AMELIORATION OF TYPE-II COLLAGEN-INDUCED ARTHRITIS IN RATS BY TREATMENT WITH THYMULIN

Objective. To investigate the effects of thymulin (serum thymic factor + Zn2+) in collagen induced arthritis (CIA) in rats. Methods, SD rats were immunized with bovine type II collagen plus Freund's incomplete adjuvant, and thymulin was administered intraperitoneally on the first day of first immunization. We determined the level of serum thymulin by rosette inhibition assay. Effects of thymulin on CIA rats were esti mated by measuring the extent of hind paw edema, the level of serum an ti-type II collagen antibody, and changes in histopathological feature s of the affected joints. Results, Serum thymulin levels in CIA rats w ere significantly lower than in untreated rats. Thymulin diminished hi nd paw swelling and onset of arthritis compared with control rats. The serum anti-type II collagen antibody level was also reduced by thymul in. Histopathological examination showed inhibition of granulation tis sue and new bone formation after injection of thymulin. Conclusion, Ou r results suggest thymulin plays a significant role in the onset and d evelopment of CIA in rats. Our data indicate thymulin may be therapeut ically effective in preventing the development of rheumatoid arthritis .