| 1. |
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| 2. |
- Björkblom, Carina, et al.
(författare)
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Estrogen- and androgen-sensitive bioassays based on primary cell and tissue slice cultures from three-spined stickleback (Gasterosteus aculeatus)
- 2007
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Ingår i: Comparative Biochemistry and Physiology - Part C. - Oxford : Elsevier. - 1532-0456 .- 1878-1659. ; 146:3, s. 431-442
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Tidskriftsartikel (refereegranskat)abstract
- Endocrine disrupting compounds are chemicals that may interfere with the endocrine system causing severe effects in organisms. The three-spined stickleback (Gasterosteus aculeatus L.) offers a potential for the assessment of endocrine disruption caused by a) estrogenic xenobiotics through the estrogen-dependent protein vitellogenin and b) androgenic xenobiotics through the androgen-dependent protein spiggin. The stickleback is presently the only known fish species with a quantifiable androgen and anti-androgen biomarker endpoint. In the current study, hepatocyte and kidney primary cell cultures and liver and kidney tissue slice cultures were prepared and used for detecting estrogenic or androgenic activity in vitro through the action of hormones or municipal sewage water. The results indicate that stickleback male hepatocyte cultures are suitable in detecting estrogenic activity and stickleback female kidney tissue slice cultures in detecting androgenic activity. The tested sewage water showed high estrogenic activity but no significant androgenic activity. Primary cell and tissue slice cultures isolated from the three-spined stickleback will allow simultaneously screening in vitro for potential estrogenic and androgenic activity of complex samples.
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| 3. |
- de Gelder, Stefan, et al.
(författare)
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Transepithelial transfer of phenanthrene, but not of benzo[a]pyrene, is inhibited by fatty acids in the proximal intestine of rainbow trout (Oncorhynchus mykiss)
- 2018
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Ingår i: Comparative Biochemistry and Physiology Part C: Toxicology and Pharmacology. - : Elsevier BV. - 1532-0456 .- 1878-1659. ; 204, s. 97-105
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 Elsevier Inc. The inclusion of vegetable oils in aquafeeds introduces contaminating polycyclic aromatic hydrocarbons (PAHs) in salmonids. Since lipophilic PAHs solubilize in micelles composed of lipids, bile salts and fatty acids, dietary lipid composition can alter intestinal transepithelial PAH transfer. We studied the uptake of two PAHs, viz. benzo[a]pyrene (BaP) and phenanthrene (PHE), in rainbow trout (Oncorhynchus mykiss) intestine. We also investigated the effects of two fatty acids, viz. fish oil-derived eicosapentaenoic acid (EPA, 20:5n-3) and vegetable oil-derived oleic acid (18:1n-9) on intestinal uptake. Radiolabeled PAHs were solubilized in micelles composed of tritiated EPA and oleic acid, respectively, and administrated to intestinal segments mounted in Ussing chambers. In the absence of micelles, PHE accumulation was two times higher than BaP in the mucosal and serosal layers of proximal and distal intestine. Administration of PHE in micelles composed of oleic acid resulted in a 50% lower accumulation of PHE in the mucosal layers of the proximal intestine compared to EPA-composed micelles. Accumulation of EPA and oleic acid in the proximal intestinal mucosa correlated negatively with the transepithelial transfer of these fatty acids across the proximal intestinal epithelium. Transepithelial PHE transfer across the proximal intestine was reduced by 30% in co-exposure with EPA-composed micelles compared to 80% with oleic acid micelles. BaP was not transferred across the intestine. We conclude that the lipid composition of an aquafeed is an important determinant of PAH bioavailability. Therefore, lipid composition should be an important consideration in choosing vegetable oils as alternatives for fish oil in aquafeeds.
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| 4. |
- Eriksson Wiklund, Ann-Kristin, et al.
