环境雌激素双酚A对脑和行为发育的影响

双酚A是一种具有代表性的环境内分泌干扰物, 其广泛使用引起的对人类和野生动物的危害不容忽视. 双酚A具有类雌激素和抗雌激素活性, 可与雌激素受体结合, 模拟或干扰体内雌激素的合成、代谢和活动, 从而影响机体的生理功能. 在脑发育过程中, 双酚A不仅影响脑内雌激素合成关键酶芳香化酶的表达和活性, 还可改变不同脑区雌激素受体(ERα和ERβ)的表达, 并因此放大或干扰雌激素对脑发育的调节作用. 经典的雌激素核受体机制和非基因组细胞信号系统均参与双酚A对脑发育的影响. 许多脑区特别是与行为相关的如下丘脑、脑干蓝斑、皮层和海马等脑区的结构、递质系统等发育受双酚A影响, 干扰其发育的性别分化, 并因此影响生殖行为、探究、焦虑和学习记忆等多种神经行为的性别分化. 双酚A影响脑发育的细胞、脑区和时间特异性, 以及对脑发育过程影响的动态变化, 使双酚A对脑发育的影响非常复杂. 发育中的脑对双酚A特别敏感, 低于环境排放安全标准剂量的双酚A已可影响脑和行为的发育. 因此, 双酚A环境排放安全标准的重新制定非常必要, 而对双酚A毒理学的进一步实验研究和流行病学研究将有助于其环境排放安全新标准的确定.     

环境内分泌干扰物雌激素的微生物降解研究进展

雌激素是一类重要的环境内分泌干扰物。微生物降解是一种去除环境雌激素与进行环境修复的最绿色、环保、经济的方法。本文从分析雌激素的主要来源和危害、归纳国内外已报道的雌激素降解菌、总结雌激素降解的相关基因和组学研究进展、阐述雌激素的降解通路和降解机制这4个方面,概括阐述了环境雌激素的微生物降解作用,并对未来雌激素降解研究的主要内容与方向提出展望。     

环境中雌激素的微生物降解

环境中的雌激素是一类重要的环境内分泌干扰物,微生物降解是去除环境雌激素的主要途径。通过归纳已报道的雌激素降解细菌、总结其降解雌激素的机制、分析雌激素降解途径以及其他真核微生物的雌激素降解作用4个方面,概括阐述了雌激素的微生物降解作用,并对未来的研究方向提出展望。     

环境雌激素的微生物代谢

环境雌激素作为一类重要的新型环境污染物,可通过干扰生物体的内分泌系统危害生物体健康。微生物降解是去除环境雌激素与进行环境修复的主要手段。本文归纳整理了目前研究较深入的雌激素降解微生物,类比阐述了其预测的降解通路与降解机制,并对后续环境雌激素降解研究的主要内容与方向进行了展望。     

环境雌激素双酚A的研究进展

环境荷尔蒙是现代生命科学领域研究的热点之一,如今越来越多的人开始关注这一话题。在我们的生活环境中充斥着各种化学有毒试剂,其中,有一类物质能够模拟或抑制内分泌激素的活动,我们称之为内分泌干扰物。内分泌干扰物有能力改变内分泌系统的结构和功能。双酚A作为一种环境雌激素,属于内分泌干扰物的一种。双酚A被广泛应用于聚碳酸酯塑料和环氧树脂的制造。双酚A具有弱雌激素效应,能够与雌激素受体结合,引起内分泌系统的应答。目前的研究表明,双酚A会透过血胎屏障影响到胚胎发育,会对神经内分泌系统、肝组织功能以及生殖器的发育造成损伤。本文主要综述了环境雌激素双酚A在小鼠发育阶段所引起的诸多不利影响,并对环境荷尔蒙未来的研究方向进行了展望。     

环境雌激素的微生物降解

雌激素作为环境内分泌干扰物的一类重要物质,生物降解法是最为经济、最为绿色和最为适用的去除方法。通过分析雌激素的主要来源和危害、国内外雌激素降解菌的筛选与鉴定、类固醇雌激素降解酶的表达与检测、雌激素降解菌的基因组学特征以及雌激素的降解途径和机制,进一步阐述了雌激素生物降解的研究现状与进展,对未来的研究工作作出了展望。     

