[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.