五溴联苯醚-镉胁迫下蚯蚓抗氧化防御反应

文章采用自然土壤染毒法,研究了Cd2+和DE-71对蚯蚓体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性的影响。结果表明,两种污染物对蚯蚓的三种酶活性均产生一定的影响,DE-71主要表现为诱导效应,而高浓度的Cd2+则会产生抑制作用,SOD和CAT较POD敏感,对环境污染有很好的指示作用。Cd2+和DE-71复合染毒对抗氧化防御系统产生一定的联合毒性效应,SOD主要由协同转变为拮抗作用;以CAT指示的联合效应则受DE-71染毒浓度的影响,当Cd2+与10和100mg/kg(干重)DE-71复合时,联合毒性作用由协同转变为拮抗,而与400mg/kg(干重)DE-71复合时则呈现协同作用;POD指标下两种污染物间则表现为拮抗作用。总体来说Cd2+与DE-71对蚯蚓的抗氧化防御反应主要表现为拮抗效应。

Toxicity of Commercial Penta-BDE and Cd in Soil on Anti-oxidant Defensive Responses of Earthworms

Natural soil test method was used to study the effect of cadmium and DE-71 on enzyme activities of earthworms.Activities of superoxide dismutase (SOD),catalase (CAT)and peroxidase (POD)were measured.Results indicted that the activities of SOD,CAT and POD of the earthworms were affected by Cd2+ and DE-71 at the tested concentrations.In general,DE-71 mainly presented induction effect while Cd2+ at high concentration may inhibit the three enzyme activities.CAT and SOD which were more sensitive than POD could be used as indicators for environmental pollution of PBDEs and Cd2+.When Cd2+ was combined with different concentrations of DE-71,different joint effects were displayed.For SOD,the joint effect was synergetic at early exposure but changed to antagonistic effect at later exposure.Similar trend was observed for CAT when Cd2+ was combined with 10 and 100mg/kg dw DE-71.It was mainly synergetic effect when combined with 400mg/kg dwDE-71.For POD,it was mainly antagonistic effect.In overall,joint effect of Cd2+ and DE-71 on the anti-oxidative system of earthworm was mainly antagonistic effect.