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1.
We are investigating the effects of in vivo exposure of prototypical enzyme inducing agents on hepatic biotransformation enzyme expression in largemouth bass (Micropterus salmoides), a predatory game fish found throughout the United States and Canada. The current study targeted those genes involved in biotransformation and oxidative stress that may be regulated by Ah-receptor-dependent pathways. Exposure of bass to β-naphthoflavone (β-NF, 66 mg/kg, i.p.) elicited a 7–9-fold increase in hepatic microsomal cytochrome P4501A-dependent ethoxyresorufin O-deethylase (EROD) activities, but did not affect cytosolic GST catalytic activities toward 1-chloro-2,4-dinitrobenzene (CDNB) or 5-androstene-3,17-dione (ADI). Glutathione S-transferase A (GST-A) mRNA expression exhibited a transient, but non-significant increase following exposure to β-NF, and generally tracked the minimal changes observed in GST–CDNB activities. Expression of the mRNA encoding glutamate-cysteine ligase catalytic subunit (GCLC), the rate-limiting enzyme in glutathione (GSH) biosynthesis, was increased 1.7-fold by β-NF. Changes in GCLC mRNA expression were paralleled by increases in intracellular GSH. In summary, largemouth bass hepatic CYP1A-dependent and GSH biosynthetic pathways, and to a lesser extent GST, are responsive to exposure to β-NF. 相似文献
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The glutathione S-transferases (GST) are a major group of conjugative enzymes involved in the detoxification of electrophilic compounds and products of oxidative stress. We have previously described the kinetics of hepatic GST conjugation in largemouth bass using a variety of synthetic GST reference substrates. In the present study, we investigated the ability of largemouth bass hepatic GSTs to conjugate 4-hydroxynon-2-enal (4HNE), a mutagenic and cytotoxic alpha-beta-unsaturated aldehyde produced during oxidative injury. Hepatic cytosolic fractions from largemouth bass rapidly catalyzed GSH-dependent 4HNE conjugation, with the rate of GST-4HNE conjugation in bass liver exceeding those of several other mammalian and aquatic species. No apparent sex-related differences in GST-4HNE activity were observed among adult bass. SDS-PAGE and Western blotting analysis of GSH affinity-purified bass liver cytosolic GST revealed the presence of two major GST subunits of approximately 30 and 27 KDa that exhibited slight cross-reactivity when probed with a rat alpha class GST antibody, but not to rat mu, pi or theta class GST. The rapid conjugation of 4HNE by hepatic GST suggests an important role for GSTs in protecting against peroxidation of polyunsaturated fatty acids in bass liver. 相似文献
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Jaime Fernando Gonzlez Renate Reimschuessel Badar Shaikh Andrew S. Kane 《Marine environmental research》2009,67(4-5):183-188
Hepatic microsomes and cytosols of channel catfish (Ictalurus punctatus), rainbow trout (Oncorhynchus mykiss), Atlantic salmon (Salmo salar), red tilapia (Oreochromis sp.), largemouth bass (Micropterus salmoides), striped bass (Morone saxatilis), hybrid striped bass (M. saxatilis × M. crysops), and bluegill (Lepomis macrochuris) (n = 8) were used to study the kinetics of phase I (ECOD, EROD, PROD, BROD) and phase II (UDP-glucuronosyltransferase (UDPGT)-, sulfotransferase (ST)- and glutathione-s-transferase (GST)-mediated) reactions. The best catalytic efficiency for ECOD and GST activities was performed by channel catfish, Atlantic salmon, rainbow trout and tilapia. The highest EROD catalytic