The Experts below are selected from a list of 378 Experts worldwide ranked by ideXlab platform
Bodil Korsgaard - One of the best experts on this subject based on the ideXlab platform.
-
17β-Estradiol Causes Abnormal Development in Embryos of the Viviparous Eelpout
2015Co-Authors: Jane E. Morthorst, Bodil Korsgaard, Nanna Brande-lavridsen, Poul BjerregaardAbstract: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 6 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
-
evidence of small modulation of ethinylestradiol induced effects by concurrent exposure to trenbolone in male eelpout Zoarces viviparus
Environmental Pollution, 2013Co-Authors: Yohana M Velascosantamaria, Poul Bjerregaard, Bodil KorsgaardAbstract:Abstract The interaction of xenobiotics is common in aquatic ecosystems; therefore, we wanted to evaluate if trenbolone (TB) modulates the effects of 17α-ethinylestradiol (EE2). Male eelpout ( Zoarces viviparus ) were exposed to 5 ng L −1 EE2 continuously for 19 d (EE2-C) or discontinuously (11 d, EE2-D) alone or in combination with low (50 ng L −1 , TBL) or high (500 ng L −1 , TBH) concentrations of TB (19 d). Exposure to EE2 caused reduced gonadosomatic index, increased plasma vitellogenin concentrations, up-regulated vtg and era mRNA expression and severe alterations in gonadal histology. TBL and TBH did not affect plasma vitellogenin, era or vtg mRNA expression. TBL and TBH did not counteract the EE2-induced increase in plasma vitellogenin and reduction in 11-ketotestosterone whereas TBH counteracted the EE2 induced increase in vtg and era mRNA expression. Exposure to TBH and EE2-C + TBH lead to severe gonadal histology alterations. TBL and EE2-D + TBH exposed fish showed less histopathological alterations.
-
effects of exposure to the xenoestrogen octylphenol and subsequent transfer to clean water on liver and gonad ultrastructure during early development of Zoarces viviparus embryos
Journal of Experimental Zoology, 2010Co-Authors: Ase Jespersen, Tina H Rasmussen, Majken Hirche, Kristine Johanne Kurstein Sorensen, Bodil KorsgaardAbstract:Female eelpouts (Zoarces viviparus L.) are exposed during early pregnancy to nominal concentrations of 100 µg/L of 4-tert-octylphenol (OP) or 0.5 µg/L of 17β-estradiol (E2). Effects on maternal metabolism and on liver and gonad development in embryos were examined and compared with controls (C) during exposure and after transfer to clean water (depuration). In the mother fish, significantly higher concentrations of plasma vitellogenin (vtg) and calcium were found in the two exposed groups, when compared with the C group after exposure and depuration. When compared, however, with the respective values after exposure, vtg had decreased significantly after depuration. The hepatosomatic index was normalized after depuration. In both exposed groups, the hepatocytes were rounded and not distinctly polygonal as in the controls. The amount of glycogen was considerably less while the number of mitochondria increased, and the rER significantly proliferated after exposure as well as after depuration. The gonads of nine of more than 28 embryos in the group treated with OP exhibited a number of abnormalities as compared with the normal gonad development in both sexes. Feminization of the male gonads in the exposed specimens and a number of histopathological features were observed in all the abnormal gonads, whereas reliable male features, such as formation of seminiferous tubules or spermioduct, were not observed. This study showed that 4t-tert-OP and 17β-estradiol exert estrogenic effects during very early development of the embryos and that depuration had a positive effect on the motherfish and her embryos. J. Exp. Zool. 313A:399–409, 2010. © 2010 Wiley-Liss, Inc.
