NDMA对淡水中鲫鱼幼苗的生态毒理效应

Ecotoxicological Effects of NDMA on Crucian carp Seedlings in Fresh Water

N-亚硝基二甲胺(NDMA)是一种高毒性和环境持久性的强致癌物质,广泛存在于人类的生活环境中。该研究以鲫鱼幼鱼为受试鱼种,采用半静态急性毒性实验测定蛋白质含量、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,研究了NDMA对鲫鱼幼鱼的毒理效应。研究结果显示,高浓度NDMA对鲫鱼幼鱼具有显著毒性,其24 h、48 h、72 h及96 h的半数致死浓度(LC50)分别为9.83、9.14、8.11和7.05 mg/L,而安全浓度(SC)为0.71 mg/L。NDMA对鲫鱼幼鱼的蛋白质含量及SOD、CAT活性产生不同的影响。随着NDMA浓度升高,蛋白质含量呈现诱导效应;SOD活性在低浓度组(1.18 mg/L与1.76 mg/L)受诱导作用,在高浓度组(3.68 mg/L)则显著抑制;CAT活性主要呈现诱导效应,但在3.68 mg/L浓度组中表现为抑制效应。随着暴露时间的延长,各指标的抑制率关系为SOD酶活性>CAT酶活性>蛋白质含量。该研究深入探讨了NDMA对鲫鱼幼鱼的急性毒性与氧化应激毒性,为预防和降低消毒副产物对水生生物的毒性提供了科学依据。

N-nitrosodimethylamine(NDMA)is a strong carcinogen with high toxicity and environmental persistence.It exists widely in human living environment and has attracted great attention.The toxic effect of NDMA on juvenile Crucian carp was studied by semi-static acute toxicity test and determination of protein content,superoxide dismutase(SOD)and catalase(CAT)activities.The results showed that high concentration of NDMA was significantly toxic to juvenile Crucian carp,and the 50%lethal concentration(LC50)at 24 h,48 h,72 h and 96 h were 9.83 mg/L,9.14 mg/L,8.11 mg/L and 7.05 mg/L,respectively.The safe concentration(SC)was 0.71 mg/L.NDMA had different effects on protein content and SOD and CAT activities of juvenile Crucian carp.With the increase of NDMA concentration,protein content showed inducible effect.SOD activity was induced in low concentration group(1.18 mg/L and 1.76 mg/L),but significantly inhib⁃ited in high concentration group(3.68 mg/L).CAT activity was mainly induced,but inhibited in 3.68 mg/L concentration group.With the extension of exposure time,the inhibition rate of each index was as SOD enzyme activity>CAT enzyme activity>protein content.In this study,the acute toxicity and oxidative stress toxicity of NDMA on juvenile Crucian carp were discussed,which provided a scientific basis for preventing and reducing the toxicity of disinfection by-products to aquatic organisms.