乙烯硫脲对FRTL-5细胞甲状腺球蛋白合成分泌及摄碘功能的影响

目的探讨乙烯硫脲(ETU)对FRTL-5细胞的甲状腺球蛋白(TG)合成分泌和摄碘能力的影响。方法用30、150和270μg/ml乙烯硫脲处理FRTL-5细胞后,用MTT法和3H掺入法测乙烯硫脲的细胞毒性;放免法和免疫细胞化学法测乙烯硫脲对TG合成分泌的影响;RT-PCR检测乙烯硫脲对nis基因和tg基因的影响;同位素示踪法检测对细胞摄碘能力的影响。结果30～270μg/ml乙烯硫脲对FRTL-5细胞无显著细胞毒性。150μg/ml和270μg/ml乙烯硫脲显著降低培养液中TG浓度,对胞浆内TG无显著影响;使nis基因转录显著降低,对tg基因无显著影响;150μg/ml和270μg/ml乙烯硫脲显著降低细胞摄碘能力。结论乙烯硫脲可抑制FRTL-5细胞分泌TG,对TG合成无显著影响;乙烯硫脲各剂量组显著降低nis基因转录,但仅在高剂量组显著降低细胞摄碘能力。     

杀草强影响Fischer大鼠甲状腺滤泡上皮细胞甲状腺球蛋白的机制研究

目的 探讨杀草强影响Fischer大鼠甲状腺滤泡上皮细胞(FRTL-5细胞)甲状腺球蛋白(TG)的机制.方法 1、10和100μg/ml杀草强处理FRTL-5细胞后,用3H掺入法测杀草强的细胞毒性;放免法和免疫细胞化学法测杀草强对TG、甲状腺转录因子1(TTF-1)的影响;免疫荧光法检测杀草强对细胞表面促甲状腺素受体(...     

过量碘对甲状腺激素代谢的损伤及硒的干预作用

目的研究过量碘性甲状腺激素代谢紊乱的机制并寻求合适的硒干预剂量。方法140只Balb/c小鼠分为7组:正常组、过量碘组(饮水含碘3000μg/L)和5个补硒组(饮水含碘3000μg/L,硒分别为0.1、0.2、0.3、0.4和0.5mg/L),共喂养16周。放射免疫法测定血清甲状腺激素水平,砷铈催化分光光度法测定尿碘和甲状腺碘水平,测定甲状腺谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)和甲状腺过氧化物酶(TPO)活性以及丙二醛(MDA)水平。结果0.1～0.5mg/L补硒组甲状腺激素水平与正常组比较差异无显著性,0.2mg/L补硒组甲状腺内碘含量较过量碘组显著下降(P<0.05),0.2～0.3mg/L补硒组甲状腺GSH-Px、SOD活性和MDA水平与正常组比较差异无显著性,0.1～0.3mg/L补硒组TPO活性与正常组比较差异无显著性。结论补充硒对过量碘导致的小鼠甲状腺氧化/抗氧化水平失衡、TPO活性水平下降都有有效的干预作用。     

小鼠甲状腺自体免疫性疾病与过量碘关系

目的探讨高剂量碘与小鼠甲状腺器官特异性免疫疾病的关系。方法采用6组BaLB/c雌性小鼠,分别给予0,1 500,3 000,6 000,12 000及24 000μg/L的碘酸钾,饲养3个月后,测TT4、TT3和促甲状腺激素（TSH）水平;同时取甲状腺作免疫组化分析及病理切片分析。结果高碘可致小鼠弥漫胶质性甲状腺肿,可升高血清TT4、TSH,甲状腺IgG抗体的水平及血清促甲状腺激素受体抗体（TSHRab）的阳性率,降低血清TT3。TT3、TT4、TSH与碘都呈显著剂量-反应关系,甲状腺IgG抗体及TSHRab阳性率水平从6 000μg/L组开始与对照组比较,差异有统计学意义。结论碘6 000μg/L以上碘剂量可诱发以体液免疫为主的小鼠甲状腺自体免疫性疾病。     

