缺碘与高碘大鼠甲状腺抗氧化能力的实验研究

目的 研究缺碘与高碘对鼠甲状腺抗氧化能力的影响，探讨自由基对甲状腺的损伤作用。方法 将Wistar大鼠随机分为3组：适碘组（NI）、高碘组（HI）、低碘组（LI），观察喂养12周、24周大鼠甲状腺及全身抗氧化能力的改变。结果 低碘组大鼠血清超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）与同期适碘对照组比较无明显变化，丙二醛（MDA）在实验的第24周显著升高；甲状腺组织匀浆SOD、GSH-Px和MDA在12周和24周均明显升高；甲状腺生物膜SOD和MDA在12周和24周均明显高于同期适碘对照组。高碘组血清、组织匀浆及甲状腺生物膜SOD、GSH-Px和MDA在实验过程中均无明显改变。结论 碘缺乏可导致Wistar大鼠甲状腺组织过氧化损伤；而碘过多在本实验期间未表现出对甲状腺的明显损伤作用。

A study on thyroid antioxidative ability of rats in iodine deficiency and iodine excess

Objective The experiment was designed to study the effect ofiodine deficiency and iodine excess on antioxidative ability of rats thyroid and the action of free radical in thyroid peroxidition damage.Methods The rats were divided into three groups randomly,normal iodine group(NI),low iodine group (LI) and high iodine group (HI).Biochemical method was used to determine the activity of SOD,GSH-Px and MDA level not only in thyroid tissue homogenization,thyroid biomembrane but also in serum at 12 and 24 weeks.Results In low iodine group the activity of SOD,GSH-Px and MDA levels were higher than those of NI group in thyroid tissue homogenization,thyroid biomembrane and serum during experiment.In HI group the activity of SOD,GSH-Px and MDA levels in tissue homogenzation,thyroid biomembrane and serum were no difference compared with the NI group.Conclusions Iodine deficiency may change the activity of antioxidation and caused the damage of thyroid by free radical,while iodine excess had not shown marked effects on the capacity of antioxidation of thyroid.