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1.
H Segner A Behrens E M Joyce K Schirmer N C Bols 《Marine environmental research》2000,50(1-5):489-493
Cytochrome P4501A (CYP1A) metabolizes a wide array of lipophilic xenobiotics. In fish liver, CYP1A is constitutively expressed at low levels, but xenobiotics can strongly induce CYP1A expression via a receptor-mediated pathway. While induction of hepatic CYP1A in teleosts by xenobiotics is well investigated, very little is known on the regulation of constitutive CYP1A expression and its induction by factors other than xenobiotics. In the present study we show that in the rainbow trout liver cell line, RTL-W1, CYP1A-catalyzed 7-ethoxyresorufin-O-deethylase (EROD) activity can be induced by a change of the culture medium, in the absence of xenobiotics. The increase in cellular EROD levels is of transient nature. Experiments with cell incubation solutions supplemented with various medium components indicate that photooxidized tryptophan is the agent causing the increase of EROD activity after medium change. 相似文献
2.
Concentrations of seven polybrominated diphenyl ether (PBDE) congeners were examined in flounder (Platichthys flesus) and sediment in three southern Baltic Sea sites, representing a range of exposure conditions, in order to evaluate spatial differences in PBDE contamination. Additionally, PBDEs were measured in muscle, liver, and gonads of flounder from one of the sites in order to examine inter-tissue distribution. Mean muscle Σ7PBDE levels, in the range of 10–21 ng g−1 lipid, showed inter-site differences attributed to the distance from the Gulf of Gdańsk, and were overall lower than reported earlier in herring, sprat, and salmon. Biota sediment accumulation factors (BSAFs) for Σ7PBDE and individual BDE congeners, in the range of 0.5–24.5, were generally consistent with predicted models for persistent hydrophobic halogenated contaminants. Wet weight (wet wt) PBDE levels in muscle and liver, but not in gonads, were related to tissue lipid content and did not correlate with the fish length and weight. These tissues differed in PBDE levels and profiles as a result of varying lipid content and presumably lipid composition and congener-specific physico-chemical properties. 相似文献
3.
Expression of flavin-containing monooxygenase(s) (FMO) correlates with salinity exposure in certain species of euryhaline fish, such as the rainbow trout, Oncorhynchus mykiss. The mechanism(s) by which salinity regulates FMO is unclear. Adult rainbow trout were infused through the dorsal aorta with either cortisol or urea. At 500 ng/ml, cortisol caused a significant increase in FMO-catalyzed thiourea oxidase activity in gill and liver microsomes. FMOI expression, however, was significantly increased by the high cortisol dose only in gill microsomes. The levels of TMAO and urea were not altered by cortisol. In the liver, urea infusion caused an increase in hepatic FMO activity. FMO expression and activity correlated with elevated tissue urea levels, but TMAO concentrations were not related. These results indicate that FMO expression and activity may be partially controlled by the osmoregulatory/stress hormone. cortisol, and concentrations of the organic osmolyte, urea, in the rainbow trout. 相似文献
4.
Michael R. Miller David E. Hinton James J. Blair John J. Stegeman 《Marine environmental research》1988,24(1-4)
Monoclonal antibody directed against a major β-naphthoflavone (BNF)-induced form of teleost cytochrome P-450, P-450E (equivalent to P-450c in rat) was used to immunolocalize this enzyme in liver, gill and heart of scup and trout. Liver sections from both species showed P-450E in the cytoplasm of hepatocytes. No regional differences were observed which might indicate zonation of cytochrome P-450E within subpopulations of hepatocytes. Scup exocrine pancreatic cells were only weakly positive. In the gill of both fish, cytochrome P-450E was restricted to the endothelium (pillar cells) of secondary lamellae, where fluorescence appeared as a chain in longitudinal sections through lamellae and as star-shaped clusters in en face views. Sections of ventricular wall in both species revealed P-450E was restricted to endothelium at margins of muscle bands limiting heart ventricular lumen. Localization in the specific cells of these and other organs may be fundamentally important in understanding the role of cytochrome P-450E. 相似文献
5.
