• 关键词：苯并芘  稀有鮈鲫  内分泌干扰效应  风险评估

• 基金项目：中国长江三峡集团公司科研项目(No.07011034,CT-12-08-01)

• 郭勇勇
• 中国科学院水生生物研究所, 武汉 430072

• 周炳升
• 中国科学院水生生物研究所, 武汉 430072

• 摘要：为评价典型有机污染物对长江三峡库区上游特有珍稀鱼类的环境风险,本实验以稀有鮈鲫为对象,研究了低剂量多环芳烃(PAHs)暴露而引起的内分泌干扰效应.将成年稀有鮈鲫暴露于不同浓度(0、0.1、0.3、1.0 和3.0 μg · L^-1)的苯并芘(BaP)中28 d,测定了体质系数、性激素含量、下丘脑-垂体-性腺(HPG)轴和肝脏中与繁殖相关基因的表达.结果显示:在雌鱼中,BaP暴露后,睾酮(T)的含量显著升高,雌二醇(E2)的水平显著下降并改变了T/E2的比值;在雄鱼中,T和E2的含量都显著下降.雌雄鱼性激素的改变可能与类固醇合成相关基因(Cyp17、Cyp19a)表达量的改变有关.BaP暴露显著抑制了雌雄鱼肝脏中卵黄蛋白原(VTG)基因的表达.以上检测到的激素或者基因表达的改变主要发生在高剂量(3.0 μg · L^-1)BaP暴露下,而长江上游库区水体中多环芳烃含量较低(< 100 ng · L^-1),因此推测,库区存在的多环芳烃不会对三峡库区上游水体中的鱼类产生内分泌干扰效应.

• Abstract：The risk of environmental contaminants on endemic fish species in the Three Gorge Reservoir (TGR) has been of great concern. The present study investigated the endocrine disruption effects of benzo(a)pyrene (BaP) on the Chinese rare minnow (Gobiocypris rarus), a type of endemic fish species mainly inhabiting upstream of the Yangtze River. Adult rare minnow were exposed to environmentally relevant concentrations of BaP (0, 0.1, 0.3, 1.0 and 3.0 μg · L^-1) for 28 d. Then, concentrations of sex hormones in the plasma and transcription of several key genes in the hypothalamic-pituitary-gonadal (HPG) axis and liver of the fish were measured. Exposure to BaP resulted in greater circulating concentrations of testosterone (T) and lower concentrations of 17β-estradiol (E2), which were accompanied by up-regulation of Cyp17 and Cyp19a mRNA expressions in the ovaries of females. For males, up-regulation of Cyp17 gene transcriptions in the tests might be partly attributed to the decreases of T and E2 levels. Furthermore, the T/E2 ratio increased in females after exposure to 3.0 μg · L^-1 of BaP. Hepatic vitellogenin (VTG) gene transcription was significantly downregulated in males and females. The present study showed that waterborne exposure to BaP altered plasma sex hormone levels and modulated gene transcriptions in the HPG axis and liver, which occurred mostly at higher concentrations (3.0 μg · L^-1) than those detected in TGR surface water. It was therefore suggested that environmental concentration of BaP alone might not disturb the endocrine system of fish in the TGR.

• Key words：benzo(a)pyrene (BaP)  Chinese rare minnow  endocrine disrupting effect  risk assessment

• 
  摘要点击次数： 1440 全文下载次数： 2569