硒缺乏与甲状腺激素代谢及功能

Ｉ型脱碘酶为含硒酶，缺硒时，该酶活性下降，使循环Ｔ４增高，外周组织Ｔ３水平下降。缺硒可加速甲状腺组织碘的耗竭，并加重某些缺碘的生物学效应，缺硒还可能与碘缺乏病的发生发展有关。以缺硒为主要病因的克山病存在甲状腺激素代谢异常，其心肌呼吸酶活性变化与缺碘引起的甲状腺功能低下相似，缺碘可缺硒引起的甲状腺激素代谢改变与克山病的发生可能有关。

Selenium Deficiency and Thyroid Hormone Metabolism and Function

Typo I 5'-deiedinase is a Se-containing enzyme. If Se is deficient, the deiodinase activity would be inhibited, the level of Circulation T4 will be elevated, and the concentration of T3 in peripheral tissues will be decreased.Se deficiency will also accelerate the iodine depletion of thyroid and may even exacerbate some detrimental effects of iodine deficency. Possibly Se deficiency is involved in the occurence and development of iodine deficient disorders. Keshan disease, with Se deficiency as the major cause, was also observed a change of thyroid hormone metabolism.The change of respiratory enzyme activities in myocardium of Keshan disease is in the way somewhat like that of hypothyroidism caused by iodine deficiency.The metabolic change of thyroid hormone after Se deficiency or iodine deficiency may be related to the occurence of Keshan disease.