慢性碘过量对Wistar大鼠甲状腺功能及垂体促甲状腺素β表达的影响  

Effects of Chronic Iodine Excess on Expression of Thyroid Stimulating Hormone β in the Pituitary of Wistar Rats

作　　者：姜雅秋[1] 李宁娜[1] 刘秀[1] 单忠艳[1] 滕卫平[1] 

机构地区：[1]中国医科大学附属第一医院内分泌科,内分泌研究所,沈阳110001

出　　处：《中国医科大学学报》2012年第12期1083-1087,共5页Journal of China Medical University

基　　金：国家自然科学基金资助项目(30800918)

摘　　要：目的探讨不同碘摄入量对垂体促甲状腺素(TSH)含量及垂体促甲状腺素β(TSHβ)表达量的影响,阐明慢性碘过量对垂体TSH细胞合成与分泌功能的影响。方法选用碘营养正常的普通Wistar大鼠60只,随机分入正常对照组、3倍碘过量组、6倍碘过量组、10倍碘过量组和50倍碘过量组。于补碘8周后处死大鼠,制备垂体组织匀浆和脑及垂体组织冰冻切片。应用化学发光免疫测定法检测血清TSH水平,应用放射免疫法检测垂体组织TSH含量,应用免疫组织化学染色法及免疫荧光染色法检测垂体TSHβ蛋白的表达,应用Image Pro-plus软件进行图像分析处理。结果与正常对照组比较,3倍碘过量组和6倍碘过量组雌鼠血清TSH水平无明显变化(P>0.05),10倍碘过量组和50倍碘过量组雌鼠血清TSH水平显著升高(P<0.05);雄鼠血清TSH水平在过量摄入碘后无明显变化。与正常对照组比较,10倍碘过量组和50倍碘过量组雌鼠垂体组织内TSH的含量明显升高(P<0.05);碘摄入量的增高并没有引起雄鼠垂体内TSH含量明显升高。与正常对照组比较,10倍碘过量组和50倍碘过量组雌鼠垂体TSHβ表达量明显增高(P<0.05),雄鼠只有50倍碘过量组TSHβ表达量明显升高(P<0.05)。结论随碘摄入量的升高,雌鼠血清TSH水平显著升高,不同碘摄入量组雌鼠垂体组织TSH含量变化与血清TSH水平变化相一致。雌鼠垂体TSHβ蛋白表达量亦随碘摄入量的升高而增加。提示慢性碘过量可能是影响垂体合成和分泌TSH的因素之一,且对雌鼠的影响更显著。Objective To investigate the effects of different iodine intake on the concenlxation of thyroid stimulating hormone （TSH） and expression of TSHβ in pituitary of Wislar rats, elucidate whether chronic iodine excess impact the synthesis and secretion of TSH cells in the pituitary. Methods Wistar rats were randomly divided into 5 groups and respectively fed with ordinary food and water with iodine concen- tration of 400, 1 000, 1 500,and 4 800 μg/L,which represents adequate,sufficient,3,6, 10 and 50 times excess of iodine. Rats were sacri- riced after 8 weeks iodine feeding,blood samples were harvested from heart,and pituitary was quickly collected after decapitation. Iodine concentration was determined in urine by arsenic cerium catalytic spectrophotometry method （WS/TI07-1999）. Radioimmunoassay was used to determine TSH, Et4, ET3 in rats serum and TSH in pituitary homogenates. Immunohistochemistry and immunofluorescence were used to de- termine the expression of TSHβ in pituitary. All of the images were analyzed by Image Pro-plus software. Data was inputted by EXCEL soft- ware, analyzed by SPSS11.5 software. ANOVA were applied for means comparison. Results Serum TSH of female rats was significantly in- creased in 10HI and 50HI groups. There was no distinguished difference in serum TSH of male rats. The TSH in pituitary of female rats was similar to serum TSH,which were increased in 10HI and 50HI groups. There was no marked difference in pituitary TSH of male rats. The expression of female rat TSHβin pituitary were increased markedly in 10HI and 50HI groups. The expression of male rat TSHβ in pituitary was raised in 50HI group. Condusion Serum TSH of female rats was significantly increased by iodine excess. The pituitary TSH of female rats was similar to those in serum,but not in male rats. TSH protein expression of pituitary was increased in female rats with iodine excess, but TSH protein expression of male rats were only increased in 50HI group, suggesting that chronic iodine excess could affect the

关 键 词：碘过量 甲状腺功能 垂体 促甲状腺素β 

分 类 号：R714.14[医药卫生—妇产科学]