高碘性甲状腺肿及酪蛋白对其拮抗作用的实验研究

Experimental study on the effects of casein in preventing iodine-induced goiter in mice

目的 用接近于流行病学调查现场实际的碘水平复制出高碘性甲状腺肿的动物模型 ,并探讨酪蛋白对甲状腺作用的可能机制。方法 将 180只雄性小鼠按照 2× 3析因设计随机分成 6组 ,分别喂以含碘 5 0 μg/L、3 0 0 μg/L和60 0 μg/L的去离子水及普通饲料或加 2 0 %酪蛋白的普通饲料 ,喂养 180d ,观察小鼠甲状腺大小、形态学、甲状腺激素、脑垂体的超微结构及尿液中碘含量。结果 在水碘 60 0 μg/L时甲状腺重量与适碘对照组比较差异已有显著性 ,甲状腺组织呈现高碘性甲状腺肿的病理学改变 ;与高碘对照组相比 ,高碘酪蛋白组小鼠的尿碘浓度增加 ,甲状腺重量减轻 ,血清T4水平降低 ,腺垂体的促甲状腺细胞呈现典型的刺激症状 ;不同浓度的碘与不同比例的酪蛋白对于小鼠的尿碘水平、T3 、T4、T3 /T4以及体重有交互作用。结论 水碘在 60 0 μg/L时小鼠甲状腺形态与功能已发生改变 ,验证了人群流行病学调查结果 ;普通饲料中加 2 0

Objective Using the iodine level found in epidemiological investigation spot to replicate the animal model and study the effects of high proportion of casein on iodine-induced goiter(IIG)in mice.Methods According to the 2 by 3 factorial design,a total of 180 male Kun Ming mice were equally and randomly divided into 6 groups,the mice in different groups were fed with water containing iodine 50,300 and 600μg/L,respectively,while with normal fodder and fodder which were added 20% casein,respectively.After 180 days,the mice were killed and studied thyroid size,morphology,sera T 3 and T 4,thyrotroph in adenohypophysis and urinary iodine.Results The thyroid weight in mice in the 600μg/L groups were significantly different from those in 50μg/L groups,and the thyroid histology showed typical colloid goiter.Compared with the control group of high iodine,the urinary iodine concentration increased,the thyroid weight decreased,sera T 4 level was lower and thyrotroph in adenohypophysis showed typical stimulated histomorphological sign in the group of high iodine and high casein.Interactions between different concentrations of iodine in water and different proportions of casein in fodder,was found in urinary iodine,T 3,T 4,T 3/T 4 and body weights of mice.Conclusions When iodine dose was 600μg/L,the thyroid morphology and function of mice had changed,which testified the epidemiological surveillance results.The fodder with 20% casein may prevent the IIG to a certain degree.