Vanparys Caroline, Dauwe Tom, Van Campenhout Karen, Bervoets Lieven, De Coen Wim, Blust Ronny, Eens Marcel
Laboratory of Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
Sci Total Environ. 2008 Aug 15;401(1-3):184-93. doi: 10.1016/j.scitotenv.2008.04.009. Epub 2008 May 21.
Biomonitoring allows an integrated evaluation of different aspects of exposure, accumulation and effects to environmental pollution, simultaneously accounting for the natural variety between individuals in an ecosystem. In this study, the effects of increased metal accumulation were evaluated at the biochemical level in terms of two biomarker responses in the great tit (Parus major), a small insectivorous songbird, along an established metal pollution gradient. Metal concentrations in internal tissues (liver and kidney) and blood indicated that lead and cadmium were the most important metals in the pollution gradient under study. At the biochemical level, induction of metal binding protein metallothionein (MT) in liver and kidney reflected cadmium concentrations in these tissues (R(2)=0.42 and R(2)=0.94 respectively, n=19), although in kidney, MT induction was not sufficient to complex all cadmium present. Secondly, the activity of the enzyme delta-aminolevulinic acid dehydratase (ALAd) in blood decreased exponentially in response to increased lead accumulation (R(2)=0.70, n=18) and represents therefore a specific effect marker for lead exposure. In the highest polluted area, an ALAd inhibition of 85% was reported. Since a higher metal exposure resulted in an increased metal accumulation and subsequent biomarker responses in a dose-dependent way, this study indicates the applicability of ALAd and MT levels in great tits for biomonitoring responses to heavy metal pollution.
生物监测能够对环境污染的暴露、积累和影响等不同方面进行综合评估，同时兼顾生态系统中个体之间的自然差异。在本研究中，沿着已确立的金属污染梯度，以小型食虫鸣禽大山雀（Parus major）的两种生物标志物反应为依据，在生化水平上评估了金属积累增加所产生的影响。内部组织（肝脏和肾脏）及血液中的金属浓度表明，铅和镉是所研究污染梯度中最重要的金属。在生化水平上，肝脏和肾脏中金属结合蛋白金属硫蛋白（MT）的诱导反映了这些组织中的镉浓度（R²分别为0.42和0.94，n = 19），不过在肾脏中，MT的诱导不足以络合所有存在的镉。其次，血液中δ-氨基乙酰丙酸脱水酶（ALAd）的活性随着铅积累的增加呈指数下降（R² = 0.70，n = 18），因此代表了铅暴露的一种特定效应标志物。在污染最严重的区域，据报道ALAd抑制率达85%。由于更高的金属暴露会以剂量依赖的方式导致金属积累增加及随后的生物标志物反应，本研究表明大山雀体内的ALAd和MT水平在生物监测对重金属污染的反应方面具有适用性。
