碘致甲状腺滤泡上皮细胞损伤在甲状腺炎发生机制中的探讨

目的 探讨过量碘对甲状腺滤泡上皮超微结构的影响,从而探讨甲状腺损伤与自身免疫甲状腺炎之间的关系.方法 NOD.H-2h4和昆明小鼠随机分人饮用正常水组和5倍、10倍、100倍高碘水组.各组动物分别于实验开始后4、8及24周处死,锇酸固定,醋酸双氧铀和柠檬酸铅双重染色,透射电镜成像.结果碘过量造成NOD.H-2h4小鼠甲状腺上皮细胞过氧体和次级溶酶体数量增多、上皮细胞凋亡、坏死、滤泡结构破坏和炎细胞的浸润,而且这种损伤与碘剂量呈正相关.结论 碘过量对甲状腺上皮细胞的氧化损伤作用可能是自身免疫甲状腺炎产生的必要条件.

A study on the mechanism of iodine-induced thyroid epithelial cell injury in the induction of autoimmune thyroiditis

OBJECTIVE: To investigate the effect of iodine excess on thyroid follicle epithelial ultrastructure and the relationship between thyroid injury and autoimmune thyroiditis. METHODS: NOD. H-2(h4) mice and Kunming mice were randomly divided into four groups receiving plain water, 5 fold, 10 fold, and 100 fold excessive iodine water. 4, 8 and 24 weeks after receiving iodine water, the mice were killed. After fixation with osmic acid and dual staining with uranyl chloride and citrate lead, thyroid gland ultrastructure was examined with electron microscopy. RESULTS: Iodine treated NOD. H-2(h4) mice exhibited marked accumulation of peroxisome and secondary lysosomes, apoptosis and necrosis of thyroid epithelial cell, damage of thyroid follicles and lymphocytic infiltration. The observed changes induced by iodine were in a dose dependent way. CONCLUSION: The oxidative injury on the thyroid epithelial cells induced by iodine excess might be the prerequisite for the creation of autoimmune thyroiditis.