| 1. |
- Carney Almroth, Bethanie, 1974, et al.
(författare)
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Protein carbonyls and antioxidant defenses in corkwing wrasse (Symphodus melops) from a heavy metal polluted and a PAH polluted site.
- 2008
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Ingår i: Marine environmental research. - : Elsevier BV. - 0141-1136. ; 66:2, s. 271-7
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Tidskriftsartikel (refereegranskat)abstract
- The use of fish in environmental monitoring has become increasingly important in recent years as anthropogenic substances, many of which function as prooxidants, are accumulating in aquatic environments. We have measured a battery of antioxidant defenses as a measure of oxidative status, as well as protein carbonylation as a measure of oxidative damage, in corkwing wrasse (Symphodus melops) captured near a disused copper mine, where water and sediment are contaminated with heavy metals, and an aluminum smelter, a site contaminated with PAHs. Results were compared to two different reference sites. Fish at the heavy metal site had lower glucose-6-phosphate dehydrogenase activity and elevated protein carbonyls (1.8 times) compared to fish from the reference site. At the PAH site, EROD was increased 2-fold, while total glutathione and methemoglobin reductase concentration, were decreased. No differences were seen in protein carbonyl levels at the PAH site. Measures of both antioxidant defenses and oxidative damage should be used when assessing effects of xenobiotics on oxidative stress in fish species.
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| 2. |
- Ek, Helene, 1976, et al.
(författare)
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Tentative biomarkers for 2,4,6-trinitrotoluene (TNT) in fish (Oncorhynchus mykiss)
- 2005
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 72:3, s. 221-230
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Tidskriftsartikel (refereegranskat)abstract
- 2,4,6-Trinitrotoluene (TNT) is the major explosive in ammunition dumped into lakes and the sea after World War II. To identify useful biomarkers of TNT-exposure for forthcoming fish monitoring studies at ammunition dumping sites, rainbow trout (Oncorhynchus mykiss) were intraperitoneal (i.p.) injected with TNT in peanut oil at doses of 0, 100, 200 or 400 mg TNT/kg body weight and sampled 72 h later. The study covered blood parameters, and hepatic antioxidant and detoxifying enzymes. Fish treated with TNT had an increased glutathione S-transferase (GST) activity and glutathione reductase (GR) activity, and a decreased percentage of oxidised glutathione (%GSSG) compared to the control group. In addition to increased methemoglobin, the increased glutathione and glutathione dependent enzyme activities indicate that TNT oxidises macromolecules and activates antioxidant defence systems which may be useful as general biomarkers of TNT-exposure. The fish bile was analysed for TNT and its metabolites by gas chromatography-mass spectrometry (GC-MS), and the toxicity of the bile was determined with the cladoceran Ceriodaphnia dubia. A dose-dependent increase in TNT, 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) was found in the hydrolysed bile of the TNT-treated fish. These results indicate that the fish are able to detoxify and excrete TNT and suggest that the detection of TNT, 2-ADNT and 4-ADNT in bile may be suitable as a direct marker of exposure to TNT. (c) 2005 Elsevier B.V. All rights reserved.
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| 3. |
- Larsson, D. G. Joakim, 1969, et al.
(författare)
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Studies of masculinization, detoxification, and oxidative stress responses in guppies (Poecilia reticulata) exposed to effluent from a pulp mill.
- 2002
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Ingår i: Ecotoxicology and environmental safety. - : Elsevier BV. - 0147-6513. ; 52:1, s. 13-20
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Tidskriftsartikel (refereegranskat)abstract
- Potential masculinization, detoxification, and oxidative stress responses were assessed in domesticated female guppies (Poecilia reticulata) exposed for 42 days to diluted effluent from a modern Swedish kraft pulp mill or a model androgen. Methyltestosterone induced male-like coloration and transformation of the anal fin into a gonopodium-like structure. The effluent did not induce any apparent changes of the anal fin morphology; however, the exposed guppies became more colored than control fish, which could be an androgenic response. A better understanding of the physiological mechanisms involved in these responses would be required for a full evaluation. Both primary effluent and effluent which had undergone activated sludge treatment caused a moderate but significant induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity. However, the general toxicity of both effluents was low, as mortality was negligible even at 25% dilutions. There was a continuous production of offspring in all groups (47-62% female fry), except by methyltestosterone-treated females, which did not reproduce. There were no indications that either effluent caused oxidative stress since hepatic glutathione reductase, glutathione S-transferase and DT-diaphorase activities remained unchanged compared with controls.
