Shenzhen Center for Chronic Disease Control, Shenzhen, 518020, People's Republic of China.
Biol Trace Elem Res. 2011 Jun;141(1-3):110-8. doi: 10.1007/s12011-010-8728-8. Epub 2010 Jun 2.
As excessive iodine intake is associated with a decrease of the activities of selenocysteine-containing enzymes, supplemental selenium was hypothesized to alleviate the toxic effects of excessive iodine. In order to verify this hypothesis, Balb/C mice were tested by giving tap water with or without potassium iodate and/or sodium selenite for 16 weeks, and the levels of iodine in urine and thyroid, the hepatic selenium level, the activities of glutathione peroxidase (GSHPx), type 1 deiodinase (D1), and thyroid peroxidase (TPO) were assayed. It had been observed in excessive iodine group that hepatic selenium, the activities of GSHPx, D1, and TPO decreased, while in the groups of 0.2 mg/L, 0.3 mg/L and 0.4 mg/L supplemental selenium, the urinary iodine increased significantly. Compared with the group of excessive iodine intake alone, supplemental selenium groups had higher activities of GSHPx, D1, and TPO. We could draw the conclusion that supplemental selenium could alleviate toxic effect of excessive iodine on thyroid. The optimal dosage of selenium ranges from 0.2 to 0.3 mg/L which can protect against thyroid hormone dysfunction induced by excessive iodine intake.
由于碘摄入过量会导致含硒半胱氨酸酶活性降低，因此推测补充硒可以减轻碘过量的毒性作用。为了验证这一假设，用添加或不添加碘酸钾和/或亚硒酸钠的自来水喂养 Balb/C 小鼠 16 周，并检测尿液和甲状腺中的碘含量、肝脏硒水平、谷胱甘肽过氧化物酶（GSHPx）、1 型脱碘酶（D1）和甲状腺过氧化物酶（TPO）的活性。在碘过量组中观察到，肝脏硒、GSHPx、D1 和 TPO 的活性降低，而在 0.2mg/L、0.3mg/L 和 0.4mg/L 补硒组中，尿碘含量显著增加。与单独摄入过量碘的组相比，补硒组的 GSHPx、D1 和 TPO 活性更高。我们可以得出结论，补充硒可以减轻碘过量对甲状腺的毒性作用。硒的最佳剂量范围在 0.2 至 0.3mg/L 之间，可以防止过量碘摄入引起的甲状腺激素功能障碍。
