摘要氯化消毒是世界各地多年的主要饮用水消毒方式。在消毒杀菌过程中，消毒剂会与原水中的某些物质反应，产生对人体健康构成潜在威胁的消毒副产物（disinfection by products，DBPs）。其具有很强的水溶性和难降解性，在水环境中广泛检出。消毒副产物已被证实对哺乳动物和人具有生殖毒性，但对两栖动物的生殖毒性等研究，特别是不同卤素取代DBPs对其生殖毒效应研究十分有限。本研究以典型消毒副产物二氯乙酸（dichloroacetic acid，DCA）和二溴乙酸(dibroacetic acid，DBA)为目标污染物，两栖生物雄性黑斑蛙为研究对象，考察不同卤素取代DBPs对雄性黑斑蛙精巢中氧化应激指标的影响。黑斑蛙分别暴露于0，1，10，50，100 μg/L浓度的 DCA、DBA14天后，测定黑斑蛙精巢内的ROS指标、脂质过氧化指标（MDA）与抗氧化酶指标。数据显示，DCA、DBA暴露后，黑斑蛙精巢内ROS水平、MDA含量显著上升，当DCA、DBA浓度为100 μg/L时，ROS水平与对照组相比均增加了1。3倍，MDA含量分别增加到了对照组的2。6和1。3倍，这表明DCA和DBA可能诱导了黑斑蛙精巢氧化应激毒性效应；抗氧化系统酶SOD、POD活性均呈现上升趋势，而酶GR和GPx活性呈下降趋势，其中，100μg/L DCA使SOD活性增加到对照组的1。8倍，100μg/L DBA使SOD活性增加到对照组的4。1倍，这表明DCA和DBA破坏了抗氧化系统平衡。这些结果表明DCA和DBA可能通过诱导黑斑蛙精巢氧化应激，破坏黑斑蛙精巢抗氧化系统，进而引起氧化损伤，产生两栖动物黑斑蛙生殖毒性。相同剂量的DCA对黑斑蛙精巢中脂质过氧化程度比DBA更严重，说明含氯取代DBPs可能对黑斑蛙的精巢造成的氧化应激效应比溴取代DBPs更严重。88237

毕业论文关键词：二氯乙酸; 二溴乙酸; 活性氧簇；抗氧化酶；生殖毒性

Abstract Chlorination disinfection has already become the main disinfection method of drinking water around the world for years。 However, disinfectants will react with certain substances in raw water and produce disinfection by products (DBPs) which pose a potential threat to human health during chlorination disinfection。 DBPs have strong water-solubility, are difficult to degrade and widely detected in the water。 It has been confirmed that DBPs have reproductive toxicity to mammals and humans, but the studies on reproductive toxicity of amphibians induced by DBPs are limited, especially the halogen-substituted analogues。 In this study, two typical DBPs—dichloroacetic acid (DCA) and dibroacetic acid (DBA) as the target pollutants, male rana nigromaculata as the research objects to investigate the effects of different halogen substituted DBPs on oxidative stress index in the testis of male rana nigromaculata。 The ROS indexes, lipid peroxidation indexes (MDA) and the antioxidant indexes in testis of rana nigromaculata were measured after exposure to 0, 1, 10, 50, 100μg/L DCA and DBA for 14 days。 After exposure to DCA and DBA，the levels of ROS and the contents of MDA in the testes were significantly increased。 When the concentrations of DCA and DBA were 100 μg/L, the ROS levels were all increased by 1。3-fold and the contents of MDA were respectively increased by 2。6- and 1。3-fold compared with the control group The results indicated that DCA and DBA might induce oxidative stress in the testis of the rana nigromaculata。 After exposure to DCA and DBA, The activities of SOD and POD were all significantly increased, while activities of GR and GPx significantly decreased。 Among these results, the activity of SOD were respectively increased by 1。8-fold and 4。1-fold after exposure to 100μg/L DCA and DBA, which indicated that DCA and DBA destroyed the antioxidant system balance。 These results suggested that DCA and DBA might induce oxidative stress, destruct the testis antioxidant system, and then cause the oxidative damage in testis of rana nigromaculata, which resulted in the reproductive toxicity of male rana nigromaculata。 The lipid peroxidation levels of DCA were more serious than those of DBA, which indicated that the oxidative stress effects of bromine-substituted DBPs might be more serious than those of chlorine-substituted DBPs on the testis of rana nigromaculata 源-于,优W尔Y论L文.网wwW.youeRw.com 原文+QQ75201,8766