四溴双酚A对太平洋真宽水蚤的急性毒性及氧化胁迫

Acute Toxicity and Oxidative Stress of Tetrabromobis-phenol A to Eurytemora pacifica

为了研究四溴双酚A(tetrabromobis-phenol A,TBBPA)对海洋桡足类的急性毒性和氧化胁迫效应,以太平洋真宽水蚤为受试生物,测定了TBBPA对其96 h急性毒性和对其体内抗氧化防御系统的影响。结果表明,TBBPA对太平洋真宽水蚤的96 h半数致死浓度(96 h-LC50)为178μg·L^(-1),95%可信区间为91~306μg·L^(-1),表现为极毒。亚致死浓度下,TBBPA能够不同程度影响太平洋真宽水蚤的抗氧化防御酶活力以及非酶物质含量。其中SOD和GST活性的变化趋势较为一致,暴露初期SOD和GST活性显著上升(P<0.05),随暴露时间延长酶活性有所下降,最终趋向对照组水平;GPx活性水平始终维持在对照组以上并且差异显著(P<0.05);暴露初期,GSH含量受轻微氧化压力而轻微升高,暴露48 h后GSH含量急剧下降并显著低于对照组(P<0.05)。太平洋真宽水蚤体内SOD、GST、GPx活性和GSH含量对TBBPA暴露均十分敏感,能够为海洋环境的TBBPA监测提供生化指标参考。

Tetrabromobisphenol A （TBBPA） is one of the most widely used brominated flame retardants. To evaluate the toxic effects of TBBPA on the marine ecosystem, the acute toxicity of TBBPA and its oxidation stress were examined in marine copepod species （Eurytemora pacifica） over 96 h exposure. The 96 h median lethal concentration （LC50） of TBBPA to E. pacifica was 178 μg·L^-1 with 95% confidential interval of 91-306 μg·L^-1, and was catagorized as “high-toxic”. The activities of superoxide dismutase （SOD）, glutathione transferase （GST）, peroxidase （GPx）, and the contents of glutathione （GSH） were also detected. Under experimental concentration （〈35.6 μg·L^-1） of TBBPA, the activities of the three antioxidant enzymes increased significantly in the early exposure compared with those in the controls, which suggested that the antioxidant enzymes could protect the animals from oxidative damage. Subsequently, the activities of SOD and GST decreased to the control levels with increased exposure time. The GSH content increased slightly at first, and became significantly lower than those in the controls after 48 h TBBPA exposure. The results indicated that the activities of SOD, GST, GPx and the GSH content were sensitive to TBBPA exposure and could be the potential biomarkers in marine ecological early warning.