efficiency was for Atlantic salmon. None of the species had either PROD or BROD activities. Rainbow trout had very similar UDPGT catalytic efficiency to tilapia, channel catfish, Atlantic salmon, largemouth bass and bluegill. Sulfotransferase conjugation had no significant differences among the species. In summary, tilapia, channel catfish, Atlantic salmon and rainbow trout had the best biotransforming capabilities; striped bass, hybrid striped bass and bluegill were low metabolizers and largemouth bass shared some capabilities with both groups. 相似文献
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GSTA is a major glutathione S-transferase gene responsible for 4-hydroxynonenal conjugation in largemouth bass liver 总被引：2，自引：0，他引：2
We have previously shown that largemouth bass (Micropterus salmoides) has a remarkable ability to conjugate 4-hydroxy-2-nonenal (4HNE), a mutagenic and cytotoxic alpha,beta-unsaturated aldehyde produced during the peroxidation of lipids. In addition, we have isolated a glutathione S-transferase cDNA (bass GSTA) that encodes a recombinant protein which is highly active in 4HNE conjugation and structurally similar to plaice (Pleuronectes platessa) GSTA. In the present study, HPLC-GST subunit analysis revealed the presence of at least two major GST isoforms in bass liver, with one peak constituting 80% of the total bass liver GST protein. Liquid chromatography mass spectrometry (LC-MS) and electrospray ionization analysis of the major bass GST subunit yielded a molecular weight of 26,396 kDa. Endo-proteinase Lys-C digestion and Edman degradation protein sequencing of this GST peak demonstrated that this protein was encoded by bass GSTA. Analysis of genomic DNA fragments isolated by nested PCR indicated the presence of a GST gene cluster in bass liver that contained GSTA, and was similar to a GST gene cluster characterized by Leaver et al., in plaice. Collectively, our data indicates the presence of a major GST in bass liver involved in the protection against oxidative stress. This GST is part of a gene cluster that may be conserved in certain freshwater and marine fish. 相似文献
7.
为探讨海水酸化和磺胺甲恶唑环境残留对珊瑚礁区生物的影响，本文以南海珊瑚礁区关键礁栖生物大马蹄螺（Trochus niloticus） 为研究对象，探究了两种环境胁迫因素对大马蹄螺的氧化胁迫作用。分别采用两个 pH 水平 （pH 8.1、 pH 7.6） 和三个磺胺甲恶唑浓度水平 （0 ng/L、100 ng/L 和 1 000 ng/L） 单独和复合暴露 28 天，测定其对大马蹄螺鳃组织的超氧化物歧化酶 （SOD）、过氧化氢酶 （CAT） 和谷胱甘肽巯基转移酶 （GST） 活性以及谷胱甘肽 （GSH） 含量和脂质过氧化水平 （LPO） 的影响。结果发现：海水酸化和磺胺甲恶唑单独暴露能够导致大马蹄螺鳃组织出现不同程度的氧化应激现象，表现为抗氧化酶 （CAT、SOD 和 GST） 活性和谷胱甘肽含量的升高。在复合暴露条件下，大马蹄螺鳃组织的抗氧化酶（CAT、SOD 和 GST） 活性和谷胱甘肽含量均受到不同程度的抑制，同时伴随着脂质过氧化水平的显著升高。这表明短期海水酸化和磺胺甲恶唑复合暴露可导致大马蹄螺鳃组织出现氧化损伤现象，进而可能对个体存活和种群繁衍造成负面影响。 相似文献
8.
The major glutathione S-transferase isoform of flounder liver, an antigenically related structural homologue of plaice GST-A, also displays mRNA homology. A 901bp cRNA probe for plaice GST-A cross-hybridised to a 1100bp flounder mRNA on northern blot analysis. The plaice antibody and cRNA probes were used to study effects of inducer treatment on GST-A expression in flounder liver. Six days after PAH treatment (3-methylcholanthrene) total hepatic GST activity was halved, levels of GST-A were 80% and GST-A mRNA levels were 25% of controls. A commercial PCB mixture (Aroclor 1254TM) had little effect on total GST or GST-A levels despite halving GST-A mRNA levels. An epoxide, trans-stilbene oxide induced total GST activity 1·4 fold and GST-A protein levels 1·8-fold and its mRNA levels 3-fold. This reduced expression of the major flounder hepatic GST by agents which induce cytochrome P4501A1 may modulate cytoxicity of environmental pollutants in this species. 相似文献
9.
