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

水生系统受到污染物的威胁，也受到全球气候变化以及城市和工业废水排放造成的温度升高和氧气水平下降（缺氧）的威胁。沿海和内陆鱼类暴露在日益增加的城市化和工业化的污染物中。内分泌干扰物是一种环境化学物质，通过改变鱼类控制繁殖、后代发育和生长的激素系统的正常功能来影响鱼类。我的建议旨在提高对为什么有些鱼类对环境内分泌干扰物更敏感的理解，以及环境条件的变化（例如温度和缺氧）如何影响鱼类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，东海岸的河口mummichog （Fundulus heteroclitus）和中部地区的淡水黑头鲦鱼（Pimephales promelas）。这两个物种对温度和溶解氧的环境变化都有一定的适应性，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）和农业生产（来自肉类生产）进入我们水道的合成雌激素的影响。我们希望在日益脆弱的环境中确定这些重要物种对内分泌干扰物的相对敏感性，以影响其性腺和后代的发育。特别令人感兴趣的是鱼类代谢和清除污染物的生理过程，通过不同组织中受体对污染物的亲和力差异做出反应，以及它们的关键性腺成熟过程对外部内分泌干扰物的恢复能力。总的来说，我实验室的研究旨在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，以及这种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善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.