Five lakes, varying from 10 to 100 hectares in area and each containing an existing population of Salmo gairdneri, were gill‐netted and stocked with tagged fish each year from 1960 to 1965 to determine the effect of regular stocking on the size and numbers of fish present. There was little natural spawning of trout in most of the lakes. Growth in length and weight of tagged fish was computed and an annual estimate of population calculated from the netting returns. Appendices give details of the statistical analyses of the data. Fish production has been correlated with the trophic status of the lakes as indicated by their temperature and oxygen content. There was no clear relationship between lake size and trout production but trout production decreased as the environment became more eutrophic. Results also showed a close inverse relationship between numbers supported and average weight achieved by the trout. It is concluded that the angling potential of local lakes can be maintained despite the eutrophication resulting from intensive agricultural development of the catchments. These lakes will produce large‐sized fish if the trout population is kept relatively small. Loss in weight in brown and rainbow trout as a result of spawning activities in local lakes and streams was found to be similar. Both male and female fish lost between 22 and 40 percent of their weight over a spawning period. This probably accounted for the observed low‐condition factor among older fish in the lake populations. 相似文献
6.
Cytochrome P-450 monooxygenases catalyze the biotransformation of a great variety of foreign, as well as endogenous, lipid-soluble compounds to more water-soluble products. As in mammals, highest concentration of cytochrome P-450 in fish is found in the liver. However, previous studies have indicated that fish kidney contains relatively high cytochrome P-450-mediated activities.1,2 We have therefore prepared and characterized subcellular fractions from the kidney of rainbow trout suitable for studies on cytochrome P-450-dependent reactions. Furthermore, as in the liver, several cytochrome P-450-mediated reactions in the kidney were induced following treatment of the fish with β-naphthoflavone. 相似文献
7.
I. R. Schultz P. N. N. L. Battelle W. A. Richland A. S. Drum M. S. L. Battelle W. A. Sequim W. L. Hayton G. A. Orner 《Marine environmental research》2000,50(1-5)
The appearance of the egg-yolk protein vitellogenin (Vg) in plasma of male fish is a sensitive indicator of exposure to estrogenic compounds. We have been studying the kinetics of Vg formation and excretion in rainbow trout with a goal towards developing an integrated pharmacokinetic–pharmcodynamic (PK–PD) model to quantitatively relate cumulative estrogenic exposure of fish to the expression and appearance of Vg in plasma. We administered graded doses of ethynylestradiol (EE2), o,p-DDT, DDD and DDE and octylphenol to male rainbow trout via a dorsal aortic cannula which allowed repetitive blood sampling from individual fish for up to 48 days after injection. The plasma concentrations of the xenobiotics and Vg were simultaneously quantified using ELISA and GC–MS or GC–ECD. In separate experiments, sexually mature trout were exposed to graded water concentrations of EE2 for 3 months and various parameters indicative of the functional status of the male reproductive system determined. These parameters included tissue-somatic indices, histopathological evaluation, spermatocrit, sperm motility (quantified using computer-assisted-motion analysis) and viability of semen based on fertilization assays using eggs harvested from untreated trout. Results from fertilization assays indicated that 12 week exposure to EE2 concentrations of 10 and 100 ng/l caused a 50% reduction in the fertilization rate of semen harvested from exposed trout. PK–PD modeling strategies proved valuable tools for linking chemical exposures to Vg formation. 相似文献
8.
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
9.