-
gonadal alterations in male eelpout Zoarces viviparus exposed to ethinylestradiol and trenbolone separately or in combination
Marine Environmental Research, 2010Co-Authors: Yohana M Velascosantamaria, Poul Bjerregaard, Bodil KorsgaardAbstract:Abstract To evaluate the interaction between 17β-trenbolone (TB) and 17α-ethinylestradiol (EE2) in relevant environmental concentrations, male eelpout Zoarces viviparus were exposed in a flow-through seawater-system for 21 days to 5 ng l −1 EE2, 5 ng l −1 or 20 ng l −1 TB or to combinations of both compounds. The effects on hepatosomatic index (HSI), gonadosomatic index (GSI) and gonadal histology were studied. No significant effects on HSI were observed in any treatment; in contrast, decreased GSI was observed in males exposed to EE2 alone or in combination with TB compared to controls ( p p −1 TB compared to control ( p > 0.05). This study shows that EE2 dramatically disrupts the spermatogenesis and low doses of 17β-trenbolone are unable to effectively counteract the morphological effects of EE2.
-
effects of 17β trenbolone in male eelpout Zoarces viviparus exposed to ethinylestradiol
Analytical and Bioanalytical Chemistry, 2010Co-Authors: Yohana M Velascosantamaria, Poul Bjerregaard, Steffen S Madsen, Bodil KorsgaardAbstract:To evaluate the interaction between 17β-trenbolone (TB) and 17α-ethinylestradiol (EE2), male eelpout, Zoarces viviparus, was exposed for 21 days (April to May 2008) to 5 ng l−1 EE2 and 5 or 20 ng l−1 TB, separately or in combination in a flow-through SW system. The effects on hepatosomatic (HSI) and gonadosomatic index (GSI), plasma vitellogenin (Vtg) concentration, gonadal histology, hepatic and testicular Vtg mRNA and estrogen receptor (ERα) mRNA expression were investigated. No effects on HSI were observed. A significant decrease was observed in the GSI of all males exposed to EE2 ( 300-fold), hepatic Vtg mRNA (>450-fold), and ERα mRNA (>100-fold) when compared to controls. This study shows that lower concentrations of 17β-trenbolone are unable to counteract the EE2 estrogenic effects when the exposure is simultaneous.
Sakae Tsuda - One of the best experts on this subject based on the ideXlab platform.
-
hypothermic preservation effect on mammalian cells of type iii antifreeze proteins from notched fin eelpout
Cryobiology, 2008Co-Authors: Yu Hirano, Yoshiyuki Nishimiya, Shuichiro Matsumoto, Michiaki Matsushita, Satoru Todo, Ai Miura, Yasuo Komatsu, Sakae TsudaAbstract:Antifreeze proteins (AFPs) can bind to the surface of ice crystals and have also been suggested to protect cells from hypothermic damage. The present study reports that type III AFPs from notched-fin eelpout, Zoarces elongatus Kner, can protect cells during hypothermic storage. This fish naturally expresses at least 13 isoforms of type III AFP (denoted NfeAFPs), the primary sequences of which were categorized into SP- and QAE-Sephadex binding groups (SP- and QAE-isoforms). We compared the preservation ability between the extracted isoform mixtures (NfeAFPs) and a recombinant single SP-isoform (RcNfeAFP6). Experiments were performed using cultivated mammalian cells (HepG2) exposed to 4 degrees C for 24-72 h. The preserved cells were evaluated by measuring LDH released, intracellular ATP, and WST-8 reduction. It appeared that the protective effect of the 2 samples increases dose-dependently at concentrations between 2 and 10 mg/ml. Under highest soluble amount of the protein (approximately 10 mg/ml), cell viability significantly improved compared with the ordinary preservation fluid (P<0.01). This effect was larger with NfeAFPs than with RcNfeAFP6 at the same concentration. The successful hypothermic preservation of cells using natural NfeAFPs may have a wide range of applications for cell engineering and clinical medical care.
