碘酸钾和碘化钾对碘缺乏大鼠甲状腺抗氧化能力的影响

目的 研究碘酸钾和碘化钾两种碘剂对碘缺乏大鼠甲状腺抗氧化能力的影响。方法 Wistar大鼠低碘喂养3个月，复制出低碘模型后，随机分为4组：适碘碘化钾组（NI），适碘碘酸钾组（NO），高碘碘化钾组（HI），高碘碘酸钾组（HO），喂养22周后测定尿碘排泄情况、甲状腺重量、血清甲状腺激素水平和甲状腺组织抗氧化能力改变，观察甲状腺形态变化。结果 HO与HI两组补碘后尿碘显升高；与NI组相比，HO组甲状腺湿重及相对重量均明显增加，HI组甲状腺相对重量明显增加，与NI相比，HO、HI组T3显升高；与NI组相比，NO、HO、HI组GPX、SOD和TAOC均显降低，HO组MDA显升高，但NO、HI组MDA无明显升高；与HI组相比，HO组的GPX、TAOC显降低。结论 碘缺乏大鼠补充大剂量碘酸钾或大剂量碘化钾后，甲肿消退速度慢；无论补充生理或大剂量碘剂，与碘化钾相比，补充碘酸钾甲状腺抗氧化物酶持续降低，大剂量碘酸钾导致甲状腺MDA含量升高。

Effects of potassium iodate and iodide on thyroid capability of antioxidation in iodine deficiency rats

Objective To study the effects of potassium iodate and iodide on thyroid conformation and its function of iodine deficiency rats.Methods 120 iodine deficiency rats were divided randomly into four groups:normal potassium iodide group (NI) , normal potassium iodate group (NO) ,high potassium iodide group (HI) ,higli potassium iodate group (HO) .Using biochemical method to determine the weight of thyroid, changes of iodine metabolism, the level of serum T3, T4, morphology and capability of thyroid antioxidation at 22 weeks. Results In HO and HI Wistar rats, the urinary iodine excretion were as 100 times high as that in NI group.The thyroid weight and the ratio of thyroid weight to body weight of HO group increased significantly( P < 0.05) ,only the ratio of thyroid weight to body weight of HI group increased significantly( P < 0.05) .The serum T3 in HO and HI groups increased significantly( P < 0.05)compared with NI group. NO, HO, HI groups compared with NI group, the activity of GPX, SOD, TAOC was decreased significantly( P < 0.01) , the MDA in HO group was increased significantly, but in NO, HI group did not change. HO group compared with HI group, the activity of GPX,TAOC was decreased significantly( P < 0.05) .Conclusion High dose potassium iodate and iodide caused the regression of iodine deficiency rat goiter slowly; potassium iodate induced antioxidant enzymes decreased compared with iodide in normal or high dose, only high dose potassium iodate lead MDA of thyroid to increase.