铯对蚯蚓CAT和SOD活性的影响

Effect of Cs^+ on Activities of Catalase and Superoxide Dismutase fromEisenia foetida

为了探索在不同质量分数Cs+的胁迫下,对过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性的影响,以蚯蚓为材料,采用人工土壤法,研究了质量分数ρCs+为50.0,87.5,125.0,162.5,200.0mg/kg的Cs+染毒1,3,7,11,15d后,蚯蚓体内CAT和SOD的活性变化.结果表明:在实验剂量范围内,染毒初期不同ρCs+对蚯蚓体内CAT和SOD活性均有诱导作用;随染毒时间的延长,高质量分数Cs+(ρCs+为162.5,200.0mg/kg)对CAT和SOD活性有明显的抑制作用;低、中质量分数的Cs+(ρCs+为50.0,87.5,125.0mg/kg)对CAT和SOD活性有诱导作用,CAT活性曲线呈"S"形变化,SOD活性曲线呈"抛物线"形变化.蚯蚓体内CAT,SOD活性与对照组相比,差异具有统计学意义(p<0.01),Cs+对蚯蚓有较强的毒性效应;CAT和SOD对环境Cs+胁迫反应灵敏,且酶活性均有峰值出现,其峰值是蚯蚓中毒反应的临界点,可间接作为检测环境污染情况的指标.

To investigate the environmental influence of cesium （Cs ＋ ） at different concentrations ,an artifi-cial soil test for the activities of catalase （CAT ） and superoxide dismutase （SOD） of Eisenia foetida was performed .The exposure concentrations of Cs＋ in the soil were selected as 50.0 ,87.5 ,125.0 ,162.5 and 200.0 mg/kg and the exposure time was chosen as 1 ,3 ,7 ,11 and 15 days .The results showed that in the experimental concentrations ,the activities of CAT and SOD were induced at the initial exposure time . With the extension of the exposure ,the activities of CAT and SOD were obviously inhibited by high con-centrations of Cs＋ （162.5 and 200.0 mg/kg） ,while induced at low and moderate concentrations of Cs＋（50.0 ,87.5 ,125.0 mg/kg） .The activity curve of CAT was an ＆quot;S＆quot; shape ,and the activity curve of SOD was a parabola .Compared with the control groups ,Cs ＋ has significantly strong toxic effects （p 〈0.01） on the activities of CAT and SOD of E. f oetida .Furthermore ,CAT and SOD are sensitive to Cs ＋ stress and peak values of the activities of both enzymes can be observed with the concentration of Cs＋ increases .Being the critical point of E. f oetida poisoning ,the peak values can be indirectly used as the environmental pol-lution indicator .