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| 4. |
- Stephensen, Eiríkur, et al.
(författare)
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Biomarker responses and chemical analyses in fish indicate leakage of polycyclic aromatic hydrocarbons and other compounds from car tire rubber
- 2003
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 22:12, s. 2926-2931
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Tidskriftsartikel (refereegranskat)abstract
- Rubber tire material contains toxic compounds including oils rich in polycyclic aromatic hydrocarbons (PAH), so-called highly aromatic (HA) oils, as well as other reactive additives used as antioxidants, antiozonants, and vulcanization accelerators. The toxicity of rubber tire leachates to aquatic organisms has been demonstrated before. However, previous Studies have focused on lethal rather than sublethal effects. We kept rainbow trout (Oncorhynchus mykiss) in tanks with two types of fires: a tire containing HA oils in the tread or a tire free of HA oils in the tread. After 1 d of exposure. an induction of cytochrome P4501A1 (CYP1A1) was evident in both exposed groups, measured as elevated ethoxyresorufin-O-deethylase (EROD) activity and increased CYP1A1 mRNA levels. After two weeks of exposure, EROD activity and CYP1A1 mRNA were still high in fish exposed to leachate from HA oil-containing tire, whereas the effect was somewhat lower in fish exposed to leachate from HA oil-free tread tire. Compounds in the tire leachates also affected antioxidant parameters. Total glutathione concentration in liver as well as hepatic glutathione reductase, glutathione S-transferase, and glucose-6-phosphate dehydrogenase activities were markedly elevated after two weeks of exposure in both groups. The responses were greater in the group exposed to leachate from HA oil-free tread tire. Vitellogenin measurements did not indicate leakage of estrogenic compounds from the tires. Chemical analyses of bile from exposed fish revealed the presence of hydroxylated PAH as well as aromatic nitrogen compounds indicating uptake of these compounds by the fish.
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| 5. |
- Stephensen, Eiríkur, et al.
(författare)
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Rubber additives induce oxidative stress in rainbow trout
- 2005
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X. ; 75:2, s. 136-143
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have demonstrated the toxicity of rubber leachate, mainly from rubber tires, to aquatic organisms. In the present study rainbow trout (Oncorhynchus mykiss) were exposed to water provided to aquaria through a rubber hose. Increased hepatic ethoxyresorufin-O-deethylase (EROD) activity, and glutathione reductase (GR) activity were observed in the exposed fish. Two common rubber additives, 2-mercaptobenzothiazole (MBT) and diphenylamine (DPA) and structurally related compounds, were identified by chemical analyses of water samples as were hydroxylated polycyclic aromatic hydrocarbons. Metabolites of these compounds were also detected in the bile of exposed fish, as were some of the parent compounds. In a following experiment, we injected rainbow trout with DPA or MBT. Both compounds affected total glutathione (tGSH) concentration in liver and MBT caused an increase in hepatic GR and glutathione S-transferase (GST) activity as well. In DPA injected fish, hydroxylated DPA was the main metabolite in the bile. Our results indicate that rubber chemicals may leach into the water surroundings where they can be taken up and metabolised by fish. Some of these chemicals can lead to up-regulation of antioxidant defences as demonstrated with DPA and MBT injections. (c) 2005 Elsevier B.V. All rights reserved.
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| 6. |
- Sturve, Joachim, 1966, et al.
