马拉硫磷对双齿围沙蚕抗氧化酶的影响

目的]研究马拉硫磷对双齿围沙蚕抗氧化酶的影响。方法]采用室内模拟方法,测试有机磷农药马拉硫磷对双齿围沙蚕的急性毒性效应,得出马拉硫磷对双齿围沙蚕96hLC50半致死浓度为33.16mg/L,安全浓度为3.32mg/L。根据急性实验结果设置6个浓度梯度：0.0018、0.018、0.18、1.8、3.6、9mg/L,研究不同暴露时间（3d和6d）下,马拉硫磷对双齿围沙蚕过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、过氧化物酶（POD）活性及丙二醛（MDA）含量的影响。结果],暴露3d,沙蚕体内的这3种抗氧化酶对污染物均很敏感。在最低浓度组（0.0018mg/L）时,3种酶活性均显著下降;在设置浓度范围内,CAT和SOD活性随马拉硫磷浓度的增大呈现下降—上升—下降的趋势,其中CAT对浓度梯度更为敏感,暴露3d后在0.018mg/L浓度时显著被诱导,而SOD在1.8mg/L浓度时活性才开始上升,且与对照差异不显著。POD活性在0.0018～1.8浓度范围内的变化趋势同CAT,在3.6和9.0mg/L浓度组又开始上升,但仍显著低于对照。相对于各自对照,随着暴露时间延长3种酶活逐渐回升。各试验组MDA含量在暴露3d后较对照组显著降低;暴露6d后,随药物浓度的增大呈上升越势,差异显著;且在同一浓度条件下,MDA含量随着暴露时间延长而增大。结论]双齿围沙蚕抗氧化物CAT、SOD和POD对有机磷污染物的胁迫十分敏感,其中CAT更为敏感。

The Effect of Malathion on the Activity of Antioxidant Enzyme of Perinereis aibuhitensis Grube

Objective] The aim was to study the effection of malathion on the activity of antioxidant enzgme of Perinereis.aibuhitensis Grube.Method]Using the indoor simulation method,the acute toxic effects of various concentrations of organophosphorus pesticide malathion on Perinereis aibuhitensis Grube were determined. The median lethal concentration (LC50 ) of malathion to Perinereis aibuhitensis Grube for 96 h was 33.16 mg/L,and the safety concentration was 3.32 mg/L. The six treatments (0.001 8,0.018,0.18,1.8,3.6,9 mg/L) were set up ,and the Perinereis aibuhitensis Grude were exposed to those treatments for 3 d and 6 d respectively,which the superoxide dismutase (SOD)activity,peroxidase (POD) ,catalase (CAT) activity and malondialdehyde (MDA)content were examined.Result] The results indicated that the CAT,SOD and POD were sensitive to the malathion,and were inhibited following a 3 d exposure to 0.001 8 mg/L . Malathion treatment led to an initial decline in CAT and SOD activity followed by a sharp increase and then declined again. The CAT was more sensitive than SOD,after exposed to malathion 3 d,the CAT activity was induced significantly at 0.018 mg/L,however,the SOD activity was increased at 1.8 mg/L,and had no siginificant difference with the control. The POD had the same change trend exposed to concentration rage of 0.001 8~1.8 mg/L,and then increased at 3.6 and 9 mg/L,but still remained signficantly lower than the control.The activity of CAT,SOD and POD increased compared to their own control with the extension of exposure time.The MDA content decreased after exposed 3 d in different concentration of malathion,but increased significantly with the increasing of concentration of malathion after exposed 6 d,and on the same concentration of malathion,the MDA contain had increased with the exposed time extend.Conclusion]Antioxidant enzyme CAT、SOD and POD of Perinereis aibuhitensis Grubs were very sensitive to the stress of organic phosphorus pollutats,and CAT was more sensitive。