The cytochrome P450 1A1 response in fish: application of immunodetection in environmental monitoring and toxicological testing     

Anders Goksyr  Astrid-Mette Husy 《Marine environmental research》1992,34(1-4)

We have developed polyclonal and, recently, monoclonal antibodies against the aromatic hydrocarbon-inducible P450 1A1 form purified from Atlantic cod (Gadus morhua). A simple, indirect enzyme-linked immunosorbent assay (ELISA) based on these antibodies has been developed in our laboratory and tested in numerous experiments with both field-collected and laboratory-exposed fish of different species. The exposure situations studied to date include complex mixtures such as polychlorinated biphenyls (PCBs), dioxins and water-soluble oil fractions, as well as defined compounds such as CB congeners, TCDD, and pesticides. Factors affecting the induction response, including sexual maturation and dietary factors, have also been investigated. The ELISA technique generally shows good correlation with contaminant exposure and catalytic measurements, but has also given new and important information in certain cases where catalytic measurements failed to reveal effects.  相似文献   

Comparison of cytochrome P450 in three butterflyfish species: Ecological implications of elevated CYP2B and CYP3A in Chaetodon capistratus     

Nicholas H. Vrolijk  Nancy M. Targett  Bruce R. Woodin  John J. Stegeman 《Marine environmental research》1995,39(1-4)

The relationship between cytochrome P450 and feeding on terpenoid-rich gorgonian corals was investigated in a species of tropical butterflyfish and compared with two other sympatric congeners that do not feed on gorgonians. Fish were collected from non-polluted waters in Belize and the levels of two cytochrome P450 isozymes (CYP2B and CYP3A) were immunoquantitated in addition to quantification of total P450. Chaetodon capistratus regularly feeds on gorgonian corals and has higher levels of total hepatic microsomal cytochrome P450 than C. ocellatus or C. striatus. The content of hepatic P450 (0.588–0.794 nmol mg⁻¹) in C. capistratus is among the highest ever reported in teleosts from non-polluted waters and is significantly greater than detected in C. ocellatus or C. striatus. Chaetodon capistratus also had a larger hepatic index (g liver per g fish) and more microsomal protein (mg protein per g liver), factors that translate into 3.3- to 8-fold more total P450 per g fish. Sexual differences in total P450 were observed between male and female C. capistratus, but not among the other species. The contents of proteins detected by immunoassay with polyclonal anti-scup P450B (CYP2B) and anti-human P4503A (CYP3A) were 2- to 10-fold and 2- to 20-fold greater, respectively, in C. capistratus than in the congeneric species. CYP2 and CYP3 gene families in mammals are thought to have evolved partially in response to dietary allelochemicals. These results suggest that these P450 isozymes may also be important in marine teleosts that feed on terpenoid-rich prey.  相似文献   

Endogenously-mediated, pretranslational suppression of cytochrome P4501A in PCB-contaminated flounder     

Adria A. Elskus  Richard Pruell  John J. Stegeman 《Marine environmental research》1992,34(1-4)

Gonadally mature fish display strong sex-related differences in the content and activity of P4501A, the major polynuclear aromatic hydrocarbon-inducible P450 form in teleosts. Such differences appear related to plasma levels of the female sex steroid, estradiol (E₂); however, neither the mechanism of estradiol suppression of P4501A nor the capacity for hormonal regulation to overcome P4501A induction by high concentrations of potent inducers are known. Gonadally mature flounder (Pseudopleuronectes americanus) were collected from Fox Island (FI), Rhode Island, a reference site, and New Bedford Harbor (NB), Massachusetts, a site highly contaminated with polychlorinated biphenyls (PCBs). Differences in flounder P4501A expression were determined at the level P4501A catalytic activity (measured as ethoxyresorufin-O-deethylase, EROD), P4501A protein content (immunoquantitated), and P4501A mRNA content (by Northern blot) as they relate to sex, reproductive status, and hepatic PCB content. Our results confirm that suppression of P4501A in gonadally mature female fish is probably due, at least in part, to elevated E₂ titers, and demonstrate that such suppression occurs at a pretranslational level and, further, that endogenous regulation of P4501A expression can ‘override’ exogenous regulation by even high concentrations of P4501A inducers.  相似文献   

Cytochrome P450 in seals: monooxygenase activities, immunochemical cross-reactions and response to phenobarbital treatment     

Anders Goksoyr  Jonny Beyer  Hvard E. Larsen  Tommy Andersson  Lars Frlin 《Marine environmental research》1992,34(1-4)

