| 1. |
- Brande-Lavridsen, Nanna, et al.
(författare)
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Abnormalities in eelpout Zoarces viviparus upon chemical exposure.
- 2013
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Ingår i: Marine Environmental Research. - : Elsevier BV. - 0141-1136 .- 1879-0291. ; 92, s. 87-94
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Tidskriftsartikel (refereegranskat)abstract
- Elevated frequencies of abnormal embryos in female eelpout Zoarces viviparus have been demonstrated in Danish, Swedish and German monitoring programmes at certain geographic locations with high levels of anthropogenic input. Pollutants present in areas with high malformation frequencies were selected and tested in a controlled laboratory experiment for their potential to induce abnormalities among eelpout embryos upon injection into pregnant eelpout. Tributyltin, 2,3,7,8-tetrachlorodibenzo-p-dioxin, pyrene, nonylphenol, 2,2',4,4'-tetrabromophenylether and heptadecafluorooctanesulfonic acid were tested, either individually or combined. Generally, the chemicals were transferred to eggs and/or embryos. Some of the exposures increased the proportion of broods with more than 10% abnormal or 5% malformed embryos, although the average percentages of abnormal development were not affected. Spinal, cranial and eye deformities were evident, similarly to what is seen in nature. Some of the exposures resulted in increased percentages of females with as well a low reproductive capacity as embryos with a low condition index.
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| 2. |
- Brande-Lavridsen, Nanna, et al.
(författare)
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Effects of Ethinylestradiol and the fungicide Prochloraz on metamorphosis and thyroid gland morphology in Rana temporaria.
- 2010
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Ingår i: The Open Zoology Journal. ; 3, s. 7-16
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Several environmental xenobiotics have been found to affect the metamorphosis of amphibians. In this study we exposed tadpoles of the Common frog Rana temporaria from hatching to metamorphosis to two known endocrine disruptors, the estrogenic pharmaceutical 17?-ethinylestradiol and the antiandrogenic/antiestrogenic fungicide Prochloraz to determine their effect on 1) days to metamorphosis and size at metamorphosis, 2) body concentrations of triiodothyronine (T3) and corticosterone, and 3) thyroid morphology. We found effects of both compounds on each of these response variables. A low dose of prochloraz (115 μg/l) and all doses of ethinylestradiol also caused a delay in metamorphosis. T3 levels were elevated in metamorphs exposed to high concentration of prochloraz (252 μg/l) but the group showed a delay in metamorphosis. A low dose of prochloraz (115 μg/l) and all doses of ethinylestradiol also caused a delay in metamorphosis but no changes in T3 levels. The delayed metamorphs weighed more than controls. Thyroid histology revealed significant differences in the high prochloraz exposure group only. Ethinylestradiol and prochloraz,however not in environmentally relevant doses, may therefore impact the thyroid axis, and may cause other sublethal effects especially in combination with other stressors likely encountered.
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| 3. |
- Brande-Lavridsen, Nanna, et al.
(författare)
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Effects of prochloraz and ethinylestradiol on sexual development in Rana temporaria.
- 2008
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Ingår i: Journal of Experimental Zoology. Part A. - : Wiley. - 1932-5223 .- 1932-5231. ; 309:7, s. 389-98
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Tidskriftsartikel (refereegranskat)abstract
- A wide range of environmental xenobiotics that mimic hormones (endocrine-disrupting chemicals) may cause alterations in sexual development or reproductive function in aquatic organisms such as amphibians when exposed during early sensitive stages. We exposed tadpoles of the Common frog, Rana temporaria, from hatch to metamorphosis, to two different endocrine disruptors, the synthetic estrogen 17 alpha-ethinylestradiol and the fungicide prochloraz. The object of the study was to assess the effects of these two compounds on the sexual development of the tadpoles by investigating sex ratio, gonadal development, sex steroid concentrations and vitellogenin induction. Histology revealed that a large percentage of all groups were juvenile hermaphrodites at metamorphosis. Tadpoles exposed to 115 and 251 microg/L prochloraz showed a significant increased proportion of males. However, the testosterone concentrations were depressed in those groups. Ethinylestradiol in concentrations of 77 and 159 ng/L EE(2) increased whole-body calcium levels in a dose-dependent manner indicating induction of the egg yolk protein vitellogenin, verified also by gel electrophoresis. The study shows that ethinylestradiol may induce vitellogenesis and prochloraz may affect the sexual development in Common frogs.
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| 4. |
- Morthorst, Jane Ebsen, et al.
(författare)
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17β-estradiol causes abnormal development in embryos of the viviparous eelpout
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:24, s. 14668-14676
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Tidskriftsartikel (refereegranskat)abstract
- Elevated frequencies of malformations among the offspring of Baltic eelpout (Zoarces viviparus) have been observed in aquatic environments receiving high anthropogenic input suggesting that manmade chemicals could be the causative agent. However, causal links between exposure to chemicals and abnormal development have never been confirmed in laboratory experiments. The purpose of this study was to investigate if exposure to 17β-estradiol (E2) causes abnormal development in larvae of the viviparous eelpout. Wild female eelpout were collected immediately after fertilization and exposed to E2 concentrations ranging from 5.7 to 133 ng L-1 for six weeks in a flow through test system. The experiment shows that E2 concentrations of 53.6 and 133 ng L-1 cause severe abnormal development among eelpout embryos. Reduced amount of ovarian fluid and increased weight of the ovarian sac indicate disturbance of ovarian function. Female plasma concentrations of E2 and vitellogenin increase in a monotonic concentration-response relationship with significant induction in the low concentration range. Our findings support the plausibility that the abnormal development among eelpout embryos encountered in monitoring programs may actually be caused by exposure to chemicals in the environment.
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