METHIMAZOLE INHIBITS PERIPHERAL LYMPHOCYTE-PROLIFERATION BY INDUCING S-QUIESCENT PHASE ARREST

The influence of methimazole (MTI) on the mitogenic proliferation of h uman brood lymphocytes was studied in vitro to evaluate the potential immunomodulatory activity of this antithyroid drug. The effects of the drug on the lymphocyte cell cycle were assessed by multiparametric fl ow cytometry. Although MTI induced an increase in the number of lympho cytes in the synthesis and G2M compartments, it failed to stimulate pr oliferation as the cells tended to accumulate in the quiescent S compa rtment. The effect was dose-dependent over a range from 0.1 to 100 mM. These in vitro results indicate that MTI possesses immunosuppressive activity. Copyright (C) 1996 International Society for Immunopharmacol ogy.