高碘对大鼠甲状腺过氧化物酶和钠碘转运体基因mRNA表达的影响  

Effects of iodine excess on TPO and NIS genes mRNA expression in rats

作　　者：肖建英[1] 孙靖靖[1] 张秀梅[1] 岳丹[1] 王翠瑶[1] 

机构地区：[1]辽宁医学院生物化学教研室,锦州121001

出　　处：《中国地方病学杂志》2008年第2期145-148,共4页Chinese Jouranl of Endemiology

基　　金：辽宁省教育厅资助项目（05L132）

摘　　要：目的观察长期碘过量对大鼠甲状腺过氧化物酶（TPO）和钠碘转运体（NIS）mRNA表达的影响。方法将SD大鼠按体质量随机分为对照（CI）组、高碘Ⅰ（HIⅠ）组、高碘Ⅱ（HIⅡ）组，分别饮用含碘5、5000、10000μg／L的自来水。6个月时取大鼠甲状腺，在光、电镜下观察甲状腺形态结构的变化；采用放射免疫法测定血清甲状腺激素水平：RT-PCR法检测甲状腺TPO、NISmRNA的表达。结果高碘组与CI组相比。部分甲状腺滤泡明显增大。滤泡腔内充满浓染胶质；血清矾、巩水平，HIⅠ组[（73．82±16．48）、（1．34±0．31）nmol／L]和HIⅡ组[（70．65±11．43）、（1．15±0．39）nmol／L]与对照组[（75．68±13．99）、（1．45±0．49）nmol／L]相比呈逐渐下降趋势，但组间差异无统计学意义（F值分别为0．371、1．163，P〉0．05）；TPO、NISmRNA表达水平，组间比较差异有统计学意义（F值分别为30．863、62．675，P〈0．05）。HIⅠ组（1．28±0．10、0．56±0．17）和HIⅡ组（1．14±0．04、0．39±0．06）均比对照组（1．39±0．08、0．71±0．13）明显降低（P〈0．05）。结论长期碘过量可造成甲状腺组织形态学改变．并且抑制甲状腺TPO、NISmRNA表达。Objective To observe the effects of iodine excess on thyroid morphology, the expression of thyroid peroxidase and sodium iodide symporter mRNA and to explore their mechanisms. Methods One-month SD rats were divided into three groups： control iodine（CI）, high iodine Ⅰ （HI Ⅰ ） and high iodine Ⅱ （HI Ⅱ ） and were fed with water containing iodine in different concentrations by adding KI03（5,5000,10 000 μg/L）respectively. Rats were sacrificed after being fed for six months. The morphology of thyroid was investigated under light microscopy and electron microscopy, the serum thyroid hormones and ratio of TPO/13-actin and NIS/13-actin were measured by radioimmunoassay and RT-PCR method. Results The major changes were increased follicles with colloid accumulation in HI groups. The levels of serum thyroid hormones TT3 and TT4 were decreased gradually from CI[（75.68 ± 13.99, 1.45 ± 0.49）nmol/L] to HIⅠ [ （73.82 ± 16.48, 1.34 ± 0.31）nmol/L]and Hill groups[（70.65 ± 11.43, 1.15± 0.39） nmol/L], but there were no significant differences among three groups（F= 0.371, 1.163, P〉 0.05）. The TPO and NIS mRNA expressions in HI Ⅰ （1.28 ± 0.10, 0.56± 0.17） and HI Ⅱ （1.14 ± 0.04, 0.39± 0.06） were significantly lower （F = 30.863, 62.675, P 〈 0.05） than those of control group （1.39 ± 0.08, 0.71±0.13）. Conclusions Chronic iodine excess leads to definite histological changes in rat thyroid,and inhibits the expressions of TPO and NIS mRNA as well as thyroid hormone synthesis,which in turn acts as a protective mechanism against iodine excess.

关 键 词：碘 甲状腺 甲状腺过氧化物酶 钠碘转运体 

分 类 号：R686[医药卫生—骨科学]