低浓度铜暴露导致梨形环棱螺氧化胁迫及DNA损伤的研究  

Exposure to Trace Copper in Bellamya purificata Inducing DNA Damage and Oxidative Stress

作　　者：张清顺[1,2,3] 熊邦喜[2] 侯建军[1,2,3,4] 

机构地区：[1]中国水产科学研究院内陆渔业生态环境和资源重点开放实验室,淡水渔业研究中心,江苏无锡214081 [2]华中农业大学水产学院,湖北武汉430070 [3]中国水产科学研究院淡水生态与健康养殖重点开放实验室,长江水产研究所,湖北荆州434000 [4]湖北师范学院生命科学学院,湖北黄石435002

出　　处：《水生态学杂志》2010年第5期49-55,共7页Journal of Hydroecology

基　　金：国家自然科学基金资助项目(No.30470342);中国水产科学研究院淡水生态与健康养殖重点开放实验室项目(No.2007FEA0205);中国水产科学研究院内陆渔业生态环境和资源重点开放实验室项目(No.YM2007-03);湖北师范学院2008年度人才项目(No.2008F14);湖北省教育厅2010年度重点项目资助

摘　　要：采用暴露重金属的方法,研究了不同浓度硫酸铜(Cu2+分别为0.00、0.005、0.01、0.02、0.05mg/L)在不同暴露时间(0～14d)下对梨形环棱螺(Bellamyapurificata)肝脏和鳃组织线粒体的活性氧(ROS)含量、肝脏和鳃组织中金属硫蛋白(MT)含量和DNA单链断裂程度的影响,探讨Cu2+对梨形环棱螺的氧化胁迫和DNA损伤及MT防御作用的机理。结果表明,Cu2+对梨形环棱螺肝脏和鳃线粒体ROS水平、肝脏和鳃组织DNA损伤和MT含量均有明显的影响。ROS含量在实验开始时持续上升,肝脏和鳃线粒体ROS分别在第7天(除0.005mg/L剂量组外)和第4天达到最高点,随后下降,但直到第10天时仍显著高于对照组。肝脏和鳃组织DNA单链断裂程度随Cu2+暴露剂量和暴露时间而显著增加。暴露于Cu2+后,F值迅速降低,随后,F值开始上升,在第2天时的F值达到峰值;随后DNA单链断裂程度继续加重,第5天后F值持续下降,至第10～14天时达到稳定水平。第10～14天时,肝脏组织0.005、0.01、0.02和0.05mg/L剂量组间的F值没有显著差异。MT在整个实验期间均处于诱导状态,0.01mg/L剂量组肝脏的MT在整个实验期间均被极显著地诱导(P<0.01),0.01mg/L剂量组的鳃组织MT除第10天外也被极显著诱导(P<0.01)。在暴露至第14天时,除0.05mg/L剂量组的肝脏MT外,其余均处于极显著诱导状态(P<0.01)。An exposure experiment was carried out to study the effects of copper at different concentrations （ Cu^2＋ 0.00, 0. 005, 0.01, 0.02, 0.05 mg/L） and different time （0 - 14 d） on concentrations of reactive oxygen species （ROS） and metallothionein （MT） and DNA single -strand breaking in livers and gills of Bellamya purificat, in order to evaluate the mechanisms of oxidative stress, DNA damnification and recovery of MT in B. purificat, which are induced by Cu^2＋ Gills and livers were chosen to evaluate these toxicological responses because they are the organs which are direct contact with environmental pollutants. The results showed that Cu^2＋ had significant in fluence on concentrations of ROS and MT, DNA single - strand breaking in gills and livers of B. purificat. The concentrations of ROS keeped increasing in the beginning of exposure, and they reached a peak value in livers on the 7^th day （except the treatments with 0. 005 mg/L） and in gills on the 4^th day, and then the concentrations of ROS decreased, but they were still significantly higher than that of control group on the first 10 day. The extents of DNA single - strand breaking in livers and gills of B. purificata was significantly increased comparing with the control group. On the first day during exposure to Cu^2＋, the F value decreased quickly, and then increased and reached a peak value till on the second day of exposure. Subsequently, the extents of DNA single - strand breaking deepened and the F value keep decreasing clearly. During the 10^th to 14^th days, the F values of DNA single-strand breaking maintained at a steady level, and there weren＇t significant difference among the groups of 0. 005, 0.01, 0.02 and 0.05 mg/L vs control groups in livers of B. purificata. The concentration of metallothionein （MT） in livers and gills of B. purificata revealed inducing effect during the whole exposing process. MTs of liver and gill in treatment with 0.01 mg/L of Cu^2＋ was extremely significantly induced （P 〈 0.01 ） e

关 键 词：CU^2+ DNA损伤 氧化胁迫 梨形环棱螺 

分 类 号：Q952.6[生物学—动物学]