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  • 1. Abrahamson, Alexandra
    et al.
    Andersson, Carin
    Jönsson, Maria E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Fogelberg, Oscar
    Orberg, Jan
    Brunstrom, Bjorn
    Brandt, Ingvar
    Gill EROD in monitoring of CYP1A inducers in fish - A study in rainbow trout (Oncorhynchus mykiss) caged in Stockholm and Uppsala waters2007In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 85, no 1, 1-8 p.Article in journal (Refereed)
  • 2.
    Abrahamson, Alexandra
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Andersson, Carin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Jönsson, Maria E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Fogelberg, Oscar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Örberg, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Brunström, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Gill EROD in monitoring of CYP1A inducers in fish: A study in rainbow trout (Oncorhynchus mykiss) caged in Stockholm and Uppsala waters2007In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 85, no 1, 1-8 p.Article in journal (Refereed)
    Abstract [en]

    The gill filament 7-ethoxyresorufin O-deethylase (EROD) assay was evaluated as a monitoring tool for waterborne cytochrome P4501 A (CYP1A) inducers using rainbow trout (Oncorhynchus mykiss) caged in urban area waters in Sweden. To compare the CYP1A induction response in different tissues, EROD activity was also analyzed in liver and kidney microsomes. Immunohistochemistry was used to localize CYP1A protein in gill and kidney. In two separate experiments fish were caged at sites with fairly high expected polyaromatic hydrocarbon (PAH) contamination. In the first experiment, gill EROD activities were analyzed in fish exposed for 1-21 days in a river running through Uppsala. The reference site was upstream of Uppsala. In the second, gill, liver and kidney EROD activities were analyzed in fish exposed for 1-5 days in fresh or brackish waters of Stockholm and in a reference lake 60 km north of Stockholm. Fish exposed for 5 days followed by 2 days of recovery in tap water in the laboratory were also examined. The gill consistently showed a higher EROD induction compared with the liver and the kidney. After I day of caging, gill EROD activity was markedly induced (6-17-fold) at all sites examined. Induction in gill was pronounced (5-7-fold) also in fish caged at the reference sites. In the 21-day exposure study gill EROD activity remained highly induced throughout the experiment (26-fold at most) and the induced CYP1A protein was exclusively confined to the gill secondary lamellae. In the 5-day exposure experiment, EROD activity peaked after I day and then declined in both gill and liver, while CYP1A immunostaining in the gill remained intense over the 5-day period. In the kidney, CYP1A staining was weak or absent. We conclude that gill EROD activity is a more sensitive biomarker of exposure to waterborne CYP1A inducers than EROD activity in liver and kidney.

  • 3.
    Andersson, Carin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Katsiadaki, Ioanna
    Lundstedt-Enkel, Katrin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Örberg, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Effects of 17α-ethynylestradiol on EROD activity, spiggin and vitellogenin in three-spined stickleback (Gasterosteus aculeatus)2007In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 83, no 1, 33-42 p.Article in journal (Refereed)
    Abstract [en]

    The three-spined stickleback (Gasterosteus aculeatus) has quantifiable biomarkers of exposure to estrogens (vitellogenin), androgens (spiggin) and aryl hydrocarbon receptor (AhR) agonists (EROD activity) and is therefore a promising test species for biomonitoring of reprotoxic chemicals in aquatic environments. In this study we evaluated the effects of 17α-ethynylestradiol (EE2) on EROD activity, induction of vitellogenin and spiggin, hepatosomatic index (HSI), ovarian somatic index (OSI) and nephrosomatic index (NSI). Adult male and female three-spined sticklebacks were exposed to concentrations of 0–170 ng EE2/l (measured concentrations) in a flow-through system for 21 days. Exposure to 170 ng EE2/l resulted in a significant 8- and 9-fold induction of gill EROD activity in males and females, respectively. In livers, EROD activity expressed in relation to microsomal protein content was suppressed due to a significant increase in microsomal protein content. Hepatic EROD activity per se expressed as picomol/min was not affected by exposure to EE2. The lowest observed effect concentration for induction of vitellogenin in males was 53.7 ng EE2/l. In females, vitellogenin levels were significantly higher in those exposed to170 ng EE2/l compared to controls. Spiggin production was significantly inhibited and NSI lower in males exposed to 170 ng EE2/l. In both females and males LSI was significantly higher in fish exposed to 170 ng EE2/l than in controls. In females exposed to 170 ng EE2/l, OSI was significantly lower and NSI higher than controls. The observed results from this study show that a synthetic estrogen can affect the well-known biomarker of exposure for dioxin-like compounds, EROD activity, and further that this response can differ between tissues. These findings are important for interpretation of biomonitoring data.

  • 4. Behrendt, Lars
    et al.
    Jonsson, Maria E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Goldstone, Jared V.
    Stegeman, John J.
    Induction of cytochrome P450 1 genes and stress response genes in developing zebrafish exposed to ultraviolet radiation2010In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 98, no 1, 74-82 p.Article in journal (Refereed)
  • 5.
    Behrendt, Lars
    et al.
    Woods Hole Oceanographic Institution.
    Jönsson, Maria E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Environmental Toxicology.
    Goldstone, Jared V.
    Woods Hole Oceanographic Institution.
    Stegeman, John J.
    Woods Hole Oceanographic Institution.
    Induction of cytochrome P450 1 genes and stress response genes in developing zebrafish exposed to ultraviolet radiation2010In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 98, no 1, 74-82 p.Article in journal (Refereed)
    Abstract [en]

    Ultraviolet (UV) radiation damages cell molecules, and has been suggested to up-regulate mammalian cytochrome P4501 (CYP1) genes through an aryl hydrocarbon receptor (AHR) mediated mechanism. In this study, embryos and larvae of zebrafish (Danio rerio) were exposed to UV to determine the effects on expression of CYP1 and stress response genes in vivo in these fish. Zebrafish embryos were exposed for varying times to UV on two consecutive days, with exposure beginning at 24 and 48h post-fertilization (hpf). Embryos exposed for 2, 4 or 6h twice over 2 days to UVB (0.62 W/m(2); 8.9-26.7 kJ/m(2)) plus UVA (2.05 W/m(2); 29.5-144.6 kJ/m(2)) had moderately (2.4+/-0.8-fold) but significantly up-regulated levels of CYP1A. UVA alone had no effect on CYP1A expression. Proliferating cellular nuclear antigen (PCNA) and Cu-Zn superoxide dismutase (SOD1) transcript levels were induced (2.1+/-0.2 and 2.3+/-0.5-fold, respectively) in embryos exposed to two 6-h pulses of 0.62 W/m(2) UVB (26.8 kJ/m(2)). CYP1A was induced also in embryos exposed to higher intensity UVB (0.93 W/m(2)) for two 3-h or two 4-h pulses (20.1 or 26.8 kJ/m(2)). CYP1B1, SOD1 and PCNA expression was induced by the two 3-h pulses of the higher intensity UVB, but not after two 4-h pulses of the higher intensity UVB, possibly due to impaired condition of surviving embryos, reflected in a mortality of 34% at that UVB dose. A single 8-h long exposure of zebrafish larvae (8dpf) to UVB at 0.93 W/m(2) (26.8 kJ/m(2)) significantly induced CYP1A and CYP1B1 expression, but other CYP1 genes (CYP1C1, CYP1C2 and CYP1D1) showed no significant increase. The results show that UVB can induce expression of CYP1 genes as well stress response genes in developing zebrafish, and that UVB intensity and duration influence the responses.

