RESUMEN
Transgenic fish are powerful models that can provide mechanistic information regarding the endocrine activity of test chemicals. In this study, our objective was to use a newly developed transgenic zebrafish line expressing eGFP under the control of the cyp19a1a promoter in the OECD Fish Short Term Reproduction Assay (TG 229) to provide additional mechanistic information on tested substances. For this purpose, we exposed adult transgenic zebrafish to a reference substance of the TG 229, i.e. prochloraz (PCZ; 1.7, 17.2 and 172.6⯵g/L). In addition to "classical" endpoints used in the TG 229 (reproductive outputs, vitellogenin), the fluorescence intensity of the ovaries was monitored at 4 different times of exposure using in vivo imaging. Our data revealed that 172.6⯵g/L PCZ significantly decreased the number of eggs laid per female per day and the concentrations of vitellogenin in females, reflecting the decreasing E2 synthesis due to the inhibition of the ovarian aromatase activities. At 7 and 14 days, GFP intensities in ovaries were similar over the treatment groups but significantly increased after 21 days at 17.2 and 172.6⯵g/L. A similar profile was observed for the endogenous cyp19a1a expression measured by qPCR thereby confirming the reliability of the GFP measurement for assessing aromatase gene expression. The overexpression of the cyp19a1a gene likely reflects a compensatory response to the inhibitory action of PCZ on aromatase enzymatic activities. Overall, this study illustrates the feasibility of using the cyp19a1a-eGFP transgenic line for assessing the effect of PCZ in an OECD test guideline while providing complementary information on the time- and concentration-dependent effects of the compound, without disturbing reproduction of fish. The acquisition of this additional mechanistic information on a key target gene through in vivo fluorescence imaging of the ovaries was realized without increasing the number of individuals.
Asunto(s)
Animales Modificados Genéticamente , Aromatasa/genética , Disruptores Endocrinos/toxicidad , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Reproducción/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Proteínas de Pez Cebra/genética , Pez Cebra/genética , Animales , Animales Modificados Genéticamente/metabolismo , Femenino , Colorantes Fluorescentes , Proteínas Fluorescentes Verdes/genética , Guías como Asunto , Organización para la Cooperación y el Desarrollo Económico , Ovario/efectos de los fármacos , Ovario/metabolismo , Regiones Promotoras Genéticas , Reproducibilidad de los Resultados , Vitelogeninas/metabolismo , Pez Cebra/metabolismoRESUMEN
This study reports the use of the recently developed EASZY assay that uses transgenic cyp19a1b-GFP zebrafish (Danio rerio) embryos to assess in vivo estrogenic activity of 33 surface (SW) and waste water (WW) samples collected across Europe that were previously well-characterized for estrogen hormones and in vitro estrogenic activity. We showed that 18 out of the 33 SW and WW samples induced estrogenic responses in the EASZY assay leading to a significant and concentration-dependent up-regulation of the ER-regulated cyp19a1b gene expression in the developing brain. The in vivo 17ß-estradiol-equivalents (EEQs) were highly correlated with, both, the chemical analytical risk quotient (RQ) based on steroidal estrogen concentrations and EEQs reported from five different in vitro reporter gene assays. Regression analyses between the vitro and in vivo effect concentrations allowed us to determine an optimal cut-off value for each in vitro assay, above which in vivo responses were observed. These in vitro assay-specific effect-based trigger values (EBTs), ranging from 0.28 to 0.58â¯ng EEQ/L define the sensitivity and specificity of the individual in vitro assays for predicting a risk associated with substances acting through the same mode of action in water samples. Altogether, this study demonstrates the toxicological relevance of in vitro-based assessment of estrogenic activity and recommends the use of such in vitro/in vivo comparative approach to refine and validate EBTs for mechanism-based bioassays.
Asunto(s)
Embrión no Mamífero/efectos de los fármacos , Monitoreo del Ambiente/métodos , Estrógenos , Agua Dulce/análisis , Contaminantes Químicos del Agua , Animales , Bioensayo , Estradiol/análisis , Estradiol/toxicidad , Estrógenos/análisis , Estrógenos/toxicidad , Pruebas de Toxicidad , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad , Pez CebraRESUMEN
Comprehension of compound interactions in mixtures is of increasing interest to scientists, especially from a perspective of mixture risk assessment. However, most of conducted studies have been dedicated to the effects on gonads, while only few of them were. interested in the effects on the central nervous system which is a known target for estrogenic compounds. In the present study, the effects of estradiol (E2), a natural estrogen, and genistein (GEN), a phyto-estrogen, on the brain ER-regulated cyp19a1b gene in radial glial cells were investigated alone and in mixtures. For that, zebrafish-specific in vitro and in vivo bioassays were used. In U251-MG transactivation assays, E2 and GEN produced antagonistic effects at low mixture concentrations. In the cyp19a1b-GFP transgenic zebrafish, this antagonism was observed at all ratios and all concentrations of mixtures, confirming the in vitro effects. In the present study, we confirm (i) that our in vitro and in vivo biological models are valuable complementary tools to assess the estrogenic potency of chemicals both alone and in mixtures; (ii) the usefulness of the ray design approach combined with the concentration-addition modeling to highlight interactions between mixture components.
