摘要
目的观察不同碘酸钾(KIO3)摄入量的大鼠模型碘代谢及甲状腺功能的变化并探讨KIO3的安全性。方法Wistar大鼠随机分为6组,分别给予低碘、适碘和高碘(分别为适碘组的5,10,50,100倍)饮食,检测3、6和12个月时尿碘水平和甲状腺含碘量,分析碘代谢变化;分别检测血清总三碘甲腺氨酸(TT3)、总甲状腺素(TT4)、游离三碘甲腺氨酸(FT3)、游离甲状腺素(FT4)浓度及甲状腺组织中三碘甲腺氨酸(T3)、甲状腺素(T4)含量来衡量甲状腺功能。结果LI组尿碘水平和甲状腺含碘量,以及血清、甲状腺组织中的甲状腺激素水平均显著低于适碘组,呈明显甲状腺功能低下;各HI组尿碘排泄量显著增加,增加幅度与碘摄入量的倍数相一致,但与适碘组比较,各HI组甲状腺含碘量最高仅2倍左右;另外,HI组随着碘摄入的增加,血清和甲状腺组织中的甲状腺激素水平也出现降低趋势,呈现一定的甲状腺功能低下。结论长期碘缺乏和碘过量均可导致大鼠甲状腺功能低下,但以碘缺乏所致的甲状腺功能低下更为明显。同时大鼠存在适应高碘的机制,对高碘摄入具有更强的耐受性,并证实KIO3的安全性。
Objective To observe the effct of different levels of iodine intake on iodine metabolism and thyroid function as well as its safety in rats. Methods Wistar rats were randomly divided into six groups： low iodine（LI）, normal iodine（NI） and 4 excessive iodine（HI, including 5,10, 50,100 folds of normal iodine）based on the iodine levels contained in their diet. 3, 6 and 1 2 months later, the iodine metabolism was through the levels of urinary iodine and iodine contents in thyroid gland. The thyroid function was determined by serum levels of TT4, TT3, FT3, FT4 and contents of T4, T3 in thyroid tissues. Resuits Urinary iodine, tissue iodine, thyroid hormones in serum and thyroid tissues in LI group were considerably lower than NI group, which indicated the status of severe hypothyroidism occurred in LI rats. HI groups showed statistically high urinary iodine paralleling to iodine intake. However, iodine contents in thyroid gland of HI groups was only within 2 folds of that in NI group. The tendency of hypothyroidism was demonstrated in HI groups with increase of iodine intake as indicated by the decreasing of thyroid hormones in serum and thyroid tissues. Conclusion Long term iodine deficiency and iodine excess can cause hypothyroidism in rats, but more obviously in iodine deficiency group. Wistar rats showed stronger tolerance to excessive iodine intake through the adaptation mechanism, and the safety of daily intake of KIO3 was confirmed.
出处
《中国公共卫生》
CAS
CSCD
北大核心
2007年第6期714-716,共3页
Chinese Journal of Public Health
基金
国家自然科学基金重点项目(30230330)
关键词
碘
碘代谢
甲状腺激素
碘酸钾
iodine
iodine metabolism
thyroid hormones
potassium iodate
