稀土元素镧-铜胁迫下蚯蚓的抗氧化防御反应  

Toxicity of the elements La and Cu in the soil and the earthworms' anti-oxidant defensive response

作　　者：李远伟[1] 王应军[1] 高鹏[2] 杜宇[1] 赵鹏[1] 

机构地区：[1]四川农业大学资源环境学院,成都611130 [2]四川省水利科学研究院,成都610072

出　　处：《安全与环境学报》2014年第4期316-323,共8页Journal of Safety and Environment

摘　　要：采用自然土壤染毒法研究了稀土元素镧(La)和铜(Cu)复合污染对蚯蚓体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响。结果表明,La和Cu复合染毒对抗氧化防御系统产生了一定的联合毒性效应,其联合毒性效应与暴露时间和不同质量比的组合密切相关。不同剂量La与不同背景质量比Cu复合时,低剂量La作用下,SOD活性呈现上升趋势;高剂量La作用下,SOD活性呈现先上升后下降的变化趋势。这表明复合胁迫使蚯蚓受到的环境胁迫作用增强,且复合胁迫超过其耐受阈值。不同剂量La与不同背景质量比Cu复合时POD活性出现明显波动,总体呈逐渐上升趋势,表明复合胁迫使蚯蚓受到的环境胁迫作用增强。不同剂量La与50 mg/kg Cu复合胁迫时,CAT活性先上升后下降,表明La的存在在一定程度上降低了Cu对蚯蚓的毒性效应;不同剂量La与200 mg/kg Cu、600 mg/kg Cu复合胁迫时,蚯蚓受到的环境胁迫作用增强。This article is engaged in an exploration of the toxicity of the elements La and Cu in the soil and the earthworms＇ antioxidant defensive response. It is often said that the earthworms can often be used as a symbol for biological evaluation of the environmental pollu tion. That is why we would like to apply the method of natural soiltest to detect the effects of La and Cu on the enzyme activities of the earthworms along with the testing of the activities of the superoxide dismutase （ SOD）, catalase （ CAT）, and the peroxidase （ POD）. At the same time, we have adopted the ultravioletvisible spectropho tometer to determinate the enzyme activity. The results of our explo ration indicate that the contents of La and Cu in the soil tend to pro duce some joint toxic effects on the antioxidant defense system, with their exposure time and the combinations of the different concentra tions affecting on the joint topicality. Our study of the activity of SOD has also shown the rising trend with the lowdosage of La tends to ap pear firstly and then goes to decline with the highdose La. It indi cates that the combined stress may help to strengthen the environmen tal stress of the earthworms and then exceed their tolerance threshold. Besides, the activity of POD also tends to fluctuate obviously; and, on the whole, the rising trend may indicate that the combined stress may also help to aggravate the environmental stress for the earth worms. For the catalase, when different concentrations of La is com bined with 50 mg/kg Cu, the activity of the catalase also tends to in creased first and then decline, which proves that La can help to de crease the toxic effect of 50 mg/kg Cu for the earthworms. Thus, it can be concluded that different concentrations of La in combination with 200 mg/kg Cu and 600 mg/kg Cu can all help to strengthen the environmental stress of the earthworms.

关 键 词：环境科学技术基础学科 镧 CU2+ 蚯蚓 酶活性 

分 类 号：X174[环境科学与工程—环境科学]