Cytochrome P450 monooxygenase activities, reflecting the expression of various subfamilies of P450, were measured in liver samples of harp and hooded seal. Differences in some of the investigated parameters were observed between the two species, between sexes, and between pups and adults. Treatment of single female pups from each species with phenobarbital (i.v. 45 mg/kg), resulted in increased levels of EROD and estradiol 2-hydroxylase activities in both species, whereas MCOD, ECOD and PROD activities were induced only in the harp seal sample. Antibodies against a dog P450 2B form (anti-dog PBD-2 IgG) gave a single band around 52kD in both species, strongest in male pups. This band seemed elevated in the PB-treated harp seal pup. Based on the single treated pup of each species, the results suggest that seals respond to PB-type treatment with a weaker response, and with different enzyme patterns, that most terrestrial mammals. Antibodies against cod P450 IAI cross-reacted with two bands in liver samples from adult seals of both species (about 54 and 52kD), but this was strongest in the hooded seal. The intensity of the bands reflected the EROD activities in the samples, suggesting the application of immunodetection in screening marine mammals for effects of environmental contamination.  相似文献   

Evidence for resistance to benzo[a]pyrene and 3,4,3'4'-tetrachlorobiphenyl in a chronically polluted Fundulus heteroclitus population     

Arzuaga X  Elskus A 《Marine environmental research》2002,54(3-5):247-251

Halogenated aromatic hydrocarbons (HAHs) and polynuclear aromatic hydrocarbons (PAHs) are major environmental contaminants. Fish species that are chronically exposed to these compounds can develop resistance to their toxic effects. In all fish species studied to date, toxicant resistance has been accompanied by decreased inducibility of the xenobiotic metabolizing enzyme, cytochrome P450 1A (CYPIA). CYP1A induction is mediated through the Aryl Hydrocarbon Receptor (AHR). Although these compounds mediate their effects through this pathway, there have been resistant populations in which one chemical class cannot induce CYPIA expression (HAHs) while the other (PAHs) can. Resistance to PAHs was examined in a HAH-resistant population of Fundulus heteroclitus collected from a site contaminated with both compound classes (Newark Bay, NJ). Fish were injected intraperitoneally with the HAH 3,4,3',4'-tetrachlorobiphenyl (PCB77), benzo[a]pyrene (B[a]P, a PAH) or vehicle and sacrificed after 2 (B[a]P) or 5 days (PCB77, vehicle). We found no significant increase in CYP1A mRNA levels in resistant Newark Bay F. heteroclitus treated with either B[a]P or PCB77, while there was a 3.9 fold (PCB77) and 4.2 fold (B[a]P) increase in CYP1A mRNA in Flax fish relative to controls. AHR labeling studies revealed significantly (P < 0.05) lower levels of hepatic AHR in Newark fish (1,770 +/- 1,693.2 DPM) relative to Flax fish (6,082.5 +/- 1,709.9 DPM). Overall, these data suggest Newark F. heteroclitus are resistant to both PAHs and HAHs at the level of CYP1A mRNA, which might be mediated, in part, though lower expression of AHR. We are currently studying the promoter sequence to determine its role in chemical resistance.  相似文献   

The Ah receptor in marine animals: phylogenetic distribution and relationship to cytochrome P4501A inducibility     

Mark E. Hahn  Alan Poland  Ed Glover  John J. Stegeman 《Marine environmental research》1992,34(1-4)

In mammals, the induction of cytochrome P4501A forms by chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, and halogenated biphenyls is under control of a soluble protein known as the Ah (aromatic hydrocarbon) receptor. Little is known about the presence and properties of the Ah receptor in other vertebrate and invertebrate species. In these studies, we sought evidence for an Ah receptor in the liver or liver-equivalent of 20 species of marine and freshwater animals, using the photoaffinity ligand 2-azido-3-[¹²⁵I] iodo-7,8-dibromodibenzo-p-dioxin (N₃[¹²⁵I]Br₂DD). Specific labeling of cytosolic proteins by N₃[¹²⁵I]Br₂DD was observed in seven species of teleost and elasmobranch fish, in PLHC-I fish hepatoma cells, and in beluga whales. No specifically labeled proteins were found in cytosol from two species of agnathan fish nor in any of nine invertebrate species representing eight classes of four phyla. The presence or absence of specifically labeled polypeptides corresponds with the inducibility of cytochrome P4501A and sensitivity to the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related planar halogenated aromatic hydrocarbons in many of these groups. Thus, Ah receptor function may have arisen early invertebrate evolution and has been conserved from elasmobranch and teleost fish to mammals.  相似文献   