We have previously shown that largemouth bass (Micropterus salmoides) has a remarkable ability to conjugate 4-hydroxy-2-nonenal (4HNE), a mutagenic and cytotoxic α,β-unsaturated aldehyde produced during the peroxidation of lipids. In addition, we have isolated a glutathione S-transferase cDNA (bass GSTA) that encodes a recombinant protein which is highly active in 4HNE conjugation and structurally similar to plaice (Pleuronectes platessa) GSTA. In the present study, HPLC-GST subunit analysis revealed the presence of at least two major GST isoforms in bass liver, with one peak constituting 80% of the total bass liver GST protein. Liquid chromatography mass spectrometry (LC–MS) and electrospray ionization analysis of the major bass GST subunit yielded a molecular weight of 26,396 kDa. Endo-proteinase Lys-C digestion and Edman degradation protein sequencing of this GST peak demonstrated that this protein was encoded by bass GSTA. Analysis of genomic DNA fragments isolated by nested PCR indicated the presence of a GST gene cluster in bass liver that contained GSTA, and was similar to a GST gene cluster characterized by Leaver et al., in plaice. Collectively, our data indicates the presence of a major GST in bass liver involved in the protection against oxidative stress. This GST is part of a gene cluster that may be conserved in certain freshwater and marine fish. 相似文献
10.
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
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Microcystin (MC) produced during cyanobacteria blooms is notably toxic to human and wildlife. Conjugation with reduced glutathione (GSH) by glutathione S-transferase (GST) and the antioxidant enzymes defenses (e.g. catalase, CAT) are important biochemical defense mechanisms against MCs toxicity. We investigated the enzymatic activity of CAT and GST and the gene expression levels of CAT and eight GST isoforms in the hepatopancreas of the globally farmed shrimp Litopenaeus vannamei 48-h after injection with a sub-lethal dose of 100 μg kg−1 of a toxic Microcystis aeruginosa extract. MCs caused up-regulation for GST Ω, μ and a MAPEG isoform, by 12-, 2.8- and 1.8-fold, respectively, and increases in the total GST enzyme activity and CAT enzyme activity. The study points to the importance of further characterization for the L. vannamei GST isoforms and GST/CAT post-translational regulation processes to better understand the key mechanisms involved in the shrimp’s defense against MC exposure. 相似文献
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采用生物毒性测试与评价方法对常用消毒剂药物三氯异氰尿酸（Trichloroisocyanuric acid，TCCA）对剑尾鱼的急性毒性及其Ⅰ、Ⅱ相代谢酶活性影响进行了研究。结果表明，TCCA对剑尾鱼的96hLG0为2．15mg／L。TCCA对剑尾鱼肝脏还原型谷光苷肽（GSH）、谷胱苷肽硫转酶（GST）和7。乙氧基异吩恶唑酮-脱乙基酶（EROD）都存在诱导作用。雌雄个体在GST和EROD的诱导响应时间有显著差异性，其中雄性个体GST对TCCA暴露响应比雌性个体敏感。 相似文献
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M. McArdle A. Elskus A. McElroy B. Larsen W. Benson D. Schlenk 《Marine environmental research》2000,50(1-5):175-179
Recent studies demonstrating feminization of effluent-exposed wild-caught male fish in the UK have prompted much research regarding the estrogenic activity of effluent from municipal sewage treatment plants (MSTPs). To investigate the estrogenicity and cytochrome P450 1A (CYP1A) induction potency of MSTP effluent, two species of fish, adult male mummichogs, Fundulus heteroclitus, and juvenile sunshine bass, Morone saxatilis x Morone chrysops, were exposed to un-chlorinated effluent (75% effluent, 25% seawater) from a large MSTP in Yonkers, NY, USA. After a 21-day static-daily (75%) renewal exposure, significant elevations over controls were observed in levels of vitellogenin (VtG) in plasma (1730%) and liver (131%) in effluent-exposed sunshine bass. In contrast, hepatic VtG was not elevated in mummichogs; plasma VtG was not measured in this species. Effluent exposure elevated hepatic CYP1A protein (140-145%) and ethoxyresorufin-O-deethylase (EROD) activity (408-598%) in both species. These findings suggest ontogenetic and/or species differences in response to estrogenic compounds in MSTP effluent. Furthermore, the elevation of CYP1A in response to sewage effluent exposure indicates the presence of additional compounds that may alter xenobiotic and/or steroid biotransformation in fish. 相似文献
14.
