三丁基锡对文蛤鳃的抗氧化酶活性及脂质过氧化的影响

在实验室条件下,观察质量浓度分别为高、中、低(0·1,1,10ng·L-1(以Sn计))3组的三丁基锡(TBT)暴露2、8、20d以及恢复7d和20d后对文蛤鳃的谷胱甘肽硫转移酶(GST)、过氧化氢酶(CAT)活性以及丙二醛(MDA)含量、还原型谷胱甘肽(GSH)含量的影响.结果显示,除了高浓度TBT(10ng·L-1)暴露在早期(2d)对GSH含量、GST和CAT活性产生抑制之外,TBT暴露对GSH含量、GST和CAT活性的作用主要为诱导效应.在暴露8d后,MDA的含量表现出显著的诱导.恢复7d后除了高浓度组对MDA还有影响外,其它各指标均恢复到与对照组相当的水平.结果表明,环境水平的TBT暴露对文蛤产生明显的氧化胁迫,抗氧化防御系统可以作为海洋环境有机锡污染监测的潜在的生物标志物.

Effects of tributyltin on antioxidant enzymes activity and lipid peroxidation in the gill of hard clam Meretrix meretrix

The effects on catalase (CAT), glutathione -S-transferase(GST) activities and content of malondialdehyde (MDA), reduced glutathione (GSH) in the gill of Meretrix meretrix were evaluated, after it had exposed to tributyltin (TBT) at environmental levels (0.1, 1, 10 ng·L^-1 as Sn) for 2, 8, 20 days and recovered for 7, 20 days, in experimental condition. The results showed that the activities of GST and CAT and GSH content in Meretrix meretrix exposed to TBT were principally induced, except that were mainly inhibited in the clams exposed to 10 ng·L^-1 for 2 days. MDA content were significantly induced after exposure for 8d. After the clams had been transferred to clean recovery tanks for 7 days, the indexes were recovered to the level corresponding to the control group, except MDA content in the clams exposed to 10 ng·L^-1 was sequentially induced. These results in the present work showed that oxidative stress in Meretrix meretrix would be produced by exposure to TBT at realistic levels in the environment. The antioxidant defense systems could act as biomarkers to monitor marine contamination of organotins.