环境内分泌干扰物对生殖健康影响的研究进展

环境内分泌干扰物(environmental endocrine disruptors,EEDs)是指环境中天然存在或污染的能够干扰机体内自然激素的合成、分泌、转运、结合、作用和消除等过程,表现出拟自然激素或抗自然激素的生理学作用的一类化合物。它们与人们的生活密不可分,比如邻苯二甲酸酯类(PAEs)和双酚A(BPA),就广泛存在于食品包装、儿童玩具及生活用品中。大量实验证据以及流行病学的调查表明环境内分泌干扰物对动物雌激素、睾酮、甲状腺素、儿茶酚胺等呈现显著的干扰效应,是生殖障碍、出生缺陷、发育异常、代谢紊乱以及某些恶性肿瘤的发病率增加的原因之一。本文归纳了环境内分泌干扰物(EEDs)对生殖健康影响的研究进展。     

二恶英对雌激素受体的干扰作用

核受体相关的肿瘤,如乳腺癌和前列腺癌的发生、发展主要依赖于性激素的分泌。环境内分泌干扰物如Ⅲ二恶英,可作为雌激素受体的诱导配体,直接或间接地与转录因子相互作用,从而干扰基因的转录。此外,二恶英还能使雌激素受体发生泛素化修饰,促进它的降解,并使雌激素依赖性的基因转录受到抑制,成为内分泌干扰因子。本文综述了二恶英的类雌激素效应、致癌性以及激素信号干扰的最新研究进展。     

环境雌激素生态影响的研究进展

环境雌激素(ｅｃｏｅｓｔｒｏｇｅｎ) ,是指能够扰乱动物内分泌活动 ,生理活性与雌激素较为相似的动物体外化学物质 ,包括人工合成化合物以及植物天然雌激素 ,由于目前所发现的干扰动物及人体内分泌系统的有机化合物绝大多数都具有激素特征 ,因此通常又将环境激素称做“干扰内分泌化合物”(ｅｎｄｏｃｒｉｎｅｄｉｓｒｕｐｔｉｎｇｃｈｅｍｉ ｃａｌｓ或ｅｎｄｏｃｒｉｎｅｄｉｓｒｕｐｔｅｒｓ)。环境激素问题只是在最近几年才引起世界关注 ,但由于环境激素污染范围广、影响大 ,对人类生存的威胁更直接 ,目前 ,西方国家将环境激素问题与臭…     

环境雄激素的危害、来源与环境行为

内分泌干扰物(EDCs)因低剂量即可导致严重的生理效应而成为研究的热点,环境雄激素就是典型的内分泌干扰物之一,它主要来源于畜禽粪尿的排放以及造纸厂和城市污水处理厂处理不彻底的废水排放,污染源的连续性排放致使环境雄激素物质在各类环境介质中被不断检出,并导致一些地区出现鱼类的雄性化现象,对环境健康和生态安全构成严重威胁。综述了环境雄激素的暴露危害、主要来源以及环境雄激素在不同环境中的浓度水平和分布特征,介绍了环境雄激素的分析检测手段,阐述了环境雄激素在环境中的迁移、吸附、降解等过程,并对环境雄激素的研究进行了展望。     

Use and role of invertebrate models in endocrine disruptor research and testing

Historically, invertebrates have been excellent models for studying endocrine systems and for testing toxic chemicals. Some invertebrate endocrine systems are well suited for testing chemicals and environmental media because of the ease of using certain species, their sensitivity to toxic chemicals, and the broad choice of models from which to choose. Such assays will be useful in identifying endocrine disruptors to protect invertebrate populations and as screening systems for vertebrates. Hormone systems are found in all animal phyla, although the most simple animals may have only rudimentary endocrine systems. Invertebrate endocrine systems use a variety of types of hormones, including steroids, peptides, simple amides, and terpenes. The most well-studied hormone systems are the molting and juvenile hormones in insects, the molting hormones in crustaceans, and several of the neurohormones in molluscs and arthropods. These groups offer several options for assays that may be useful for predicting endocrine disruption in invertebrates. A few invertebrate phyla offer predictive capabilities for understanding vertebrate endocrine-disrupting chemicals. The echinoderms, and to a lesser extent molluscs, have closer evolutionary relationships with the vertebrates than the arthropods and these phyla. The recently identified estrogen receptor structure within the genome of the marine gastropod, Aplysia, indicates that the estrogens, and probably the basic steroid receptor, are quite old evolutionarily. This review of the recent literature confirms the effects of some endocrine-disrupting chemicals on invertebrates--tributyltin on snails, pesticides on insects and crustaceans, and industrial compounds on marine animals.     

