Collagen-induced arthritis and pro-/antioxidant status in Wistar and Lewis rats

Abstract

The aim of this study was to investigate the development of collagen-induced arthritis (CIA) in male and female Wistar and Lewis rats and establish relationships between clinical status and the levels of serum oxidative products. CIA was induced in 64 rats divided randomly into three groups. Animals of the 1st group received one 0.1 ml injection of bovine type II collagen (CII, in dose of 0.1 mg/rat) emulsified in incomplete Freund’s adjuvant (IFA). Rats of the 2nd group were immunized twice: on day 0 (dose of CII 0.1 mg/rat) and day 7 (dose of CII 0.05 mg/rat), and the animals of the 3rd group received one 0.1 ml injection of emulsion consisting of CII (0.1 mg/rat) in IFA and muramyldipeptide (MDP, in dose of 3 mg/ml). Serum oxidative products such as malondialdehyde (MDA), anti-oxidative enzyme catalase (CAT), total antioxidant activity (AOA), and arthritic profiles based on paw swelling, development of polyarthritis and histological changes in joints were measured in rats with CIA. Our findings have demonstrated that CIA develops in both sexes of Wistar and Lewis rats and the disease that occurs is an inflammatory erosive arthritis. Examination of the clinical course of the disease and the subsequent histological analysis disclosed a slight less aggressive disease in Wistar than in Lewis rats and in female than in male animals. The most severe arthritis developed in the 3rd group of male Lewis rats. CIA induced significant changes in the parameters of the pro-/antioxidant status of serum. Comparison of the oxidative statuses of both strains of rats with CIA and those of healthy animals revealed more elevated MDA levels in the serum of Wistar than Lewis rats. More evidently in the serum of these rats the level of total AOA was reduced, especially in the 3rd group of animals. More susceptible to CIA, Lewis rats showed a lower MDA production as compared with Wistar animals, and the lowest CAT activity in the serum of these rats was observed. In conclusion, attenuated inflammatory response and pathomorphological changes in joints were more observed in female animals of both strains. Male Lewis rats were most susceptible to CIA. On the basis of increased lipid peroxidation and decreased levels of AOA and enzyme CAT activity, CIA rats are subject to oxidative stress. Keywords: collagen-induced arthritis, pro-/antioxidant status, rats