Carbonyl reductase (CBR) is an enzyme involved in protection from oxidative stress. In rainbow trout (Oncorhynchus mykiss), the hepatic mRNA abundance of the two isoforms (A and B) is increased after exposure to treated sewage effluents, as well as after exposure with β-naphthoflavone (β-NF) and the pro-oxidant paraquat. In this study, we show that the same chemicals similarly increase the single known hepatic CBR mRNA level and CBR catalytic activity in the coastal living eelpout (Zoarces viviparus). Hepatic CBR mRNA abundance and catalytic activity were also compared between eelpout collected at contaminated and reference sites on the Swedish west coast, but no differences were observed. In conclusion, CBR is a potential biomarker candidate for monitoring the exposure and effects of AhR agonists and/or pro-oxidants in the marine environment, but more research is needed to investigate temporal regulation as well as dose dependency for different chemicals. The mRNA and enzymatic assays presented in this study provide two additional tools for researchers interested in expanding their biomarker battery. 相似文献
15.
The aim of the present study was to investigate the responses of phase I and II biotransformation enzymes and levels of PAHs in the Mediterranean mussel (Mytilus galloprovincialis, Lamarck, 1819) collected from three sites at different distance from an oil refinery. Phase I enzyme activities as NAD(P)H-cyt c red, NADH ferry red, B(a)PMO and phase II as UDPGT, GST were measured in digestive gland while 16 PAHs (US-EPA) in whole soft tissue. An added value to the data obtained in the present study rely on the RDA analysis which showed close correlations between PAHs levels and phase I enzyme activities in mussels collected in front of the refinery. And again a significant spatial correlation between B(a)P levels and NADPH-cyt c red activities was observed using linear models. No differences among sites for B(a)PMO and phase II GST activities were observed, while the application of UDPGT as biomarkers requires further investigation. 相似文献
16.
采用半静态染毒实验研究了菲和Cd2+单一及复合污染下胁迫9 d和清水释放2 d过程中毛蚶体内活性氧(ROS)、谷胱甘肽(GSH)含量和谷胱甘肽硫转移酶(GST)活性的变化。结果表明,菲和Cd2+单独胁迫能诱导毛蚶体内ROS含量的增加及GSH含量、GST活性的降低,且随染毒浓度的增加,对各指标影响愈明显,存在剂量-效应关系。毛蚶体内GSH和GST的变化趋势具有一致性。菲和Cd2+复合污染对毛蚶体内的氧化胁迫效应整体大于二者单独污染。在清水释放阶段,单一及复合污染胁迫组各指标均能恢复至对照组水平。表明毛蚶体内抗氧化系统适合作为监测海洋多环芳烃和重金属复合污染的生物标志物。 相似文献
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Seasonal variations in the antioxidant enzymes (catalase, superoxide dismutase [SOD], NADH-DT diaphorase), biotransformation enzyme, glutathione-S-transferase (GST) and microsomal lipid peroxidation in digestive tissue of barnacle, Balanus balanoides, from polluted and non-polluted populations have been evaluated. Relationships with accumulated polyaromatic hydrocarbon (PAH) concentration in barnacle tissues and environmental parameters (water temperature, salinity, dissolved oxygen concentration, water pH) were determined. As a general trend, maximum antioxidant enzyme and GST activities were detected in the pre-monsoon period or summer (March-June) followed by a gradual decrease during the monsoon (July October) with a minimum in the post-monsoon period or winter (November February). This pattern was similar to tissue concentrations of PAHs, resulting in a significant positive correlation with antioxidant enzymes, mainly catalase and SOD. Microsomal lipid peroxidation exhibited an almost reverse trend of seasonal variation to that of antioxidant enzyme activities indicating an enhanced susceptibility of barnacle tissues to oxidative stress. Among the environmental parameters, only water temperature seemed to have a significant effect on observed variations of antioxidant enzymes and GST activities. The barnacles from polluted and non-polluted populations exhibited seasonal differences in the activities of all the enzymes studied, particularly catalase, SOD and GST, suggesting the possibility of some biochemical adaptation in organisms from a chronically polluted environment. The results indicated that antioxidant defense components, catalase and SOD, are sensitive parameters that could be useful biomarkers for the evaluation of contaminated aquatic ecosystems. The results also suggested the potentiality of barnacle, B. balanoides, as a bioindicator organism against organic pollution. 相似文献
18.
