Tabata A, Miyamoto N, Ohnishi Y, Itoh M, Yamada T, Kamei T, Magara Y
Institute of Environmental Ecology, Metocean Environment Inc., 1334-5 Riemon Oh-igawa-cho, Shida-gun, Shizuoka, 421-0212 Japan.
Water Sci Technol. 2003;47(9):51-7.
Mature male medaka were continually exposed to four chemicals, p-n-nonylphenol (p-n-NP), nonylphenol (p-NP), bisphenol-A (BPA) and 17beta-estradiol (E2) to evaluate their estrogenic activities in the laboratory. In order to understand the effect of the chlorination that is applied widely in water and wastewater treatment, the above chemicals were chlorinated and then exposed to mature male medaka. Furthermore, in the case of vitellogenin, a is a female specific protein induced by the exposure to test waters containing the above chemicals after 5 weeks, medaka was returned to uncontaminated tap water to determine whether male medaka have a self recovery function from the effect of estrogenic chemicals. Much greater vitellogenin compared to the background levels were induced in the male medaka by separate exposure to 100 microg/L of p-NP, 1,000 microg/L of BPA and 0.05 microg/L of E2. The levels of vitellogenin increased with increasing exposure periods. The relative potencies of these chemicals descended in the order of E2>>p-NP>BPA. Vitellogenin levels inducible by these chemicals were drastically reduced as a result of the chlorination for 24 hours. However, a moderate increase in hepatocyte somatic index (HSI) meant the hepatic fatness was observed as a result of chlorination. It is not clear at this stage whether or not the formation of chlorination byproducts is responsible for this moderate increase in HSI. The vitellogenin concentration of male medaka exposed to chemicals for 5 weeks decreased gradually after return to the uncontaminated water. However, the vitellogenin concentration did not return to the initial normal levels even after 5 weeks. A clear relationship between the serum vitellogenin concentration and the hepatic vitellogenin concentration was also found. Since quantitative analytical procedures for hepatic vitellogenin are easier than those of the serum vitellogenin, measuring the estrogenic effect using the measurement of vitellogenin in liver is recommended.
在实验室中，将成年雄性青鳉持续暴露于四种化学物质，对叔壬基酚（p - n - NP）、壬基酚（p - NP）、双酚A（BPA）和17β - 雌二醇（E2），以评估它们的雌激素活性。为了了解广泛应用于水和废水处理中的氯化作用的影响，将上述化学物质进行氯化处理，然后使其暴露于成年雄性青鳉。此外，就卵黄蛋白原而言，其是在暴露于含有上述化学物质的试验水体5周后诱导产生的一种雌性特异性蛋白质，将青鳉放回未受污染的自来水中，以确定雄性青鳉是否具有从雌激素化学物质的影响中自我恢复的功能。单独暴露于100微克/升的p - NP、1000微克/升的BPA和0.05微克/升的E2时，雄性青鳉体内诱导产生的卵黄蛋白原比背景水平高得多。卵黄蛋白原的水平随着暴露时间的增加而升高。这些化学物质的相对效力按E2>>p - NP>BPA的顺序递减。经过24小时的氯化处理后，这些化学物质诱导产生的卵黄蛋白原水平大幅降低。然而，肝细胞体指数（HSI）适度增加意味着氯化处理导致观察到肝脏脂肪含量增加。现阶段尚不清楚氯化副产物的形成是否是导致HSI适度增加的原因。暴露于化学物质5周的雄性青鳉，在放回未受污染的水中后，其卵黄蛋白原浓度逐渐降低。然而，即使在5周后，卵黄蛋白原浓度也未恢复到初始正常水平。还发现血清卵黄蛋白原浓度与肝脏卵黄蛋白原浓度之间存在明显的关系。由于肝脏卵黄蛋白原的定量分析程序比血清卵黄蛋白原的程序更容易，因此建议使用肝脏中卵黄蛋白原的测量来评估雌激素效应。
