补碘对缺碘大鼠甲状腺功能及形态的影响

目的研究不同剂量补碘对缺碘Wistar大鼠甲状腺的影响。方法于2003-03～2004-03取中国医科大学实验动物部4周龄Wistar大鼠经低碘饲料喂养3个月建立缺碘大鼠模型,对其进行8个月的1倍、3倍和6倍补碘,3个补碘量分别对应于前期流行病调查所见的3个农村社区的碘摄入水平。观察缺碘大鼠经不同剂量补碘后甲状腺功能、形态的变化。结果在补充1倍、3倍和6倍碘后,缺碘甲状腺质量分数未能恢复,仍然为甲状腺肿,甲状腺内碘潴留。电镜下缺碘引起的内质网扩张和线粒体肿大在补碘后未见恢复,且随补碘剂量的增加,超微结构损伤呈现加重的趋势。结论对缺碘动物单纯补碘可能难以纠正起初缺碘引起的甲状腺损伤,甲状腺可能处于亚临床病理状态。

Effect of iodine supplement on thyroid of iodine - deficient rats

Objective To study the effect of chronic iodine supplement on thyroid of iodine-deficient rats.Methods Iodine-deficient rat models were made by giving 4- week-old rats iodine-deficient fodder for 3 months.These iodine-deficient rats were then supplemented for 8 months 1-,3- and 6- fold iodine which corresponded to the 3 levels of iodine intake found in our epidemiological study in 3 rural communities.Then changes of thyroid after iodine supplement were observed.Results After supplement of 1-,3- and 6- fold iodine to iodine-deficient rats for 8 months,thyroid relative weight did not recover,and iodine accumulated in thyroid.The ultrastructure injuries of swelling mitochondria and dilating endoplasmic reticulum in epithelial cells of iodine-deficient thyroid did not recover,but became worse with iodine supplement increase.Conclusion Iodine supplement alone can not correct the injuries resulting from iodine deficiency;moreover,a sub-pathological state might occur.