were done. Radiographic and histopathological changes in the joints were compared. Results All three groups showed signs of arthritic changes, confirmed by histopathological and radiographic changes. Severe arthritic changes were seen in the rats injected with 4 mg/kg of body weight of collagen. There was a significant increase in C-reactive protein, TNF-TNF-α, super oxide dismutase and total glutathione levels in the plasma in arthritis rats and the changes were more significant with 4 mg/kg of collagen. Conclusion These results demonstrated that the optimal dose to inject to experimental animals in order to get server arthritic changes was 4 mg/kg of collagen with complete Freund's adjuvant suspension. Severe arthritis changes induced significant elevation in plasma C-reactive protein and TNF-TNF-α levels.