不同碘摄入水平与人群甲状腺疾病关系

目的 观察不同碘摄入水平与正常人群甲状腺疾病之间的关系.方法 选择甲状腺功能正常的健康志愿者,年龄为18～24岁.随机分为7组,各组每人每天补充500,750,1000,1250,1500,1750,2000μg的碘剂,为期4周.采用放免法测定血清甲状腺过氧化物酶抗体(TPOAb)、甲状腺球蛋白抗体(TGAb),采用化学发光法测定血清游离T4(FT4),灵敏促甲状腺激素(sTSH)浓度.结果 志愿者接受500～2000μg/d的碘剂2周后即出现亚临床甲状腺功能减退的发生.补充500 μg/d碘剂量组人群亚临床甲状腺功能减退的发病率较低(15.00%)且随补碘时间的延长发病率稳定不变,除1750μg/d组稍有下降外,其余各组的亚临床甲状腺功能减退的发病率随着补充碘剂时间的延长,人群呈现发病率上升的趋势,发病率在28.00%～47.37%之间.4周后各剂量组未见临床甲状腺功能减退患者.结论 甲状腺功能正常的健康人群在短期内摄入包括膳食在内的高剂量碘(840～2340μg),将出现以亚临床甲状腺功能减退为主的功能异常症状.     

甲状腺素干扰物对甲状腺滤泡细胞分泌甲状腺球蛋白功能的影响

目的了解几种典型甲状腺素干扰物对甲状腺滤泡(FRTL-5)细胞分泌甲状腺球蛋白功能的影响,探讨其干扰甲状腺素水平的细胞学机制及建立甲状腺素干扰物甄别方法的可行性。方法将大鼠FRTL-5细胞体外培养后接种于24孔培养板,每孔细胞数2×105个,待细胞贴壁后分别加入受试物丙硫氧嘧啶、叶枯宁[N,N-甲撑-双(2-氨基-5-巯基-1,3,4-噻二唑)]、磺胺二甲嘧啶和杀草强,各设1组溶剂对照,置CO2孵箱培养48h后,每孔取1ml培养液,用放射免疫法测定甲状腺球蛋白的浓度。结果4个实验组的甲状腺球蛋白浓度与对照组相比均降低,差异有显著性(P<0.05),且可能存在剂量-效应关系。结论降低甲状腺细胞合成或分泌甲状腺球蛋白可能是这4种甲状腺素干扰物的作用机制之一。FRTL-5细胞分泌甲状腺球蛋白的功能是一个相对灵敏的指标,与其他体内体外实验结合可用于甲状腺素干扰物的一阶段甄别(初筛)方法。     

硒对小鼠高碘性氧化损伤的干预作用研究

目的:研究高碘性甲状腺肿形成的机制并寻求合适的硒干预剂量。方法:140只Balb/c小鼠分为7组:正常组、高碘组(饮水含碘3000μg/L)和5个补硒组(饮水含碘3000μg/L,硒分别为0.1、0.2、0.3、0.4、0.5mg/L),共喂养16w。放射免疫法测定甲状腺激素水平,测定血浆、肝脏、肾脏和甲状腺组织谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)活性,丙二醛(MDA)水平。结果:高碘组GSH-Px、SOD活性下降,MDA含量升高,而经饮水补充0.2~0.3mg/L硒组各项指标与正常组无显著性差异。结论:高碘会导致小鼠抗氧化能力下降,而经饮水补充0.2~0.3mg/L硒是有效的干预剂量。     

碘缺乏和碘过量对甲状腺自身免疫影响的实验研究

目的观察碘对大鼠免疫细胞(CD4/CD8)、甲状腺球蛋白抗体(thyroglobulin autoanti-body,TGAb)、甲状腺过氧化物酶抗体(thyroid peroxidase autoantibody,TPOAb)的作用,探讨碘对甲状腺自身免疫应答的影响。方法将Wistar大鼠分为6组(1)低碘组(LI)摄碘量<1μg/d;(2)适碘组(NI)摄碘量为6.15μg/d;(3)5倍碘组(5HI)摄碘量为30.75μg/d;(4)10倍碘组(10HI)摄碘量为61.50μg/d;(5)50倍碘组(50HI)摄碘量为307.50μg/d;(6)100倍碘(100HI)摄碘量为615.00μg/d。采用流式细胞仪检测外周血CD4和CD8免疫细胞数量,应用放射免疫分析法(RIA)检测血清中TGAb和TPOAb水平。结果LI组大鼠外周血CD4细胞为(57.9±4.3)%,NI组为(51.2±4.9)%,两组比较,差异有统计学意义。100HI组CD8细胞为(18.4±3.1)%,NI组为(26.5±4.1)%,两组比较,差异有统计学意义。LI组CD4/CD8比值为2.4±0.40,100HI组为2.7±0.4,均高于NI组的1.9±0.3。LI组TGAb含量为(1510±221)CPM,明显低于NI组的(2099±220)CPM;50HI组和100HI组的TGAb含量分别为(3986±286)和(3550±378)CPM,较NI组明显升高。TPOAb含量在10HI组和50HI组分别为(2066±184)和(2141±163)CPM,均明显低于NI组的(2372±245)CPM。结论碘会直接或间接影响CD4/CD8细胞数量和甲状腺自身抗体(TGAb、TPOAb)生成水平,参与甲状腺自身免疫反应。低碘或100倍高碘的摄入,可不同程度地激活Wistar大鼠的免疫状态。在甲状腺自身免疫应答中,碘对甲状腺球蛋白和甲状腺过氧化物酶抗原的影响不相同。     

