Effect of iodine supplement on thyroid of iodine-deficient rats / 中国实用内科杂志

ABSTRACT

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.