维生素A对高碘小鼠甲状腺形态结构的影响

Effects of vitamin A on morphology of mice thyroid under excessive iodine

目的观察维生素A（VA）对高碘小鼠甲状腺形态结构的影响。方法将昆明种小鼠分为4组：正常对照（NI）组、高碘（HI）组、高碘＋VA1（HI＋VA1）组和高碘＋VA2（HI＋VA2）组。90d后，测定小鼠体质量和甲状腺质量，光镜和电镜下观察甲状腺形态结构的改变。结果HI组小鼠体质量明显高于NI组（q=2．93，P〈0．05），甲状腺质量明显增加（q=4．72，P〈0．01），HI＋VA1、HI＋VA2组与NI组比较，甲状腺质量也明显增加（q=3．21、2．89，P〈0．05），与HI组相比有降低趋势，但差异无统计学意义（P〉0．05）；HI组光镜下出现胶质潴留性甲状腺肿（甲肿）现象，而随着补充VA的增高，高碘甲肿率有减少趋势；电镜下HI组甲状腺滤泡细胞呈现损伤表现．HI＋VA1、HI＋VA2组与HI组相似，未见明显改善作用。结论高碘可以引起小鼠甲状腺胶质潴留性肿大．并造成甲状腺滤泡上皮细胞损伤，而补充VA可能具有部分拈抗高碘性甲状腺肿发生的作用。

Objective To study the effects of Vitamin A （VA） on morphology of mice thyroid exposed to excessive iodine. Methods Kunming mice were divided into 4 groups： normal control（NI） group, high iodine （HI） group, high iodine plus vitamin A 1（HI ＋ VA 1） group and high iodine plus vitamin A 2（HI ＋ VA 2） group. After ninety days, body and thyroid weights were measured, and the morphology of thyroid was investigated under light and electron microscope. Results Compared with NI, both body and thyroid weights increased markedly in HI, but the weight of thyroid had a descending tendency in HI ＋ VA1 and HI ＋ VA2. The colloid goiter was found under light microscope, and the damages of follicular epithelium cell appeared under electron microscope in HI. But with the increase of Vitamin A dose, the rate of iodine excessive goiter was decreased. Conclusions Iodine excess may cause colloid goiter and damage of follicles epithelial cell,which can be partially antagonized by Vitamin A.