碘缺乏与碘过多对大鼠甲肿形成及功能的影响

EFFECT OF IODINE DEFICIENCY AND EXCESS ON GOITER FORMATION AND THYROID FUNCTION IN RATS

目的;研究碘缺乏与碘过多对大鼠甲状腺肿形成及其功能的影响。方法:实验分为三组,适碘组(对照组)、低碘组、高碘组,观察甲状腺及垂体重量,甲状腺组织及尿液的碘含量,血清及甲状腺组织激素水平。结果:低碘组甲状腺及垂体重量明显高于对照组,血清T_4及组织T_3、T_4、组织及尿碘含量均明显低于对照组,血清T_3在12周时代偿性增高,24周时明显下降。高碘组甲状腺及垂体重量,血清T_4及组织碘含量无明显改变,尿碘明显高于对照组,血清T_3及组织T_4于24周时明显低于对照组。结论:碘缺乏可引起大鼠甲肿和功能低下,而高碘尚未能引起甲肿,但抑制了甲状腺激素的合成和释放。

The experiment was designed to study the effect of iodine deficiency and excess on goiter formation and thyroid function in rats. Methods: The rats were kept on a normal iodine diet (NI 6.9μgI/d), a low iodine diet(LI 1 .35μgI/d) and a high iodine diet(HI 555μgI/d) for 24 weeks respectively. After 12 and 24 weeks, the rats were killed and the thyroid pituitary were weighed, iodine content in thyroid tissue and urine and the throid hormones in serum and thyroid tissue were measured. Results: The results showed that in LI rats thyroid and pituitary weight were higher, the serum and tissue hormones and iodine in urine and tissue were lower than NI. In HI rats the thyroid and pituitary weight, serum T4 and tissue iodine were shown no difference, serum T3 and tissue T4 declined markedly at 24 week. The urine iodine was significantly higher than NI. Conclusion: Based on the results we concluded that iodine deficiency caused overt goiter and hypothyroidism. Iodine excess did not induce goiter in Wistar rats during our experiment, while did have an inhibitory effect on thyroid function.