  • 6.
    Beijer, Kristina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Abrahamson, Alexandra
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Brunström, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    CYP1A inhibition in fish gill filaments: a novel assay applied on pharmaceuticals and other chemicals2010In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 96, no 2, 145-150 p.Article in journal (Refereed)
    Abstract [en]

    The gill filament 7-ethoxyresorufin O-deethylase (EROD) assay was originally developed as a biomarker for cytochrome P4501A (CYP1A) induction by Ah-receptor agonists in water. In this study, the assay was adapted to measure inhibition of CYP1A activity in fish gill filaments ex vivo. The experiments were carried out using gill arch filaments from beta-naphthoflavone (betaNF)-exposed three-spined stickleback (Gasterosteus aculeatus). Candidate CYP1A inhibitors were added to the assay buffer. Nine selected pharmaceuticals and five known or suspected CYP1A-modulating chemicals were examined with regard to their ability to reduce EROD activity in gill filaments. Ellipticine, a well characterized CYP1A inhibitor, was the most effective inhibitor of the compounds tested. At a concentration in the assay buffer of 1 microM the antifungal azoles ketoconazole, miconazole and bitertanol, and the plant flavonoid acacetin reduced gill EROD activity by more than 50%, implying IC50 values below 1 microM. These compounds have previously been shown to inhibit EROD activity in liver microsomes from fish and mammals at similar concentrations. The proton pump inhibitor omeprazole reduced the gill EROD activity by 39% at 10 microM. It is concluded that the modified gill filament EROD assay is useful to screen for waterborne pollutants that inhibit catalytic CYP1A activity in fish gills.

  • 7.
    Bernabó, Ilaria
    et al.
    Department of Animal Biology, University of Calabria, Italy.
    Brunelli, Elivra
    Department of Animal Biology, University of Calabria, Italy.
    Berg, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Bonacci, Antonella
    Department of Animal Biology, University of Calabria, Italy.
    Tripepi, Sandro
    Department of Animal Biology, University of Calabria, Italy.
    Endosulfan acute toxicity in Bufo bufo gills: ultrastructural changes and nitric oxide synthase localization2008In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 86, no 3, 447-456 p.Article in journal (Refereed)
    Abstract [en]

    Endosulfan is an organochlorine pesticide used in agriculture for a wide range of crops. Endosulfan concentrations of up to 0.7 mg/L can be found in ponds and streams near sprayed agricultural fields. We investigated the short-term toxicity of endosulfan in common toad (Bufo bufo) tadpoles after 24, 48, and 96 h of exposure. Acute toxicity was evaluated at nominal concentrations ranging from 0.01 to 0.6 mg/L: concentrations that could be found after the application of pesticide. Our results show that 0.43 mg/L of endosulfan caused 50% mortality (LC(50)). The effects of a sublethal endosulfan concentration (0.2mg/L) on gill apparatus morphology were evaluated by scanning and transmission electron microscopy. Immunohistochemical methods were also applied to detect the expression pattern of the inducible isoform of nitric oxide synthase (iNOS) in the gills using the confocal laser scanner microscope. Exposure to 0.2mg/L of endosulfan caused an apparent increase in mucus production, the occurrence of secretory vesicles and lamellar bodies, a widening of intercellular spaces and additionally there was evidence of an inflammatory response in the gill apparatus. The morphological alterations occurred after 24h and were more pronounced after 48 and 96 h of exposure. Altered morphology and increased mucus secretion indicate impaired gas exchange and osmoregulation in the gills. In addition, there was an increase of iNOS expression after 24 and 48 h which may reflect hypoxia and inflammation in the gill epithelium. Our results clearly indicate that short-term exposure to a sublethal concentration of endosulfan, near the high end of the environmental range, disrupts gill morphology and function in B. bufo tadpoles.

  • 8.
    Brunelli, Elvira
    et al.
    Department of Animal Biology, University of Calabria, Italy.
    Bernabó, Ilaria
    Department of Animal Biology, University of Calabria, Italy.
    Berg, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Lundstedt-Enkel, Katrin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Bonacci, Antonella
    Department of Animal Biology, University of Calabria, Italy.
    Tripepi, Sandro
    Department of Animal Biology, University of Calabria, Italy.
    Environmentally Relevant Concentrations of Endosulfan Impair Development, Metamorphosis and Behaviour in Bufo bufo Tadpoles2009In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 91, no 2, 135-142 p.Article in journal (Refereed)
    Abstract [en]

    Endosulfan is a widely used organochlorine pesticide with well-documented neurotoxic effects in both humans and laboratory animals (mammals and fish). Neurotoxicity has been implied also in amphibians after short-term exposure to endosulfan. Little is known about effects of chronic exposure of endosulfan in amphibians. Previously, we examined the short-term toxicity of endosulfan in common toad (Bufo bufo) tadpoles and determined the LC50 value to 0.43 mg/L. In the present study, we investigated the effects of endosulfan on B. bufo tadpoles after chronic exposure to ecologically relevant concentrations. Tadpoles were exposed in a static renewal test, from shortly after hatching (Gosner stage 25) to completed metamorphosis, to 0.01, 0.05 and 0.1 mg endosulfan/L (nominal). The exposure period lasted 43–52 days. Mortality, larval growth (mass), development (reached Gosner stage at various times and deformities presence), metamorphosis and behaviour (swimming activity) were monitored regularly over the entire course of larval development. Our results show that 0.05 and 0.1 mg endosulfan/L caused impaired behaviour, prolonged time to metamorphosis, increased incidences of mouth and skeletal malformations as well as mortality, and reduced body weight (observed also at 0.01 mg/L) in B. bufo tadpoles. Behavioural effects occurred at exposure day 4, before any other effects occurred, indicating a neurotoxic effect. Endosulfan levels found in groundwater and surface water range from 0.1 to 100 μg/L and after extraordinary runoff events, concentrations exceed 0.5 mg/L in surface water.

  • 9. Ewald, G
    et al.
    Sundin, Peter
    Skramstad, J
    Froyen, P
    Distribution of C-14 from ingested, radiolabelled dichlorostearic, stearic and oleic acids in body and in lipids of perch, Perca fluviatilis1996In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 36, no 1-2, 129-139 p.Article in journal (Refereed)
  • 10.
    Gyllenhammar, Irina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Eriksson, Hanna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Söderqvist, Anneli
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Lindberg, Richard
    Department of Chemistry, Umeå University.
    Fick, Jerker
    Department of Chemistry, Umeå University.
    Berg, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Clotrimazole exposure modulates aromatase activity in gonads and brain during gonadal differentiation in Xenopus tropicalis frogs2009In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 91, no 2, 102-109 p.Article in journal (Refereed)
    Abstract [en]

    Clotrimazole is a pharmaceutical used for treatment of fungal infections. It has been found in surface waters outside municipal wastewater treatment plants but data are scarce regarding its effects on aquatic organisms. It is known that clotrimazole and other imidazole fungicides are inhibitors of the enzyme aromatase (CYP 19). Aromatase converts androgens into estrogens and is suggested to be involved in the sex differentiation in amphibians. The aim of the present study was to evaluate effects of larval exposure to clotrimazole on aromatase activity in brain and gonads, and on gonadal differentiation in Xenopus tropicalis frogs. Another purpose was to determine if larval exposure to ethynylestradiol (EE(2)), at a concentration known to cause male-to-female sex reversal, affects aromatase activity in brain and gonads during gonadal differentiation. Tadpoles were exposed from shortly after hatching (Nieuwkoop and Faber developmental stages 47-48) until complete metamorphosis (NF stage 66) to 6, 41, and 375 nM clotrimazole or 100 nM (nominal) EE(2). Aromatase activity was measured in the brain and gonad/kidney complex of tadpoles during gonadal differentiation (NF stage 56) and, in the clotrimazole experiment, also at metamorphosis. In clotrimazole-exposed tadpoles gonadal aromatase activity increased over exposure time in the 41 and 375 nM groups but did not differ significantly from the control group. Gonadal aromatase activity was increased in both sexes exposed to 41 and 375 nM clotrimazole at metamorphosis. Brain aromatase activity was decreased in tadpoles (NF stage 56) exposed to 375 nM clotrimazole, but at metamorphosis no differences were seen between groups or between sexes. No effects of clotrimazole on sex ratio or gonadal histology were noted at completed metamorphosis. EE(2)-exposed tadpoles had a slightly decreased gonadal aromatase activity, though not significantly different from control group, and there was no effect of EE(2) on brain aromatase activity. All EE(2)-exposed tadpoles developed ovaries. These findings indicate that estrogen-induced ovarian differentiation is not paralleled by increased gonadal aromatase activity in X. tropicalis. Further studies are needed, especially on developmental reproductive toxicity, to assess the risk for endocrine disruption in wild amphibians posed by clotrimazole and other imidazole fungicides.