(författare)
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Effects of dredging in Göteborg Harbor, Sweden, assessed by biomarkers in eelpout (Zoarces viviparus)
- 2005
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Ingår i: Environmental Toxicology and Chemistry. - 0730-7268. ; 24:8, s. 1951-1961
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Tidskriftsartikel (refereegranskat)abstract
- We used a battery of biomarkers in fish to study the effects of the extensive dredging in Goteborg harbor situated at the river Gota alv estuary, Sweden. Eelpout (Zoarces viviparus) were sampled along a gradient into Goteborg harbor, both before and during the dredging. Biomarker responses in the eelpout before the dredging already indicated that fish in Goteborg harbor are chronically affected by pollutants under normal conditions compared to those in a reference area. However, the results during the dredging activities clearly show that fish were even more affected by remobilized pollutants. Elevated ethoxyresorufin-O-deethylase activities and cytochrome P4501A levels indicated exposure to polycyclic aromatic hydrocarbons. Elevated metallothionein gene expression indicated an increase in metal exposure. An increase in general cell toxicity, measured as a decrease in lysosomal membrane stability, as well as effects on the immune system also could be observed in eelpout sampled during the dredging. The results also suggest that dredging activities in the Gota alv estuary can affect larger parts of the Swedish western coast than originally anticipated. The present study demonstrates that the application of a set of biomarkers is a useful approach in monitoring the impact of anthropogenic activities on aquatic environments.
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| 7. |
- Sturve, Joachim, 1966, et al.
(författare)
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Effects of redox cycling compounds on DT diaphorase activity in the liver of rainbow trout (Oncorhynchus mykiss)
- 2005
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Ingår i: Comp Hepatol. - : Springer Science and Business Media LLC. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: DT diaphorase (DTD; NAD(P)H:quinone oxidoreductase; EC 1.6.99.2) catalyses the two electron reduction of quinones, thus preventing redox cycling and consequently quinone dependent production of reactive oxygen species. In rat and mouse, a wide range of chemicals including polyaromatic hydrocarbons, azo dyes and quinones induces DTD. Bifunctional compounds, such as beta-naphthoflavone (beta-NF) and benzo(a)pyrene (B(a)P), induce DTD together with CYP1A and phase II enzymes by a mechanism involving the aryl hydrocarbon receptor (AHR). Monofunctional induction of DTD is mediated through the antioxidant response element and does not lead to the induction of AHR dependent enzymes, such as CYP1A. The aim of this study was to investigate the effects of prooxidants (both bifunctional and monofunctional) on the activity of hepatic DTD in rainbow trout (Oncorhynchus mykiss) in order to evaluate DTD suitability as a biomarker. We also investigated the effect of beta-NF on hepatic DTD activity in perch (Perca fluviatilis), shorthorn sculpin (Myoxocephalus scorpius), eelpout (Zoarces viviparus), brown trout (Salmo trutta) and carp (Cyprinus carpio). In addition, the effect of short term exposure to prooxidants on catalase activity was investigated. RESULTS: In rainbow trout, hepatic DTD activity is induced by the bifunctional AHR agonists beta-NF and B(a)P and the monofunctional inducers naphthazarin, menadione and paraquat. Although exposure to both B(a)P and beta-NF led to a strong 7-ethoxyresorufin-O-deethylase (EROD) induction, none of the monofunctional compounds affected the rainbow trout EROD activity. DTD was not induced by beta-NF in any of the other fish species. Much higher DTD activities were observed in rainbow trout compared to the other fish species. Catalase activity was less responsive to short term exposure to prooxidants compared to DTD. CONCLUSION: Since rainbow trout hepatic DTD activity is inducible by both monofunctional and bifunctional inducers, it is suggested that rainbow trout DTD may be regulated by the same mechanisms, as in mammals. The fact that DTD is inducible in rainbow trout suggests that the enzyme may be suitable as a part of a biomarker battery when rainbow trout is used in environmental studies. It appears as if DTD activity in rainbow trout is higher and inducible compared to the other fish species studied.
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