Microsomal cytochrome P-450 function in fish evaluated with polyclonal and monoclonal antibodies to cytochrome P-450E from scup (Stenotomus chrysops)     

John J. Stegeman  Bruce R. Woodin  Sang S. Park  Pamela J. Kloepper-Sams  Harry V. Gelboin 《Marine environmental research》1985,17(2-4)

Monooxygenase reactions catalyzed by cytochromes P-450 are paramount in the oxidative metabolism of many xenobiotics, determining both the persistence and effects of numerous types of compounds. Immunological probes are proving useful in evaluating the functions of P-450 isozymes in microsomal preparations from many species. The regulation of specific isozymes by endogenous and exogenous factors can also be evaluated with such probes. Here we describe studies on the activities apparently catalyzed by induced P-450 in fish, evaluated with both polyclonal and monoclonal antibodies to cytochrome P-450E, the apparent major β-naphthoflavone(BNF) or methylcholanthrene(MC)-inducible isozyme purified from scup (S. chrysops) liver.  相似文献   

Identification of cytochrome P450 1B-like sequences in two teleost fish species (scup, Stenotomus chrysops and plaice, Pleuronectes platessa) and in a cetacean (striped dolphin, Stenella coeruleoalba).     

C A Godard  M J Leaver  M R Said  R L Dickerson  S George  J J Stegeman 《Marine environmental research》2000,50(1-5):7-10

The cytochromes P450 (CYP) constitute a multigene family of enzymes playing a critical role in the oxidation of many endogenous and xenobiotic substrates. The CYP1 family is of particular interest in environmental toxicology because its members are dominant in the metabolism of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and aryl amines. Three members of the CYP1 family, CYP1A1, CYP1A2, and CYP1B1, have been identified in mammals. We report here on the identification and cloning of cytochrome P4501B-like sequences from two teleost fish species and a marine mammal. Sequences clustering with CYP1B1 in phylogenetic analysis were obtained from liver cDNA of scup (Stenotomus chrysops), genomic DNA of plaice (Pleuronectes platessa), and liver cDNA of striped dolphin (Stenella coeruleoalba).  相似文献   

Estrogenic and CYP1A response of mummichogs and sunshine bass to sewage effluent     

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   

Cytochrome P450 gene diversity and function in marine animals: past, present, and future     

J. J. Stegeman   《Marine environmental research》2000,50(1-5)

The biotransformation of xenobiotics by microsomal cytochromes P450 is known to be pivotal in the effects of some compounds, and thought to be so for many. A knowledge of CYP gene diversity and CYP function and regulation in aquatic species is pursued, expecting that it will disclose mechanisms, allow predictions regarding species differences in susceptibility, and provide markers for exposure to xenobiotics. As well, it is hoped that such knowledge will provide clues to CYP endogenous functions, and to the origin and functional significance of CYP gene diversity. The knowledge of CYP in marine and other aquatic species is expanding rapidly. The diversity of CYP genes in non-mammalian vertebrates may approximate that in mammals. At present, cloning studies have identified members of gene families 1 to 4 have been cloned from one or more fish species. Where known, the gene structures of fish CYP genes are like those of mammalian homologues. Only one CYP1A gene has been identified in most fish species examined. Fish CYP1As, including multiple forms from recent divergence in some genera, have structural and catalytic properties more like CYP1A1, but also have properties that are 1A2-like, consistent with fish CYP1As representing the CYP ancestral to both CYP1A1 and CYP1A2. A number of genes cloned from several species have been classified in the 3A subfamily. Fish CYP3As catalyze steroid 6β-hydroxylase, and have other properties consistent with mammalian 3As. Recently identified CYP4 genes classify to novel subfamilies but apparently are homologues of mammalian CYP4 genes, and may act on similar substrates. The greatest diversity of fish CYP genes is in family 2; there are now six fish CYP2 subfamilies known. Four of these are novel subfamilies, although cladistic analysis suggests distinct relationships to mammalian CYP2 subfamilies. Heterologous expression and characterization of some of these CYP have identified similar functions among genes in different subfamilies. For example, fish CYP2Ns and CYP2Ps are related to mammalian CYP2Js, and CYP2P3 and CYP2J2 have strikingly similar functions as fatty acid epoxygenases and hydroxylases, with nearly identical regio- and enantioselectivity for metabolism of arachidonic acid. In addition to sequence and catalytic similarities, there also are indications that CYP regulation, tissue and cellular localization are similar between fish and mammals. Yet even in cases where orthology is strongly suggested, e.g. CYP1A, there appear to be taxonomic differences in active site structure suggesting potential differences in involvement of CYP1A in toxicity. In contrast to fish, CYP diversity and functions in aquatic invertebrates are poorly known. Investigators have identified novel gene families and subfamilies in crustaceans (CYP2L; CYP45), molluscs (CYP30, CYP10) and sponges (CYP38). CYP4C genes occur in crustaceans, molluscs and echinoderms, and a new subfamily (CYP4Y) in molluscs. The future? There is no doubt that new CYP will continue to be discovered in non-mammalian vertebrates; some (e.g. CYP51) can be predicted confidently. And, there is no doubt that the numbers known in invertebrates will expand greatly. In insects and C. elegans the numbers are very high, and even slime molds have 18 CYP genes. It is virtually certain that CYP genes with unique functions will be discovered. While the knowledge of CYP genes is increasing, knowledge of CYP function and regulation lag well behind. Technical approaches to speed the aquisition of such knowledge are available. The information will be essential to discern the role that CYP play in the disposition and toxicity of xenobiotics, during development as well as in adults. Yet, when such data are in hand, we may have to face the paucity of information on the diversity, function and regulation other enzymes, notably the glutathione S-transferases, glucuronyl transferases and sulfotransferases, in aquatic species. Discerning orthologous relationships among CYP genes, as well as those for phase II enzymes, could highlight gene lineages associated with conserved and endogenous functions. Understanding CYP endogenous functions, as well as their metabolism of xenobiotics, may reveal fully the ways that chemicals cause toxicity. [Support: Sea Grant NA46RG0470-R/P61, EPA R-829890, NIH ES07381].  相似文献   

