二溴海因对吉富罗非鱼血浆的氧化胁迫效应

采用半静态水质接触染毒法,研究不同浓度(0、0.06、0.3、1.5 mg·L^-1)、不同时间(1、2、4、8、16、26 d)下二溴海因对吉富罗非鱼血浆总还原性谷胱甘肽(T-GSH)、氧化型谷胱甘肽(GSSG)、谷胱甘肽-S-转移酶(GST)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)、谷胱甘肽过氧化物酶(GPx)及总抗氧化能力(T-AOC)的影响。结果表明:随着暴露时间的延长,血浆SOD、GR先降低后趋于稳定,T-GSH、GSH/GSSG、CAT、GST呈先升高后下降的趋势,且16 d出现显著性升高,GPx在1 d和16 d时被诱导,T-AOC仅在16 d时被诱导。CAT、GPx、T-GSH、GSH/GSSG、T-AOC等指标表现出浓度依赖现象,T-AOC与二溴海因呈剂量效应关系。除CAT、GR外,解除胁迫10 d后各抗氧化指标均未恢复到正常水平。上述结果显示,二溴海因对吉富罗非鱼血浆的抗氧化系统有显著的影响, T-AOC宜作为生物标志物,高浓度的二溴海因暴露能造成血液中抗氧化系统的不可逆损伤。

Effects of 1,3-Dibromo-5,5-Dimethylhydantoin(DBDMH) on Plasma Antioxidant Defense System in GIFT Nile Tilapia

1,3-dibromo-5,5-dimethylhydantoin(DBDMH) is widely used as a disinfectant in aquaculture. However, it may pose toxicity to aquatic organisms. In this study, GIFT Nile tilapias were exposed to different DBDMH concentrations(0, 0.06, 0.3, and 1.5 mg·L^-1) for 16 days, followed by a recover period of 10 days. A suit of plasma parameters were detected on days 1, 2, 4, 8, 16 and 26(after 10-day recovery). These parameters were:total-glutathione contents(T-GSH), oxidized glutathione content(GSSG), glutathione-S-transferase activity(GSTs), superoxide dismutase activity(SOD), catalase activity(CAT), glutathione reductase activity(GR), glutathione peroxidase activity(GPx) and total antioxidant capacity activity(T-AOC). Results indicated that SOD and GR activities decreased initially and then maintained stable. T-GSH content, GSH/GSSG ratio, and CAT and GST activities showed initial increase followed by reduction, whereas all these parameters had a significant increment on the day 16. GPx activity displayed a significant rise on day 1 and day 16. T-AOC activity increased only on day 16. The activities of CAT, GPx, T-GSH, and T-AOC and GSH/GSSG ratio revealed a dose-dependent pattern. T-AOC activity showed a dose-effect relationship with DBDMH concentrations. Ten day recovery in water free of DBDNH did not have antioxidant indicators return to the normal levels, except CAT and GR activities. The present study suggests that DBDMH significantly influences the plasma antioxidant defense system of GIFT Nile tilapia and that T-AOC activity can be used as a sensitive biomarker to monitor the DBDMH pollution. DBDMH at high concentrations causes irreversible damages to GIFT Nile tilapia.