Urinary iodine and thyroid status of New Zealand residents

OBJECTIVES: The aim of this project was to assess the clinical significance of our low iodine excretions in terms of thyroid hormone status and thyroid volume in an adult population in a low soil iodine area of the South Island of New Zealand. DESIGN AND SETTING: Two-hundred and thirty-three residents of Otago, New Zealand collected two 24 h urine samples for assessment of iodine status. Thyroid status was determined from serum total T(4), TSH and thyroglobulin, and thyroid volumes. Relationships between urinary iodide excretion and measures of thyroid status were determined and subjects were allocated to one of three groups according to low, medium and high iodide excretion, for comparison of thyroid hormones and thyroid volumes. RESULTS: Significant correlations were found for relationships between measures of urinary iodide excretion and thyroid volume and thyroglobulin. Multiple regression analysis of data for subjects divided into three groups according to 24 h urinary iodide excretion (<60, 60-90; >90 microg iodide/day) or iodide/creatinine ratio (<40; 40-60; >60 microg/g Cr) showed significant differences in thyroid volume (P=0.029; P=0.035, respectively) and thyroglobulin (P=0.019; P=0.005, respectively) among the groups. CONCLUSIONS: The results of this study confirm the low iodide excretions of Otago residents, and indicate that the fall in iodine status is being reflected in clinical measures of thyroid status, including enlarged thyroid glands and elevated thyroglobulin. Our observations suggest the possible re-emergence of mild iodine deficiency and goitres in New Zealand. This situation is likely to worsen should iodine intakes continue to fall and continued monitoring of the situation is imperative.     

磺胺二甲嘧啶对FRTL-5细胞基因表达谱的影响

目的研究磺胺二甲嘧啶对FRTL5细胞基因表达谱的影响,探讨环境甲状腺素干扰物的作用机制。方法指数生长期细胞经20μgml磺胺二甲嘧啶处理24h后,用TRIzol法提取RNA,用9753位点的cDNA芯片检测基因表达情况,实验组和对照组细胞分别用Cy3dCTP和Cy5dCTP标记,计算Cy3和Cy5的比值,找出差异表达基因。结果芯片经扫描分析后,发现表达有差异的基因共有679条占芯片上基因总数的70%,其中395(40%)条基因表达增加,284(30%)条基因表达下降,涉及基因表达调控、细胞周期调控、细胞免疫,细胞代谢等众多事件。结论磺胺二甲嘧啶对FRTL-5细胞的毒性效应,其机制涉及多种基因。     

过量碘对甲状腺细胞组织蛋白水解酶的作用研究

目的探讨甲状腺蛋白水解酶在过量碘性甲状腺损伤中的作用。方法选取FRTL细胞系为研究对象,正常组培养基内不加碘,高碘组分别含碘(碘化钾)1、5、10、50、100mmol/L,培养6、12、24、48、72h,荧光分光光度法测定蛋白酶B(CB)活性,Lowry法测定蛋白酶D(CD)活性,荧光定量PCR法测定CB和CD的mRNA水平。结果50mmol/L碘作用12h开始出现CB活性的下降,但是需作用24h始出现CD活性的下降。50mmol/L碘作用24h,高碘组CB、CDmRNA水平均较正常组显著下降。结论CB和CD活性的下降是过量碘导致的甲状腺胶质潴留的重要原因之一。     

Induction of hepatic cytochrome P4501A1/2B activity and disruption of thyroglobulin synthesis/secretion by mono-ortho polychlorinated biphenyl and its hydroxylated metabolites in rat cell lines

