首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Though there is some information on cytotoxicity of copper nanoparticles and silver nanoparticles on human cell lines, there is no information on their genotoxic and cytotoxic behaviour in bivalve molluscs. The aim of this study was to investigate the genotoxic impact of copper oxide and silver nanoparticles using mussels Mytilus galloprovincialis. Mussels were exposed to 10 μg L−1 of CuO nanoparticles and Cu2+ and Ag nanoparticles and Ag+ for 15 days to assess genotoxic effects in hemocytes using the comet assay. The results obtained indicated that copper and silver forms (nanoparticles and ionic) induced DNA damage in hemolymph cells and a time-response effect was evident when compared to unexposed mussels. Ionic forms presented higher genotoxicity than nanoparticles, suggesting different mechanisms of action that may be mediated through oxidative stress. DNA strand breaks proved to be a useful biomarker of exposure to genotoxic effects of CuO and Ag nanoparticles in marine molluscs.  相似文献   

2.
Enteromorpha prolifera (Scheldt Estuary) and E. linza (Thermaikos Gulf) were incubated at three salinities with 100 and 200microgL(-1)Cd and Zn. The objective was to measure effects of Cd, Zn and nitrogen (N) status on the pools of metal-binding non-protein thiols: glutathione and phytochelatins, (gamma-glutamyl-cysteinyl)(n)-glycine (PC). In E. linza, ammonium pools were higher, but amino acid pools, total N and protein contents were lower than in E. prolifera. Reduced glutathione (GSH) pools were positively correlated with free glutamate and protein contents. In E. linza GSH pools increased and the ratio of reduced to oxidized glutathione (GSH:(GSH+0.5GSSG)), an indicator of oxidative stress, decreased with Cd contents, indicating Cd-induced glutathione oxidation. Total glutathione pools (reduced plus oxidized) ranged from 16nmolSgdwt(-1) in controls (at 0.5micromolCdgdwt(-1)) to 179nmolSgdwt(-1) (at 1.9micromolCdgdwt(-1)) at the highest cadmium dosage. Cadmium stimulated PC synthesis in E. prolifera which suggests that in N-rich algae, glutathione pools were high enough for PC synthesis. In both species GSH and protein increased with Zn contents, whereas GSH:(GSH+0.5GSSG) decreased, which would indicate Zn-induced oxidative stress; in E. linza, at the highest salinity the glutathione redox ratio decreased from 0.61 (at 2.9micromolZngdwt(-1)) to 0.26 (at 4.9nmolSgdwt(-1)) (at 0.5molCdgdwt(-1)). PCs were not synthesized in response to Zn, which may have resulted in Zn-induced GSH oxidation. The presence of both oxidative effects (Cd, Zn) and detoxification (Cd) could be identified by observing the responses of glutathione and PC pools to metal stress.  相似文献   

3.
The comparative toxicity of a variety of oxidative stressors was studied in the epithelioma papulosum cyprini line from carp using the neutral red cytotoxicity assay. LC50's decreased in the order t-butylhydroperoxide > hydrogen peroxide > diquat > paraquat. The cytotoxicity of hydrogen peroxide was significantly reduced when the cells were grown in L-15 medium rather than MEM and this could be attributed to elevated cellular glutathione and metallothionein levels and higher activities of GSH-dependent detoxification systems. The protective effect of metallothionein in radical scavenging was demonstrated by decreased toxicity of the redox-cycling toxicants, diquat and menadione after metallothionein levels had been pre-induced by Cd-exposure. This study demonstrates the relationship between toxic effects of oxidative stressors and expression of detoxification systems in fish.  相似文献   

4.
When cultured in Dulbecco's minimal essential medium the established epithelioma papulosum cyprini cell line from carp was found to be vitamin E-deficient due to the very low level of vitamin E in the medium and the foetal calf serum used as supplement. The toxicity of oxidative stressors to this cell line was evaluated by means of the neutral red cytotoxicity assay and it was found that an organic hydroperoxide, t-butylhydroperoxide was extremely cytotoxic and that the redox-cycling agents diquat and menadione were less toxic. When grown under vitamin E supplementation (25 microM), the toxicity of these chemicals was reduced by at least an order of magnitude in concentration demonstrating the protective effect of vitamin E. These data show the importance of vitamin E status for interpretation of in vitro and in vivo data and that this in vitro system is useful for mechanistic studies.  相似文献   

