【作者】 刘睿智；

【导师】 王重刚；

【作者基本信息】 厦门大学 ， 动物学， 2006， 硕士

【摘要】 在室内实验条件下将褐菖鲉(Sebastiscus marmoratus)置于含0号柴油水溶性成分(diesel oil soluble fraction, DWSF)的海水中,浓度分别为0.02、0.1和0.5 mg/L。每天更换一半相同浓度的海水,并于暴露后第0、7、28、84 d以及解除污染成分的第7、28 d取样,通过测定肝脏中解毒系统两个阶段代表性酶EROD及GST活力,以及胆汁中多环芳烃(PAHs)典型代谢物含量,研究污染物在褐菖鲉体内的代谢情况及其对代谢系统的影响;对血清和性腺中性类固醇激素如睾酮、雌二醇水平用免疫放射法进行测定,采用酶联免疫吸附方法检测血清中卵黄蛋白原(VTG)的含量,并对性腺进行组织学观察。同时,观察菲、芘、苯并(a)芘等PAHs对褐菖鲉胚胎及仔鱼发育各项指标的影响。探讨DWSF对褐菖鲉生殖及早期发育的影响和可能的作用机制。1.观察了低浓度长期的DWSF暴露后褐菖鲉PAHs代谢与肝脏解毒酶之间的关系。结果显示,PAHs典型代谢物的含量和肝脏两种解毒酶EROD、GST的活性均可被DWSF诱导。EROD活力先显著诱导升高而后下降,显示褐菖鲉在长期慢性暴露下发展的适应机制。2.对DWSF暴露后褐菖鲉机体与生殖机能有关的生理生化指标及性腺的组织学变化进行观察,未发现明显的性腺组织损伤,性体指数也没有明显影响。最长暴露天数雄鱼性腺中17β-雌二醇升高,此天数最高浓度组血清中VTG被显著诱导。17β-雌二醇水平升高可能是VTG水平升高的主要原因。雌鱼血清和性腺中睾酮和17β-雌二醇含量下降,这将对卵细胞的发育、成熟和卵细胞的质量产生不利影响。显示DWSF对鱼体具有生殖干扰作用,对雄鱼具有雌激素效应,并降低雌鱼的生殖能力。3.将褐菖鲉胚胎分别暴露于梯度浓度的Ph,Py和BaP培养液中,观察发现暴露组胚胎24 h死亡率升高、胚胎和仔鱼心率下降、发育时间延缓、孵化率降低、仔鱼的畸形率升高。PAHs引发的胚胎和仔鱼的毒性效应基本上随暴露浓度的升高而升高,并随其结构中苯环数的增加有增强趋势。结果中MDA含量增加显示这几种PAHs暴露对仔鱼产生了氧化胁迫,GSH含量的增加及GST活力的升高显示了仔鱼的抗氧化防御系统对PAHs暴露的敏感反应。对DWSF的主要成分PAHs暴露的敏感性显示出用鱼类早期发育指标作为环境监测生物标志物的更多还原

【Abstract】 In experimental condition, Sebastiscus marmoratus were exposed to diesel oil soluble fraction (DWSF) at concentrations of 0.02, 0.1, 0.5 mg/L. Samples were taken after exposure for 0, 7, 28, 84 days and transferred to recovery tank for 7, 28 days, respectively. Hepatic EROD, GST activities, content of GSH and biliary PAHs metabolites were detected to investigate possible influence on hepatic detoxifcation system. Effects on reproductive potential of the fish were studied by detecting sex hormone levels in serum and gonad, and vitellogenin (VTG) content in serum.Fertilized eggs were exposed to pyrene (Py), phenanthrene (Ph) and benzo(a)pyrene (BaP) at concentrations of 0.01, 0.1, 1 and 10μg/L,to study effects of polycyclic aromatic hydrocarbons (PAHs) on embryos and larvae of S. marmoratus. Early life stage test indices included mortality, malformation rate, heart beat rate, hatching time, important enzymes activities, and so on. The results showed:1. DWSF exposure influenced hepatic detoxifying enzymes activities in S. marmoratus. Contents of biliary PAHs metabolites were elevated, and the activities of EROD and GST were both induced by DWSF. The enzymes activities may be altered by the defense mechanism of the fish. EROD activities increased firstly and decreased subsequently, which suggested a compensatory or adaptive mechanism occurrence in chronically exposed to the populations.2.There was little change in gonad morphology and gonadosomatic index (GSI) after exposed to the concentrations of DWSF for 84 days. It was observed that 17β– estradiol content of spermary and VTG content of serum were increased in the male fish. Increase of 17β–estradiol content in serum should be responsible for the increase of VTG content. Sex hormone level was declined at the same time in the female fish, which will do harm to the development and mature of ovum. All indices suggested that DWSF exposure had brought reproductive toxic effect, especially caused estrogenic effect to male S. marmoratus.3. PAHs caused toxic effect on early life stages of S. marmoratus. Embryos were exposed to different concentrations of Ph, Py and BaP through water. Mortality rate of更多还原