Pathiratne A, Chandrasekera L W H U, Pathiratne K A S
Department of Zoology, Faculty of Science, University of Kelaniya, Kelaniya, Sri Lanka.
Environ Monit Assess. 2009 Sep;156(1-4):361-75. doi: 10.1007/s10661-008-0490-4. Epub 2008 Aug 8.
The present study reports the first analysis of water pollutants in Sri Lankan waters using a suite of biomarkers in Nile tilapia (Oreochromis niloticus) residing in Bolgoda Lake which receives urban, industrial and domestic wastes from multiple sources. The fish were collected from the lake in the dry period (April 2005) and wet periods (September 2005, October 2006) and the levels of biomarkers viz. hepatic ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST), metallothioneins, biliary fluorescent aromatic compounds, brain and muscle cholinesterases (ChE) were compared with those of the laboratory reared control fish and the fish obtained from a less polluted water body, Bathalagoda reservoir (reference site). The results revealed that biomarker levels of the fish collected from the reference site were not significantly different from the controls. Hepatic EROD and GST activities in fish from Bolgoda Lake were induced 4.2-16.6 folds and 1.4-3.3 folds respectively compared with the control fish. Analysis of bile in the lake fish revealed recent uptake of naphthalene, pyrene and benzo(a)pyrene type polycyclic aromatic hydrocarbons (PAHs). The induction of EROD activities in feral fish reflects the exposure of fish to aryl hydrocarbon receptor agonists including PAHs present as pollutants in the Bolgoda Lake. Cholinesterase activity in the fish inhabiting one sampling site of Bolgoda Lake was lower (22-40% inhibition) than the activity measured in the control fish indicating the presence of anticholinesterase pollutants in the area. Hepatic metallothionein levels in the lake fish were higher (1.9-3.2 folds) in comparison to the controls indicating metal exposure. The results support the potential use of these biomarkers in Nile tilapia in assessing pollution in tropical water bodies.
本研究首次利用尼罗罗非鱼（Oreochromis niloticus）体内的一系列生物标志物，对斯里兰卡水域的水污染物进行了分析。这些罗非鱼生活在博尔戈达湖，该湖接收来自多个源头的城市、工业和生活污水。研究人员在旱季（2005年4月）和雨季（2005年9月、2006年10月）从湖中采集了罗非鱼，并将其体内生物标志物的水平，即肝脏乙氧基异吩唑酮-O-脱乙基酶（EROD）、谷胱甘肽S-转移酶（GST）、金属硫蛋白、胆汁荧光芳香化合物、脑和肌肉胆碱酯酶（ChE），与实验室饲养的对照鱼以及从污染程度较低的水体——巴塔拉戈达水库（参考位点）获取的鱼进行了比较。结果显示，从参考位点采集的鱼的生物标志物水平与对照鱼没有显著差异。与对照鱼相比，博尔戈达湖罗非鱼的肝脏EROD和GST活性分别诱导了4.2至16.6倍和1.4至3.3倍。对湖鱼胆汁的分析表明，近期它们摄取了萘、芘和苯并(a)芘类多环芳烃（PAHs）。野生鱼中EROD活性的诱导反映了鱼类接触到包括博尔戈达湖污染物中存在的PAHs在内的芳烃受体激动剂。在博尔戈达湖一个采样位点栖息的鱼的胆碱酯酶活性低于对照鱼（抑制率为22 - 40%），这表明该区域存在抗胆碱酯酶污染物。与对照鱼相比，湖鱼肝脏中的金属硫蛋白水平更高（1.9至3.2倍），表明存在金属暴露。这些结果支持了尼罗罗非鱼体内的这些生物标志物在评估热带水体污染方面的潜在用途。
