Cu^(2+)对克氏原螯虾(Procambarus clarkii)肝胰腺的蛋白质氧化损伤效应

Oxidative Damages of Proteins in Hepatopancreas of Procambarus clarkii Exposed to Cu^2+

克氏原螯虾(Procambarus clarkii)是一种潜在的水质环境污染的指示生物,为研究水体中不同浓度的重金属Cu2+对其肝胰腺组织的蛋白质氧化损伤作用,在测得Cu2+致克氏原螯虾96 hLC50为30 mg·L-1后,将螯虾分别暴露于0、0.5、1.0、3.0、5.0、10.0 mg·L-1的Cu2+溶液中,并在暴露24、48、72、96 h后测定各处理组肝胰腺组织的活性氧自由基(ROS)、总抗氧化能力(T-AOC)、谷胱甘肽过氧化物酶(GSH-PX)活性、蛋白质羰基(PCO)含量以及DNA-蛋白质交联(DPC)系数。结果表明,在暴露24h时,随着Cu2+浓度的升高,ROS、T-AOC和GSH-PX水平的变化规律相似,均为先上升后下降,PCO含量和DPC系数随暴露浓度的升高而增加;在暴露48、72、96 h后,ROS、T-AOC、PCO水平和DPC系数均表现为先升后降的趋势,GSH-PX活性在染毒96 h后,随着浓度的升高而下降。PCO含量的变化具有一定的剂量-效应关系。结果提示,肝胰腺的蛋白质氧化损伤可能是重金属Cu2+致克氏原螯虾毒性效应的主要机制之一。

Crayfish Proeambarus clarkii is an ideal indicator of freshwater pollution. An experiment was designed to study the effects of Cu^2＋ on oxidative damages of proteins in hepatopancreas of Procambarus clarkii. The crayfishes were exposed to various concentrations of Cu^2＋（0, 0.5, 1.0, 3.0, 5.0 and 10.0 mg·L^-1） for 96 h. Reactive oxygen species（ROS ）, total antioxidant capacity（T-AOC ）, glutathione peroxidase （GSH-PX）, protein carbonyl （PCO） content, and DNA-protein crosslinking（DPC ） in the hepatopancreas tissues were determined at 24, 48, 72 and 96 h, respectively. ROS contents, T-AOC activity and DPC rates increased at lower, but decreased at higher concentrations of Cu^2＋ after exposure for 48, 72 and 96 h. PCO contents increased with Cu^2＋ concentrations and showed a dose-effect relationship. With Cu^2＋ concentration increasing, GSH-PX activity had ＂rise and decline＂ pattern at 24 h, while all decreased at 96 h. These results suggest that Cu^2＋ oxidative damages of proteins in the hepatopancreas may be one mechanisms of coPPer toxicity to Procambarus clarkii.