Winter flounder (Pleuronectes americanus) from Boston Harbor, Massachusett, undergo a progressive series of hepatic changes involving hydropic vacuolation of epithelial cells, biliary hyperplasia, and hepatocellular and cholangiocellular neoplasia. Severely affected fish often exhibit grossly visible lesions. To examine cell proliferation associated with these conditions, evidence for DNA synthesis was sought. Boston winter flounder livers were screened endoscopically to select fish with and without grossly visible hepatic lesions, and then injected intraperitoneally with bromodeoxyuridine (BrdU) 3 h before euthanasia. Incorporation of this nucleotide analog was visualized immunohistochemically in formalin-fixed, paraffin-embedded tissues. Basal epithelia in the gill and intestine stained strongly, as did renal hemopoietic epithelia. In contrast, renal tubular epithelia and cardiomyocytes did not stain. Normal appearing hepatocytes stained occasionally, whilst more frequent staining was observed in vacuolated and neoplastic hepatic epithelia. We conclude (1) that the BrdU assay as described here has potentially widespread application to the study of cell proliferation in fish tissues; (2) that vacuolated cells may actively proliferate in winter flounder liver from Boston Harbor; and (3) vacuolated cells may be involved in the neoplastic transformation of hepatic epithelia. 相似文献
10.
11.
J. P. Boon J. J. van Zanden W. E. Lewis B. N. Zegers A. Goksyr A. Arukwe 《Marine environmental research》2002,54(3-5)
The short-term effects of the commercial PBDE flame retardant mixtures Penta-BDE and Octa-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 1 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 CYP1A 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-17β for Vtg and Zrp expression, and β-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
12.
The incidence of hepatoma, epidermal and other forms of cancerous growths in fish is well documented (Halver, 1967; Matsushima & Sugimura, 1976; Dawe et al., 1964). In fish, as in mammals, cancer may be a result of metabolically activated carcinogens. In mammals the primary enzyme system involved in the activation of environmental carcinogens is the cytochrome P-450 linked mixed-function oxidase (MFO). The hepatic microsomes of the species offish studied contain variable levels of cytochrome P-450. Liver microsomes of the trout Salmo trutta lacustris are surprisingly active in metabolising benzo-[a]pyrene (BP) and other compounds preferentially metabolised by polycyclic aromatic hydrocarbon (PAH)-specific cytochrome P-450. This finding may be significant, because it is apparent that the detrimental effects of PAHs require metabolic activation.We have studied the production of reactive intermediates of BP by following their binding to DNA and by measuring the specific nucleotide-BP metabolite complexes by chromatography. Untreated S. trutta liver microsomes catalyse the production of reactive intermediates of BP which bind to nucleotides of DNA at a rate that is 3–4 times higher than that catalysed by control rat liver microsomes. The most prominent DNA-BP metabolite adducts produced by trout liver microsomes are the nucleoside adduct of BP-7, 8-diol-9,10-epoxide and 9-OH-BP-4,5-oxide and other phenol oxides. In contrast to the trout, another fish species, roach (Rutilus rutilus), has extremely low activity. Although the in vitro binding of BP to DNA is not strictly correlated to in vivo binding or biological effects, our results show that reactive intermediates are formed by trout liver and thus the prerequisite for chemical carcinogenesis or mutagenesis is ful filled. This is further supported by the fact that in Ames's test, trout liver preparations produce mutagenic products from promutagens. 相似文献
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14.
D R Livingstone C L Mitchelmore S C O'Hara P Lemaire J Sturve L F?rlin 《Marine environmental research》2000,50(1-5):57-60
The present study investigated the proposed involvement of contaminant-stimulated reactive oxygen species (ROS) production in disease processes in fish. NAD(P)H-dependent ROS production of subcellular fractions was determined by the iron/EDTA-mediated oxidation of 2-keto-4-methiolbutyric acid. Hepatic cytosolic NADPH-dependent and microsomal NAD(P)H-dependent ROS production were increased 51-160% (P < 0.05) in rainbow trout (Oncorhynchus mykiss) 15 weeks after a single i.p. injection of polychlorobiphenyl (PCB) (100 mg Clophen A50 kg-1 wet wt.). Hepatic microsomal NADH-dependent ROS production was 114% higher in perch (Perca fluviatilis) from PCB-contaminated Lake J?rnsj?n compared to clean Lake V?nern, Sweden. Hepatic mitochondrial NADH-dependent, cytosolic NADH-dependent and microsomal NADPH-dependent ROS production were variously elevated up to 160% in flounder (Platichthys flesus) at various sites along two pollution transects near to the ports of Rotterdam and Amsterdam, Netherlands. Overall the data indicate increased potential for ROS production in liver of fish exposed to field pollution, and support the hypothesis of oxidative stress as a mechanism of contaminant-mediated disease in fish. 相似文献
15.