Tracy K. Collier S.Denise Connor Bich-Thuy L. Eberhart Bernadita F. Anulacion Anders Goksoyr Usha Varanasi 《Marine environmental research》1992,34(1-4)
We are currently analyzing hepatic cytochrome P4501A and associated monooxygenase activities in fish sampled in several regional and national monitoring programs, including the National Benthic Surveillance Project of NOAA's Status and Trends Program, damage assessment studies of the Exxon Valdez oil spill, and intensive surveys of specific embayments, such as Puget Sound, Washington. Thus far, apparent contaminant-related increases in the activities of cytochrome P4501A-dependent monooxygenases have been readily measured in most test species. The results presented in this paper show that, for II species of fish, there is excellent concordance between hepatic activities of aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin-O-deethylase (EROD); moreover, levels of cytochrome P4501A determined by an enzyme-linked immunosorbent assay (ELISA) are also generally concordant with results from catalytic assays. The use of both a catalytic assay and immunoquantitation is recommended, because of the additional quality assurance provided by concurrent use of an immunoquantitation technique, which is desirable in large monitoring programs. 相似文献
19.
Almli B Egaas E Christiansen A Eklo OM Lode O Källqvist T 《Marine environmental research》2002,54(3-5):237-240
In order to evaluate the gill glutathione S-transferase (GST) activity as a biomarker of effect of fungicide exposure in juvenile brown trout (Salmo trutta), the fungicides propiconazole [(R,S)-1-[2-(2,4-diclophenyl)-4-propyl-1,3-dioolan-2-ylmetyl]-1H-1,2,4-triazole] and fenpropimorph [(+/-)-cis-4-[3-(4-tert-butylphenyl)-2-metyl propyl]-2,6 dimetylmorfolinc] were administrated in the water separately and together in a static system (80 microg/l for each pesticide) for 5 days. The combined fungicides gave a significant decrease in gill GST activity towards 1-chloro-2,4-dinitrobenzene (CDNB), whilst hepatic GST-activity was not significantly changed. Furthermore, continuous exposure to 540 ug/l thiabendazole[2-(thiazol-4'-yl)benzimidazole] in a flow-through system for 4 days significantly increased the gill glutathione S-transferase (GST) activity towards CDNB, whilst hepatic GST and cytochrome P450 (CYP 1A) activities were not increased by the treatment. 相似文献
20.
Altered glutathione S-transferase catalytic activities in female brown bullheads from a contaminated central Florida lake. 总被引：2，自引：0，他引：2
Brown bullheads (Ameriurus nebulosus) are a demersal freshwater species that can be found in a number of polluted ecosystems. The purpose of the present study was to determine the overall capacity for in vitro glutathione S-transferase (GST) detoxification by brown bullheads, and to see if bullhead GST catalysis was altered in bullheads from a polluted site. Brown bullhead liver cytosolic GSTs catalyzed the conjugation of 1-chloro-2,4-dinitrobenzene (CDNB) over a large range of substrate concentrations, with apparent Km and Vmax for CDNB at fixed nucleophile (glutathione, GSH) concentrations of 1.8-1.9 mM and 12.1-14.6 mumol CDNB conjugated/min/mg, respectively. Bullhead GSTs were also highly active toward other substrates such as ethacrynic acid (ECA), delta 5-androstene-3,17-dione (ADI), and nitrobutyl chloride (NBC). Initial rate GST catalytic activities toward CDNB, NBC, ECA, and ADI were significantly lower in female bullheads from a contaminated lake (Lake Apopka Marsh) as compared to female bullheads inhabiting a nearby control site (Lake Woodruff). No site differences were observed with respect to male bullhead GST activities. These studies suggest that brown bullheads efficiently carry out GST conjugation of diverse electrophilic substrates. However, bullhead GST catalysis may be compromised in bullheads inhabiting polluted ecosystems. 相似文献