Comparative sensitivity and mechanisms of action of endemic fish species to environmental endocrine disruptors

水生系统正受到污染物的威胁，以及全球气候变化引起的气温上升和氧气水平下降(缺氧)以及市政和工业废水排放的威胁。沿海和内陆鱼类暴露在日益城市化和工业化带来的污染中。内分泌干扰物是一种环境化学物质，通过改变控制繁殖、后代发育和生长的荷尔蒙系统的正常功能来影响鱼类。我的建议旨在提高对为什么一些鱼对环境内分泌干扰物更敏感的理解，以及环境条件(例如温度和缺氧)的变化如何影响鱼体内污染物的相互作用。我们将对两种加拿大鱼类进行研究，即东部海岸的河口木鼠和中部地区的淡水鱼(Pimephales Proelas)。这两个物种对环境温度和溶解氧的变化都有一定的适应能力，使它们成为很好的模式物种。我们将重点关注通过污水(来自服用避孕药的妇女)进入我们的水道的合成雌激素和来自农业经营(来自肉类生产)的合成雄激素的影响。我们希望根据这些重要物种的性腺和后代在日益脆弱的环境中的发育情况来确定它们对内分泌干扰物的相对敏感性。特别令人感兴趣的是鱼类代谢和清除(清除)污染物的生理过程，通过不同组织中对污染物的受体亲和力的差异做出反应，以及它们关键的性腺成熟过程对外部内分泌干扰物暴露的弹性。总体而言，我实验室的研究试图了解内分泌干扰物影响内分泌状态的机制、影响内分泌状态的因素以及内分泌状态受损对鱼类繁殖、生长和发育的影响。通过更好地了解不同物种的作用机制，我们将能够更好地预测如何改进水生系统管理以保护鱼类健康。

Aquatic systems are under threat from contaminants, as well as from increasing temperature and decreasing levels of oxygen (hypoxia) from global climate change and release of municipal and industrial effluents. Coastal and inland fish are exposed to contaminants from increasing urbanization and industrialization. Endocrine disruptors are environmental chemicals that affect fish by altering the normal functioning of their hormone systems which control reproduction, offspring development and growth. My proposal seeks to improve understanding of why some fish are more sensitive to environmental endocrine disruptors, and how changes in environmental conditions (e.g., temperature and hypoxia) affect the interaction of the contaminants within the fish. We will undertake studies on two Canadian fish species, the estuarine mummichog (Fundulus heteroclitus) of the east coast and the freshwater fathead minnow (Pimephales promelas) of the central region. Both species are somewhat resilient to environmental changes in temperature and dissolved oxygen, making them good model species. We will focus on the effects of synthetic estrogens which enter our waterways via sewage (from women taking birth control pills) and synthetic androgens from agricultural operations (from meat production). We hope to determine the relative sensitivity to endocrine disruptors of these important species in terms of their gonadal and offspring development in increasingly vulnerable environments. Of particular interest are the physiological processes by which the fish metabolize and clear (remove) the contaminants, respond via differences in receptor affinity to the contaminants in different tissues, and the resilience of their critical gonadal maturation process to exposure to external endocrine disruptors. Overall, studies in my laboratory seek to understand the mechanisms by which endocrine disruptors affect endocrine status, the factors affecting such, and the consequences of this impaired endocrine status on reproduction, growth and development in fish. By better understanding mechanisms of action in different species, we will be better able to make predictions of how to improve aquatic systems management to protect fish health.