不同质量浓度铅对草鱼鱼种抗氧化性能的影响

Effects of High Concentration Pb^(2+) on Antioxidant Capability in Juvenile Grass Carp(Ctenopharyngodon idellus)

将草鱼暴露于不同水平(0、72、1442、88 mg/L)的硝酸铅水溶液中,分别于12、24、48、96 h测定草鱼肝、鳃组织中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。试验结果表明,当鱼经不同质量浓度Pb2+处理24 h后,其肝脏的GSH-Px活性表现为诱导效应;而鳃在低质量浓度(72 mg/L)Pb2+处理也表现诱导效应,但高质量浓度Pb2+(144、288 mg/L)处理24 h后,其GSH-Px活性表现为抑制效应。与肝GSH-Px相比,草鱼肝SOD经Pb2+处理后其活性抑制更加明显,表明肝SOD对Pb2+的毒性反应比肝GSH-Px敏感。同时,草鱼经不同质量浓度Pb2+处理12 h后,肝与鳃的MDA含量均比对照组明显增加。上述研究结果表明,水体铅可能通过诱导草鱼肝脏与鳃发生氧化损伤而发挥毒性作用,并进一步损伤机体结构及其生理功能。

Grass carp（Ctenopharyngodon idellus） was exposed to Pb2＋ at concentrations of 0,72,144 or 288 mg /L,and activities of glutathion peroxidase（GSH-Px）,and dismutase（SOD） and contents of malonyldialdehyde（MDA） in hepatopancrease and gills were determined at 12,24,48 and 96 h after the exposure during the acute toxicity test.Results showed that the activity of GSH-Px in the hepatopan crease was higher in the fish exposed to Pb2＋ of different concentrations for 24 h than that in the control group.In the gills,however,the fish exposed to lower concentration（72 mg/L） of Pb2＋ showed an induction of the activity of GSH-Px,but a depressed activity of GSH-Px when the fish exposed to higher concentrations（144,288 mg /L） of Pb2＋ for 24 h.Compared with GSH-Px activity,the activity of SOD in the hepatopancrease was more significantly depressed,indicating that SOD was more sensitive to Pb2＋ toxitciy pancreas than GSH-Px.There was significant higher MDA contents in the hepatopancreas and gills in the fish exposed to of different concentrations for 12 h than that in the control fish.The results suggest that Pb2＋ in water body exert toxicity to grass carp through oxidative damage in hepatopancreas and gills,which in turn damage the physiological functions and structures in the fish.