The use of polyclonal antibodies raised against rat and trout cytochrome P450 CYP1A1 orthologues to monitor environmental induction in the channel catfish (Ictalurus punctatus)     

M.J.J. Ronis  Malin Celander  Lars Frlin  Thomas M. Badger 《Marine environmental research》1992,34(1-4)

Induction of hepatic cytochrome P450-dependent microsomal mono-oxygenase by xenobiotics is a well-established phenomenon in teleost fish. As in laboratory mammals, fish possess multiple forms of cytochrome P450 that display overlapping substrate specificity. One such isoform, CYP1A1, which has been cloned and sequenced from rainbow trout, has been shown to be orthologous to rat CYP1A1 and, as in mammals, is inducible up to several hundred-fold by planar aromatic hydrocarbons, PCBs and dioxins. It has been suggested that induction of CYP1A1 orthologues might provide a sensitive biomonitor for environmental pollution by mixtures of such compounds. In the current study, polyclonal antibodies directed against CYP1A1 purified from rat and trout liver were used to monitor induction of the CYP1A1 orthologue in hepatic microsomes from the fresh water species, the channel catfish (Ictalurus punctatus). Catfish from a local fish farm were induced in the laboratory by three daily injections of 50 mg/kg of the PCB mixture Aroclor 1254 and compared with fish taken from a site in central Arkansas—the Bayou Meto, known to be polluted with dioxin. Hepatic microsomal activities towards ethoxyresorufin (EROD) and pentoxyresorufin (PROD) were measured and Western blot analysis carried out with the two antibodies. EROD was elevated in both the Aroclor-treated fish and in the Bayou Meto fish compared with untreated fish farm controls; smaller but significant increases were observed in PROD. Spearman's rank correlations of 0·74 and 0·89 were observed between EROD and immunoquantified cross-reactivity towards the rat CYP1A1 and trout CYP1A1 antibodies.  相似文献   

Role of biotransformation in determining aldicarb toxicity in fish     

E. PerkinsJr.  D. Schlenk 《Marine environmental research》2000,50(1-5)

The carbamate pesticide, aldicarb, demonstrates significant acute toxicity in fish, and is readily biotransformed by most organisms studied. In fish, both the cytochrome P450 (CYP) and the flavin monooxygenase systems (FMO) are involved in bioactivating aldicarb to aldicarb sulfoxide, which is a more potent inhibitor of acetylcholinesterase (AChE). Channel catfish (Ictalurus punctatus), along with many other fresh water species, do not express FMO and are relatively resistant to the effects of aldicarb. This project examined the toxicity, AChE inhibition, metabolism, and toxicokinetic of aldicarb in channel catfish, and compared these values with an aldicarb-sensitive species, rainbow trout, which expresses FMO. Studies of in vitro and in vivo aldicarb biotransformation in catfish suggest that a low rate of bioactivation (10 times slower V_max), resulting in less initial conversion to the activated metabolite, aldicarb sulfoxide, may be a contributing factor to resistance of channel catfish to aldicarb toxicity. These data are supported by toxicokinetic and enzyme inhibition studies. This work demonstrates that differences in FMO expression among fish species may have significant influence on toxicity resulting from exposure to some xenobiotics.  相似文献   