  • 11.
    Gyllenhammar, Irina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Holm, Lena
    Institutionen för anatomi och fysiologi, SLU.
    Eklund, Rosita
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Berg, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Reproductive Toxicity in Xenopus tropicalis after Developmental Exposure to Environmental Concentrations of Ethynylestradiol2009In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 91, no 2, 171-178 p.Article in journal (Refereed)
    Abstract [en]

    Reproductive disorders in wildlife and humans have been linked to developmental exposure to endocrine disrupting chemicals. In frog tadpoles, environmental concentrations of ethynylestradiol (EE2) disrupt gonadal differentiation which results in female-biased sex ratios at metamorphosis indicating sex-reversal of genotypic males. It is not known if developmental exposure to estrogens results in reduced reproductive success in amphibians. The objective of this work was to investigate if exposure to environmentally relevant concentrations of EE2 during sex differentiation impairs reproductive organ development, fertility, and sexual behavior in adult frogs. A specific aim was to evaluate if testicular structure and function was affected in males that were not sex-reversed. Xenopus tropicalis tadpoles were exposed until metamorphosis to 6, 60, and 600 pM EE2. Eight months after metamorphosis, reproductive organ morphology and fertility were evaluated. Larval EE2-exposure caused an increased proportion of phenotypic females indicating that sex-reversal of genotypic males is persistent. Sex-reversal was implied at concentrations as low as 6 pM (1.8 ng/l), which is comparable to levels observed in the environment. EE2-exposed males that were not sex-reversed had a significantly reduced fertilization rate compared with control males. Histological evaluation revealed that EE2-exposed males had a reduced amount of spermatozoa in the testis. Among frogs with ovaries there was a significantly higher percentage that lacked oviducts in the group exposed to 600 pM EE2 compared with control females. No effect of EE2 on sexual behavior was noted. The results indicate that reproduction in wild frogs might be impaired by estrogenic environmental pollutants. Similarities between the present effects and those reported in fish, birds and mammals after developmental exposure to estrogens suggest that X. tropicalis is a promising animal model for research on developmental reproductive toxicity.

  • 12. Haldén, A Norman
    et al.
    Arnoldsson, K
    Haglund, P
    Mattsson, A
    Ullerås, E
    Sturve, J
    Norrgren, L
    Retention and maternal transfer of brominated dioxins in zebrafish (Danio rerio) and effects on reproduction, aryl hydrocarbon receptor-regulated genes, and ethoxyresorufin-O-deethylase (EROD) activity.2011In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 102, no 3-4, 150-61 p.Article in journal (Refereed)
    Abstract [en]

    Brominated dioxins have recently been detected in Baltic Sea biota. Due to their similarities to the highly toxic chlorinated dioxins, concern has been raised about their potential biological effects. The present study investigated retention and effects of brominated dioxins in adult zebrafish, as well as maternal transfer and effects on offspring. We exposed adult zebrafish for nine weeks via feed to 2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD) or to a mixture of brominated dioxins (Baltic Sea mixture), which was designed to reflect relative concentrations found in Baltic Sea biota. We studied spawning success, gonad morphology, hepatic vitellogenin gene expression, and offspring early life-stage development to investigate effects on zebrafish reproduction. Hepatic ethoxyresorufin-O-deethylase (EROD) activity and hepatic expression of a number of aryl hydrocarbon receptor (AHR)-regulated genes were studied to investigate if the brominated dioxins can activate gene transcription through the AHR pathway in zebrafish. In addition, glutathione reductase activity and expression of genes involved in adaptive responses to intracellular stress were studied to investigate potential stress effects of brominated dioxins. After nine weeks of exposure, all brominated dioxins spiked to the feed were detected in female fish and transferred to eggs. Exposure to the Baltic Sea mixture and TBDD clearly induced AHR-regulated genes and EROD activity. Exposure to TBDD reduced spawning success, altered ovarian morphology and reduced hepatic vitellogenin gene expression, which implies that TBDD has a similar effect pattern as the chlorinated analogue. Overall, our results show that dietary exposure to sublethal concentrations of brominated dioxins may impair reproductive physiology in fish and induce AHR-regulated genes.

  • 13. Hernroth, Bodil
    et al.
    Baden, Susanne P
    Holm, Kristina
    André, Tove
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. j.
    Söderhäll, Irene
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. jämförande fysiologi.
    Manganese induced immune suppression of the lobster, Nephrops norvegicus2004In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 70, no 3, 223-231 p.Article in journal (Refereed)
    Abstract [en]

    Manganese (Mn) is one of the most abundant elements on earth, particularly in the soft bottom sediments of the oceans. As a micronutrient Mn is essential in the metabolic processes of organisms. However, at high concentrations the metal becomes a neurotoxin with well-documented effects. As a consequence of euthrophication, manganese is released from bottom sediments of coastal areas and the Norway lobsters, Nephrops norvegicus, can experience high levels of bioavailable Mn2+. Here, we present the first report showing that Mn also affects several fundamental processes in the mobilisation and activation of immunoactive haemocytes. When N. norvegicus was exposed to a realistic [Mn2+] of 20 mg l(-1) for 10 days 24.1 mug ml(-1) was recorded in the haemolymph. At this concentration the total haemocyte count was reduced by ca. 60%. By using BrdU as a tracer for cell division, it was shown that the proliferation rate in the haematopoietic tissue did not increase, despite the haemocytepenia. A gene coding for a Runt-domain protein, known to be involved in maturation of immune active haemocytes in a variety of organisms, was identified also in haemocytes of N. norvegicus. The expression of this gene was >40% lower in the Mn-exposed lobsters as judged by using a c DNA probe and the in situ hybridisation technique. In response to non-self molecules, like lipopolysaccharide, (LPS), the granular haemocytes of arthropods are known to degranulate and thereby release and activate the prophenoloxidase, system, necessary for their immune defence. A degranulation assay, tested on isolated granular haemocytes, showed about 75% lower activity in the Mn-exposed lobsters than that for the unexposed. Furthermore, using an enzymatic assay, the activation per se of prophenoloxidase by LPS was found blocked in the Mn-exposed lobsters. Taken together, these results show that Mn exposure suppressiA fundamental immune mechanisms of Norway lobsters. This identifies a potential harm that also exists for other organisms and should be considered when increasing the distribution of bioavailable Mn, as has been done through recently introduced applications of the metal.

