镉和汞对赤子爱胜蚓超氧化物歧化酶活性的影响

Effects of Cadmium and Mercury on Superoxide Dismutase Activity of Eisenia foetida

采用人工土壤方法,以赤子爱胜蚓为材料,研究了土壤中重金属Cd2+和Hg2+单一及复合染毒对赤子爱胜蚓体内超氧化物歧化酶(SOD)活性的影响.结果表明:在实验剂量范围内(ρ2Cd+32.5～197.5 mg/kg,ρ2H+g25.0～157.5mg/kg),Cd2+单一染毒时,随着Cd2+质量分数的增加,蚯蚓体内SOD活性表现出先升高后下降趋势,总体呈抛物线形;Hg2+单一染毒时,随着Hg2+质量分数的增加,第2天和第4天SOD活性表现出先下降后升高的趋势,第6天和第8天SOD活性是先升高后下降,呈"抛物线"变化(除第2天外).Cd2+和Hg2复合染毒时,低质量分数的Cd2+与Hg2+复合染毒时,蚯蚓体内SOD活性有显著升高的趋势(p<0.01),表现为协同作用;高质量分数的Cd2+与Hg2+复合染毒时,SOD活性明显降低(p<0.05),表现为拮抗作用.

In an artificial soil test,the activity of superoxide dismutase（SOD） in the body of earthworm（Eisenia foetida） was determined in the presence of cadmium（Cd） and/or mercury（Hg）.The results showed that in the presence of Cd2＋ with a concentration ranging from 32.5 to 197.5 mg/kg,SOD activity in E.foetida increased first and then decreased with the increase in Cd2＋ concentration,exhibiting a parabola curve,while in the presence of Hg2＋ with a concentration ranging from 25.0 to 157.5 mg/kg,change in SOD activity in the earthworm also exhibited a parabola curve,decreasing first and then increasing at day 2 and day 4,and decreasing first and then increasing at day 6 and day 8.Under exposure of both Cd2＋ and Hg2＋ at lower concentrations,SOD activity in E.foetida increased significantly（p0.01）,thus showing a synergistic effect.In contrast,with higher concentrations of Cd2＋ and Hg2＋,SOD activity in E.foetida decreased significantly（p0.05）,showing an antagonistic effect.