Gene structure of the novel cytochrome P4501D1 genes in stickleback (Gasterosteus aculeatus) and medaka (Oryzias latipes)     

Goldstone JV  Stegeman JJ 《Marine environmental research》2008,66(1):19-20

The cytochrome P450 1 (CYP1) family has expanded with the addition of the CYP1B and CYP1C subfamilies. We recently identified a new CYP1 subfamily in zebrafish, CYP1D, with a single gene, CYP1D1. Here we examined sequences found in other fish genomes, i.e., stickleback (Gasterosteus aculeatus) and medaka (Oryzias latipes), for similarities among fish CYP1D1 genes. The full-length deduced amino acid sequences for CYP1D1 in these two species averaged about 43% identity to the CYP1As, but nearly 50% when sequence alignment ambiguities were masked. CYP1D1 has seven exons, similar in size and position to the exons in CYP1D1 and CYP1A in zebrafish. However, the intronic distances were substantially smaller in the medaka and stickleback. There also were differing numbers of putative xenobiotic response elements in the CYP1D1 of the various species. Whether the stickleback or medaka genes are inducible by aryl hydrocarbon receptor (AHR) agonists is yet to be determined.  相似文献   

Cloning and sequencing of the complete coding region of CYP3A30 from Fundulus heteroclitus     

M. Celander  J. J. Stegeman 《Marine environmental research》2000,50(1-5)

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Growth hormone effect on xenobiotic-metabolizing activities of rainbow trout     

J.P. Cravedi  E. Perdu-Durand  A. Paris  P. Prunet 《Marine environmental research》1995,39(1-4)

In recent years several studies reported the regulation by growth hormone (GH) of the expression of a variety of P450 forms in mammals. However the effect of GH on the xenobiotic-metabolizing enzymes of fish are still unknown. The aim of this work was to investigate the effects of ovine GH—a growth hormone known to be efficient in trout—on the cytochrome P450 level and on aryl hydrocarbon hydroxylase, aminopyrine-N-demethylase, glucuronyl transferase and glutathione transferase activities in trout. The GH-implanted trout (n = 50) each received a single cholesterol pellet containing ovine GH and were compared to control animals (n = 50) receiving a single cholesterol pellet without GH. After 15 days fish were killed and the liver and gills were excised for the measurement of xenobiotic-metabolizing enzyme activities. GH treatment significantly decreased the level of hepatic cytochrome P450 and the activities of cytochrome P450 dependent monooxygenases. In contrast, no significant effect of the treatment was observed on the glutathione transferase and UDP-glucuronyl transferase activities. Moreover, GH treatment had no effect on branchial phase I and phase II enzyme activities. This study provides evidence that GH level significantly affects the expression of several members of the hepatic cytochrome P450 family in trout.  相似文献   

Cloning and analysis of the CYP1A promoter from the atlantic killifish (Fundulus heteroclitus)     

Powell WH  Morrison HG  Weil EJ  Karchner SI  Sogin ML  Stegeman JJ  Hahn ME 《Marine environmental research》2004,58(2-5):119-124

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Partial purification and properties of cytochrome P450 from digestive gland microsomes of the common mussel, Mytilus edulis L.     

Cinta Porte  Philippe Lemaire  Laurence D. Peters  David R. Livingstone   《Marine environmental research》1995,39(1-4)