  • 14. Holbech, Henrik
    et al.
    Schröder, Kristoffer D
    Nielsen, Marie L
    Brande-Lavridsen, Nanna
    Holbech, Bente Frost
    Bjerregaard, Poul
    Estrogenic effect of the phytoestrogen biochanin A in zebrafish, Danio rerio, and brown trout, Salmo trutta.2013In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 144-145, 19-25 p.Article in journal (Refereed)
    Abstract [en]

    UNLABELLED: Isoflavones with estrogenic activity produced in Fabaceae plants are known to leach from agricultural areas to freshwater systems, but the effect of waterborne isoflavones in fish has not been thoroughly characterized. Therefore, the estrogenic effect of waterborne biochanin A was investigated in zebrafish (Danio rerio) and juvenile brown trout (Salmo trutta). Exposure of juvenile brown trout to 10 μg biochanin AL(-1) or higher caused marked vitellogenin induction after 9-10 days of exposure and so did exposure to 186 μg biochanin AL(-1) for 6h. Following 8d of exposure, a NOEC for induction of vitellogenin production in male zebrafish was 70 and LOEC 114 μg biochanin AL(-1). Exposure to 209 μg biochanin AL(-1) from hatch to 60 days post hatch (dph) caused a skewing of the sex ratio toward more phenotypic female zebrafish, but did not cause induction of vitellogenin in male and undifferentiated fish.

    IN CONCLUSION: (1) biochanin A elicits estrogenic effects in trout at environmentally realistic concentrations, (2) brown trout plasma vitellogenin concentrations respond to lower biochanin A exposure concentrations than vitellogenin concentrations in zebrafish homogenates and (3) concerning vitellogenin induction, the hypothesis should be tested if short term tests with zebrafish may show a higher sensitivity than partial life cycle tests.

  • 15.
    Jaensson, Alia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Department of Environmental Toxicology.
    Olsén, K. Håkan
    Södertörns University.
    Prolonged cypermthrin exposure increases sex steroid plasma hormone levels in mature male brown trout (Salmo trutta) parr in spawning groupsIn: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514Article in journal (Refereed)
  • 16.
    Jaensson, Alia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Scott, Alexander
    Moore, Andrew
    Kylin, Henrik
    Olsén, K. Håkan
    Effects of a pyrthroid pesticide on endocrine reponses to female odour and reproductive behaviour in male parr of brown trout (Salmo trutta)2007In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 81, no 1, 1-9 p.Article in journal (Refereed)
    Abstract [en]

    Reproductive behaviour of brown trout (Salmo trutta L.) from an anadromous stock was studied in a large stream water aquarium. Four adult males and two ovulated females were placed in the aquarium together with eight mature male parr. Four of the parr were exposed during the previous 4 days to two concentrations (0.1 or 1.0 μg l−1) of the pyrethroid pesticide cypermethrin (a disrupter of olfactory receptor function) and four of the parr to the solvent ethanol. The behaviour of all fish was followed for 24 h and then blood and milt was collected. Exposure to the higher concentration of cypermethrin disturbed the reproductive behaviour of the parr. They displayed fewer courting events, spent less time near the nesting females and had lower volumes of strippable milt. They also had significantly lower amounts of 11-ketotestosterone (11-KT) in the blood plasma than the control group. The higher cypermethrin group also had significantly lower levels of all these variables than the lower cypermethrin group, apart from strippable milt that showed no significant differences between two groups. No significant differences in non-reproductive behaviours were observed between any of the groups. In the control fish, there were significant positive correlations between (a) the number of courting events and the amount of time spent near the female, (b) blood plasma levels of 17α,20β-dihydroxy-4-pregnen-3-one (17,20β-P) and time spent near the female and (c) plasma levels of 17,20β-P and the number of courting events. Further, in control fish, higher plasma levels of 17,20β-P were observed in parr interacting with a female compared to those with no female contacts. A priming experiment confirmed a previous study that cypermethrin damages olfactory reception. Parr exposed to cypermethrin had significantly lower blood plasma levels of 17,20β-P and 11-KT than control males after exposure to ovarian fluid and urine (known to contain reproductive priming pheromones). When ethanol-exposed males were exposed to ovarian fluid and urine they had significantly higher plasma levels of 17,20β-P compared to those exposed to water only.

  • 17.
    Jonsson, Maria E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Brunstrom, Bjorn
    Brandt, Ingvar
    The zebrafish gill model: Induction of CYP1A, EROD and PAH adduct formation2009In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 91, no 1, 62-70 p.Article in journal (Refereed)
  • 18.
    Jönsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Abrahamson, Alexandra
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Brunström, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Cytochrome P4501A induction in rainbow trout gills and liver following exposure to waterborne indigo, benzo(a)pyrene and 3,3',4,4',5-pentachlorobiphenyl2006In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 79, no 3, 226-232 p.Article in journal (Refereed)
    Abstract [en]

    We have developed a gill-filament based ethoxyresorufin O-deethylase (EROD) assay to be used as a tool to monitor cytochrome P4501A (CYP1A) induction in caged fish. The present study aimed to compare temporal patterns of EROD induction in gills and liver of rainbow trout (Oncorhynchus mykiss) exposed in the laboratory to readily metabolized and persistent CYP1A inducers, i.e. indigo, benzo[a]pyrene (BaP), and 3,3',4,4',5-pentachlorobiphenyl (PCB#126). Branchial and hepatic EROD activities were examined in fish exposed for 6, 12, or 24h and in fish exposed for 24h and then held in clean water for 2 or 14 days. Furthermore, branchial CYP1A protein expression was localized by immunohistochemistry. All compounds strongly induced branchial EROD activity within 6 h. The highest EROD inductions observed for indigo, BaP, and PCB#126 were roughly similar in gills (52-, 76-, and 74-fold), but differed considerably in liver (11-, 78-, and 200-fold). In indigo- and BaP-exposed fish, both hepatic and branchial EROD activities decreased rapidly in clean water. In PCB#126-exposed fish, decreased branchial and increased hepatic EROD activities were observed following transfer to clean water. The substances gave rise to immunostaining for CYP1A at different cellular sites. All inducers increased the CYP1A-immunostaining in the gill filament secondary lamellae, but PCB#126 also induced a pronounced CYP1A immunoreactivity in cells near the basal membrane of the epithelium of the primary lamellae. The observation that the low BaP and indigo concentrations induced EROD activity markedly in the gills but only slightly or not at all in the liver, supports the contention that readily metabolized AhR agonists may escape detection when hepatic EROD activity is used for environmental monitoring. The results show that gill filament EROD activity is a sensitive biomarker both for persistent and readily metabolized AhR agonists in polluted water.

  • 19.
    Jönsson, Maria E
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Brunström, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    The zebrafish gill model: induction of CYP1A, EROD and PAH adduct formation2009In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 91, no 1, 62-70 p.Article in journal (Refereed)
    Abstract [en]

    Zebrafish (Danio rerio) is a common model species in fish toxicology, and the zebrafish gill is potentially useful in screening waterborne pollutants. We have previously developed a gill-based ethoxyresorufin-O-deethylase (EROD) assay, and proposed gill EROD activity as a biomarker for exposure to waterborne aryl hydrocarbon receptor (AHR) agonists. In this study we modified the gill EROD assay for use in zebrafish. We used immunohistochemistry to localize CYP1A induction, and microautoradiography to localize irreversible binding of the prototypic polycyclic aromatic hydrocarbon, 7,12-dimethylbenz[a]anthracene (DMBA) in zebrafish gills. Gill filament and liver microsomal EROD activities were measured after waterborne exposure of zebrafish and rainbow trout to benzo[a]pyrene (BaP) or beta-naphthoflavone (betaNF). The results showed considerably lower relative EROD induction by betaNF (1microM) in zebrafish than in rainbow trout, both in gills (13-fold versus 230-fold compared to control) and in liver (5-fold versus 320-fold compared to control). The induced hepatic EROD activity was similar in the two species, whereas the basal activity was considerably higher in zebrafish than in rainbow trout. In zebrafish gills, betaNF enhanced DMBA adduct formation and CYP1A immunostaining. Ellipticine blocked DMBA adduct formation and EROD activity following betaNF exposure but had no effect on CYP1A immunostaining. A notable finding was that the localization of DMBA adducts differed from that of CYP1A protein in betaNF-induced fish; CYP1A immunoreactivity was evenly distributed in the gills whereas DMBA adduction was confined to the leading edges of the filaments and the gill rakers, i.e., structures being highly exposed to DMBA-containing inhaled water. The results show that the modified method is suitable for determination of gill EROD activity in zebrafish, although rainbow trout seems more sensitive. They also imply that the sites of DMBA adduct formation in zebrafish gills are markedly influenced by kinetic factors.

