2,2',4,4'-四溴联苯醚胁迫对尼罗罗非鱼肝脏抗氧化防御系统的影响

Effects of 2,2’,4,4’-tetrabromodiphenyl ether on antioxidant defense system in liver of tilapia

为探索四溴联苯醚对鱼类抗氧化防御系统的毒性效应及其对鱼类健康的潜在危害,采用半静态水质接触染毒法,设置5、50和500μg·L^(-1)3个暴露浓度,1、3、7、15和30 d5个采样时间,研究了BDE-47对罗非鱼肝脏抗氧化防御系统的影响。结果表明:BDE-47暴露下罗非鱼肝脏抗氧化酶活性或抗氧化因子含量发生了显著变化,显示出BDE-47暴露可引起生物体产生氧化应激并造成氧化损伤;从罗非鱼肝脏抗氧化酶对BDE-47暴露的响应情况来看,SOD、CAT和GSH是相对敏感的抗氧化指标;BDE-47暴露浓度与罗非鱼肝脏SOD、CAT、GST和GPx活性以及GSH和GSSG含量之间没有明显的剂量-效应或时间-效应关系;总体来看,CAT和GSH呈现出先升高后降低的变化趋势;GST和GPx呈现出先升高后降低并恢复至正常水平的变化趋势;GSSG呈现出升高趋势;SOD在低浓度BDE-47(5μg·L^(-1))暴露下表现为先升高后降低的变化趋势,在高浓度BDE-47(50和500μg·L^(-1))暴露下表现为先降低后升高的变化趋势。

In order to explore the toxic effects of tetrabrominated diphenyl ether on the antioxidant defense system of fish and thus its potential harm to fish health,the effects of 2,2’,4,4’-tetrabromodiphenyl ether(BDE-47)on the antioxidant defense system of tilapia liver were studied using the semi-static water exposure method.There were three exposure concentrations of 5,50 and 500μg·L^(-1),and different sampling times of 1,3,7,15 and 30 d.The results showed that the activity of antioxidant enzymes or the content of antioxidant factors in the liver of tilapia significantly changed after exposure to BDE-47,indicating BDE-47 exposure could cause oxidative stress and oxidative damage.According to the response of antioxidant enzymes in livers of tilapia exposed to BDE-47,SOD,CAT,and GSH were relatively sensitive antioxidant parameters.There was no significant dose-effect or time-effect relationships between BDE-47 exposure concentration and the activities of SOD,CAT,GST,and GPX,or the contents of GSH and GSSG in liver of tilapia.In general,CAT and GSH showed a trend of increasing firstly and then decreasing later.GST and GPX showed a trend of increasing firstly,then decreasing later,and finally returning to normal level.GSSG showed an increasing trend.SOD increased firstly and then decreased at low BDE-47 concentration of 5μg·L^(-1),whereas it decreased firstly and then increased at high BDE-47 concentrations of 50 and 500μg·L^(-1).