-
co operative effect of the isoforms of type iii antifreeze protein expressed in notched fin eelpout Zoarces elongatus kner
FEBS Journal, 2005Co-Authors: Yoshiyuki Nishimiya, Ai Miura, Sakae Tsuda, Ryoko Sato, Manabu TakamichiAbstract:We found that Notched-fin eelpout, which lives off the north east coast of Japan, expresses an antifreeze protein (AFP). The liver of this fish contains DNAs that encode at least 13 type III AFP isoforms (denoted nfeAFPs). The primary sequences of the nfeAFP isoforms were categorized into SP- and QAE-sephadex binding groups, and the latter were further divided into two subgroups, QAE1 and QAE2 groups. Ice crystals observed in HPLC-pure nfeAFP fractions are bipyramidal in shape with different ratios of c and a axes, suggesting that all the isoforms are able to bind ice. We expressed five recombinant isoforms of nfeAFP and analyzed the thermal hysteresis (TH) activity of each as a function of protein concentration. We also examined the change in activity on mixing the isoforms. TH was estimated to be 0.60 °C for the QAE1 isoform, 0.11 °C for QAE2, and almost zero for the SP isoforms when the concentrations of these isoforms was standardized to 1.0 mm. Significantly, the TH activity of the SP isoforms showed concentration dependence in the presence of 0.2 mm QAE1, indicating that the less active SP isoform becomes ‘active’ when a small amount of QAE1 is added. In contrast, it does not become active on the addition of another SP isoform. These results suggest that the SP and QAE isoforms of type III AFP have different levels of TH activity, and they accomplish the antifreeze function in a co-operative manner.
Jean Clobert - One of the best experts on this subject based on the ideXlab platform.
-
Permanent genetic resources added to Molecular Ecology Resources Database 1 October 2011-30 November 2011.
Molecular Ecology Resources, 2012Co-Authors: . Molecular Ecology Resources Editorial Office, Aluana G Abreu, A. Albaina, Tilman J Alpermann, Vanessa E Apkenas, S. Bankhead-dronnet, Sara Bergek, Michael L Berumen, Chang-hung Cho, Jean ClobertAbstract:This article documents the addition of 139 microsatellite marker loci and 90 pairs of single-nucleotide polymorphism sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Aglaoctenus lagotis, Costus pulverulentus, Costus scaber, Culex pipiens, Dascyllus marginatus, Lupinus nanus Benth, Phloeomyzus passerini, Podarcis muralis, Rhododendron rubropilosum Hayata var. taiwanalpinum and Zoarces viviparus. These loci were cross-tested on the following species: Culex quinquefasciatus, Rhododendron pseudochrysanthum Hay. ssp. morii (Hay.) Yamazaki and R. pseudochrysanthum Hayata. This article also documents the addition of 48 sequencing primer pairs and 90 allele-specific primers for Engraulis encrasicolus.
Lars Forlin - One of the best experts on this subject based on the ideXlab platform.
-
Persistent organic pollutants and related biological responses measured in coastal fish using chemical and biological screening methods
2017Co-Authors: Zhanna Tairova, Lars Forlin, Anders Bignert, Jens Gercken, Thomas Lang, Jakob Strand, Rossana Bossi, Martin M. Larsen, Jenny Hedman, Nicolai F. FrickeAbstract:The aim of this study was to investigate the spatial distribution, levels of dioxin-like compounds (DLC), and biological responses in two fish species. The viviparous eelpout (Zoarces viviparus) was collected from various locations in the Baltic Sea and in fjords of Kattegat and Skagerrak, while shorthorn sculpin (Myoxocephalus scorpius) was obtained at the polychlorinated biphenyl (PCB) polluted site in North West Greenland. Significant differences were detected both in contaminant levels and relative contributions from either polychlorinated dibenzodioxins (PCDD) or polychlorinated dibenzofurans (PCDF or furans) and mono-ortho- and non-ortho (coplanar) polychlorinated biphenyls (dl-PCB). Fish from the eastern Baltic Sea generally displayed higher contributions from PCDD/F compared to dl-PCB, whereas dl-PCB were generally predominated in fish from Danish, Swedish, and German sites. Levels of dl-PCB in muscle tissues were above OSPAR environmental assessment criteria (EAC) for PCB118, indicating a potential risk of adverse biological effects in the ecosystem, whereas levels of the total WHO-TEQs were below threshold for sea food suggesting limited risks for humans. No significant relationships between levels of DLC (expressed as WHO-TEQ), and biological responses such as the induction of CYP1A enzymatic activity and fry reproductive disorders were observed in eelpout. No marked relationship between WHO-TEQ and combined biological aryl hydrocarbon receptor-mediated transactivity (expressed as AhR-TEQ) was noted. However, there was a positive correlation between polycyclic aromatic hydrocarbon (PAH) metabolites and induction of CYP1A activity, suggesting that PAH exhibited greater potential than DLC to produce biological effects in eelpout from the Baltic Sea.