  • 20.
    Jönsson, Maria E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Carlsson, Carina
    Smith, Richard W.
    Part, Peter
    Effects of copper on CYP1A activity and epithelial barrier properties in the rainbow trout gill2006In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 79, no 1, 78-86 p.Article in journal (Refereed)
  • 21.
    Jönsson, Maria E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Carlsson, Carina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Smith, Richard W.
    Pärt, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Effects of copper on CYP1A activity and epithelial barrier properties in the rainbow trout gill2006In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 79, no 1, 78-86 p.Article in journal (Refereed)
    Abstract [en]

    The effects of copper on P-naphthoflavone (beta NF)-induced ethoxyresorufin O-deethylase (EROD) activity were studied in rainbow trout (Oncorhynchus mykiss) gill filaments (after in vivo exposure) and in gill cells cultured as both primary cultures and as polarised epithelia, i.e. with water in the apical compartment and culture medium in the basolateral compartment. In the in vivo study beta NF and copper were added to the water, in primary cultures both chemicals were added to the culture medium and in cultured epithelia copper was added to the apical water whilst beta NF was added to the basolateral culture medium. In primary cultures this investigation was repeated with and without foetal bovine serum (FBS) supplementation of the culture media. Gill barrier properties, specifically polyethylene glycol (PEG-4000) permeability (i.e. paracellular permeability), sodium efflux and transepithelial electrical resistance (TER) were also investigated in cultured gill cell epithelia after apical treatment with copper. Two micromolar copper had no effect on EROD activity in gill filaments in vivo irrespective of whether EROD was induced by 0.01, 0.1 or 1.0 mu M beta NF Similarly, 0.5-100 mu M copper had no effect on EROD induction in cultured epithelia. In primary cultures copper did reduce EROD induction but the effective concentration was dependent on whether the cells were supplemented with FBS, i.e. EROD activity was reduced by all copper concentrations of 5 and above if FBS was included, but only by 1000 mu M if FBS was omitted. In cultured epithelia PEG-4000 permeability increased, whilst sodium efflux and TER were unaffected following treatment with 75 mu M copper. Based on these results we conclude that the branchial monooxygenase system is a less sensitive target for copper than the barrier properties of the gill. Indeed, these data suggest the apical membrane of the gill epithelial cells minimises the uptake of waterborne copper and therefore protects the intracellular environment, including the CYP1A system. This could enable the freshwater fish gill to retain their potential of first-pass metabolism of waterborne organic compounds whilst simultaneously being exposed to waterborne copper.

  • 22.
    Jönsson, Maria E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Gao, Kai
    Olsson, Jan A.
    Goldstone, Jared V.
    Brandt, Ingvar
    Induction patterns of new CYP1 genes in environmentally exposed rainbow trout2010In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 98, no 4, 311-321 p.Article in journal (Refereed)
  • 23.
    Jönsson, Maria E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Environmental Toxicology.
    Gao, Kai
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Environmental Toxicology.
    Olsson, Jan A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Environmental Toxicology.
    Goldstone, Jared V
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Environmental Toxicology.
    Induction patterns of new CYP1 genes in environmentally exposed rainbow trout2010In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 98, no 4, 311-321 p.Article in journal (Refereed)
    Abstract [en]

    The cytochrome P4501 (CYP1) gene family comprises four subfamilies in fish: CYP1A, CYP1B, CYP1C, and CYP1D. Only two CYP1 genes, CYP1A1 and CYP1A3, are so far known in rainbow trout (Oncorhynchus mykiss). The present study aimed to identify other CYP1 subfamily genes in rainbow trout, to establish methods for quantitative mRNA expression analysis of these genes, and to determine their basal and induced mRNA expression in gills and liver. Another goal was to examine their mRNA expression in environmentally exposed fish. We cloned four new transcripts, denoted rbCYP1B1, rbCYP1C1, rbCYP1C2, and rbCYP1C3. Levels of these and the previously known rbCYP1A transcripts were determined by real-time PCR in unexposed fish, fish exposed to the potent aryl hydrocarbon receptor (AhR) agonist 3,3',4,4',5-pentachlorobiphenyl (PCB126), and fish caged in various waters in the Uppsala region (Sweden). The mRNA expression patterns observed in unexposed rainbow trout (basal levels) were markedly similar to those reported for orthologous genes in other species. All six transcripts were induced by PCB126 in gills and liver, suggesting all genes to be AhR regulated. The caged fish showed clear rbCYP1 induction in gills at all monitoring sites (up to 70-fold the basal level), whereas the liver responses were weak; induction (up to 5-fold) was recorded only at the Uppsala municipal sewage treatment plant outlet. Gill filament EROD activity was induced at all caging sites. Most interestingly, the rbCYP1 gene response patterns in gills differed among caging sites and among subfamilies. The EROD induction seemed to only reflect induction of rbCYP1A transcription. Response patterns of multiple CYP1 genes in gills and liver could provide an improved monitoring strategy. Such patterns could be used to characterize complex mixtures of AhR agonists and antagonists in aquatic environments.

  • 24.
    Kellner, Martin
    et al.
    Sodertorn Univ, Sch Nat Sci Technol & Environm Studies, Sodertorn, Sweden.
    Porseryd, Tove
    Sodertorn Univ, Sch Nat Sci Technol & Environm Studies, Sodertorn, Sweden.
    Hallgren, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Porsch-Hällström, Inger
    Sodertorn Univ, Sch Nat Sci Technol & Environm Studies, Sodertorn, Sweden.
    Hansen, S.H.
    Univ Copenhagen, Fac Hlth & Med Sci, Dept Pharm, DK-1168 Copenhagen, Denmark.
    Olsén, K. Håkan
    Sodertorn Univ, Sch Nat Sci Technol & Environm Studies, Sodertorn, Sweden.
    Waterborne citalopram has anxiolytic effects and increases locomotor activity in the three-spine stickleback (Gasterosteus aculeatus)2016In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 173, 19-28 p.Article in journal (Refereed)
    Abstract [en]

    Citalopram is an antidepressant drug, which acts by inhibiting the re-uptake of serotonin from the synaptic cleft into the pre-synaptic nerve ending. It is one of the most common drugs used in treatment of depression, it is highly lipophilic and frequently found in sewage treatment plant effluents and surface waters around the world. Citalopram and other selective serotonin re-uptake inhibitors have, at concentrations that occur in nature, been shown to have behavioural as well as physiological effects on fish and other animals. This study is the result of several different experiments, intended to analyse different aspects of behavioural effects of chronic citalopram exposure in fish. Our model species the three-spine stickleback is common in the entire northern hemisphere and is considered to be a good environmental sentinel species. Female three-spine sticklebacks were exposed to 0, 1.5 and 15 μg/l nominal concentrations of citalopram for 21 days and subjected to the novel tank (NT) diving test. In the NT test, the fish exposed to 1.5 μg/l, but not the 15 μg/l fish made a significantly higher number of transitions to the upper half and stayed there for significantly longer time than the fish exposed to 0 μg/l. The 15 μg/l group, however, displayed a significantly lower number of freeze bouts and a shorter total freezing time. The test for locomotor activity included in the NT test showed that fish treated with 1.5 and 15 μg/l displayed a significantly higher swimming activity than control fish both 5–7 and 15–17 minutes after the start of the experiment. In the next experiment we compared fish exposed to 1.5 μg/l and 0.15 μg/l to pure water controls with regard to shoaling intensity and found no effect of treatment. In the final experiment the propensity of fish treated with 1.5 μg/l to approach an unknown object and aggressive behaviour was investigated using the Novel Object test and a mirror test, respectively. The exposed fish ventured close to the unknown object significantly more often and stayed there for significantly longer time than unexposed fish. The aggression test yielded no statistically significant effects. It is concluded that citalopram changes the behaviour of the three-spine stickleback in a way that is likely to have ecological consequences and that it must not be considered an environmentally safe pharmaceutical.

