Understanding endocrine disruptor effects in fish at various levels of biological organization

工业和城市排放物，如纸浆和造纸厂的废水和污水，含有被称为“内分泌干扰物”的化合物。 这些化合物的化学结构使它们能够模仿鱼类激素，如雌激素和睾丸激素。 当鱼类暴露于内分泌干扰物时，它们正常的激素系统就会改变。 这可能会导致卵巢和睾丸变小，“间性”（卵巢和睾丸组织都在一个性腺中），生殖激素的血液水平降低以及可以产生的后代数量变化。 我实验室的研究重点是了解污染物是如何干扰鱼类生殖系统的正常功能的。 我们对内分泌干扰污染物可能对沿海系统产生的影响感到关切。 因此，我们使用一种常见的东海岸咸水小鱼，mummichog（Fundulus heteroclitus）进行研究。 在实验室工作，我们将鱼的不同生命阶段暴露于雌激素和雄激素，以及雌激素和雄激素拮抗剂（阻断而不是模仿天然激素）。 然后，我们确定在什么样的生命阶段（例如，发育中的胚胎/幼虫、青少年、生殖性成虫）发生影响。 当我们了解了哪些生命阶段受到影响时，我们就会研究污染物产生影响的生化机制。 我们主要感兴趣的是内分泌干扰物对发育中的鱼类和生殖成体卵巢和睾丸正常功能的影响。 通过确定内分泌干扰物的作用机制，我们希望能够开发鱼类生物测定法，从而能够评估工业和城市污水对鱼类生殖影响的潜力。 长期目标是了解内分泌干扰物对野生鱼类的影响机制，从而找到保护我们沿海环境的方法。

Industrial and municipal discharges, such as pulp and paper mill effluents and sewage, contain compounds known as "endocrine disruptors". These compounds have chemical structures which make them able to mimic fish hormones, such as estrogen and testosterone. When fish are exposed to the endocrine disruptors, their normal hormone systems are altered. This can result in effects such as smaller ovaries and testes, "intersex" (in which both ovary and testis tissue are in one gonad), lower blood levels of reproductive hormones and changes in the numbers of offspring that can be produced. Research in my lab is focused on understanding how pollutants which are endocrine disruptors work to interfere with normal functioning of fish reproductive systems. We are concerned with the effect that endocrine disrupting contaminants can have in coastal systems. We therefore do our studies using a common east coast saltwater minnow, the mummichog (Fundulus heteroclitus). Working in the lab, we expose different life stages of the fish to estrogens and androgens, as well as estrogen and androgen antagonists (block rather than mimic the natural hormones). We then determine at what life stages (e.g., developing embryos/larvae, juveniles, reproductive adults) the effects occur. When we understand what life stages are being affected, we then investigate the biochemical mechanisms by which the contaminants have their effects. We are primarily interested in the effect that the endocrine disruptors have on normal functioning of the ovary and testis in developing fish and in reproductive adults. By determining the mechanisms by which endocrine disruptors work, we hope to be able to develop fish bioassays which will be able to assess the potential of industrial and municipal effluents to cause reproductive effects in fish. The long-term goal is to understand mechanisms of endocrine disruptor effects in wild fish, and therefore to find ways to protect our coastal environments.