(författare)
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Cardiotoxic and neurobehavioral effects of sucralose and acesulfame in Daphnia : Toward understanding ecological impacts of artificial sweeteners
- 2023
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Ingår i: Comparative Biochemistry and Physiology - Part C. - 1532-0456 .- 1878-1659. ; 273
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Tidskriftsartikel (refereegranskat)abstract
- Artificial sweeteners are widely used in food and pharmaceuticals, but their stability and persistence raise concerns about their impact on aquatic life. Although standard toxicity tests do not reveal lethal effects, recent studies suggest a potential neurotoxic mode of action. Using environmentally relevant concentrations, we assessed the effects of sucralose and acesulfame, common sugar substitutes, on Daphnia magna focusing on biochemical (acetylcholinesterase activity; AChE), physiological (heart rate), and behavioural (swimming) endpoints. We found dose-dependent increases in AChE and inhibitory effects on heart rate and behaviour for both substances. Moreover, acesulfame induced a biphasic response in AChE activity, inhibiting it at lower concentrations and stimulating at higher ones. For all endpoints, the EC50 values were lower for acesulfame than for sucralose. Additionally, the relationship between acetylcholinesterase and heart rate differed depending on the substance, suggesting possible differences in the mode of action between sucralose and acesulfame. All observed EC50 values were at μg/l levels, i.e., within the levels reported for wastewater, with adverse effects observed at as low as 0.1 μg acesulfame /l. Our findings emphasise the need to re-evaluate risk assessment thresholds for artificial sweeteners and provide evidence for the neurotoxic effects of artificial sweeteners in the environment, informing international regulatory standards.
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| 5. |
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| 6. |
- Gao, Kai, et al.
(författare)
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Cytochrome P450 1A, 1B, and 1C mRNA induction patterns in three-spined stickleback exposed to a transient and a persistent inducer
- 2011
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Ingår i: Comparative Biochemistry and Physiology - Part C. - : Elsevier BV. - 1532-0456 .- 1878-1659. ; 154:1, s. 42-55
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Tidskriftsartikel (refereegranskat)abstract
- Cytochrome P450 1 (CYP1) mRNA induction patterns in three-spined stickleback (Gasterosteus aculeatus) were explored for use in environmental monitoring of aryl hydrocarbon receptor (AHR) agonists. The cDNAs of stickleback CYP1A, CYP1B1, CYP1C1, and CYP1C2 were cloned and their basal and induced expression patterns were determined in the brain, gill, liver and kidney. Also, their induction time courses were compared after waterborne exposure to a transient (indigo) or a persistent (3,3',4,4',5-pentacholorbiphenyl PCB 126) AHR agonist. The cloned stickleback CYP1s exhibited a high amino acid sequence identity compared with their zebrafish orthologs and their constitutive tissue distribution patterns largely agreed with those reported in other species. PCB 126 (100 nM) induced different CYP1 expression patterns in the four tissues, suggesting tissue-specific regulation. Both indigo (1 nM) and PCB 126 (10 nM) induced a strong CYP1 expression in gills. However, while PCB 126 gave rise to a high and persistent induction in gills and liver, induction by indigo was transient in both organs. The number of putative dioxin response elements found in each CYP1 gene promoter roughly reflected the induction levels of the genes. The high responsiveness of CYP1A,CYP1B1, and CYP1C1 observed in several organs suggests that three-spined stickleback is suitable for monitoring of pollution with AHR agonists.
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| 7. |
- Holbech, Henrik, et al.
(författare)
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Comparison of zebrafish (Danio rerio) and fathead minnow (Pimephales promelas) as test species in the Fish Sexual Development Test (FSDT).
- 2012
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Ingår i: Comparative Biochemistry and Physiology - Part C. - : Elsevier BV. - 1532-0456 .- 1878-1659. ; 155:2, s. 407-15
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Tidskriftsartikel (refereegranskat)abstract
- Results are presented from a validation (with 5 laboratories) of the Fish Sexual Development Test (FSDT) developed to detect endocrine disrupters (EDs) and included in the OECD (Organisation for Economic Co-operation and Development) working program. The aromatase-inhibiting fungicide prochloraz was tested in zebrafish (Danio rerio) and fathead minnow (Pimephales promelas). The fish were exposed during sexual differentiation and development from 0 to 60 days post hatch (dph). After exposure, the vitellogenin (VTG) concentrations were quantified in head/tail homogenate and the sex ratio was determined (defined as female, male, intersex or undifferentiated). NOEC/LOEC and EC(x) designs were compared to optimize the test approach. Results show that both species are highly sensitive to prochloraz during sexual development. They respond by skewing of the sex ratio towards male phenotype and by a VTG decline in females. The NOEC/LOEC approach is preferred because sex ratio is difficult to analyze with a regression model. The mean NOEC/LOEC for prochloraz on the sex ratio was 43.3/134 μg/L and 101/293 μg/L for zebrafish and fathead minnow, respectively. The mean NOEC/LOEC on the decline in female VTG concentration was 65/110 μg/L and ~30/68 μg/L respectively. In conclusion, zebrafish and fathead minnow are suitable species in the FSDT and their sexual differentiation is equally labile to EDs.
