Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, College of Life Science, South China Normal University, Guangzhou 510631, China.
Aquat Toxicol. 2010 Aug 15;99(2):281-90. doi: 10.1016/j.aquatox.2010.05.010. Epub 2010 May 19.
Due to the wide distribution and persistence of perfluorooctane sulfonate (PFOS), an increasing number of studies are focusing on the toxicological effects of PFOS exposure in mammalian and fish model species. The results of these studies (on estrogenic activity, development and reproduction, etc.), however, are largely inconsistent owing to differences in exposure conditions (exposure time, concentrations, species and test methods, etc.). Oviparous fish species such as zebrafish and common carp are commonly used in PFOS exposure experiments, but no information is available on ovoviparous fish species. Thus, this study adopted as its model the swordtail (Xiphophorus helleri), a small, hardy and easily raised ovoviparous fish species. Males with a xiphoid caudal fin were employed to investigate vitellogenin (VTG) mRNA expression under exposure to a range of PFOS concentrations (0, 0.1, 0.5 and 2.5mg/l PFOS) for three weeks, with one-week recovery in clean water. Females were used to investigate the reproductive toxicity of PFOS exposure, and were exposed to the same concentrations as the males for up to six weeks. Finally, juveniles (20-30 days old) were exposed to 0 and 0.1mg/l PFOS for 90 days to check for developmental impairment. VTG mRNA expression was significantly inhibited at one and two weeks, with up-regulation at three weeks, in all of the exposure groups, but was stimulated only in the 2.5mg/l group at four weeks. The hepatosomatic index (HSI) was elevated in the 2.5mg/l male group at three weeks and in the juvenile group. The gonadal somatic index (GSI) was elevated in the 0.5mg/l female group and in the female juveniles. The 14-day survival rates for offspring differed significantly among the groups. Harmful effects were observed on the growth of the juveniles, but not on the sex ratio or the secondary sex characteristics of the young males. Histopathological changes in the liver were detected in both the male and female groups with the highest exposure. The overall results indicate that differences in model species may influence test results. Juveniles possess excellent qualities for sublethal chemical assessments employing the HSI and GSI under long-term exposure conditions.
由于全氟辛烷磺酸（PFOS）的广泛分布和持久性，越来越多的研究集中在哺乳动物和鱼类模式物种中 PFOS 暴露的毒理学效应上。然而，由于暴露条件（暴露时间、浓度、物种和测试方法等）的差异，这些研究的结果（关于雌激素活性、发育和繁殖等）在很大程度上不一致。斑马鱼和鲤鱼等卵生鱼类通常用于 PFOS 暴露实验，但关于卵胎生鱼类的信息尚不清楚。因此，本研究以剑尾鱼（Xiphophorus helleri）为模型，剑尾鱼是一种小型、耐寒且易于饲养的卵胎生鱼类。采用具有剑尾的雄性鱼来研究在一系列 PFOS 浓度（0、0.1、0.5 和 2.5mg/l PFOS）下暴露三周时卵黄蛋白原（VTG）mRNA 表达的情况，在清洁水中恢复一周。雌性鱼用于研究 PFOS 暴露的生殖毒性，暴露于与雄性鱼相同的浓度长达六周。最后，将幼鱼（20-30 天大）暴露于 0 和 0.1mg/l PFOS 中 90 天，以检查其发育障碍情况。在所有暴露组中，在第一和第二周 VTG mRNA 表达显著受到抑制，在第三周上调，而在第四周仅在 2.5mg/l 组中受到刺激。在三周时，2.5mg/l 雄性组和幼鱼组的肝体比（HSI）升高。在 0.5mg/l 雌性组和雌性幼鱼中，性腺体比（GSI）升高。各组间的 14 天幼鱼存活率差异显著。观察到幼鱼生长受到有害影响，但对幼鱼的性别比例或年轻雄性的第二性征没有影响。在暴露水平最高的雄性和雌性组中均检测到肝脏的组织病理学变化。总体结果表明，不同的模式物种可能会影响测试结果。幼鱼在长期暴露条件下具有良好的 HSI 和 GSI 进行亚致死化学评估的品质。
