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- Hallgren, Stefan, et al.
(författare)
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Anxiogenic behaviour induced by 17α-ethynylestradiol in male guppies (Poecilia reticulata)
- 2011
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Ingår i: Fish Physiology & Biochemistry. - : Springer Science and Business Media LLC. - 0920-1742 .- 1573-5168. ; 37:4, s. 911-918
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Tidskriftsartikel (refereegranskat)abstract
- Behaviour studies are used in toxicology research as they are excellent tools to measure physiological end-points caused by exogenous chemicals. In mammals both reproductive and non-reproductive behaviours have been used for a long period of time, whereas in teleost fishes non-reproductive behaviours have received little attention compared to reproductive behaviours. Recent advances in measuring stress related behaviours in zebrafish have provided additional tools to understand behaviour toxicology in fish. One species with well documented reproductive behaviour disturbed by different toxicants is the guppy, which is better suited than zebrafish for reproductive behaviour studies and therefore might be a better model organism for comparative behaviour studies in fish toxicology. Here we report new applications for non-reproductive behaviours in guppy and test these behaviours on males treated with the endocrine disruptor 17α-ethynylestradiol at environmentally relevant concentrations. 17α-ethynylestradiol increased freezing and bottom-dwelling when fish were placed in a non-familiar aquarium, but did not significantly affect shoaling behaviour. These results are similar to the anxiogenic behaviours seen in rats treated perinatally with 17α-ethynylestradiol and add more concern to the impacts of endocrine disruptors on aquatic wildlife.
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| 2. |
- Hallgren, Stefan, 1978-, et al.
(författare)
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Effects on Guppy brain aromatase activity following short-term steroid and 4-Nonyl phenol exposures
- 2010
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Ingår i: Environmental Toxicology. - : Wiley. - 1520-4081 .- 1522-7278. ; 25:3, s. 261-271
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Tidskriftsartikel (refereegranskat)abstract
- Brain oestrogen production, performed by the enzyme aromatase, can be disrupted/affected in teleost fish exposed to endocrine disruptors found in polluted aquatic environments. The guppy (Poecilia reticulata) was previously studied and confirmed to suffer negative effects on reproductive behaviours following inhibition of the brain aromatase reaction. Here Adult guppies (Poecilia reticulata) of both genders were subjected to known endocrine disruptors: the androgen androstenedione (A), the synthetic oestrogen 17α-ethynylestradiol (EE2) and the oestrogenic surfactant 4-nonylphenol (NP), at high (50 μg/L) and at environmentally relevant concentrations (10 ng/L EE2, 5 μg/L NP and 0.7 μg/L A) for two weeks followed by measurements of brain aromatase activity (bAA). In the adult males, bAA was stimulated by A and EE2 at 50 μg/L. Female activity was also stimulated by the higher oestrogenic treatment. At environmentally relevant concentrations only the EE2 treatment affected bAA, and only in males. The alkylphenolic substance NP produced no effect in either of the experiments, not on males nor females. The results indicate that short-term steroid treatments have stimulatory effects on guppy brain aromatase even at concentrations that can be found in the environment. We thus suggest bAA of adult guppies to be a suitable bioindicator of endocrine disruptors.
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| 3. |
- Jaensson, Alia, et al.
(författare)
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Effects of copper on olfactory-mediated endocrine responses and reproductive behaviour in mature male brown trout Salmo trutta parr to conspecific females
- 2010
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 76:4, s. 800-817
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the effects of copper (CuSO4) on the ability of mature male brown trout Salmo trutta parr to detect and react both physiologically and behaviourally to female pheromones were studied. The study was composed of two parts. In the first experiment, priming effects of the female pheromone prostaglandin F2α (PGF2α) were evaluated by determining the amount of milt produced and the blood plasma levels of 11-ketotestosterone (11-KT) and 17α,20β-dihydroxy-4-pregnen-3-one (17,20β-P) after the PGF2α exposure. In the second experiment, male parr were placed in a large stream tank together with a group of adult males and ovulated females and their individual behaviours were recorded. In the priming experiment, the amount of expressible milt was significantly lower, less than half, in groups exposed during 4 days to 10 or 100 µg l−1 copper compared with control parr only exposed to water. No significant differences were observed in plasma levels of 11-KT and 17, 20β-P. During the behavioural experiment, exposed parr spent less time with the female and had a lower number of courting events. Blood plasma levels of 11-KT were, however, significantly higher in the group exposed to 100 µg l−1 copper compared with the control group. Furthermore, the exposed group spent significantly less time swimming upstream than did the control group. The present study demonstrates that exposure to copper affects reproductive behaviours and endocrinology of S. trutta male parr.
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