  • 25.
    Kunce, Warren
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Stoks, Robby
    Univ Leuven, Lab Aquat Ecol Evolut & Conservat, Leuven, Belgium..
    Johansson, Frank
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Single and mixture impacts of two pyrethroids on damselfly predatory behavior and physiological biomarkers2017In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 190, 70-77 p.Article in journal (Refereed)
    Abstract [en]

    Direct mortality due to toxicity of single pesticide exposure along a concentration gradient, while the most common, is only one important parameter for assessing the effects of pesticide contamination on aquatic ecosystems. Sub-lethal toxicity can induce changes in an organism's behavior and physiology that may have population -level ramifications and consequences for ecosystem health. Additionally, the simultaneous detection of multiple contaminants in monitored watersheds stresses the importance of gaining a greater understanding of the toxicities of combined exposures, particularly at low, environmentally relevant concentrations. Using larvae of the Azure Damselfly (Coenagrion paella), we conducted a combined exposure investigation of two widely-used pyrethroid insecticides presumed to share the same neurotoxic mechanism of action, and estimated their effect on predatory ability, mobility and three physiological biomarkers (Glutathione S-transferase; GST, respiratory electron transport system; ETS, and malondialdehyde; MDA). Deltamethrin exposure (0.065 mu g/L and 0.13 mu g/L) was found to reduce the predatory ability, but it did not affect the larvae's mobility. Esfenvalerate exposure (0.069 mu g/L and 0.13 mu g/L), on the other hand, induced no significant changes in predatory ability or mobility. The decrease in predatory ability after the combination exposure (0.067 mu g/L deltamethrin and 0.12 mu g/L. esfenvalerate) did not significantly differ from the impact of the single deltamethrin exposures. Glutathione-S-transferase was induced after single esfenvalerate exposure and the lower deltamethrin concentration exposure, but seemingly inhibited after exposure to the higher concentration of deltamethrin as well as the combination of both pyrethroids. Our data indicate that sub-lethal exposure to deltamethrin reduces predatory ability and suggest that sub-lethal combined exposure to deltamethrin and esfenvalerate inhibits the GST detoxification pathway. These effects can eventually result in a lower emergence of adults from contaminated ponds.

  • 26.
    Kvarnryd, Moa
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Grabic, Roman
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Berg, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
    Early life progestin exposure causes arrested oocyte development, oviductal agenesis and sterility in adult Xenopus tropicalis frogs2011In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 103, no 1-2, 18-24 p.Article in journal (Refereed)
    Abstract [en]

    Levonorgestrel (LNG) is a commonly used pharmaceutical progestin found in the environment. Information on the long-term toxicity of progestins following early life exposure is scant. We investigated the effects of developmental LNG exposure on sex differentiation, reproductive organ development and fertility in the model frog Xenopus tropicalis. Tadpoles were exposed to 0, 0.06 or 0.5 nM LNG via the water from hatching until metamorphosis. At metamorphosis effects on gonadal differentiation were evaluated using a subsample of frogs. Remaining animals were held unexposed for nine months, at which time reproductive organ structure, function and fertility were determined. LNG exposure severely impaired oviduct and ovary development and fertility. All adult females in the 0.5 nM group (n = 10) completely lacked oviducts. They also displayed a significantly larger fraction of immature oocytes, arrested in meiotic prophase, than control females. Upon mating with unexposed males, only one of 11 LNG-exposed females laid eggs, whereas all control females did. No effects on testicular development, sperm count or male fertility were observed. At metamorphosis, no effects on sex ratio or gonadal histology were evident. The effects on ovarian and oviductal development were detected at adult age but not at metamorphosis, emphasising the importance of investigating the long-term consequences of developmental exposure. This is the first developmental reproductive toxicity study of a progestin in an aquatic vertebrate. Considering that several progestins are present in contaminated surface waters, further investigation into the sensitivity of frogs to progestins is warranted to understand the risk such compounds may pose to wild frog populations.

  • 27.
    Olsén, Håkan
    et al.
    Södertörns Högskola.
    Ask, Katarina
    Södertörns Högskola.
    Olsén, Hanna
    Södertörns Högskola.
    Porsh-Hällström, Inger
    Södertörns Högskola.
    Hallgren, Stefan
    Södertörns Högskola.
    Effects of the SSRI citalopram on behaviours connected to stress and reproduction in Endler guppy, Poecilia wingei.2014In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 148, 113-121 p.Article in journal (Refereed)
  • 28. Oweson, Carolina
    et al.
    Li, Chenghua
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology.
    Söderhäll, Irene
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology.
    Hernroth, Bodil
    Effects of manganese and hypoxia on coelomocyte renewal in the echinoderm, Asterias rubens (L.)2010In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 100, no 1, 84-90 p.Article in journal (Refereed)
    Abstract [en]

    Manganese (Mn) is a naturally abundant metal and particularly so in soft-bottom oceanic sediments where it generally occurs bound in a four-valent colloidal state as MnO2. When hypoxic conditions occur in bottom waters, the metal reduces to the bioavailable ion Mn2+ and can reach concentrations known to have immunotoxic effects in the crustacean Nephrops norvegicus, reducing numbers of circulating haemocytes as a consequence. However, we have previously shown that Mn seems to have a contrasting effect on the echinoderm Asterias rubens in which it triggers the proliferation of haematopoietic cells and increases coelomocyte numbers. Since elevated Mn levels mostly co-occur with hypoxia in nature, here we investigated whether hypoxia has a negative effect on haematopoiesis. Proliferation and differentiation of coelomocytes and cells in the coelomic epithelium of A. rubens were compared after 3 days of exposure to realistic levels of Mn, hypoxia or a combination of these two parameters. We can confirm that Mn elevated numbers of coelomocytes and increased proliferation of epithelial cells, but hypoxia did not affect these levels. However, hypoxia did affect differentiation of these cells as judged by investigating the expression of a Runt domain transcription factor, which was also cloned and sequenced. Through comparative quantification using a real time PCR technique, we found that exposure to hypoxia had a clearly stimulating effect on mRNA expression of Runt gene in both coelomocytes and epithelial cells. These results indicate that during hypoxic conditions the composition of coelomocyte sub-populations changed.

  • 29.
    Pettersson, Irina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Arukwe, Augustine
    Lundstedt-Enkel, Katrin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Mortensen, Anne
    Berg, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Physiology and Developmental Biology, Environmental Toxicology.
    Persistent sex-reversal and oviducal agenesis in adult Xenopus (Silurana) tropicalis frogs following larval exposure to the environmental pollutant ethynylestradiol2006In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 79, no 4, 356-365 p.Article in journal (Refereed)
    Abstract [en]

