汞暴露对金鱼幼鱼抗氧化防护的影响

将金鱼幼鱼置于质量浓度为0、0.2、1、5、10μg/L的Hg2+溶液中,分别在汞暴露1、7、15d时取样,测定不同质量浓度Hg2+暴露下超氧化物歧化酶、过氧化氢酶活性及丙二醛含量。结果显示,超氧化物歧化酶和过氧化氢酶均表现出在较长的暴露时间及较高质量浓度Hg2+胁迫下的诱导效应,丙二醛含量也因Hg2+暴露而明显积累。金鱼幼鱼为了减弱汞胁迫带来的损害,其超氧化物歧化酶和过氧化氢酶活性均有增强的趋势,同时丙二醛含量也因汞胁迫造成的膜脂过氧化而逐渐积累。

The Effects of Hg2+ Exposure on Antioxidation Defenses in Goldfish Juveniles

Since biochemical and physiological indices of goldfish(Carassius auratus) change with mercury concentration to cope with water environmental mercury stress,understanding of the changes in antioxidation system in the juveniles subjected to mercury stress will be important to assess the potential risk of mercury pollution in aquaculture.In this study,the goldfish juveniles were exposed to the different concentrations of Hg2+(0,0.2,1,5 and 10 μg/L) during the exposure period(1 d,7 d and 15 d) when superoxide dismutase(SOD) and catalase(CAT) activities as well as malondialdehyde(MDA) content were sampled and analyzed.The results showed that the activities of SOD and CAT were induced to increase significantly under higher concentration of Hg2+ and with longer exposure time,and the MDA content was also found remarkably increasing in response to mercury exposure.In conclusion,SOD and CAT activities were enhanced to attenuate the damage resulting from the mercury stress,and MDA content was gradually accumulated to be resulted from membrane lipid peroxidation due to mercury stress.