Hartl Mark G J, Kilemade Michael, Sheehan David, Mothersill Carmel, O'Halloran John, O'Brien Nora M, van Pelt Frank N A M
Environmental Research Institute, University College Cork, Ireland.
Mar Environ Res. 2007 Aug;64(2):191-208. doi: 10.1016/j.marenvres.2007.01.002. Epub 2007 Jan 17.
Hatchery-reared turbot (Scophthalmus maximus L.) were exposed for 3 weeks, under laboratory conditions, to sediment collected from polluted sites in Cork Harbour and a reference site at Ballymacoda, Co. Cork, Ireland. The potential of surficial sediment for inducing hepatic biomarkers was assessed at two levels of biological organisation: expression of cytochrome P450 [Western blotting analysis and 7-ethoxy-resorufin O-dealkylase (EROD), 7-benzoxy resorufin O-dealkylase (BROD), 7-methoxy resorufin O-dealkylase (MROD), 7-pentoxy-resorufin O-dealkylase (PROD) activities] and DNA integrity (Comet assay). Positive controls were generated, either by exposing turbot to cadmium chloride-spiked seawater (Comet assay) or to beta-naphthaflavone by intraperitoneal injection (cytochrome P450 induction). The induction of cytochrome P450 activity (EROD, MROD and PROD) in animals following a 7-day exposure to contaminated sediments was significantly higher than those exposed to reference site sediment and remained elevated thereafter; BROD was not induced. DNA single-strand breaks were also significantly higher following exposure to contaminated sediments throughout the experiment. Although no direct correlation between induction of alkoxyresorufin O-dealkylase activities and a particular chemical class was established, the induction of MROD and PROD activities in fish exposed to sediments containing complex contaminant mixtures, appeared to be more sensitive than conventional EROD activity assays. We conclude from the present laboratory study that S. maximus is a suitable sentinel species for the assessment of moderately contaminated sediments and therefore allows for the further development of this model for future, ecologically relevant, field studies.
在实验室条件下，将孵化场养殖的大菱鲆（Scophthalmus maximus L.）暴露于从爱尔兰科克郡科克港污染场地及巴利马科达一个参考场地采集的沉积物中3周。在两个生物组织水平上评估表层沉积物诱导肝脏生物标志物的潜力：细胞色素P450的表达[蛋白质免疫印迹分析以及7-乙氧基异吩恶唑酮-O-脱烷基酶（EROD）、7-苯氧基异吩恶唑酮-O-脱烷基酶（BROD）、7-甲氧基异吩恶唑酮-O-脱烷基酶（MROD）、7-戊氧基异吩恶唑酮-O-脱烷基酶（PROD）活性]以及DNA完整性（彗星试验）。通过将大菱鲆暴露于氯化镉加标的海水中（彗星试验）或通过腹腔注射β-萘黄酮（细胞色素P450诱导）来生成阳性对照。在暴露于受污染沉积物7天后，动物体内细胞色素P450活性（EROD、MROD和PROD）的诱导显著高于暴露于参考场地沉积物的动物，且此后一直保持升高；BROD未被诱导。在整个实验过程中，暴露于受污染沉积物后DNA单链断裂也显著更高。尽管未确定烷氧基异吩恶唑酮-O-脱烷基酶活性的诱导与特定化学类别之间的直接相关性，但在暴露于含有复杂污染物混合物的沉积物的鱼类中，MROD和PROD活性的诱导似乎比传统的EROD活性测定更敏感。我们从当前的实验室研究得出结论，大菱鲆是评估中度污染沉积物的合适指示物种，因此可为未来与生态相关的野外研究进一步开发该模型。