5.
本文以黑褐新糠虾(Neomysis awatschensis)为受试生物,分别研究两者单独及联合暴露21 d后的氧化应激效应,并结合综合生物标志物响应(Integrated Biomarker Response,IBR)评估其毒性。结果表明:PS单独暴露时,过氧化氢酶(Catalase,CAT)、谷胱甘肽硫转移酶(Glutathione S-transferase,GST)、超氧化物歧化酶(Superoxide dismutase,SOD)和谷胱甘肽过氧化物酶(Glutathione peroxidase,GPX)活性随暴露浓度升高被显著抑制,丙二醛(Malondialdehyde,MDA)含量随暴露浓度增加逐渐上升,而谷胱甘肽(Glutathione,GSH)含量仅在97.4μg·L-1暴露下显著上升;BDE-47单独暴露时,CAT、GST和GSH含量均被抑制,MDA和GPX活性仅在较高浓度下被显著诱导,SOD活性在低浓度被诱导,在最高浓度下恢复至空白水平。联合暴露时,CAT和SOD活性随PS投加浓度升高表现出先诱导后抑制的效应,且均显著高于BDE-47单独暴露组,MDA含量随PS投加浓度升高表现出诱导效应。GST和GPX活性与空白水平相近,低浓度PS暴露组中的GSH含量也有相似的变化规律。可见,PS能减缓BDE-47对黑褐新糠虾抗氧化防御系统的氧化胁迫,在低浓度PS联合暴露组中尤其显著。  相似文献   

6.
采用卤虫致死和细胞毒活性筛选模型,对蕾二歧灯芯柳珊瑚Dichotella gemmacea (valenciennes)乙醇提取物及各有机相进行了克生活性测定.结果表明,克生活性物质主要集中在石油醚相中.采用GC/MS技术对石油醚相进行了分析,鉴定了20个低极性化合物,主要为甾醇类、脂肪类化合物.推测甾醇类化合物是蕾二歧灯芯柳珊瑚的主要克生活性物质.  相似文献   

7.
采用卤虫致死和细胞毒活性筛选模型,对1种中国南海短指软珊瑚Sinularia sp.的乙醇提取物及各有机相进行了克生活性测定。结果表明,克生活性物质主要集中在石油醚相中。采用GC/MS技术,对石油醚相进行了分析,鉴定了15个化合物,主要为脂类和甾体类化合物;从石油醚相的甾醇部分鉴定了6个化合物,主要为麦角甾醇衍生物,占总甾醇含量的75.7%。推测甾醇类化合物是短指软珊瑚Sinularia sp.的主要克生活性物质。  相似文献   

8.
Oxidative stress by increased production of reactive oxygen species such as superoxide has been implicated in the toxicity of PCB's and non-target toxicity of many pesticides. We report the development of a microplate-based method for determination of early stage oxidative stress using an established cell line (EPC) from a skin tumour of carp Cyprinus carpio L. and 2',7'-dichlorodihydrofluorescein diacetate (H(2)-DCFDA) as a fluorescent probe for detection of reactive oxygen species (ROS) formation. Sublethal concentrations of the herbicide Paraquat, an established redox cycling agent and a crude PCB mixture, Arochlor 1254 elicited a linear increase in ROS formation over 2 h exposure which was some 45- and 10-fold higher, respectively, than attributable to basal respiration, confirming the suitability and response of the test system. Whilst in vivo studies in mammals have implicated early stage oxidative stress in the toxicity of pesticides, we did not observe an increase in ROS production after exposure of EPC cells to sublethal concentrations of Carbaryl, 2,4-DDT, Lindane or Malathion implying that this is not the causative mechanism of acute toxicity in this fish cell line. The apparent involvement of oxidative stress in their mammalian toxicity may therefore be an indirect effect or dependent upon compound metabolism.  相似文献   

9.
In this study we have investigated protein changes in plasma of juvenile Atlantic cod (Gadus morhua) induced by crude North Sea oil and North Sea oil spiked with alkyl phenols and polycyclic aromatic hydrocarbons, a surrogate produced water composition. Using a proteomic approach, we identified 137 differentially expressed proteins at different levels of crude oil exposure. Many of the induced protein changes occurred at low levels of exposure. The results obtained with protein expression profiles after exposure to oil and surrogate produced water indicate effects on fibrinolysis and the complement cascade, the immune system, fertility-linked proteins, bone resorption, fatty acid metabolism as well as increased oxidative stress, impaired cell mobility and increased levels of proteins associated with apoptosis. Although the number of individuals and samples in this study is limited within each treatment group, the protein changes observed in this study represent a first screening for potential biomarker candidates in cod plasma reflecting potential effects of crude oil and produced water exposure on fish.  相似文献   