-
effects of the brominated flame retardants hexabromocyclododecane hbcdd and tetrabromobisphenol a tbbpa on hepatic enzymes and other biomarkers in juvenile rainbow trout and feral eelpout
Aquatic Toxicology, 2004Co-Authors: D Ronisz, Farmen E Finne, H Karlsson, Lars ForlinAbstract:Brominated flame retardants (BFRs) leak out in the environment, including the aquatic one. Despite this, sublethal effects of these chemicals are poorly investigated in fish. In this study, a screening of selected biomarkers in juvenile rainbow trout (Oncorhynchus mykiss) and feral eelpout (Zoarces viviparus) was performed after exposure to hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA). Rainbow trout was injected intraperitoneally (i.p.) with HBCDD or TBBPA. Two out of four short-term experiments with HBCDD showed an increase in the activity of catalase. A 40% increase in liver somatic index (LSI) could be observed after 28 days. HBCDD did also seem to have an inhibitory effect on CYP1A's activity (ethoxyresorufin-O-deethylase (EROD)). A putative peroxisome proliferating activity of the compound was investigated without giving a definite answer. HBCDD did not seem to be estrogenic or genotoxic. TBBPA increased the activity of glutathione reductase (GR) after 4, 14 and 28 days in rainbow trout suggesting a possible role of this compound in inducing oxidative stress. The compound did not seem to be estrogenic. TBBPA seemed to compete with the artificial substrate ethoxyresorufin in vitro, during the EROD assay. In eelpout, only one 5 days in vivo experiment was performed. Neither of the compounds gave rise to any effect in this fish. This was the first screening of sublethal effects of the two chemicals in fish, using high doses. Our results indicate that there is a need for further studies of long-term, low-dose effects of these two widely used flame retardants.
-
Male-biased sex ratios of fish embryos near a pulp mill: Temporary recovery after a short-term shutdown
2002Co-Authors: D. Joakim G. Larsson, Lars ForlinAbstract:In a previous study we showed that broods from the viviparous eelpout (Zoarces viviparus) were significantly male biased in 1998 in the vicinity of a large kraft pulp mill on the Swedish Baltic coast. One suggested hypothesis was that masculinizing compounds in the effluent were affecting gonadal differentiation of the embryos, resulting in skewed sex ratios. In this article, we present further evidence for a causal relationship between the exposure to the effluent and the malebiased sex ratios. Analyses of historical samples showed that the eelpout produced male-biased broods close to the mill in 1997 in addition to 1998. During 1999, the mill was shut down for 17 days, coinciding with the period when the gonads of the eelpout embryos differentiate. Subsequently, in the fall of 1999, the sex ratios were no longer male biased; however, the following year (2000), a significant male bias reappeared. Investigations at 13 sites for up to 4 years showed a relatively stable sex ratio around 50/50, with the exceptions by the mill and with few observations of deviating ratios at other sites. Several reports document endocrine disturbances in fish near pulp and paper mills, including the expression of male secondary sex characters in female fish. The repeatedly identified male bias at the investigated mill, the normalization after mill shutdown, and the reappearance the following year indicate that pulp mill effluents also can affect sex ratios of nearby fish. Key words: androgenic, endocrine disruptors, gonadal differentiation, masculinization, ovary, testis. Environ Health Perspect 110:739–742 (2002). [Onlin
-
interaction of isosafrole β naphthoflavone and other cyp1a inducers in liver of rainbow trout oncorhynchus mykiss and eelpout Zoarces viviparus
Comparative Biochemistry and Physiology Part C: Pharmacology Toxicology and Endocrinology, 1998Co-Authors: D Ronisz, Lars ForlinAbstract:The CYP1A enzyme in liver of rainbow trout (Oncorhynchus mykiss) and eelpout (Zoarces viviparus) was induced by intraperitoneal injections of isosafrole (ISF), beta-naphthoflavone (BNF), retene, 3,3',4,4'-tetrachlorobiphenyl (TCB), Clophen A50 and combinations of these compounds. The livers were sampled 5 days after injection and the microsomal fraction was used to measure the activity of CYP1A (as ethoxyresorufin-O-deethylase (EROD)) and the level of the enzyme (measured semiquantitatively as absorbance using enzyme-linked immunosorbant assay (ELISA)). Induction of CYP1A above the additive effect was observed when ISF was given together with BNF or retene. It was suggested that ISF may stabilize the enzyme or its mRNA or that ISF metabolites inhibit CYP1A processing of BNF and retene, thus increasing the effective doses of these compounds in fish liver. The results indicate a need for further studies of interactions between different CYP1A inducers in fish and a comparison of CYP1A response between different fish species. These results may have implications for the use of CYP1A induction in fish as a biomarker in aquatic systems, since a high EROD activity could be due not only to the presence of one potent inducer, but to synergistic effects of two or more inducers at low concentrations.
