Machado Anderson Abel de S, Wood Chris M, Bianchini Adalto, Gillis Patricia L
Environment Canada, Water Science and Technology Directorate, Burlington, ON, L7R-4A6, Canada,
Ecotoxicology. 2014 Sep;23(7):1345-58. doi: 10.1007/s10646-014-1277-8. Epub 2014 Jul 5.
Subcellular biochemical biomarkers are valuable early warning indicators of environmental contaminant effects. Thus, the present study evaluated several biomarkers and the relationships among them in wild freshwater mussels (Lasmigona costata) from a gradient of metal exposure and differential levels of other urban-related influences in the Grand River (ON, Canada). The biomarkers examined are related to metal exposure [gill ion and metal concentrations (Na, K, Ca, Mg, Cd, Cu, Ni, Pb and Zn)], oxidative status [reactive oxygen species (ROS), catalase (CAT), superoxide dismutase (SOD), antioxidant capacity (ACAP)], sulfhydryl (SH) metabolism [glutathione (GSH), protein sulfhydryl groups (SH protein), glutathione S-transferase (GST), glutathione reductase (GR)], and lipid peroxidation. Gill metal concentration increased proportionally to waterborne metal concentration and disturbances in osmotic and divalent cations (Ca and Mg) concentrations were observed. This suggests that the observed effects are associated with metal exposure, although simultaneous relationships with other contaminants are also possible. Oxidative status biomarkers (ROS, SOD, CAT and ACAP) were more sensitive to urban-influences than gill metal concentration. In contrast, biomarkers involving SH metabolism (GSH, SH protein, total SH, GR and GST) were more correlated with gill metal concentration. Oxidative damage occurred when both metal and urban-related influences were high. Mechanistically, the way of dealing with oxidative stress changed when mussels were exposed to high levels of contaminants. The reduction in ROS content, SOD and CAT activity, and ACAP accompanying the stimulation of detoxification metabolism via SH (GSH and SH protein contents, GST and GR activities) and their association with gill metal concentration are discussed.
亚细胞生化生物标志物是环境污染物影响的重要早期预警指标。因此，本研究评估了来自加拿大安大略省格兰德河金属暴露梯度和其他城市相关影响不同水平的野生淡水贻贝（Lasmigona costata）中的几种生物标志物及其相互关系。所检测的生物标志物与金属暴露[鳃离子和金属浓度（钠、钾、钙、镁、镉、铜、镍、铅和锌）]、氧化状态[活性氧（ROS）、过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、抗氧化能力（ACAP）]、巯基（SH）代谢[谷胱甘肽（GSH）、蛋白质巯基（SH蛋白）、谷胱甘肽S-转移酶（GST）、谷胱甘肽还原酶（GR）]以及脂质过氧化有关。鳃金属浓度与水体金属浓度成比例增加，并且观察到渗透和二价阳离子（钙和镁）浓度的紊乱。这表明所观察到的影响与金属暴露有关，尽管也可能与其他污染物存在同时关系。氧化状态生物标志物（ROS、SOD、CAT和ACAP）比鳃金属浓度对城市影响更敏感。相反，涉及SH代谢的生物标志物（GSH、SH蛋白、总SH、GR和GST）与鳃金属浓度的相关性更强。当金属和城市相关影响都很高时会发生氧化损伤。从机制上讲，当贻贝暴露于高水平污染物时，应对氧化应激的方式会发生变化。讨论了ROS含量、SOD和CAT活性以及ACAP的降低，同时伴随着通过SH（GSH和SH蛋白含量、GST和GR活性）刺激解毒代谢，以及它们与鳃金属浓度的关联。
