环境雌激素双酚A的样品前处理技术与分析检测研究进展

双酚A是重要的化工原料,也是常见的酚类环境雌激素,其污染问题广受关注。对环境、食品和生物样品中双酚A的样品前处理技术和分析检测进行了全面报道,包括常规溶剂提取、固相萃取、固相微萃取、液相微萃取、分子印迹聚合物萃取等提取技术,以及色谱分析、毛细管电泳分析、免疫分析、电化学分析、化学发光分析等检测方法,为双酚A环境雌激素的样品前处理和分析测定提供参考。     

雌激素对心肌Nrf2及GST和GCL的影响

雌激素的抗氧化作用与核转录相关因子(Nrf2)信号分子及其Nrf2/ARE信号路径有密切关系.Nrf2/ARE在调节机体抗氧化酶和Ⅱ相解毒酶的表达过程中起着非常重要的作用.利用原代培养心肌细胞缺氧/复氧模型,在雌激素预孵化条件下,研究了雌激素对谷胱甘肽-S-转移酶(GST)和谷氨酸半胱氨酸连接酶(GCL)表达及Nrf2核转移的影响,结果表明:雌激素能够明显增加GST和GCL的表达,促进Nrf2核转移.雌激素通过促进Nrf2入核及GST和GCL的表达发挥抗氧化作用.     

甾体雌激素的污染水平及转化机制*

近年来内分泌干扰物的污染逐渐引起国内外学者的注意,一些天然甾类雌激素及合成甾体类雌激素被发现具有很强的雌效应,环境中极小量的雌激素就能对人和动物的健康带来不可预测的危害。作者结合最近国内外的研究成果,对甾体雌激素的种类、来源及分布、环境浓度、转化机制等方面进行了综述。     

生殖健康类雌激素在地下环境中的迁移能力评价

 当存在雌激素污染风险的研究区缺乏数据或监测难度大时,为了判断地下环境中雌激素迁移能力,对地下水污染风险进行预警,需要先结合雌激素物质自身结构和在环境中的活性初步评估其在地下的淋溶迁移能力。本文在环境雌激素中选出直接影响生殖健康类雌激素物质81种,依据地下水污染指数(groundwater ubiquity score,GUS)法,对生殖健康类雌激素在地下环境中的迁移能力进行评价。结果表明,81种雌激素中,高淋溶迁移性的占69.14%,一般迁移性的占7.40%;其中包含于EPA优先控制有毒有机污染物名单中的雌二醇、雌三醇、雌酮、DDT和DDE的GUS值分别为3.58、7.73、3.19、-3.34和-2.68。5种雌激素中,雌三醇的GUS值最大,为7.73。本研究的81种雌激素中,GUS值高于雌三醇的有20种以上;所选生殖健康类雌激素在地下环境中的迁移主要受有机碳吸附系数(K_oc)的影响。     

Fatty acid modulation of antiestrogen action and antiestrogen-binding protein in cultured lymphoid cells

Summary Nonsteroidal antiestrogens reversibly and specifically inhibited the proliferation of two estrogen receptornegative lymphoid cell lines (EL4 and Raji) in a dose-dependent manner. [³H]Thymidine incorporation of concanavalin A-stimulated primary splenocytes was also inhibited by 10^–6 M clomiphene (1-[4-(2-diethylaminoethoxy)phenyl]-1,2-diphenyl-2-chloroethylene). The antiproliferative effect could be prevented by the simultaneous presence in the growth medium of 10^–5 M linoleic acid or 10^–5 M arachidonic acid but not by 10^–6 M estradiol. Both lymphoid cell lines had high affinity antiestrogen-binding sites whose affinity could be altered by conditions of growth. Growth of EL4 cells in RPMI 1640 medium supplemented with charcoal-pretreated 5% fetal calf serum (charcoal-stripped medium) resulted in significantly higher affinity (K_d 0.54 nM±0.11 nM; n=6) than growth in medium supplemented with untreated serum (complete medium) (K_d=1.68 nM±0.48 nM; n=6) (p<0.001). This change in affinity was partly due to removal of fatty acids from the growth medium by charcoal pretreatment, since addition of 10^–5 M linoleic acid or 10^–5 M gamma-linolenic to charcoal-stripped medium decreased the affinity of the antiestrogen-binding protein. In contrast, growth in 10^–5 M stearic acid or 10^–5 M oleic acid did not significantly alter the affinity of the antiestrogen-binding protein, whereas 10^–5 M palmitic acid significantly increased its affinity. The same fatty acids were also tested for their intrinsic effects on EL4 cell proliferation. Oleic, linoleic and gamma-linolenic acids were growth stimulatory while stearic and palmitic acids were not. Thus linoleic and gamma-linolenic acids whose presence in the growth medium was associated with decreased affinity of [³H]tamoxifen (1-[4-(2-dimethylaminoethoxy)phenyl]-1,2-diphenylbut-1(Z)-ene) binding to the intracellular antiestrogen-binding protein were also growth stimulatory. Unsaturated fatty acids have previously been shown to inhibit binding of [³H]tamoxifen to the antiestrogen-binding protein in a cell-free system. The present observations demonstrate that unsaturated fatty acids also modify the affinity of the antiestrogen-binding protein in intact cells.     

性激素诱导大鼠前列腺增生的免疫组织化学研究

Ｗｉｓｔａｒ雄性大鼠６５只分为正常对照组和实验组．后者均做双侧睾丸摘除术，术后３周根据不同的处理方法分为单纯阉割组、雄激素（Ｔ）处理组和不同比例雌雄激素处理组．以免疫组化ＡＢＣ法观察大鼠前列腺腹叶（ＲＶＰ）内雄激素受体（ＡＲ）和雌激素受体（ＥＲ）含量的变化。结果表明ＲＶＰ内ＥＲ变化不明显，ＡＲ含量在各实验组不同：单纯阉割组动物ＡＲ逐渐减少，雌激素（Ｅ２）与Ｔ同时处理较单用Ｔ处理ＡＲ增加更为显著，Ｅ２增加ＲＶＰ内ＡＲ含量的这种作用须在大鼠体内Ｔ大于一定含量时方能实现。提示Ｅ２可通过增加ＲＶＰ内ＡＲ的含量协同Ｔ对ＲＶＰ正常及异常生长的调节作用，本文对这种效应进行了讨论。     

类固醇激素对雌性实验鼠攻击行为的调节

通过分析讨论大鼠、小鼠的母性攻击行为和激素在怀孕、分娩、哺乳三个时期的变化、母性攻击行为的变化与激素水平变化之间的关系以及激素对母性攻击行为的调控 ,探讨激素对母性攻击行为的调节 .     

邻苯二甲酸丁基苄酯与邻苯二甲酸二丁酯的雌激素生物活性比较

通过采用体内小鼠子宫增重法检测环境雌激素邻苯二甲酸丁基苄酯(BBP)和邻苯二甲酸二丁酯(DBP)的雌激素活性.结果表明,BBP和DBP都具有较强的雌激素效应,且BBP的雌激素效应大于DBP.     

环境雌激素对人体和动物影响机制的研究进展

对环境雌激素的种类、特点、活性检测方法、作用机制及其对机体的影响进行了综述,重点 从整体和细胞水平回顾了各类环境雌激素对机体不同组织器官影响机制的研究进展,并对这一研 究领域的发展提出展望.