    It is known that estrogen-like environmental pollutants can feminise gonadal differentiation in frogs resulting in female-biased sex-ratios at metamorphosis. The long-term effects on reproductive function in frogs following larval exposure to pollutants are less known. Amphibian test systems which allow life-cycle studies are therefore needed. The aim of the present study was to characterise long-term estrogenic effects on the reproductive system of the emerging model species Xenopus (Silurana) tropicalis following larval exposure to ethynylestradiol (EE2). EE2 is a synthetic estrogen that has been detected in sewage effluents and in surface waters. Newly hatched tadpoles (Niewkoop Faber (NF) stage 48) were exposed to the nominal EE2 concentrations 0 (control), 1, 10, and 100 nM (with analytical chemistry support) until complete metamorphosis (NF stage 66). Effects on the reproductive organs were determined in juveniles (I month after metamorphosis) and in 9-month-old frogs. Larval exposure to EE2 caused female-biased phenotypic sex-ratios in both juvenile and adult frogs, which is in agreement with previous work on other frog species. Nearly all (97%) of the 63 EE2-exposed 9-month-old frogs had ovaries. Histological evaluation of the gonads of the 9-month-old frogs showed that they were sexually mature. Among the adult frogs with ovaries there was a dose-dependent increase in the frequency of individuals lacking oviducts. Adult frogs exposed to 100 nM EE2 that had ovaries but no oviducts had lower levels of estrogen receptor alpha (ER alpha) mRNA in the brain than control animals and those exposed to 100 nM EE2 that had ovaries as well as oviducts. EE2 exposure did not cause any significant changes in ER alpha mRNA levels in the ovaries of the adult frogs. The reduced level of ER alpha mRNA in the brain of individuals with ovaries lacking oviducts suggests an organizing effect of EE2 on the central nervous system. The results show that transient early life-stage exposure to an environmental pollutant can induce effects on the reproductive organs and the central nervous system that persist into adulthood. Overall, our data suggest that X. tropicalis, which has a shorter generation time than the well-established model species Xenopus laevis, is a suitable model organism for research on developmental reproductive toxicity in anuran species.

  • 30.
    Reyhanian, Nasim
    et al.
    Södertörns Högskola.
    Volkova, Kristina
    Södertörns Högskola.
    Hallgren, Stefan
    Södertörns Högskola.
    Bollner, Tomas
    Södertörns Högskola.
    Olsson, Per-Erik
    Örebro Universitet.
    Olsén, Håkan
    Södertörns Högskola.
    Porsch-Hällström, Inger
    Södertörns Högskola.
    17α-ethynyl estradiol affect anxiety and shoaling behavior in adult zebra fish (Danio rerio).2011In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 104, no 1-2, 41-48 p.Article in journal (Refereed)
    Abstract [en]

    Ethinyl estradiol is a potent endocrine disrupting compound in fish and ubiquitously present in the aquatic environment. In this study, we exposed adult zebra fish (Danio rerio) males to 0, 5 or 25 ng Ethinyl estradiol/L for 14 days and analyzed the effects on non-reproductive behavior. Effects of treatment of the exposed males was shown by vitellogenin induction, while brain aromatase (CYP 19B) activity was not significantly altered. Both concentrations of Ethinyl estradiol significantly altered the behavior in the Novel tank test, where anxiety is determined as the tendency to stay at the bottom when introduced into an unfamiliar environment. The effects were, however, opposite for the two concentrations. Fish that were exposed to 5 ng/L had longer latency before upswim, fewer transitions to the upper half and shorter total time spent in the upper half compared with control fish, while 25 ng Ethinyl estradiol treatment resulted in shorter latency and more and longer visits to the upper half. The swimming activity of 25, but not 5 ng-exposed fish were slightly but significantly reduced, and these fish tended to spend a lot of time at the surface. We also studied the shoaling behavior as the tendency to leave a shoal of littermates trapped behind a Plexiglas barrier at one end of the test tank. The fish treated with Ethinyl estradiol had significantly longer latency before leaving shoal mates and left the shoal fewer times. Further, the fish exposed to 5 ng/L also spent significantly less time away from shoal than control fish. Fertilization frequency was higher in males exposed to 5 ng/L Ethinyl estradiol when compared with control males, while no spawning was observed after treatment with 25 ng/L. The testes from both treatment groups contained a normal distribution of spermatogenesis stages, and no abnormality in testis morphology could be observed.

    In conclusion, we have observed effects on two behaviors not related to reproduction in zebra fish males after treatment with Ethinyl estradiol, adding to the ecological consequences of contamination of aquatic environments with estrogenic substances.

  • 31.
    Sebire, Marion
    et al.
    Cefas Weymouth Lab, Weymouth DT4 8UB, Dorset, England..
    Davis, Jessica Elphinstone
    Cefas Weymouth Lab, Weymouth DT4 8UB, Dorset, England..
    Hatfield, Robert
    Cefas Weymouth Lab, Weymouth DT4 8UB, Dorset, England..
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Katsiadaki, Ioanna
    Cefas Weymouth Lab, Weymouth DT4 8UB, Dorset, England..
    Prozac affects stickleback nest quality without altering androgen, spiggin or aggression levels during a 21-day breeding test2015In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 168, 78-89 p.Article in journal (Refereed)
    Abstract [en]

    Pharmaceuticals are increasingly being used in human and veterinary medicine, and their presence in the aquatic environment may present a threat to non-target aquatic organisms. The selective serotonin reuptake inhibitor fluoxetine (Prozac) has been reported to affect diverse behaviours (feeding, aggression, and reproduction) and also the endocrine system (steroid biosynthesis pathway) in fish. To investigate these claims further, and in particular effects on androgen synthesis, male three-spined sticklebacks (Gasterosteus aculeatus) were exposed to fluoxetine at 0, 3.2, 10 and 32 mu g/L in a flow-through system for 21 days. Their sex was determined prior to exposure using a non-invasive method to collect DNA for determining the genetic sex, reported here for the first time. This was necessary as the exposure required males of a non-breeding status which had not developed secondary characteristics. Post exposure a number of biochemical (serotonin, steroid and spiggin levels) and apical (aggressive behaviour) endpoints were measured. No effects were detected on morphometric parameters, spiggin or androgen (11-ketotestosterone) levels. However, all fluoxetine-exposed male fish had higher cortisol levels in comparison to the control fish, although this effect only persisted throughout the whole exposure duration at the highest concentration (32 mu g/L). In addition, the ratio of 5-HIAA/5-HT (serotonin metabolite/serotonin) was significantly lower in the brains of males exposed to fluoxetine at all concentrations tested. Although we found no differences in the number of nests built by the males, the quality of the nests produced by the fluoxetine-exposed males was generally inferior consisting only of a basic, rudimentary structure. Males exposed to 32 mu g/L of fluoxetine displayed a delayed response to a simulated threat (rival male via own mirror image) and were less aggressive (number of bites and attacks) toward their mirror image, but these differences were not statistically significant. In summary, fluoxetine exposure resulted in reduced serotonergic activity in the male three-spined stickleback brain suggesting that the mechanism of action between humans and fish is at least partially conserved. Furthermore, this study provided additional evidence of cross-talk between the serotonergic and stress axes as demonstrated by the perturbations in cortisol levels. This potentially complex interaction at brain level may be responsible for the effects observed on nest quality, an endpoint with serious ecological consequences for this species. Finally, despite our hypothesis (an effect on steroid biosynthesis, based on limited literature evidence), we observed no effects of fluoxetine exposure (at the concentrations and duration employed) on male stickleback androgen levels.

