Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Environ Sci Technol. 2012 Mar 20;46(6):3465-71. doi: 10.1021/es203951z. Epub 2012 Mar 8.
The link between metal exposure and toxicity is complicated by numerous factors such as exposure route. Here, we exposed a marine fish (juvenile blackhead seabream Acanthopagrus schlegelii schlegelii) to copper either in a commercial fish diet or in seawater. Copper concentrations in intestine/liver were correlated linearly with influx rate, but appeared to be less influenced by uptake pathway (waterborne or dietary exposure). Influx rate best predicted Cu accumulation in the intestine and liver. However, despite being a good predictor of mortality within each pathway, influx rate was not a good predictor of mortality across both exposure pathways, as waterborne Cu caused considerably higher mortality than dietary Cu at a given influx rate. We show that the use of gill Cu accumulation irrespective of the exposure route as a model for observed fish mortality provided a clear relationship between accumulation and toxicity. Investigation of gill Cu accumulation may shed light on the different accumulation strategies from the two exposure pathways. This correlation offers potential for the use of branchial Cu concentration as an indicator of long-term Cu toxicity, allowing for differences in the relative importance of the uptake pathways in different field situations.
金属暴露与毒性之间的关系很复杂，受到许多因素的影响，如暴露途径。在这里，我们将铜暴露于商业鱼类饲料或海水中，以暴露于一种海洋鱼类（幼年黑鲷 Acanthopagrus schlegelii schlegelii）。肠/肝中的铜浓度与流入率呈线性相关，但似乎较少受摄取途径（水传播或饮食暴露）的影响。流入率最能预测铜在肠和肝脏中的积累。然而，尽管在每种途径内死亡率都是一个很好的预测因子，但流入率并不是两种暴露途径死亡率的良好预测因子，因为在给定的流入率下，水传播的铜比饮食中的铜导致更高的死亡率。我们表明，使用鳃部铜积累而不考虑暴露途径作为观察到的鱼类死亡率模型，提供了积累与毒性之间的明确关系。对鳃部铜积累的研究可能揭示了两种暴露途径之间不同的积累策略。这种相关性为使用鳃部铜浓度作为长期铜毒性的指标提供了潜力，允许在不同的现场情况下，摄取途径的相对重要性存在差异。
