不同剂量碘与甲状腺形态与功能的剂量反应关系

目的 研究不同剂量碘与小鼠甲状腺组织形态和功能的剂量反应关系.方法 用随机区组实验设计方法将初断乳昆明小鼠分为适碘和不同剂量高碘共7组,其饮水含碘量依次为50μg/L,250μg/L,500μg/L,1000μg/L,1500μg/L,2000μg/L,3000μg/L,喂养100天,观察甲状腺重量、肿大率、组织形态学改变及血清激素水平.结果 甲状腺绝对重量、相对重量及肿大率与碘剂量呈明显的正相关关系,前二者在250μg/L时与对照组比较已有显著性差异,甲状腺肿大率在500μg/L时与对照比较差异显著;血清TT₃与碘剂量无明显相关关系,TT₄则表现为正相关,碘浓度为3000μg/L时与对照组比较差异有显著性,相反FT₃则呈负相关趋势,但无统计学意义,但在3000μg/L时与对照组比较表现出显著性差异;甲状腺组织为胶质性甲状腺肿,且随碘剂量的增加,甲状腺滤泡上皮细胞逐渐变为扁平,核呈梭形,滤泡腔逐渐扩大,胶质逐渐增多.结论 饮水含碘量在50μg/L～3000μg/L之间时,小鼠甲状腺形态和功能与碘剂量呈明显的剂量反应关系,当碘离子浓度为250μg/L,即可引起甲状腺肿大,且为胶质性甲状腺肿的组织改变.

Study on Dose-reaction Relationship Between Different Iodine Dose an d Morphology and Function of Thyroid in Mice

Objective To study the dose-reaction relationship between different iodine and the morphology and function of thyroid in mice.Methods KM mice after weaning were divided into seven groups by randomized block design.The mice were given drinking water including different iodine doses which were 50μg/L,250μg/L,500μg/L,1 000μg/L,1500μg/L,2 000μg/L,3 000μg/L respectively.After being fed 100days,the absolute and relative weight of thyroid,goiter rate,the thyroid morphology and serum thyroid hormone level were observed.Results The positive correlation was observed between the absolute and relative weight of thyroid,goiter rate and different iodine doses.And the absolute and relative weight of thyroid in 250μg/L group was significantly different from that in 50μg/L group.Yet,the goiter rate in 500μg/L group was different from that in 50μg/L group.Zero correlation was observed between the level of serum TT₃ and different iodine doses,the positive correlation was observed between the level of serum TT₄ and different iodine doses,and serum TT₄ level in 3 000μg/L group was significantly higher than that in 50μg/L group.Yet serum FT₃ level showed negative correlation tendency,which had not found statistically differnet,but serum FT₃ level in 3 000μg/L group was remarkably higher than that in 50μg/L group.The thyroid morphology is colloid goiter,and with iodine dose increasing,the follicular epithelial cells gradually become thallus,the nuclear become shuttle,the cavity of follicle gradually spread,colloid content gradually increasing.Conclusion The positive correlation was observed between the morphology,thyroid function in mice and iodine doses ranging from 50 μg/L-3 000μg/L,and that the dose of iodine was 250μg/L could result in colloid goiter.