碘缺乏和碘过量大鼠动物模型的复制及其碘代谢的对比观察

Reproduction of rat models of iodine deficiency and iodine excess and the observation on their iodine metabolism

目的以适碘动物为对照(NI),复制碘缺乏(LI)与碘过量(HI)大鼠动物模型并观察其碘代谢的变化。方法给予Wistar大鼠低碘饮食和不同剂量的高碘(KI)饮食(分别是正常碘摄入量的5、10、50、100倍),分别于实验3、6和12个月后处死,观察其碘代谢变化。结果LI组表现为以体格发育迟滞、尿碘及甲状腺碘显著降低为主要特征的碘缺乏状态;碘过量的各组(5、10、50、100HI组)尿碘排泄量则明显增加,增加的幅度分别与碘摄入水平相一致,但甲状腺含碘虽然均比NI组增高,但增高的幅度远不及尿碘水平,而且不与碘摄入水平相一致,仅为NI组甲状腺含碘量的2倍左右。结论碘缺乏和碘过量大鼠动物的模型是成功的,大鼠对长期高碘摄入比碘缺乏具有更强的耐受性,甲状腺对高碘环境存在适应机制。

Objective To reproduce animal models of iodine excess(HI) and iodin e deficiency(LI) compared with iodine adequate group(NI) and to observe their io dine metabolism. Methods Wistar stain rats were fed with diet of different level s of 5,10,50,100 folds of adequate iodine (potassium iodide) as iodine excess gr oups(5?10?50?100 HI). The animals were sacrificed at 3, 6 and 12 months later af ter intervention and their iodine metabolism were observed. Results Physical ret ardation, lower urinary iodine and iodine content in the thyroid glands were rev ealed in LI group compared with NI group. The iodine excess groups showed signi ficantly high urinary iodine, parallel to the iodine intake, however increased i odine content in thyroid tissues within 2 folds of iodine of NI group is not par allel to the iodine intake. Conclusions The experimental animal models of iodine deficiency and iodine excess are successful. Wistar rats with an excess of a lo ng term iodine intake demonstrate a strong tolerance to iodine excess through th e adaptation mechanism.