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| 8. |
- Jönsson, Maria E., et al.
(författare)
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Toxicity and cytochrome P450 1A mRNA induction by 6-formylindolo[3,2-b]carbazole (FICZ) in chicken and Japanese quail embryos
- 2016
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Ingår i: Comparative Biochemistry and Physiology - Part C. - : Elsevier BV. - 1532-0456 .- 1878-1659. ; 179, s. 125-136
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Tidskriftsartikel (refereegranskat)abstract
- The tryptophan derivative formylindolo[3,2-b]carbazole (FICZ) binds with high ligand affinity to the aryl hydrocarbon receptor (AHR) and is readily degraded by AHR-regulated cytochrome P450 family 1 (CYP1) enzymes. Whether in vivo exposure to FICZ can result in toxic effects has not been examined and the main objective of this study was to determine if FICZ is embryotoxic in birds. We examined toxicity and CYP1 mRNA induction of FICZ in embryos from chicken (Gallus domesticus) and Japanese quail (Coturnix japonica) exposed to FICZ (2200 jag kg(-1)) by yolk and air sac injections. FICZ caused liver toxicity, embryo mortality, and CYP1A4 and CYP1A5 induction in both species with similar potency. This is in stark contrast to the very large difference in sensitivity of these species to halogenated AHR agonists. We also exposed chicken embryos to a low dose of FICZ (4 mu g kg(-1)) in combination with a CYP inhibitor, ketoconazole (KCZ). The mixture of FICZ and KCZ was lethal while FICZ alone had no effect at 4 mu g kg(-1). Furthermore, mixed exposure to FICZ and KCZ caused stronger and more long-lasting hepatic CYP1A4 induction than exposure to each compound alone. These findings indicate reduced biotransformation of FICZ by co-treatment with KCZ as a cause for the enhanced effects although additive AHR activation is also possible. To conclude, FICZ is toxic to bird embryos and it seems reasonable that the toxicity by FICZ involves AHR activation. However, the molecular targets and biological events leading to hepatic damage and mortality are unknown.
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| 9. |
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| 10. |
- Li, Zhi-Hua, et al.
(författare)
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Modulation of antioxidant defence system in brain of rainbow trout (Oncorhynchus mykiss) after chronic carbamazepine treatment
- 2010
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Ingår i: Comparative Biochemistry and Physiology - Part C. - : Elsevier BV. - 1532-0456 .- 1878-1659. ; 151:1, s. 137-41
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the effect of long-term exposure to CBZ on the antioxidant system in brain tissue of rainbow trout. Fish were exposed to sublethal concentrations of CBZ (1.0mug/L, 0.2mg/L or 2.0mg/L) for 7, 21, and 42days. Oxidative stress indices (LPO and CP) and activities of antioxidant enzymes (SOD, CAT, GPx and GR) in fish brain were measured. In addition, non-enzymatic antioxidant (GSH) was determined after 42days exposure. Carbamazepine exposure at 0.2mg/L led to significant increases (p<0.05) of LPO and CP after 42days and, at 2.0mg/L, after 21days. Activities of the antioxidant enzymes SOD, CAT, and GPx in CBZ-treated groups slightly increased during the first period (7days). However, activities of all measured antioxidant enzymes were significantly inhibited (p<0.05) at 0.2mg/L exposure after 42days and after 21days at 2.0mg/L. After 42days, the content of GSH in fish brain was significantly lower (p<0.05) in groups exposed to CBZ at 0.2mg/L and 2.0mg/L than in other groups. Prolonged exposure to CBZ resulted in excess reactive oxygen species formation, finally resulting in oxidative damage to lipids and proteins and inhibited antioxidant capacities in fish brain. In short, a low level of oxidative stress could induce the adaptive responses of antioxidant enzymes, but long-term exposure to CBZ could lead to serious oxidative damage in fish brain.
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