【摘要】 采用急性毒性实验方法,将克氏原螯虾分别暴露在浓度为7.5、10、15、30mg·L-1的Cd2+溶液中96h,实验期间对肝胰腺、触角腺、鳃等组织的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活力及随时间变化进行了检测。结果表明,在10mg·L-1Cd2+胁迫下,肝胰腺和触角腺中SOD和CAT活力在胁迫初期急剧升高,72h后降低并趋于稳定,而鳃中SOD和CAT两种酶的活力在96h内变化不显著(P>0.05);当Cd2+浓度为30mg·L-1时,肝胰腺、触角腺和鳃中的SOD、CAT酶活力显著受到了抑制(P<0.05)。通过比较发现,克氏原螯虾鳃中SOD和CAT活力要明显低于肝胰腺和触角腺中这两种酶的活力(P<0.05),并且肝胰腺和触角腺对Cd2+的应激反应要比鳃更为敏感。由以上结果可以看出,肝胰腺和触角腺中的抗氧化酶系统在Cd2+胁迫初期发挥了一定的抵御作用,而到后期抗氧化酶活性明显受到了抑制;另外低浓度的镉(7.5mg·L-1)对肝胰腺和触角腺中的SOD和CAT酶活起到了激活作用,而高浓度的镉(30mg·L-1)对3个组织中的抗氧化酶起到了明显的抑制作用。更多还原

【Abstract】 The correlation between heavy metals pollution and crustacean’s response is widely studied. The crayfish,Procambarus clarkii,has been extensively studied as a bioindicator of the effects of pollutants and also for its economic importance. This study aimed at evaluating the role of antioxidant defenses during cadmium-induced oxidative stress. The superoxide dismutases(SOD) and catalase(CAT) in hepatopancreas,antennary gland and gill of crayfish were investigated,which induced by cadmium at different concentrations and exposure times. Results showed:when crayfish were treated with 10 mg·L-1 Cd2+,the activities of SOD and CAT in hepatopancreas and antennary gland were first increased swiftly at earlier stage and then decreased to a stable lower level after 72 hours,while SOD and CAT activities in gill were not affected significantly(P>0.05) . When crayfish were exposed to a higher concentration(30 mg·L-1) ,the activities of SOD and CAT in hepatopancreas,antennary gland and gill were inhibited significantly(P<0.05) . In addition,SOD and CAT activities in gill were lower significantly than those in hepatopancreas and antennary gland(P<0.05) ,the stress response to Cd2+ were more sensitive in hepatopancreas and antennary gland than in gill. These suggested that the antioxidant enzyme system in hepatopancreas and antennary gland played an important role on resisting Cd2+ at the earlier stage,while the activities of antioxidant enzyme were inhibited significantly at the later stage. In addition,the lower concentration of cadmium(7.5 mg·L-1) induced the activities of both SOD and CAT in hepatopancreas and antennary gland,while the higher concentration of cadmium(30 mg·L-1) inhibited significantly the activities of antioxidant enzyme in the three kind of tissues,this indicated that the antioxidase system might be damaged by the higher concentration of cadmium.更多还原