硒碘对大鼠谷胱甘肽过氧化物酶活力及甲状腺激素代谢的影响──Ⅱ．硒碘营养状态对大鼠甲状腺激素代谢的影响

用四种硒水平饲料和两种碘含量饮水饲养大鼠观察了其甲状腺激素（ＴＨ）代谢。硒组间肝脏、肾脏Ⅰ型脱碘酶（ＩＤⅠ）活力、血清Ｔａ含量差异显著；两碘组间甲状腺重量、甲状腺过氧化物酶（ＴＰＯ）活力。甲状腺碘含量、肾脏ＩＤⅠ及大脑Ⅱ型脱碘酶（ＩＤⅡ）活力差异明显；Ⅰ－（不加碘）组中甲状腺ＩＤⅠ活力与血清三碘甲腺原氨酸（Ｔａ）含量呈显著正相关。提示硒缺乏通过ＩＤⅠ影响ＴＨ代谢继而影响大脑ＩＤⅡ活力并可加重碘缺乏的效应；低碘时甲状腺ＩＤⅠ在维持循环Ｔａ含量中起重要作用；碘缺乏有可能增加硒缺乏的效应；硒、碘对ＴＨ代谢的影响可能在一定程度上取决于自身和对方的营养状态。

Effects of selenium and iodine on glutathione peroxidase activity and thyroid hormone metabolism in rats Ⅱ. Effect of selenium and iodine status on thyroid hormone metabolism in rats

Thyroid hormone(TH)metabolism in rats fed diets with various selenium levels and drinking water with two iodine levels was observed. Hepatic and renal type Ⅰ iodothyronine deiodinase(ID Ⅰ) activities and serum T 3 contents among the Se treated groups were significantly different.The differences of thyroid weight,thyroidal peroxidase (TPO)activity, thyroidal iodine content, and renal ID Ⅰ and cerebral type Ⅱiodothyronine deiodinase(IDⅡ)activities between two iodine groups were significant. A good correlation between thyroidal ID Ⅰ activity and serum T3 content in subgroup Ⅰ(No iodine added ) was found.These results suggest that Se deficiency can affect TH metabolism through changing ID Ⅰ activity with resultant reduction in cerebral IDⅡ activity and aggravation of the effect of iodine deficiency. Thyroidal ID Ⅰ seems to play an important role in the maintenance of the circulating T3 level in iodine-deficient rats. Effects of Se and iodine on TH metabolism may be interrelated.