硫酸锰废渣浸出液对斑马鱼的毒性及抗氧化酶活性的影响

Acute Toxicity of Leachate of Manganese Sulphate Waste Residue to Brachydanio rerio and Toxic Effect on Its Antioxidant Enzymes Activities

已有研究表明,堆积在湘西花垣河河岸的硫酸锰废渣含有多种重金属,可能是导致花垣河河水和沉积物重金属污染的主要原因。为了评价硫酸锰废渣的潜在生态风险和对水生动物的毒性,本研究分析了硫酸锰废渣浸出液中的主要重金属成分,用浸出液对斑马鱼进行了急性毒性实验,观察在急性胁迫下斑马鱼的体征变化,测定了斑马鱼在亚致死浓度下的生化指标的变化。结果表明,硫酸锰废渣浸出液中的主要重金属成分为Mn、Cd、Pb、Cu和Zn。在浸出液的急性胁迫下,斑马鱼出现呼吸放缓,静止不动,体表条纹消失等中毒症状,直至死亡。在硫酸锰废渣浸出液的亚致死浓度胁迫下,观察了斑马鱼3种组织(肝脏、鳃和肌肉)的SOD、CAT、GST和GPx活性的变化。斑马鱼3种组织(肝脏、鳃和肌肉)的SOD酶和CAT酶活性的变化与浸出液胁迫的关系较为复杂,而GST酶和GPx酶的活性变化与浸出液胁迫的关系能直观地反映出浸出液对斑马鱼的损伤作用。因此,在斑马鱼3种组织中,4种不同的抗氧化酶对硫酸锰废渣浸出液的胁迫响应机制可能是不同的。

Previous work indicated that a large amount of manganese sulphate waste residue （MSWR） was piled up along the bank of Huayuan River in the west of Hunan Province and that MSWR contains some heavy metals, which has led to the pollution of the river water and sediment. In order to evaluate the potential ecological risk and the toxic effect of MSWR on aquatic animals, the metal composition of MSWR leachate was analyzed. Brachydanio rerio was exposed to the leachate of MSWR and their physical signs were observed in the acute toxic test. Moreover, the variations of biochemical parameters of Brachydanio rerio were measured at sub-lethal concentration of the MSWR leachate. The results demonstrated that the main heavy metals of MSWR leachate include Mn, Cd, Pb, Cu and Zn. In the acute toxic test, a series of toxic effects on Brachydanio rerio occurred, including breathing slowly, staying still, and the disappearance of their body stripes and final death. The activities of four antioxidant enzymes, including superoxide dismutase （SOD）, catalase （CAT）, glutathione S-transferase （GST） and glutathione peroxidase （GPx）, were investigated in the liver, gill and muscle of Brachydanio rerio exposed to a sub-lethal concentration of the MSWR leachate. No obvious relationship between the activities of SOD and CAT enzymes and the concentrations of MSWR leachate was observed in the exposed liver, gill and muscle of Brachydanio rerio, while the variations of GST and GPx enzymes activities may serve as an indicator of the damage of Brachydanio rerio from the leachate of MSWR. It is concluded that the response mechanism of four studied antioxidant enzymes may be different in the three tissues of Brachydanio rerio exposed to the leachate of MSWR.