10.
Oxidative stress induced by microcystins was evaluated in an estuarine worm, Laeonereis acuta (Nereididae). Ten organisms were exposed to lyophilized cells of a toxic Microcystisaeruginosa strain RST9501 ( approximately 2 microg/mL microcystins, MC); 10 were exposed to lyophilized cells of a nontoxic Aphanotece sp. strain RSMan92 and 10 were maintained without cyanobacterial cells. Exposure time was 48 h. The enzymatic antioxidant defenses, as well as the oxidative damage, were analyzed. Toxic and nontoxic cyanobacteria lowered catalase activity with no changes in glutathione reductase and glutathione-S-transferase activities. This may have led to toxin intracellular accumulation, which should favor oxidative stress generation, observed by the high lipid peroxide and DNA-protein crosslink levels in the group exposed to MC.  相似文献   

11.
Nrf2参与水生动物氧化应激调控的研究进展   总被引:1,自引:0,他引:1  
环境变化会诱导机体活性氧(reactive oxygen species, ROS)水平升高,从而产生氧化应激。氧化应激对所有生物的生存、生长、发育和进化都具有深远的影响。核因子E2相关因子2 (nuclear factor erythroid 2 related factor 2, Nrf2)被公认为细胞氧化应激调控的主导者,与伴侣蛋白Kelch样环氧氯丙烷相关蛋白1 (kelch-like ECH-associated protein 1, Keap1)一起控制数百个解毒酶和抗氧化蛋白编码基因的表达。近年来, Nrf2在水生动物中逐渐获得重视,并在一些模式鱼类如斑马鱼、鲤鱼及其他一些鱼类和水生无脊椎动物中得到研究。介绍了Nrf2的结构以及调控机制,回顾了近年来水生动物Nrf2通路参与氧化应激调控所取得的进展。研究表明, Nrf2在水生动物中广泛存在,在非生物(金属、有机污染物、无机盐、药物及微塑料等)、生物(细菌、病毒、有毒藻类)以及生境变化(冰融、盐胁迫)诱导的氧化应激调控中发挥重要作用。Nrf2一经激活入核,在小Maf蛋白的协助下与抗氧化反应元件(antioxidant-responseelement,ARE)结合,启动一系列ARE驱动基因的表达,并和孕烷X受体(pregnane X receptor, Pxr)、丝裂原活化蛋白激酶(mitogen-activated protein kinase, MAPK)以及芳烃受体(arylhydrocarbonreceptor,AhR)等细胞通路协同作用参与一系列生理过程。Nrf2在水生动物响应环境变化过程中发挥重要的细胞保护机制,有望发展成为抗逆育种潜在的基因靶点。  相似文献   

12.
In order to examine factors that may contribute to the reported resistance of rainbow trout, Shasta strain, to the well-known hepatocarcinogenic effects of 2-acetylaminofluorene (AAF), the in-vitro and in-vivo metabolism of [14C]AAF in trout has been examined. Trout (compared to rat) liver microsomes metabolized AAF more efficiently, producing 3-fold larger amounts of ring-hydroxylated metabolites (7-hydroxy-AAF and 5-hydroxy-AAF), but 5-fold less N-hydroxy-AAF. Freshly isolated trout hepatocytes extensively metabolized AAF to form the same ring-hydroxylated metabolites and their respective glucuronide and sulfate conjugates. N-OH-AAF (plus its conjugates) and covalently-bound AAF derivatives amounted, respectively, to < 1% and 1.4–1.6% of total metabolites. Liver DNA of trout treated with AAF contained a single AAF-DNA adduct identified as N-(deoxyguanosin-8-yl)-2-aminofluorene (the major persistent AAF-DNA adduct found in rat liver). The level of this adduct (12 attomoles/μg DNA) was about 1000-fold lower than the level of AAF-DNA adduct previously reported in rat liver. The data show that trout liver, compared to rat liver, is considerably less efficient in metabolizing AAF to carcinogenic metabolites, and more efficient in forming nontoxic products, thus possibly explaining, in part, the resistance of trout to AAF-induced hepatocarcinogenesis.  相似文献   

