title: Sister-chromatid exchanges in lymphocytes from methimazole-induced hypothyroid mice.
abstract: The inhibitory effect of an antithyroid drug on mouse T lymphocytes was investigated. Inbred C57BL/6 mice were provided with an antithyroid drug, methimazole, for 2, 4 and 6 weeks and the in vitro responses of the lymphocytes were studied. The proliferative responses of T lymphocytes from the spleen of methimazole (MMI)-treated mice significantly (p < 0.05) decreased following concanavalin A stimulation, and the inhibitory effect became prominent with the increased duration of MMI treatment. A concomitant increase in the frequency of induced sister-chromatid exchanges was also observed in these T lymphocytes. When the splenocytes were stimulated with concanavalin A for 24 h, their ability to produce interleukin-2 (IL-2) was significantly decreased (p < 0.05). The results indicated that methimazole interfered with the normal proliferation of T lymphocytes by suppressing the production of IL-2, a cytokine also known as T cell growth factor, as well as inducing a higher incidence of sister-chromatid exchange during cell division.
authors.affiliation: Department of Anatomy, Faculty of Medicine, Chinese University of Hong Kong, Shatin, New Territories.
authors.forename: W K
authors.initials: WK
authors.lastname: Liu
authors.forename: K W
authors.initials: KW
authors.lastname: Tsui
authors.forename: K W
authors.initials: KW
authors.lastname: Lai
authors.forename: Y
authors.initials: Y
authors.lastname: Xie
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology; D007037:Hypothyroidism / Q000139:chemically induced / Q000378:metabolism; D007166:Immunosuppressive Agents / Q000633:toxicity*; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D008297:Male; D008713:Methimazole / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D012854:Sister Chromatid Exchange; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism
chemical_list: D007166:Immunosuppressive Agents; D007376:Interleukin-2; D003208:Concanavalin A; D008713:Methimazole