Beckett G J, Nicol F, Rae P W, Beech S, Guo Y, Arthur J R
University Department of Clinical Chemistry, Royal Infirmary, Edinburgh, UK.
Am J Clin Nutr. 1993 Feb;57(2 Suppl):240S-243S. doi: 10.1093/ajcn/57.2.240S.
This paper compares the effects of combined iodine and selenium deficiency, of single deficiencies of these trace elements, and of no deficiency on thyroid hormone metabolism in rats. In rats deficient in both trace elements, thyroidal triiodothyronine (T3), thyroidal thyroxin (T4), thyroidal total iodine, hepatic T4, and plasma T4 were significantly lower, and plasma thyroid-stimulating hormone (TSH) and thyroid weight were significantly higher than in rats deficient in iodine alone. Plasma and hepatic T3 concentrations were similar in the dietary groups. Hepatic type I iodothyronine deiodinase (ID-I) activity was inhibited by selenium deficiency irrespective of the iodine status. Type II deiodinase (ID-II) activity in the brain was significantly higher and in pituitary, significantly lower in combined deficiency than in iodine deficiency alone. These data show that selenium can play an important role in determining the severity of the hypothyroidism associated with iodine deficiency.
本文比较了碘和硒联合缺乏、这些微量元素单一缺乏以及不缺乏对大鼠甲状腺激素代谢的影响。在两种微量元素都缺乏的大鼠中，甲状腺三碘甲状腺原氨酸（T3）、甲状腺甲状腺素（T4）、甲状腺总碘、肝脏T4和血浆T4显著降低，而血浆促甲状腺激素（TSH）和甲状腺重量显著高于仅碘缺乏的大鼠。各饮食组的血浆和肝脏T3浓度相似。无论碘状态如何，肝脏I型碘甲状腺原氨酸脱碘酶（ID-I）活性均受硒缺乏的抑制。联合缺乏时，大脑中的II型脱碘酶（ID-II）活性显著升高，而垂体中的则显著低于仅碘缺乏时。这些数据表明，硒在确定与碘缺乏相关的甲状腺功能减退的严重程度方面可发挥重要作用。
