Cd^(2+)对长江华溪蟹谷胱甘肽系统的影响  

Effects of Cd^(2+) on Glutathione System of Hepatopancreas and Gills in Freshwater Crab Sinopotamon yangtsekiense

作　　者：刘娜[1] 闫博[1] 李涌泉[1] 王茜[1] 王兰[1] 

机构地区：[1]山西大学生命科学与技术学院,太原030006

出　　处：《环境科学》2008年第8期2302-2307,共6页Environmental Science

基　　金：国家自然科学基金项目(30570194);山西省自然科学基金项目(20041082)

摘　　要：采用急性毒性方法,研究了Cd2+对长江华溪蟹(Sinopotamon yangtsekiense)肝胰腺和鳃谷胱甘肽系统的影响.Cd2+浓度设置为7.25、14.5、295、8和116 mg/L,同时设对照组.分别在24、487、2和96 h用分光光度法测定了还原型谷胱甘肽(GSH)和氧化型谷胱甘肽(GSSG)含量,谷胱甘肽过氧化物酶(GPx)、谷胱甘肽硫转移酶(GST)和谷胱甘肽还原酶(GR)活力以及GSH/GSSG比值.结果显示,随着Cd2+浓度的增加和处理时间的延长,肝胰腺中GSH含量呈现逐渐降低的趋势,在96 h、Cd2+浓度116 mg/L时GSH含量降至最低值(28.805±2.239)mg/g;GPx活力先升后降;GSSG含量和GST与GR活力均无显著变化.鳃中GSH、GSSG含量和GPx活力的变化趋势与肝胰腺基本一致,GST和GR活力则随着Cd2+浓度的增大和处理时间的延长逐渐降低,在96 h、Cd2+浓度116 mg/L时GST和GR活力较对照组分别下降了44%和79%.肝胰腺和鳃中GSH/GSSG比值随着Cd2+浓度的增大和处理时间的延长逐渐降低.结果表明,Cd2+对GSH和GSSG含量,GPx、GST、GR活力均产生了不同程度的影响;GSH/GSSG比值的变化能灵敏反映Cd2+对水生动物的胁迫程度及毒性大小,可作为一种准确敏感的生物学指标用以指示Cd2+污染.Laboratory experiment was carried out to determine the oxidative status in freshwater crab Sinopotamon yangtsekiense exposed to Cd^2＋（7.25,14.5,29,58 and 116mg/L） for different treating times（24,48,72 and 96 h）.The indexes were measured in the hepatopancreas and gills of the crab,which include the levels of reduced glutathione（GSH） and oxidized glutathione（GSSG）,the activities of glutathione peroxidase（GPx）,glutathione S-transferase（GST） and glutathione reductase（GR）,as well as the ratio of GSH/GSSG.In the hepatopancreas,there was a gradual decrease in the level of GSH and it was（28.805±2.239）mg/g at 116mg/L for 96 h while there was an initial elevation and later decrease in the activity of GPx which associated with no significant differences in the level of GSSG and the activities of GST and GR compared with controls.In the gills,with the increase of concentration of Cd^2＋ and duration in treatment,the level of GSH was decreased gradually while there was no pronounced change of the level of GSSG.The activity of GPx was enhanced notably and then was reduced,and the activities of GST and GR were decreased by 44% and 79% after exposed to Cd^2＋ for 96 h.There were evident reduction in the ratio of GSH/GSSG in both hepatopancreas and gills.The results demonstrated that the changes in the studied indicators of oxidative stress（GSH,GSSG,GPx,GST,GR and GSH/GSSG ratio） may sensibly reflect the oxidative stress to aquatic animal induced by Cd^2＋ and the GSH/GSSG ratio could be considered as a biological monitoring index of the pollution induced by Cd^2＋ in aquatic ecosystems.

关 键 词：长江华溪蟹 肝胰腺 鳃 谷胱甘肽系统 CD^2+ 

分 类 号：X174[环境科学与工程—环境科学]