饲料铅暴露对罗非鱼肝胰脏抗氧化防御系统及显微结构的影响

Effects of dietary Pb on antioxidant defense systems and microstructure of hepatopancreas in tilapia(Oreochromis niloticus)

将罗非鱼暴露于不同水平(0、100、400和800μg·g-1)饲料铅60d后,对肝胰脏中丙二醛(MDA)含量和抗氧化防御系统相关指标进行测定,并观察其肝胰脏显微结构变化.结果表明,随着饲料铅暴露剂量的增加,罗非鱼肝胰脏中MDA含量呈上升趋势,总抗氧化能力(T-AOC)和谷胱甘肽(GSH)水平呈下降趋势,谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)活性被铅诱导升高;随着铅暴露剂量增加,罗非鱼肝胰脏病理损伤逐渐加剧.以上研究结果揭示饲料铅可能通过诱导罗非鱼肝胰脏发生氧化损伤而发挥毒性作用,损害其结构和功能.

Tilapia were exposed to dietary Pb at concentrations of 0, 100, 400 and 800 μg·g^-1 dry weight for 60 days, and effects of dietary Pb on microstructure, malonyldialdehyde （MDA）content and antioxidant ability of hepatopancreas were investigated. The results show that MDA content in hepatopancreas increased and total antioxidant capacity （T-AOC） and glutathione （GSH） levels decreased with the increases of dietary Pb concentrations. Glutathione peroxidase （GSH-Px） and superoxide dismutase （SOD） activities were induced by dietary Pb. Pb concentration-related lesions could be detected in histological sections of hepatopancreas. The results above suggest that oxidative damage may be one of the reasons for dietary Pb toxicity on hepatopancreas of tilapia.