-
Temporal aspects of induction of hepatic cytochrome P450 1A and conjugating enzymes in the viviparous blenny (Zoarces viviparus) treated with petroleum hydrocarbons
Aquatic Toxicology, 1994Co-Authors: Malin Celander, Dag Broman, Lars ForlinAbstract:The heavy gas oil fraction of distilled North Sea crude oil was intraperitoneally injected into the marine teleost viviparous blenny (Zoarces viviparus). The effects were compared with those of the model inducer, β-naphthoflavone (β-NF), on the hepatic cytochrome P450 1A (P450 1A or CYP 1A) system and on conjugating enzymes in a time course study over 14 days. The injection of heavy gas oil resulted in temporal responses in P450 1A protein content and P450 1A catalytic activity similar to those obtained with β-NF, although differences existed in terms of their effects on CYP1A1 mRNA levels and on the total P450 content. In contrast to β-NF, heavy gas oil had no effect on UDP-glucuronosyltransferase, glutathione S-transferase and glutathione reductase activities. GC-MS analyses of pooled bile, the major route of excretion of organic hydrocarbons, of viviparous blenny treated with heavy gas oil revealed that besides naphthalene the bile also contained polycyclic aromatic hydrocarbons (PA11s) such as phenanthrenes, anthracene, pyrenes, fluoranthene, benzo(a)anthracene and chrysene. None of these compounds were detected in bile from control fish, with the only exception of 3-methylphenanthrene. This study indicates the usefulness of the P450 1A system in the viviparous blenny as a sensitive biomarker in monitoring studies in petroleum oil contaminated areas in Northern Europe.
. Molecular Ecology Resources Editorial Office - One of the best experts on this subject based on the ideXlab platform.
-
Permanent genetic resources added to Molecular Ecology Resources Database 1 October 2011-30 November 2011.
Molecular Ecology Resources, 2012Co-Authors: . Molecular Ecology Resources Editorial Office, Aluana G Abreu, A. Albaina, Tilman J Alpermann, Vanessa E Apkenas, S. Bankhead-dronnet, Sara Bergek, Michael L Berumen, Chang-hung Cho, Jean ClobertAbstract:This article documents the addition of 139 microsatellite marker loci and 90 pairs of single-nucleotide polymorphism sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Aglaoctenus lagotis, Costus pulverulentus, Costus scaber, Culex pipiens, Dascyllus marginatus, Lupinus nanus Benth, Phloeomyzus passerini, Podarcis muralis, Rhododendron rubropilosum Hayata var. taiwanalpinum and Zoarces viviparus. These loci were cross-tested on the following species: Culex quinquefasciatus, Rhododendron pseudochrysanthum Hay. ssp. morii (Hay.) Yamazaki and R. pseudochrysanthum Hayata. This article also documents the addition of 48 sequencing primer pairs and 90 allele-specific primers for Engraulis encrasicolus.
