Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal,
Environ Sci Pollut Res Int. 2015 Sep;22(18):14241-7. doi: 10.1007/s11356-015-4630-4. Epub 2015 May 15.
Under stressful conditions, organisms often try to detoxify by mobilizing certain energy sources with costs to various functions, e.g. growth or reproduction. Cellular energy allocation (CEA) is a commonly used methodology to evaluate the energetic status of an organism. In the present study, the effects of copper (Cu) and silver (Ag) were evaluated on the total energy budget of Enchytraeus crypticus (Oligochaeta) over periods of exposure (0-2, 2-4 and 4-8 days). The parameters measured were the total energy reserves available (protein, carbohydrate and lipid budgets) and the energy consumption (based on electron transport system activity) being further integrated to obtain the CEA. Results showed that Enchytraeids responded differently to Ag and Cu, mobilizing lipids and proteins in response to Ag and carbohydrates and proteins in response to Cu. Overall, it was possible to distinguish between effect concentrations (reproduction effect concentrations-EC10 and EC50), with EC10 causing an increase in energy consumption (Ec); while for the EC50, the increase in Ec is followed by a steep decrease in Ec, with a corresponding decrease in CEA in the longer exposure periods. These results could be linked with effects at higher levels of biological organization (effects on reproduction) providing evidences that CEA can be used as faster and sensitive endpoints towards metal exposure in E. crypticus.
在应激条件下，生物通常会通过动员某些能源来解毒，这些能源会对各种功能（例如生长或繁殖）产生成本。细胞能量分配（CEA）是评估生物体能量状态的常用方法。在本研究中，评估了铜（Cu）和银（Ag）对 0-2、2-4 和 4-8 天暴露期内真涡虫（Oligochaeta）总能量预算的影响。测量的参数包括可用的总能量储备（蛋白质、碳水化合物和脂质预算）和能量消耗（基于电子传递系统活性），进一步整合以获得 CEA。结果表明，真涡虫对 Ag 和 Cu 的反应不同，Ag 会动员脂质和蛋白质，而 Cu 则动员碳水化合物和蛋白质。总体而言，有可能区分作用浓度（生殖作用浓度-EC10 和 EC50），EC10 导致能量消耗增加（Ec）；而对于 EC50，Ec 的增加之后是 Ec 的急剧下降，较长暴露期内 CEA 相应下降。这些结果可以与更高层次的生物学组织（对繁殖的影响）的影响联系起来，为 CEA 可作为真涡虫金属暴露的更快和更敏感的终点提供了证据。
