汞和砷单一及联合暴露对日本沼虾的氧化应激效应

发布时间：2018-05-06 01:23

本文选题：汞 + 砷　；参考：《生态毒理学报》2016年06期

【摘要】：为深入探讨汞(Hg)和砷(As)对水生生物的慢性毒性效应,以日本沼虾(Macrobrachium nipponense)为受试生物,以超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、金属硫蛋白(MT)和丙二醛(MDA)为测试分子标志物,研究上覆水中不同浓度Hg和As单一及联合暴露对日本沼虾肝胰腺的氧化损伤及联合作用机制。结果表明:Hg和As单一及联合暴露对4种分子标志物均可产生不同程度的抑制或激活效应。其中,SOD活性均受到抑制,且高浓度As(1000μg·L-1)暴露10 d的抑制率最大,高达59.13%;而CAT活性整体被激活,Hg单独暴露下的激活效应要高于As,且在联合暴露组中随着暴露时间的增加呈现出显著的剂量效应关系(P0.05);MT和MDA含量在Hg和As的暴露下均显著增加(P0.05)。其中MT对Hg的螯合能力大于As,As单独暴露3 d后MDA变化较小,但10 d后其含量显著增加(P0.05)。析因方差分析发现,Hg-As对机体的联合作用机制主要表现为协同作用。综合生物标志物响应指数(IBR)评价证实,联合毒性要高于单独毒性,Hg与As在高浓度下联合暴露10 d的IBR值最大,毒性最强,高浓度As单独暴露处理组的毒性次之;同时,机体自身随暴露时间延长对Hg也表现出一定的解毒功能。
[Abstract]:In order to investigate the chronic toxicity of HG and As3) to aquatic organisms, Macrobrachium nipponensewas used as the tested organism, and superoxide dismutase (SOD), catalase (CATN), metallothionein (MTT) and malondialdehyde (MDA) were used as molecular markers. The oxidative damage to hepatopancreas of Macrobrachium japonicus by single and combined exposure of Hg and as in overlying water was studied. The results showed that the single and combined exposure of as and Hg could inhibit or activate the four molecular markers in different degrees. The activity of sod was inhibited, and the inhibitory rate of high concentration of As(1000 渭 g L ~ (-1) was the highest in 10 days. The activation effect of CAT activity was higher than that of As. in the combined exposure group, there was a significant dose-effect relationship between P0.05MMT and MDA contents in the combined exposure group. The contents of P0.05MT and MDA increased significantly under the exposure of Hg and as, and the activation effect was higher than that of As-HG alone, and the concentration of P0.05T and MDA increased significantly with the increase of exposure time in the combined exposure group. The chelating ability of MT to Hg was higher than that of Asmas alone for 3 days, but the content of MDA increased significantly after 10 days of exposure. The analysis of variance showed that the mechanism of Hg-As combined action was mainly synergistic. The comprehensive biomarker response index (IBR) evaluation confirmed that the combined toxicity was higher than the IBR value of combined exposure of as and Hg alone for 10 days, the toxicity was the highest, and the toxicity of as alone exposed group was the second, at the same time, there was no significant difference between the two groups. With the prolongation of exposure time, the organism also showed certain detoxification function.
【作者单位】：南京水利科学研究院生态环境研究中心;河海大学环境学院;江苏省水文水资源勘测局;
【基金】：江苏省水利科技重大项目(2015005) “十二五”水专项-“淮河流域水质-水量-水生态联合调度关键技术研究与示范”课题(No.2014ZX07204-006-01) 公益性行业科研专项经费项目—“淮河流域防洪工程体系多目标协同调控研究”课题(201501007)
【分类号】：X171.5

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