Activities of dipeptidyl peptidases in BXSB mice and MRL/lpr mice with lupus erythematosus-like syndrome

Activities of peptidases were examined in tissues of male BXSB and male MRL/Mp-lpr/lpr (MRL/lpr) mice which are animal models of human systemic lupus erythematosus. Female BXSB and male MRL/+ + mice without histopathological changes were used as controls. Activity of DPP II in the spleen, kidney, and liver showed an increase at 13 and 20 weeks of age, while that of DPP IV was decreased at 20 weeks of age, as compared to control mice. The ratio of DPP II/DPP IV activities in the tissues was significantly increased and these findings agree with our previous results in the tissues of NZB mice and in the serum of patients with lupus erythematosus, underscoring the importance of hydrolytic enzymes in the pathogenesis of autoimmune diseases.