  • 32.
    Smith, R. W.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Blaney, S. C.
    Dowling, K.
    Sturm, A.
    Jonsson, M.
    Houlihan, D. F.
    Protein synthesis costs could account for the tissue-specific effects of sub-lethal copper on protein synthesis in rainbow trout (Oncorhynchus mykiss)2001In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 53, no 3-4, 265-277 p.Article in journal (Refereed)
  • 33.
    Strömqvist, Marie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Environmental Toxicology.
    Tooke, Nigel
    Brunström, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Environmental Toxicology.
    DNA methylation levels in the 5′ flanking region of the vitellogenin I gene in liver and brain of adult zebrafish (Danio rerio): Sex and tissue differences and effects of 17α-ethinylestradiol exposure2010In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 98, no 3, 275-281 p.Article in journal (Refereed)
    Abstract [en]

    Vitellogenin is produced in the liver of sexually mature female fish in response to endogenous estrogens. Exogenous estrogens also induce synthesis of vitellogenin in the liver of male and juvenile fish and vitellogenin is a frequently used biomarker for estrogen exposure. The epigenetic state, e.g. histone acetylation and DNA methylation, in the region of a gene or in its 5' flanking region influences the gene expression. DNA methylation positions in multicellular eukaryotes are mostly found on cytosine bases located 5' to guanine, i.e. in CpG sites. Here, we have for the first time analyzed the DNA methylation levels of three CpG sites located in the 5' flanking region of the vitellogenin I gene in liver and brain from adult zebrafish (Danio rerio) utilizing Pyrosequencing technology. This sequencing technique allows determination of methylation levels of multiple individual CpG sites. Our purpose was to assess any differences in methylation levels related to sex, tissue and exposure to estrogen. Out of the seven vitellogenin genes identified in the zebrafish, vitellogenin I is the most highly expressed during vitellogenesis. We found that the methylation levels of all three CpG sites were higher in male liver than in female liver. In brain, which does not express vitellogenin, females and males showed similar, high methylation levels in the analyzed CpG positions. Exposure of adult zebrafish to 17alpha-ethinylestradiol (100 ng/L) for 14 days decreased the methylation levels in the 5' flanking region of vitellogenin I in the liver in both females and males. These results suggest that induced expression of vitellogenin in fish following exposure to estrogens might involve alterations in DNA methylation.

  • 34.
    Svensson, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Fick, Jerker
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Brunström, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Environmental concentrations of an androgenic progestin disrupts the seasonal breeding cycle in male three-spined stickleback (Gasterosteus aculeatus)2014In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 147, 84-91 p.Article in journal (Refereed)
    Abstract [en]

    Synthetic steroid hormones from contraceptive pharmaceuticals have become global aquatic contaminants. Progestins, the synthetic analogs to progesterone, are receiving increasing attention as contaminants and have been shown to impair reproduction in fish and amphibians at low ng L-1 concentrations. Certain progestins, such as levonorgestrel have androgenic properties and seem to be several orders of magnitude more potent in terms of reproductive impairment in fish than non-androgenic progestins and progestagens. We recently reported that levonorgestrel has strong androgenic effects in female three-spined sticklebacks (Gasterosteus aculeatus), including induction of the normally male-specific glue protein spiggin and suppression of vitellogenesis. In light of this we investigated if exposure to levonorgestrel could disrupt the highly androgen-dependent seasonal reproductive cycle in male sticklebacks. Male sticklebacks that were in the final stage of a breeding period were exposed to various concentrations of levonorgestrel for six weeks in winter conditions in terms of light and temperature, after which reproductive status was evaluated from gross morphology, histology and key gene transcript levels. During the experimental period the controls had transitioned from full breeding condition into the non-breeding state, including regression of secondary sex characteristics, cessation of spiggin production in the kidney, and resumption of spermatogenesis in the testes. This is ascribed to the natural drop in plasma androgen levels after breeding. However, in the groups concurrently exposed to levonorgestrel, transition to the non-breeding condition was dose-dependently inhibited. Our results show that levonorgestrel can disrupt the seasonal breeding cycle in male sticklebacks. The fitness costs of such an effect could be detrimental to natural stickleback populations. Some effects occurred at a levonorgestrel concentration of 6.5 ng L-1, well within the range of levonorgestrel levels in surface waters and may therefore occur in progestin-contaminated waters. Furthermore, the effects by levonorgestrel in the present study were likely mediated mainly by its androgenic activity, and the low concentration at which they occurred makes levonorgestrel one of the most potent androgenic contaminants known.

  • 35.
    Svensson, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Mustafa, Arshi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Fick, Jerker
    Department of Chemistry, Umeå University, Linnaeus väg 6, Umeå, SE-90 187, Sweden.
    Schmitz, Monika
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Brunström, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Developmental exposure to progestins causes male bias and precocious puberty in zebrafish (Danio rerio)2016In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 177, 316-323 p.Article in journal (Other academic)
    Abstract [en]

    Progestins are aquatic contaminants that in low concentrations can impair fish reproduction. The mechanisms are likely multiple since different progestins interact with other steroid receptors in addition to progesterone receptors. Puberty is the process when animals first acquire the capability to reproduce and it comprises maturation of sperm and eggs. In zebrafish, puberty is initiated around 45 days post fertilization (dpf) in females and around 53-55 dpf in males, and is marked by increased production of pituitary gonadotropins. We exposed juvenile zebrafish from 20 to 80 dpf to the androgenic progestin levonorgestrel at concentrations of 5.5, 79 and 834 ng L-1 and to the non-androgenic progestin progesterone at concentrations of 3.7, 77 and 1122 ng L-1, during sexual differentiation and puberty. Levonorgestrel exposure caused 100% males even at the lowest concentration tested whereas progesterone did not affect the sex ratio. Transcript levels of the gonadal genes amh, CYP11B and CYP19a1a indicated that the masculinizing effect of levonorgestrel occurred very rapidly. Transcript concentrations of gonadotropins in pituitaries were low in control fish at 44 dpf, but high at 55 dpf and onward. In fish exposed to levonorgestrel or progesterone gonadotropin transcript concentrations were high already at 44 dpf, indicating that both progestins caused precocious puberty. Gonad histology at 50 dpf confirmed a well advanced sexual maturation, but only in males. Our results show that progestins can affect sexual development in fish and that the androgenic progestin levonorgestrel induces a male phenotype at concentrations similar to those detected in aquatic environments.

  • 36.
    Säfholm, Moa
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Jansson, Erika
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Fick, Jerker
    Berg, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Mixture effects of levonorgestrel and ethinylestradiol: Estrogenic biomarkers and hormone receptor mRNA expression during sexual programming2015In: Aquatic Toxicology, ISSN 0166-445X, E-ISSN 1879-1514, Vol. 161, 146-153 p.Article in journal (Refereed)
    Abstract [en]

    Synthetic progesterone (progestins) and estrogens are widely used pharmaceuticals. Given that their simultaneous unintentional exposure occurs in wildlife and also in human infants, data on mixture effects of combined exposures to these hormones during development is needed. Using the Xenopus (Silurana) tropicalis test system we investigated mixture effects of levonorgestrel (LNG) and ethinylestradiol (EE2) on hormone sensitive endpoints. After larval exposure to LNG (0.1 nM), or EE2 (0.1 nM) singly, or in combination with LNG (0.01, 0.1, 1.0 nM), the gonadal sex ratio was determined histologically and hepatic mRNA levels of genes encoding vitellogenin (vtg beta1) and the estrogen (esr1, esr2), progesterone (ipgr) and androgen (or) receptors were quantified using quantitative PCR. All EE2-exposed groups showed female-biased sex ratios and increased vtgbeta1 mRNA levels compared with the controls. Compared with the EE2-alone group (positive control) there were no significant alterations in vtg betal levels or in sex ratios in the co-exposure groups. Exposure to LNG-alone caused an increase in ar mRNA levels in females, but not in males, compared to the controls and the co-exposed groups, indicating that co-exposure to EE2 counteracted the LNG-induced or levels. No treatment related impacts on the mRNA expression of esr1, esr2, and ipgr in female tadpoles were found, suggesting that these endpoints are insensitive to long-term exposure to estrogen or progestin. Due to the EE2-induced female-biased sex ratios, the mRNA expression data for the low number of males in the EE2-exposed groups were not statistically analyzed. In conclusion, our results suggest that induced vtg expression is a robust biomarker for estrogenic activity in exposure scenarios involving both estrogens and progestins. Developmental exposure to LNG caused an induction of hepatic or mRNA expression that was antagonized by combined exposure to EE2 and LNG. To our knowledge this is the first study to report effects of combined exposures to EE2 and LNG during the period of sexual programming.

1 - 36 of 36
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