Hotz C S, Fitzpatrick D W, Trick K D, L'Abbé M R
Department of Foods and Nutrition, University of Manitoba, Winnipeg, Canada.
J Nutr. 1997 Jun;127(6):1214-8. doi: 10.1093/jn/127.6.1214.
The interaction of dietary selenium and iodine on the activities of the selenoenzymes, selenium-dependent glutathione peroxidase (GSH-Px), and type I deiodinase (DI-I), and the thyroid hormones thyroxine (T4) and triiodothyronine (T3) were studied. Male weanling Sprague-Dawley rats were fed an AIN-93G diet for 6 wk with modified selenium and iodine concentration as follows: three levels each of iodine and selenium (0.03, 0.2 added and 1.0 added mg iodine/kg diet, and 0.05, 0.18 added and 1.0 added mg selenium/kg diet) were used in a 3 x 3 factorial design. Renal, but not hepatic, DI-I activity was lower in rats with low selenium intake than in controls. Circulating T3 concentration was not affected by the dietary levels of iodine or selenium. Unlike in liver, kidney and erythrocytes, thyroidal GSH-Px activity was not lower than in controls in rats with low selenium intake, but was significantly higher when iodine intake was low. Significant interactions of iodine and selenium on serum T4 and thyroidal GSH-Px activity were observed. Serum T4 was maintained at control levels when both dietary iodine and selenium were low, but not when iodine alone, or selenium alone, was low. Activity of thyroidal GSH-Px was lowest in rats fed a diet containing high iodine and low selenium. The results suggest that high iodine intake, when selenium is deficient, may permit thyroid tissue damage as a result of low thyroidal GSH-Px activity during thyroid stimulation. A moderately low selenium intake normalized circulating T4 concentration in the presence of iodine deficiency.
研究了膳食硒和碘对硒酶、硒依赖性谷胱甘肽过氧化物酶（GSH-Px）和Ⅰ型脱碘酶（DI-I）活性以及甲状腺激素甲状腺素（T4）和三碘甲状腺原氨酸（T3）的相互作用。雄性断乳Sprague-Dawley大鼠用AIN-93G饮食喂养6周，其中硒和碘浓度进行了如下调整：碘和硒各有三个水平（0.03、添加0.2和添加1.0毫克碘/千克饮食，以及0.05、添加0.18和添加1.0毫克硒/千克饮食），采用3×3析因设计。低硒摄入大鼠的肾脏而非肝脏DI-I活性低于对照组。循环T3浓度不受膳食碘或硒水平的影响。与肝脏、肾脏和红细胞不同，低硒摄入大鼠的甲状腺GSH-Px活性不低于对照组，但碘摄入低时显著更高。观察到碘和硒对血清T4和甲状腺GSH-Px活性有显著相互作用。当膳食碘和硒都低时，血清T4维持在对照水平，但单独碘低或单独硒低时则不然。甲状腺GSH-Px活性在高碘低硒饮食喂养的大鼠中最低。结果表明，当硒缺乏时，高碘摄入可能会因甲状腺刺激期间甲状腺GSH-Px活性低而导致甲状腺组织损伤。在碘缺乏的情况下，适度低硒摄入可使循环T4浓度正常化。
