【作者】 侯建军； 张清顺； 熊邦喜； 邹桂伟；

【Author】 HOU Jian-Jun~(1,2,3) ZHANG Qing-Shun~2 XIONG Bang-Xi~2 ZOU Gui-Wei~3 (1.Department of Biology,Hubei Normal University,Huangshi 435002,China 2.College of Fisheries,Huazhong Agricultural University,Wuhan 430070,China; 3.Yangtze River Fisheries Research Institute,Chinese Academy of Fishery Sciences, Jingzhou 434000 China)

【机构】 湖北师范学院生命科学学院； 华中农业大学水产学院； 中国水产科学研究院长江水产研究所；

【摘要】 本实验采用暴露重金属的方法,研究了不同浓度氯化镉(Cd²⁺分别为0 mg/L、0.05 mg/L、0.10 mg/L、0.20 mg/L、0.50 mg/L)在不同暴露时间（0—14d）下对梨形环棱螺（Bellamya purificata）过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、谷胱甘肽硫转移酶（GST）的活性、还原性谷胱甘肽（GSH）和丙二醛（MDA）含量的影响,以探讨Cd²⁺对梨形环棱螺的氧化胁迫作用机理。结果表明:Cu²⁺对梨形环棱螺肝脏和鳃中CAT、SOD、GST、GSH和MDA均有明显影响,表现出时间剂量效应。0.05和0.10剂量组肝脏中SOD活性一直处于诱导状态,0.20和0.50剂量组肝脏中SOD活性在前10 d处于诱导状态,第14 d时活性则受到抑制;0.05、0.10和0.20剂量组鳃组织中的SOD活性一直处于诱导状态,0.50剂量组酶活性在第2d时处于极显著升高（p<0.01）,然后酶活性出现波动,第14 d时略低于对照组,无显著差异。0.05和0.10剂量组肝脏CAT在暴露的前7d活性被诱导,然后活性下降,到第10-14d时酶活性在对照组水平附近波动;0.20和0.50剂量组在第2d时酶活性显著升高（p<0.05）,随后酶活性一直下降直至第10 d,活性极显著被抑制（p<0.01）,0.20剂量组维持这一水平,而0.05剂量组活性有所回升,但第14d时仍显著地低于对照组（p<0.05）;鳃组织中的各剂量组CAT在暴露的前7d处于诱导状态（0.50剂量组第4d除外）,然后酶活性急剧下降,在第10-14d酶活性被极显著抑制（p<0.01）。结果表明,低浓度Cd²⁺胁迫对梨形环棱螺抗氧化指标的影响表现为一个动态的变化过程,抗氧化指标间的相关关系密切。低浓度的Cd²⁺暴露可引发梨形环棱螺的氧化应激和脂质过氧化。上述指标均对Cd²⁺污染敏感,可以作为将来Cd²⁺污染监测的生物标志物。更多还原

【Abstract】 An exposure experiment was conducted to study the effects of Cd2+ at different concentrations and different times on its antioxidant enzymes activities(superoxide dismatase,catalase and glutathione S-transferase) and concentrations of glutathione and MDA in liver and gill of Bellamya purificat.The results showed that Cd2+ had a time-dosage effect on superoxide dismatase(SOD), catalase(CAT),glutathione S-transferase(GST),glutathione(GSH) and MDA.The SOD,CAT and GST could be sharply induced in a short time of exposure,while with exposure time prolonging,and the activities of SOD,CAT and GST were restraint.When the exposure time further increased,the activities of enzymes in treatments with 0.005mg/L of Cu2+ fluctuated around the normal value,in treatments with 0.05 mg/L of Cu2+ were restrained,but induced with 0.01mg/L of Cu2+.The activities of enzymes in treatments with 0.02 mg/L of Cu2+ was induced in liver,but reversed in gill.Changes of GSH concentration in livers and gills were similar in inducement of a short time.GSH concentrations in livers were induced in five days after exposure,and that in gills were induced in four days after exposure. Moreover,the treatments with low dosage showed inducement phenomenon while high dosage showed restraint phenomenon.The MT(concentration of metallothionein) of livers and gills showed inducement in the whole process,which increased extremely significantly within 12 hours,and decreased later,then increased again and reached to a peak value and at last fell to a stable level.Thereinto,MT in livers in treatments with 0.01 mg/L of Cu2+ was extremely significantly induced during the whole process(P<0.01),and that in gills except in the 10th day were extremely significantly induced during the whole process(P<0.01) too.In the 14th day,except MT in livers in treatments with 0.05 mg/L of Cu2+,all showed an extremely significant inducement phenomenon(P<0.01).更多还原