13.
过氧化氢酶(CAT)和硒谷胱甘肽过氧化物酶(Se-GPx)在抗氧化防御体系中扮演重要的角色,在清除多余的活性氧自由基(ROS)防止机体氧化损伤方面具有重要的作用.本文利用RACE-PCR方法首次从脊尾白虾肝胰腺组织中克隆获得了CAT cDNA全长序列,该基因全长2649 bp,包括5′非编码区(UTR) 78 bp、开放阅读框(ORF)1554 bp和3′非编码区(UTR) 1017 bp,共编码517个氨基酸,预测分子量为58.46 kDa,理论等电点为6.64,利用PROSITE tools预测CAT基因的功能位点,发现该氨基酸序列包括酶活性中心序列“FDRERIPERVVHAKGAG”,亚铁血红素结合信号序列“RLFSYPDTH”和 3个催化位点残基His71,Asn144和Tyr354.同源性分析表明,脊尾白虾CAT氨基酸序列与其他物种的相似性为68%-92%.荧光定量PCR分析结果表明,CAT基因在肝胰腺、血细胞、心脏、肌肉、卵巢、鳃、胃和眼柄均有表达,其中在肝胰腺中表达量最高.低盐胁迫后脊尾白虾鳃和肝胰腺中CAT和GPx基因分别在48 h和6 h达到最大值,且与对照组差异显著(P< 0.05),表明CAT和GPx基因参与了低盐胁迫反应,并表现出一定时间效应关系.综合分析结果指出脊尾白虾CAT基因是CAT家族主要成员之一,可能在低盐环境胁迫过程中具有重要的作用.  相似文献   

14.
This study investigated the effects of pollution and its interaction with temperature on the oxidative status of the ribbed mussel Aulacomya atra in the southern Atlantic Patagonian coast. Animals were collected from four sites with different degree and type of human activity impact, during the summer and winter of 2011. Seawater chromium, copper, manganese, nickel and zinc concentrations were measured, as well as metal accumulation, lipid peroxidation, protein oxidation, reduced glutathione levels, and enzymatic activities of superoxide dismutase and glutathione-S-transferase in gills and digestive glands.Metal bioaccumulation and oxidative stress responses in both tissues were generally higher in mussels from harbor areas. Water temperature had a remarkable effect on gill SOD activity and protein oxidation during winter in mussels from all locations.Methodologically, we conclude that measuring both metal bioaccumulation and oxidative stress responses allowed for a more accurate assessment of the biological effects of metal present in seawater.  相似文献   

15.
16.
海水中的高溶解氧浓度、低温和UV辐射导致了氧胁迫是北极海洋细菌面临的主要胁迫因素之一。本文对北极细菌Pseudoalteromonas sp.A2对H2O2导致的氧胁迫的应答特征进行了转录组测序和基因差异表达的比较分析,以期发现与氧胁迫相关的关键功能基因。研究表明,与对照组相比,1 mmol/L的H2O2可导致菌株A2转录组的很大变化,包括109个基因的显著上调与174个基因的显著下调。COG分析表明,在功能已知的基因中,与转录后修饰、蛋白质转换和分子伴侣相关的基因大部分显著上调,而与氨基酸运输和代谢等相关基因则大部分显著下调。值得指出的是,有18个与鞭毛相关的基因和4个与热激蛋白相关的基因显著上调;同时,有9个与细胞色素和细胞色素氧化酶相关的基因和5个与TonB依赖受体相关的基因显著下调。在GO分析表明具有抗氧化活性的18个基因中,只有1个基因的表达显著上调,而有2个显著下调。简言之,RNA-Seq表明,除了传统的抗氧化基因和应激蛋白外,鞭毛相关基因和功能未知基因在菌株Pseudoalteromonas sp.A2的氧胁迫适应性中起着重要作用。该转录组分析和氧胁迫相关基因的发现有助于了解北极细菌的氧胁迫适应机制。  相似文献   

17.
Every day new extraordinary properties of nanoparticles (a billionth of a meter) are discovered and worldwide millions are invested into nanotechnology and nanomaterials. Risks to marine organisms are still not fully understood and biomarkers to detect health effects are not implemented, yet. We used the filter feeding blue mussel as a model to analyse uptake and effects of nanoparticles from glass wool, a new absorbent material suggested for use in floating oil spill barriers. In both, gills and hepatopancreas we analysed uptake of nanomaterials by transmission electronmicroscopy (TEM) in unstained ultrathin sections over a period of up to 16 days. Lysosomal stability and lipofuscin content as general indicators of cellular pathology and oxidative stress were also measured. As portals of uptake, diffusion and endocytosis were identified resulting in nanoparticle accumulation in endocytotic vesicles, lysosomes, mitochondria and nuclei. Dramatic decrease of lysosomal membrane stability occurred after 12h of exposure. Lysosomal damage was followed by excessive lipofuscin accumulation indicative of severe oxidative stress. Increased phagocytosis by granulocytes, autophagy and finally apoptosis of epithelial cells of gills and primary and secondary digestive tubules epithelial cells indicated progressive cell death. These pathological responses are regarded as general indices of toxic cell injury and oxidative stress. By the combinational use of biomakers with the ultrastructural localisation of nanoparticle deposition, final evidence of cause-effect relationships is delivered.  相似文献   

