Institute of Environmental Pollution and Health, College of Environmental and Chemical Engineering, Shanghai University, Nanchen Rd 333, Baoshan District, Shanghai 200444, PR China.
Chemosphere. 2013 Oct;93(6):1104-10. doi: 10.1016/j.chemosphere.2013.06.025. Epub 2013 Jul 3.
The fertilized eggs of Japanese medaka (Oryzias latipes) were exposed to estrone (E1) at 5-5000 ng L(-1) for 15 d, and the hatched fry were exposed continuously to the same concentrations for the additional 15 d. Adverse effects on hatchability, time to hatching, and gross abnormalities occurred at 50 ng L(-1) or above. Then the fry were divided into a continual exposure group, and a water recovery group. When the fry were exposed to E1 for another 60 d, there was a decrease in the hepatosomatic index (HSI) of males and the influence disappeared in the water recovery group. The gonadosonatic index (GSI) of females at 500 ng L(-1) decreased significantly in another 60 d exposure. While the fry were maintained in dechlorinated tap water for 60 d, a significant decrease in female GSI was observed at 50 ng L(-1) or above. An increased GSI was found in males in both continual exposure and water recovery groups at all E1 treatments. Quantitative RT-PCR showed that vitellogenin-I (Vtg-I) gene expressions in the female liver were significantly down-regulated at 50 ng L(-1) in the continual exposure group, and at 500 ng L(-1) in the water recovery group, while male Vtg-I genes were significantly up-regulated for all E1 treatments. In addition, all E1 treatments caused sex reversal of males. These results suggest that E1 at 5 ng L(-1) or above have unrecoverable impacts on the gonadal growth and development of medaka, even if only early life stages were exposed to E1.
日本青鳉（Oryzias latipes）受精卵在 5-5000ng/L 的雌酮（E1）中暴露 15 天，孵化出的幼鱼在相同浓度下继续暴露 15 天。在 50ng/L 或以上的浓度下，孵化率、孵化时间和明显的形态异常等方面出现不良反应。然后将幼鱼分为连续暴露组和水回收组。当幼鱼再暴露于 E1 60 天时，雄性的肝体比（HSI）下降，而在水回收组中这种影响消失。在另一个 60 天的暴露中，500ng/L 的雌酮使雌性的性腺体比（GSI）显著下降。当幼鱼在脱氯自来水（tap water）中维持 60 天时，在 50ng/L 或以上浓度下，雌性 GSI 显著下降。在连续暴露和水回收组中，所有 E1 处理都使雄性 GSI 增加。实时定量 RT-PCR 显示，连续暴露组中 50ng/L 的 E1 使雌性肝脏中的卵黄蛋白原-I（Vtg-I）基因表达显著下调，水回收组中 500ng/L 的 E1 使基因表达显著上调，而所有 E1 处理都使雄性 Vtg-I 基因显著上调。此外，所有 E1 处理都导致雄性性反转。这些结果表明，即使只在早期生命阶段暴露于 E1，浓度为 5ng/L 或以上的 E1 对青鳉的性腺生长和发育也有不可恢复的影响。