Cytochrome P450 from the digestive gland of M. edulis was partially purified by sodium cholate solubilization, 4–15% polyethylene glycol fractionation, and octyl-Sepharose affinity, DEAE-Sephacel ion-exchange and hydroxylapatite chromatography (yields of up to 7–10%). Three peaks were resolved by DEAE-Sephacel chromatography (termed peaks 1–3). P450 specific content was increased from 26 to 800 pmol per mg protein, and the ratio of P450 content to NADPH-cytochrome c (P450) reductase activity reduced by a factor of 250. Oxidised spectrum λmax of P450 was 410.5 ± 1.5 nm. Type II difference spectra were seen with both type II (clotrimazole, metyrapone) and type I (α-naphthoflavone, 7-ethoxycoumarin) compounds. Western blotting with polyclonal anti-P4501A from perch (Perca fluviatilis) gave a single band of approximately 54 kDa molecular weight. A reconstituted system containing peak 2 or 3, rat liver P450 reductase, lipid and NADPH metabolised benzo[a]pyrene to diones, diols, phenols and putative protein adducts. Peak 2 plus cumene hydroperoxide was indicated to produce diones and protein adducts only. Peak 2 alone was indicated to produce diones and phenols. The major free metabolites in all cases were diones (53–100%). The results indicate the existence of a P4501A-like enzyme in M. edulis, possibly with unusual properties as indicated by the difference spectra, metabolism in absence of NADPH and added P450 reductase, and predominance of diones.  相似文献   

Quantification of cytochrome P4501A1 and catalytic activities in liver microsomes of isosafrol- and β-Naphthoflavone-treated rainbow trout (Oncorhynchus mykiss)     

Malin Celander  Lars Frlin 《Marine environmental research》1992,34(1-4)

The effects of isosafrol (ISF) or β-naphthoflavone (βNF) treatments on cytochrome P450 (P450) levels in rainbow trout liver were investigated using immunochemical and catalytic techniques. The discrepancies in catalytic activities and ELISA quantification of rainbow trout P4501A1 protein levels between ISF- and βNF-treated fish indicate that important differences exist between the responses induced by βNF and ISF treatments in the rainbow trout liver.  相似文献   

The expression of CYP1A,vitellogenin and zona radiata proteins in Atlantic salmon (Salmo salar) after oral dosing with two commercial PBDE flame retardant mixtures: absence of short-term responses     

Boon JP  van Zanden JJ  Lewis WE  Zegers BN  Goksøyr A  Arukwe A 《Marine environmental research》2002,54(3-5):719-724

The short-term effects of the commercial PBDE flame retardant mixtures Penta-BDE and cta-BDE on the expression of cytochrome P450 1A (CYP1A), vitellogenin (Vtg) and zona radiata proteins (Zrp) were investigated in juvenile salmon (Salmo salar). For this purpose, groups of fish were dosed twice (oral intake at days I and 4) with 10 and 50 mg/kg body weight of both commercial mixtures. The fishes were sacrificed at day 7 (n = 5 for each group) and 14 (n = 6 for each group), and blood, liver, fillet, and brain were collected. Blanks and positive controls were also part of the experiment. The expressions of Vtg, Zrp, and CYPIA were measured with several techniques (EROD, ELISA, Western, Northern and Slot Blot). The values in the groups of fish treated with Penta-BDE or Octa-BDE did not significantly differ from the reference group for any of the parameters tested. In contrast, the positive control groups treated with estradiol-17beta for Vtg and Zrp expression, and beta-naphthoflavone for CYP1A expression did show a significant response, indicating the potential sensitivity of the fishes for the parameters measured. Since the results of the chemical analyses showed concentrations of a number of PBDE congeners in liver, fillet, and brain that were about three orders of magnitude above those of fish from the North Sea, it is concluded that the short-term toxicity of both commercial PBDE mixtures for these endpoints was low.  相似文献   

7-ethylresorufin O-deethylase activity and level of DNA-adducts in trout treated with benzo(a)pyrene     

Jean-Franois Masfaraud  Annie Pfohl-Leszkowic  Christian Malaveille  Grard Keith  Gilles Monod 《Marine environmental research》1992,34(1-4)

In fish, as well as in mammals, it is well known that the cytochrome P450-dependent oxidative metabolism of xenobiotics can generate DNA-reactive species. Moreover, this metabolism is known to be inducible by several compounds of environmental significance, such as polychlorobiphenyls, polycyclic aromatic hydrocarbons (PAHs) and dioxins. Consequently, we studied the relationship between the degree of induction of the cytochrome P4501A, expressed as that of 7-ethylresorufin O-deethylase (EROD) activity, and the level of DNA-adducts, using the post-labelling assay, in the liver of rainbow trout exposed to benzo(a)pyrene (a representative PAH). The results showed a significant 2- to 4-fold increase in EROD activity 2, 4 and 8 days after treatment, paralleled by an increase in DNA-adduct levels. This work further emphasizes the involvement of cytochrome P4501A in the metabolism of benzo(a)pyrene into genotoxic metabolites in rainbow trout.  相似文献