中文摘要：

目的观察碘缺乏和碘过量小鼠甲状腺胰岛素样生长因子I（IGF—I）的水平及在甲状腺形态变化中的作用。方法选用Balb／c小鼠48只，体质量约16g，雌雄各半。按体质量、性别将小鼠随机分为3组：碘缺乏组（U，饲料中含碘量为50μg/kg，饮去离子水）；适碘组（对照，NI，饲料中含碘量为300μg／kg，饮去离子水）、碘过量组（HI，饲料中含碘量为300μg／kg，饮水中含碘量14700μg／kg）；每组16只。喂养12周后处死．取小鼠甲状腺，测量甲状腺的绝对及相对质量，HE染色，光镜下观察小鼠甲状腺的形态学变化；RT—PCR法检测IGF-ImRNA表达；免疫组化法检测甲状腺IGF—I蛋白质表达。结果小鼠甲状腺的绝对质量和相对质量．组间比较差异有统计学意义（F值分别为315．881、405．921，P均〈0．01）；其中LI组[（10．71±4．03）mg，（44．98±15．39）mg／100g体质量]和HI组[（3．42±1．17）mg，（13．50±3．89）mg／100g体质量]高于NI组[（2．11±0．53）mg，（8．35±1．98）mg／100g体质量，P均〈0．01]。光镜下，LI组小鼠滤泡体积变小，数量增多，上皮细胞呈柱状或高柱状，增生呈复层，滤泡腔内胶质减少或缺如；而HI组小鼠发生了胶质蓄积，滤泡增大，未见滤泡增生。甲状腺IGF—ImRNA表达，u组（1．03±0．32）明显高于NI组（0．65±0．19），组间比较差异有统计学意义（F=7．518，P〈0．01），HI组与NI组比较有下降趋势，但差异无统计学意义（P〉0．05）。甲状腺IGF—I蛋白质表达，LI组小鼠甲状腺滤泡上皮细胞内棕黄色颗粒明显多于NI组和HI组，而HI组却少于NI组。结论碘缺乏和碘过量小鼠发生甲状腺肿，甲状腺IGF—ImRNA和蛋白表达的改变，可能参与碘缺乏和碘过量导致甲状腺形态改变的过程，甲状腺自分泌的IGF—I在缺碘性和高碘性甲状腺肿形成过程中可能起重要调节作用。

英文摘要：

Objective To study the expression level of thyroid insulin-like growth factor- I （IGF- I ） in iodine deficiency and excess mice and the effect of thyroid gland IGF- I in the thyroid morphological change. Methods Forty-eight Balb/c mice were chosen as studied objects, weighing about 16 g. They were divided into three groups： low iodine（LI, iodine content of 50 μg/kg in feed, drinking deironized water） group, normol（NI, iodine content of 300 μg/kg in feed, drinking deironized water） group and high（HI, iodine content of 300 μg/kg in feed, iodoine of content 14 700 μg/kg in drinking） group, 16 mice in each group. Mice were put to death after 12 weeks and taken out of their thyroid gland. The body weight, absolute and relative weights of thyroid gland were measured and the morphological change of thyroid gland were observed under microscope. The expression levels of thyroid gland IGF- I mRNA and protein were detected by RT-PCR and immunohistochemistry, respectively. Results There were statistical significances between groups of thyroid absolute and relative weights（F = 315.881,405.921, all P 〈 0.01 ）. LI group[ （10.71 ± 4.03）mg, （44.98 ± 15.39）mg/100 g body weight] and HI group [ （3.42 ± 1.17）mg, （13.50 ± 3.89）mg/100 g body weight] had heavier thyroid absolute and relative weights than NI group[（2.11 ± 0.53）mg, （8.35 ± 1.98）mg/100 g body weight, all P 〈 0.01]. Under microscopy, the thyroid follicle capaeity grew down andthe follicle quantity grew up in LI group, the epithelium was stylolitic, the colloid diminished or absence in follicular cavity, while HI group presented colloid accumulation without follicular hyperplasia. The expression level of thyroid gland IGF- I mRNA in LI group（1.03 ± 0.32） was more than that in NI（0.65 ± 0.19） and HI（0.59 ± 0.20） groups（F= 7.518, P〈 0.01）. In contrast to NI, there was no difference in the expression level of thyroid gland IGF-I mRNA in HI group（P 〉 0.05）. The brownish particles of LI group w