摘要
目的研究缺碘大鼠补充不同质量浓度碘后脑内甲状腺激素受体与激素结合动力学参数的变化。方法复制Wistar低碘大鼠,然后根据饮用不同质量浓度的碘水来分组。选用第2代20日龄仔鼠实验,测定甲状腺功能状态,利用放射配体结合分析法测定脑内T3受体。结果①血清T3浓度:低碘组(LI)、高碘组(HI)、适碘组(AI)与正常对照组(N)相比,差异无显著意义(P> 0.05)。血清FT3:LI组、HI组明显高于N组(P< 0.05);②血清T4和FT4:LI组和HI组均显著低于N组(P< 0.05);③受体最大结合容量(MBC):LI组明显高于N组(P< 0.05)。结论LI组血中TT4和FT4低于N组,而脑中T3核受体MBC高于N组,提示甲状腺功能低下(甲低)状态下,脑组织中T3核受体有代偿性升高。高碘状态下缺碘大鼠脑细胞核T3核受体、MBC虽略有升高,但血中TT4和FT4却低于正常,提示长期缺碘后过量补碘会出现碘性甲低。长期缺碘后,即使补充适量碘也会出现一过性碘性甲状腺功能亢进(甲亢)。
Objective To study the variation of kinetic parameters of T3 conjoining with its receptor in the brain of iodine deficiency rats after iodine admitted. Methods Constructed animal model of iodine deficiency rats were divided into 4 groups at age of 20 day by the uptake of iodine-nutrition(low iodine group (LI), high iodine group(HI), appropriate iodine group(AI) and control). Extracted cell nuclei from rat brains. Two main kinetic parameters of T3 receptor(T3R), affinity constant (Ka) and maximal binding capacity (MBC), were determined by radio-ligand analysis. The thyroid hormones levels in serum were also measured by ELISA. Results On serum TT3, there were no significant difference among these 4 groups, but a slightly decrease in LI group. In LI and HI groups, FT3 were significantly higher than that of control. Both LI and HI group had decreased TT4 and FT4 level than those of control (P < 0.05) . The receptor MBC in LI group was significantly augmentor than that of control, but there was no significant difference between HI and control(N). The Ka of T3R in various groups was nearly similar (P > 0.05). Conclusions T3R MBC was higher in LI group than that in normal group which means that the elevation of T3R MBC might be a compensation for iodine-deficiency during brain development retardation. Although T3R MBC is also slightly elevated in HI group, however, TT4 and FT4 are decreases than that of control. Which suggested that after being iodine deficiency for a long time a transient iodine-induced hyperthyroidism could appear when supplies with appropriate iodine.
出处
《中国地方病学杂志》
CAS
CSCD
北大核心
2004年第3期198-200,共3页
Chinese Jouranl of Endemiology
基金
国家自然科学基金资助项目(19975055)
