摘要
不同碘营养状态Wistar大鼠分别于饲养3、6、12个月时处死,放射免疫法测定血清甲状腺激素水平。放射性核素分析法检测大鼠脑组织Ⅱ型脱碘酶(DⅡ)和肝组织Ⅰ型脱碘酶(DⅠ)的活性。结果显示在早期碘缺乏状态下,动物出现以低T_4为主要表现的甲减,DⅠ和DⅡ活性代偿性上调。高碘在转录后直接抑制DⅠ的活性,使血清TT_3和FT_3下降,而DⅡ的活性增高,可能是由于T_4和T_3对酶的底物诱导失活所致。
Wistar rats with different levels of iodine nutrition were killed after 3, 6 and 12 months of experiments. Serum thyroid hormones were assayed with RIA. The activity of type Ⅰ deiodinase （ D Ⅰ ） and type Ⅱ deiodinase （D Ⅱ ） was measured based on the release of radioiodide from the ^125Ⅰ-labeled substrate. The result showed that hypothyroidism reflected by decreased T4 happened during the initial phase of iodine deficiency. The activity of D Ⅰ and D Ⅱ in rats was raised significantly in iodine deficiency groups. An excess of iodine inhibited D Ⅰ activity resulting in decreased serum TT3 and FT3. However, D Ⅱ activity increased in rats with iodine excess, attributing to the inactivation of T3 and T4 to the substrate of D Ⅱ enzyme.
出处
《中华内分泌代谢杂志》
CAS
CSCD
北大核心
2007年第6期515-516,共2页
Chinese Journal of Endocrinology and Metabolism
基金
国家自然科学基金重点项目(30230330)
国家自然科学基金(30271154)
天津市科技发展计划项目(05YFGDSF02700)
关键词
碘化物过氧化物酶
碘缺乏
碘过量
Iodide peroxidase
Iodine deficiency
Iodine excess