Pollutant-induced cell injury in fish liver: Use of fluorescent molecular probes in live hepatocytes
Michael N. Moore 《Marine environmental research》1992,34(1-4)
This study was conducted to test whether live cells from the liver of fish could be used to detect early changes that are indicative of pollutant-induced liver damage. Low-molecular-weight fluorescent molecular probes were inserted into isolated hepatocytes from dab (Limanda limanda) from a contaminated site and a reference site in the North Sea. These included bioprobes for endoplasmic reticulum (ER), cytochrome P-450-associated 7-ethoxyresorufin-O-deethylase (EROD), oxyradicals, reduced glutathione (GSH) and microtubules (MT). Endocytosis of Texas Red-albumin was used as an integrated indicator of hepatocyte performance. Findings showed increases in ER-associated fluorescence, EROD and oxyradical generation, with a marked decrease in endocytosis in hepatocytes from fish caught at the contaminated site. These results indicate that fish from the historically contaminated site were impacted by organic xenobiotics which induced the biotransformation system, radical production and cell injury. 相似文献
16.
Our goal was to study the involvement of cytochrome P450 genes in estrogen metabolism and the extent to which the potentially carcinogenic 4-hydroxyestradiol metabolite is formed by channel catfish (Ictalurus punctatus; CC). Estradiol metabolism and ethoxyresorufin-O-deethylase (EROD) activity were assessed in several tissues from fish collected from three variably contaminated sites in the Mississippi River Delta, from laboratory control fish, and from fish exposed to 20 mg/kg benzo(a)pyrene (BaP) i.p. for 4 days. Liver EROD activity was induced by BaP, but Delta fish EROD activities were not statistically higher than activities in control fish. Gill microsomal EROD activity was also induced by BaP, but activities were 8- to 77-fold lower than those from liver. The predominant estrogen metabolites formed by CC liver, gill and gonad microsomes were 2-hydroxyestradiol and estrone as detected by GC/MS. Liver and gill 2-hydroxyestradiol formation was induced in BaP-dosed fish. The trends in hydroxyestradiol formation in field collected fish were more variable. In all fish liver microsomes there was more 2- compared to 4-hydroxyestradiol formed. However, BaP-treatment increased the 4:2 hydroxyestradiol ratio from 0.04 in control fish to 0.2 in BaP-exposed fish, suggesting that BaP induces the formation of the potentially genotoxic estrogen metabolite. No detectable 4-hydroxyestradiol was produced by gill and gonad microsomes. These results will ultimately help in determining which fish P450 genes are susceptible to environmental contamination and may be involved in estrogen genotoxicity. 相似文献
17.
Hayes RA Regondi S Winter MJ Butler PJ Agradi E Taylor EW Kevin Chipman J 《Marine environmental research》2004,58(2-5):665-669
Metallothionein has been assayed in a range of aquatic animal tissues as an indicator of metal exposure. We sequenced chub (Leuciscus cephalus) metallothionein cDNA which showed over 90% homology to common carp, goldfish and stone loach and 77% homology to rainbow trout sequences for metallothionein. We then used the extended primer method to develop an accurate quantitative competitive RT-PCR assay for metallothionein mRNA. RT-PCR was used to measure metallothionein mRNA in feral chub from a range of field sites, with different levels of heavy metal pollution, in the West Midlands, UK. Measurements were complemented by analysis of liver and gill metallothionein protein by capillary electrophoresis. There was no significant difference in the metallothionein protein levels between fish of different rivers and there was no evidence of elevation of mRNA at the sites of highest metal exposure. The level of metal exposure (e.g. zinc, nickel and cadmium each ranging between 15 and 28 microg/l ) at the pH (7.5-8.5) of these rivers appears insufficient to elevate hepatic or gill metallothionein in chub. A lack of elevation of hepatic metallothionein mRNA in chub exposed to zinc, copper and manganese for 24 h and 10 days in the laboratory also suggests a non-responsiveness of this species. 相似文献
18.