As the active metabolites of polychlorinated biphenyl (PCBs), hydroxylated polychlorinated biphenyls (OH-PCBs) are found in wildlife and human tissues. They have been proposed as main contributors for endocrine disruption of PCBs in living organisms. In this study, mono-ortho PCB 156 and its hydroxylated metabolites 4'-OH-PCB 159, 4'-OH-PCB 121, and 4'-OH-PCB 72 were selected to investigate the toxic effects on rat hepatoma H4IIE cell line and rat thyroid follicle FRTL-5 cell line at concentrations of 1, 10(2), 10(4) nM. 7-Ethoxyresorufin-O-deethylase (EROD) and 7-pentoxyresorufin-O-dealkylase (PROD) activities were determined with micro-EROD/PROD to indicate cytochrome P4501A1 (CYP1A1) and cytochrome P4502B (CYP2B) induction in the H4IIE cell after exposure for 72 h. To assess thyroid disruption of these compounds, thyroglobulin concentrations also were detected inside FRTL-5 cell with immunocellularchemistry and in its medium with radioimmunoassay after exposure for 24 h. Significant inductions of EROD activity by PCB156 at 10(2) and 10(4) nM (p < 0.05) were observed, but no effects by the three OH-PCBs in H4IIE cell line. 7-Pentoxyresorufin-O-dealkylase activities were induced only by 10(4) nM of PCB156 and the three OH-PCBs (p < 0.05). Meanwhile, significant increases of thyroglobulin concentrations were observed in the medium of FRTL-5 cell exposed to 4'-OH-PCB 121 and 4'-OH-PCB 72 at all of the test concentrations (p < 0.05), but not to the other compounds. The results demonstrated that mono-ortho PCBs mainly could be metabolized to hydroxylated metabolites through CYP1A1 instead of CYP2B. Moreover, after being metabolized, OH-PCBs still sustained the ability to induce PROD activity and did exhibit the disruption on thyroglobulin synthesis/excretion in rat cells.     

应用FRTL-5细胞甄别农药亚乙基硫脲、二甲戊乐灵甲状腺素干扰效应

目的　了解亚乙基硫脲 (ETU)、二甲戊乐灵对FRTL 5细胞分泌甲状腺球蛋白的影响。方法　首先用MTT法测这两种化学物的细胞毒性。然后根据细胞毒性结果确定染毒剂量并用放免法测细胞培养液甲状腺球蛋白的浓度。结果　MTT实验中 ,当二甲戊乐灵浓度大于 5ng μl,亚乙基硫脲浓度大于 36 0ng μl时 ,有明显细胞毒性。亚乙基硫脲和二甲戊乐灵在中高剂量均可引起甲状腺球蛋白浓度显著降低。结论　这两种化学物可能干扰甲状腺球蛋白的合成和分泌。     

Selenium concentration in serum of women with thyroid gland disease

The aim of this study was to estimate the concentration of total selenium in serum women with thyroid gland disease. Selenium was determined by atomic absorption spectrometry using the hydride generation technique (HG-AAS). Selenium was determined in 30 patients with thyroid gland disease and in 12 healthy controls. Selenium concentration of serum was variously in patients than in control group and patients with different thyroid gland disease. The average concentration of selenium in control group was 0.0694 microg/ml, in goiter group 0.0529 microg/ml, in hyperactivity group 0.0441 microg/ml, in hypofunction group 0.0520 microg/ml.g/ml.     

Temporal patterns in perchlorate, thiocyanate, and iodide excretion in human milk

BACKGROUND: Perchlorate and thiocyanate interfere with iodide uptake at the sodium-iodide symporter and are potential disruptors of thyroid hormone synthesis. Perchlorate is a common contaminant of water, food, and human milk. Although it is known that iodide undergoes significant diurnal variations in serum and urinary excretion, less is known about diurnal variations of milk iodide levels. OBJECTIVES: Variability in perchlorate and thiocyanate excretion in human milk has not been examined. Our objective was to determine variability of perchlorate, thiocyanate, and iodide in serially collected samples of human milk. METHODS: Ten lactating women were asked to collect six milk samples on each of 3 days. As an alternative, subjects were asked to collect as many milk samples as comfortably possible over 3 days. Samples were analyzed for perchlorate, iodide, and thiocyanate by ion chromatography coupled with mass spectrometry. RESULTS: Individual perchlorate, iodide, and thiocyanate levels varied significantly over time; there was also considerable variation among individuals. The iodide range, mean +/- SD, and median for all samples (n = 108) were 3.1-334 microg/L, 87.9 +/- 80.9 microg/L, and 55.2 microg/L, respectively. The range, mean +/- SD, and median of perchlorate in all samples (n = 147) were 0.5-39.5 microg/L, 5.8 +/- 6.2 microg/L, and 4.0 microg/L. The range, mean +/- SD, and median of thiocyanate in all samples (n = 117) were 0.4 -228.3 microg/L, 35.6 +/- 57.9 microg/L, and 5.6 microg/L. The data are not symmetrically distributed; the mean is higher than the median in all cases. CONCLUSIONS: Iodine intake may be inadequate in a significant fraction of this study population. Perchlorate and thiocyanate appear to be common in human milk. The role of these chemicals in reducing breast milk iodide is in need of further investigation.