| 1. |
- Carney Almroth, Bethanie, 1974-, et al.
(författare)
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Early-age changes in oxidative stress in brown trout, Salmo trutta
- 2010
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Ingår i: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY. - 1096-4959. ; 155:4, s. 442-448
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Tidskriftsartikel (refereegranskat)abstract
- Fish are often used as models for studies investigating the ability of xenobiotics to induce oxidative stress, though age or developmental stage of the individuals studied has been given little attention. Oxidative stress in other organisms is associated with aging as well as with periods of rapid growth, which occurs in young brown trout. We measured protein carbonyls, 20S proteosome activity and glutathione (GSH) levels in farmed Salmo trutta in four different age groups from 5 months to 3 years. We found an increase in protein carbonyls and a decrease in 20S proteosome activity in both brain and liver tissues of the fish with increasing size and age. Total GSH levels in liver tissue declined as fish aged and the GSSG:GSH ratio increased. Five month and 1 year old trout were treated with paraquat (PQ) to induce oxidative stress. Five month old fish showed no changes in the measured parameters while 1 year old fish had both an increase in protein carbonylation in liver tissue and a decrease in 20S proteosome activity in brain tissue. These results indicate that oxidative stress biomarkers are affected by age or rapid growth in brown trout, and that individuals of different ages respond differently to oxidative stress induced by PQ.
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| 2. |
- Carney Almroth, Bethanie, 1974-, et al.
(författare)
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Oxidative damage in rainbow trout caged in a polluted river.
- 2008
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Ingår i: Marine Environmental Research. ; 66:1, s. 90-91
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Carney Almroth, Bethanie, 1974-, et al.
(författare)
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Oxidative stress, evident in antioxidant defences and damage products, in rainbow trout caged outside a sewage treatment plant
- 2008
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Ingår i: Ecotoxicology and Environmental Safety. ; 70:3, s. 370-378
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Tidskriftsartikel (refereegranskat)abstract
- Sewage treatment plants (STPs) are common sources of a wide variety of chemicals entering into the aquatic environment. We have investigated the effects of STP effluent on oxidative stress parameters in rainbow trout via measurements of several enzymatic antioxidants as well as the molecular antioxidant glutathione (GSH). In addition, we have measured levels of oxidative damage, i.e. protein carbonyls and lipid peroxides. Our findings indicate that STP effluent does contain prooxidants that affect fish. Oxidative damage was a more consistent indicator of exposure to prooxidants than antioxidant enzymes. Protein carbonyls and lipid peroxides were both elevated (1.3- and 1.8-fold increases, respectively) in fish caged at the STP site compared with reference site as was the amount of oxidized GSH (GSSG), which showed a 3-fold increase. Antioxidant enzymes showed no clear-cut response. Additionally, older pollutants that have been present in down stream sediment for decades had no effects on the parameters measured here.
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| 4. |
- 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. - 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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| 5. |
- 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. - 0166-445X. ; 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.
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| 7. |
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| 8. |
- Sturve, Joachim, 1966-, et al.
(författare)
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Oxidative stress in rainbow trout (Oncorhynchus mykiss) exposed to sewage treatment plant effluent.
- 2008
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Ingår i: Ecotoxicology and environmental safety. - 1090-2414. ; 70:3, s. 446-52
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Tidskriftsartikel (refereegranskat)abstract
- Effluents from sewage treatment plants (STPs) can be regarded as "hot spots" of discharge releasing large amounts of chemicals into the aquatic environment. Many of these compounds are toxic to organisms due to their ability to form reactive oxygen species (ROS) and cause oxidative stress. In order to investigate if STP effluents contain compounds that may cause oxidative stress, rainbow trout (Oncorhynchus mykiss) were exposed to effluent from a Swedish STP at different dilutions in a flow-through system. Antioxidant enzymes analyzed were glutathione reductase (GR), catalase (CAT) and DT-diaphorase (DTD). Catalytic activities of CYP1A (EROD) and the conjugating enzyme glutathione-S transferase (GST) were also analyzed. Results indicate that the effluent contains prooxidants since the activities of the antioxidant enzymes GR, CAT, and DTD were all elevated after 5 days of exposure. A prolonged exposure resulted in an inhibition of DT diaphorse activity, suggesting a depleted cellular ROS defence. EROD activities increased in a dose- and time-dependent manner, which suggests the presence of aryl hydrocarbon receptor (AHR) ligands such as polycyclic aromatic hydrocarbons (PAHs) in the effluent. These results indicate that STPs do not have the capacity to biodegrade harmful chemicals sufficiently to protect the aquatic environment. However, STPs are designed to remove nutrients and not persistent pollutants from the sewage and effort should be made to diminish the amount of chemicals entering the sewage in the first place.
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