18.
Oxidative damage in rainbow trout caged in a polluted river   总被引:1,自引:0,他引:1  
Sewage treatment works (STWs) are a common source of chemicals entering into the aquatic environment. In order to assess effects of these effluents on oxidative stress parameters in aquatic organisms, we caged rainbow trout at five sites: upstream, near an STW effluent, and three sites downstream in the river Viskan in western Sweden for 14 days during autumn, 2006. We then measured protein carbonyls in plasma as well as 20S proteosome activity and lipid peroxidation products, i.e. MDA and 4-HNE, in liver samples. Levels of both lipid and protein oxidative damage products were elevated in fish caged near the STW effluent while 20S activity showed no differences. This argues that complex mixtures of chemicals entering into the aquatic environment do have deleterious effects on fish. Additionally, oxidative stress parameters can serve as a biomarker in aquatic organisms.  相似文献   

19.
We studied the accumulation of polychlorinated biphenyls (PCBs), 1,1,1.trichloro-2,2-bis[p-chlorophenyl]ethane (DDT) and its metabolites, and vitamins A and E in the top levels of the Baltic Sea food web. The investigation focused on the transfer of contaminants and vitamins to the ringed seal (Phoca hispida baltica) and the grey seal (Halichoerus grypus) from their main prey species. The trophic level of the seals was investigated using stable isotopes of nitrogen and the results indicated that both species of Baltic seal feed at approximately the same level. PCBs accumulated to a greater extent in the grey seal than in the ringed seal. Biomagnification factors for DDT compounds were similar for both species of Baltic seal (85-140). Differences in observed DDT levels were due to different prey selection by the two species, while differences in PCB levels indicated a species-specific metabolic system. There was a clearly greater accumulation of DDT compounds than of PCBs in both species of seal. The supply of dietary vitamin A was normally above the recommended level in all the seal populations studied. Low levels of hepatic vitamin A in the Baltic seals could therefore indicate the toxic effects of a high level of persistent organic pollutants on vitamin A dynamics, at least in the ringed seal. In the grey seals, low hepatic vitamin A levels could also be explained by lower levels of dietary vitamin A, compared to the reference grey seals, as it is not known if seals can store unlimited amounts of vitamin A. The greater uptake of vitamin E by Baltic seals, compared to seals in the reference areas, demonstrated by elevated levels of vitamin E in the blubber, could be a response to oxidative stress caused by the high contaminant load. These results further support our previous hypothesis that the toxic effects of environmental contaminants could be causing the observed divergence in vitamin levels between the Baltic seals and the reference seal populations.  相似文献   

20.
Crustacea experience periods of starvation during moulting or when limited food availability occurs. The effects of starvation on Crustacea physiological responses have been demonstrated, whereas the effects of starvation on Crustacea immune parameters remain to be more fully studied. In the present study the effects of starvation on immune parameters and antioxidant enzyme activities of the crab Carcinus aestuarii were evaluated for the first time. Treated crabs were starved for 7 days, whereas control crabs were fed daily with mussels. Total haemocyte count (THC), haemocyte diameter and volume, haemocyte proliferation, cell-free haemolymph (CFH) glucose and total protein levels, and phenoloxidase (PO) activity in both haemocyte lysate (HL) and CFH were measured in crabs. In addition, superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in both gills and digestive gland from crabs, in order to evaluate whether starvation induced oxidative stress in C. aestuarii. THC increased significantly in starved crabs, with respect to controls, whereas no significant variations were observed in haemocyte diameter, volume and proliferation. In CFH of starved animals glucose concentration significantly increased, whereas total protein concentration significantly reduced. A significantly higher PO activity was recorded in HL from starved crabs, than in control crabs. Conversely, PO activity did not vary significantly in CFH. Starvation did not cause significant alterations in antioxidant enzyme activities in both gills and digestive gland. Results obtained demonstrated that starvation influenced crab immune parameters, but did not induce oxidative stress. Results also indicated that C. aestuarii can modulate its cellular and biochemical parameters in order to cope with starvation.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号