果糖-1,6-二 磷酸酶(fructose-1,6-bisphosphatase,FBP, EC 3. 1.3.11)可催化果糖-1,6-二磷酸水解成果糖-6-磷酸和无机磷酸盐,是糖异生途径中的关键酶之一。本研究运用SMART RACE技术从鲈鱼Lateolabrax japonicus肝脏中分离克隆了FBP基因的全长cDNA序列,该基因全长1 357 bp,其中5’非翻译区和3’非翻译区分别为42 bp和301 bp,开放阅读框为1 014 bp,共编码337个氨基酸。蛋白质分子量约为36.7 kD,理论pI为6.90。氨基酸序列分析表明,鲈鱼FBP与其它动物的肝脏型FBP相似性很高,与裸盖鱼、彩虹胡瓜鱼、斑马鱼、异育银鲫和大西洋鲑的肝脏型FBP的同源性分别为94.3%,90. 8%,89.3%,88.1%和84.1%。系统发育分析显示,鲈鱼FBP与其它鱼类的肝脏型FBP成簇后再与哺乳动物的肝脏型FBP聚成一支,然后才与哺乳动物的肌肉型FBP汇成簇。同时用RT-PCR分析了FBP基因在鲈鱼肝脏、肌肉、心脏、眼、肠、肾脏、脂肪、脾脏、鳃和大脑等10个组织的表达,结果表明FBP仅在肝脏、肾脏和肠这3个组织中有较高的表达,与糖异生发生组织基本一致,因此推测该FBP属于肝脏型。 相似文献
19.
牙鲆鳃淋巴样组织内免疫相关细胞的超微结构 总被引：2，自引：0，他引：2
利用电镜技术观察海水鱼类牙鲆鳃小片的基本结构及其免疫相关细胞的分布和形态。牙鲆的鳃小片主要由扁平上皮细胞和柱细胞构成 ,血窦腔极为发达。鳃小片在功能上可分为两个区 :气体交换区和免疫区。气体交换区位于上半部分 ,血窦内主要分布着红细胞 ;免疫区位于鳃小片基部 ,血窦腔中分布着各种免疫相关细胞 :淋巴细胞、单核细胞、中性粒细胞和酸性粒细胞。此外 ,还观察到了泌氯细胞和粘液细胞。研究结果证明 ,牙鲆的鳃在局部粘膜免疫中具有重要的作用 ,是鱼类免疫体系中的有机组成成分之一 相似文献
20.
Vertebrate flavin-containing monooxygenases (FMOs) have only been isolated from mammalian organisms. However, many FMO substrates include pesticides which may adversely affect fish and other aquatic organisms residing in adjacent waterways to treated fields. Although FMO activities have been identified in fish, the exact isoform profile is uncertain. Utilizing prochiral methyl tolyl sulfides (MTS) and isoform-selective antibodies, an attempt was made to identify specific FMO isoforms which may be involved in sulfoxidation reactions which have been shown to bioactivate thioether pesticides, such as aldicarb. Rainbow trout hepatic microsomes treated with detergent to eliminate cytochrome P450 contributions catalyzed the formation of the sulfoxide of MTS in 75% S enantiomeric excess. These catalytic results contrast activities of the five other FMO isoforms including FMO1 (> 98% R) and FMO3 (50% R). Benzydamine N-oxidation was also observed as were methimazole, thiourea, and aldicarb sulfoxidation reactions. Antibodies to FMO1 recognized a single protein of 60 kDa in trout liver microsomes, while anti-FMO3 antibodies only slightly reacted with a 55-kDa microsomal protein. These results indicate a novel isoform profile in rainbow trout liver implicating either a mixture of competing FMO isoforms or a FMO1-like isoform displaying unique catalytic activity. 相似文献