Orally Induced Adjuvant-like Arthritis in the Rat

Adjuvant-like arthritis was produced in Sprague-Dawley rats during 14 days of oral administration of 2-amino-5-bromo-6-(3-fluorophenyl)-4(3H)-pyrimidinone. Inflammatory changes about and in the hindlimb joints were similar to those described by Pearson for adjuvant-induced polyarthritis. Lymphoid hyperplasia, elevation of serum IgG levels, and localization of fluorescein-labeled globulin in disseminated inflammatory lesions implicate an immunologic effect. Rats treated twice weekly for 64 days developed lymphocytic thyroiditis and showed less inflammation in the joints.