Endocrine modulation and the fragile balance of homeostasis--an overview

Endocrine modulation by natural and synthetic chemicals and the eventually resulting beneficial or adverse effects for human and animal health are controversially debated not only among scientists but particularly in the public. Most information is available on so-called environmental estrogens, however the amount of information on substances interfering with other hormonal axes steadily increases, particularly on those exhibiting (anti)androgenic activities. The aim of this paper is to summarize existing data and to give an overview on the potential pathways leading to interferences of environmental hormones with homeostasis and eventually resulting health effects. Experimental evidence suggests the hypothesis that fetal and neonatal organisms may be at risk if exposed to environmental estrogens. In contrary, it appears as if phytoestrogens, particularly those with selective estrogen receptor modulator- (SERM-)like activities have the potential to be useful in medical application, both as dietary means and as pharmaceuticals. Lacking valid information about the detailed analysis of the molecular mode of action for environmental estrogens, the possibility for an ultimate classification of environmental estrogens in "dangerous endocrine disruptors" and phytoestrogens in "useful pharmaceuticals" cannot be supported conclusively. Nevertheless both activities are likely.     

Genetic susceptibility and environmental estrogen-like compounds

Environmental chemicals with estrogenic activities have been suggested to be able to interact with the endocrine system. Endogenous estrogen is synthesized in the ovarian theca cells of premenopausal women or in the stromal adipose cells of the breast of postmenopausal women and minor quantities in peripheral tissue. These cells, as well as breast tissue, express all the necessary enzymes for this synthesis, CYP17, CYP11a, CYP19, 17-beta-hydroxysteroid hydrogenase, steroid sulfatase as well as enzymes further hydroxylating estradiol, such as CYP1A1, CYP3A4, CYP1B1, catechol-o-methyltransferase (COMT). Polymorphisms in these enzymes may have a possible role in the link between environmental estrogens and hormone-like substances and the interindividual risk of breast cancer.     

环境雌激素的生殖毒性的分子机理研究进展

环境激素（environmental endocrines,EEs）是外源性激素,可模拟体内天然激素与机体内的受体以及相应靶点结合,导致内分泌系统以及生殖系统功能紊乱。环境激素所产生的效应十分复杂,因此,进一步明确其毒性机理将为环境激素所致危害的预防和治疗提供理论依据。就环境雌激素的生殖、发育等毒性机理作一综述。     

A Computational Model to Predict Rat Ovarian Steroid Secretion from In Vitro Experiments with Endocrine Disruptors

A finely tuned balance between estrogens and androgens controls reproductive functions, and the last step of steroidogenesis plays a key role in maintaining that balance. Environmental toxicants are a serious health concern, and numerous studies have been devoted to studying the effects of endocrine disrupting chemicals (EDCs). The effects of EDCs on steroidogenic enzymes may influence steroid secretion and thus lead to reproductive toxicity. To predict hormonal balance disruption on the basis of data on aromatase activity and mRNA level modulation obtained in vitro on granulosa cells, we developed a mathematical model for the last gonadal steps of the sex steroid synthesis pathway. The model can simulate the ovarian synthesis and secretion of estrone, estradiol, androstenedione, and testosterone, and their response to endocrine disruption. The model is able to predict ovarian sex steroid concentrations under normal estrous cycle in female rat, and ovarian estradiol concentrations in adult female rats exposed to atrazine, bisphenol A, metabolites of methoxychlor or vinclozolin, and letrozole.     

Hormone als Schadstoffe?

Environmental estrogens Endocrine disrupters are environmental substances which interfere with the hormone system of organisms and thereby induce adverse effects. They exert their biological activity either by disrupting hormone metabolism or by imitating the biological action of the endogenous hormones. In the aquatic environment, an important group of endocrine disrupters is represented by the estrogen‐active compounds, which mimic the female sex hormone, 17β‐estradiol. Both laboratory experiments and field studies on fishes have demonstrated that already very low concentrations of environmental estrogens are able to induce disturbances in the hormone system and hormone‐regulated processes of fishes.     

Insights into endocrine-immunological disturbances in autoimmunity and their impact on treatment

The neuroendocrine immune (NEI) system is regarded as a fundamental network for the maintenance of health status (homeostasis), and it plays an important role in several systemic diseases, including autoimmune disorders. Among the major players of NEI pathways are steroid hormones of the adrenal (cortisol) and gonadal glands (sex hormones), neurohormones such as melatonin, and more recently the vitamin D endocrine system. Estrogens, melatonin and chronic stress (inducing decreased adrenal glucocorticoid release over a long time) strongly modulate the NEI system and stimulate the immune response. The vitamin D endocrine system is regarded as a potential immunosuppressive factor. Consequently, estrogens (especially in patients affected by B-cell-driven immunity) and melatonin should be avoided, and glucocorticoids (as replacement therapy) and vitamin D are allowed in the treatment of autoimmunity.