Asunto(s)
Aromatasa/metabolismo , Encéfalo/metabolismo , Estradiol/farmacología , Genisteína/farmacología , Animales , Animales Modificados Genéticamente , Aromatasa/genética , Encéfalo/efectos de los fármacos , Pez Cebra , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismoRESUMEN
In zebrafish, there exists a clear need for new tools to study sex differentiation dynamic and its perturbation by endocrine disrupting chemicals. In this context, we developed and characterized a novel transgenic zebrafish line expressing green fluorescent protein (GFP) under the control of the zebrafish cyp19a1a (gonadal aromatase) promoter. In most gonochoristic fish species including zebrafish, cyp19a1a, the enzyme responsible for the synthesis of estrogens, has been shown to play a critical role in the processes of reproduction and sexual differentiation. This novel cyp19a1a-eGFP transgenic line allowed a deeper characterization of expression and localization of cyp19a1a gene in zebrafish gonads both at the adult stage and during development. At the adult stage, GFP expression was higher in ovaries than in testis. We showed a perfect co-expression of GFP and endogenous Cyp19a1a protein in gonads that was mainly localized in the cytoplasm of peri-follicular cells in the ovary and of Leydig and germ cells in the testis. During development, GFP was expressed in all immature gonads of 20 dpf-old zebrafish. Then, GFP expression increased in early differentiated female at 30 and 35dpf to reach a high GFP intensity in well-differentiated ovaries at 40dpf. On the contrary, males consistently displayed low GFP expression as compared to female whatever their stage of development, resulting in a clear dimorphic expression between both sexes. Interestingly, fish that undergoes ovary-to-testis transition (35 and 40dpf) presented GFP levels similar to males or intermediate between females and males. In this transgenic line our results confirm that cyp19a1a is expressed early during development, before the histological differentiation of the gonads, and that the down-regulation of cyp19a1a expression is likely responsible for the testicular differentiation. Moreover, we show that although cyp19a1a expression exhibits a clear dimorphic expression pattern in gonads during sexual differentiation, its expression persists whatever the sex suggesting that estradiol synthesis is important for gonadal development of both sexes. Monitoring the expression of GFP in control and exposed-fish will help determine the sensitivity of this transgenic line to EDCs and to refine mechanistic based-assays for the study of EDCs. In fine, this transgenic zebrafish line will be a useful tool to study physiological processes such as reproduction and sexual differentiation, and their perturbations by EDCs.
Asunto(s)
Aromatasa/genética , Gónadas/metabolismo , Diferenciación Sexual/genética , Proteínas de Pez Cebra/genética , Pez Cebra , Animales , Animales Modificados Genéticamente , Aromatasa/metabolismo , Embrión no Mamífero , Femenino , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Células Germinativas/metabolismo , Células Germinativas/fisiología , Gónadas/fisiología , Proteínas Fluorescentes Verdes/genética , Masculino , Ovario/embriología , Ovario/metabolismo , Diferenciación Sexual/fisiología , Testículo/embriología , Testículo/metabolismo , Pez Cebra/embriología , Pez Cebra/genética , Proteínas de Pez Cebra/metabolismoRESUMEN
The present study was conducted to assess the effects of Cd exposure on estrogen signaling in the zebrafish brain, as well as the potential protective role of Zn against Cd-induced toxicity. For this purpose, the effects on transcriptional activation of the estrogen receptors (ERs), aromatase B (Aro-B) protein expression and molecular expression of related genes were examined in vivo using wild-type and transgenic zebrafish embryos. For in vitro studies, an ER-negative glial cell line (U251MG) transfected with different zebrafish ER subtypes (ERα, ERß1 and ERß2) was also used. Embryos were exposed either to estradiol (E2 ), Cd, E2 +Cd or E2 +Cd+Zn for 72 h and cells were exposed to the same treatments for 30 h. Our results show that E2 treatment promoted the transcriptional activation of ERs and increased Aro-B expression, at both the protein and mRNA levels. Although exposure to Cd, does not affect the studied parameters when administered alone, it significantly abolished the E2 -stimulated transcriptional response of the reporter gene for the three ER subtypes in U251-MG cells, and clearly inhibited the E2 induction of Aro-B in radial glial cells of zebrafish embryos. These inhibitory effects were accompanied by a significant downregulation of the expression of esr1, esr2a, esr2b and cyp19a1b genes compared to the E2 -treated group used as a positive control. Zn administration during simultaneous exposure to E2 and Cd strongly stimulated zebrafish ERs transactivation and increased Aro-B protein expression, whereas mRNA levels of the three ERs as well as the cyp19a1b remained unchanged in comparison with Cd-treated embryos. In conclusion, our results clearly demonstrate that Cd acts as a potent anti-estrogen in vivo and in vitro, and that Cd-induced E2 antagonism can be reversed, at the protein level, by Zn supplement. Copyright © 2016 John Wiley & Sons, Ltd.
Asunto(s)
Encéfalo/efectos de los fármacos , Intoxicación por Cadmio/prevención & control , Cadmio/toxicidad , Embrión no Mamífero/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Pez Cebra , Zinc/uso terapéutico , Animales , Animales Modificados Genéticamente , Aromatasa/genética , Aromatasa/metabolismo , Encéfalo/metabolismo , Encéfalo/patología , Cadmio/química , Intoxicación por Cadmio/embriología , Intoxicación por Cadmio/metabolismo , Intoxicación por Cadmio/veterinaria , Línea Celular , Embrión no Mamífero/metabolismo , Embrión no Mamífero/patología , Antagonistas de Estrógenos/química , Antagonistas de Estrógenos/toxicidad , Estrógenos/agonistas , Estrógenos/química , Estrógenos/metabolismo , Enfermedades de los Peces/embriología , Enfermedades de los Peces/metabolismo , Enfermedades de los Peces/patología , Enfermedades de los Peces/prevención & control , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Genes Reporteros/efectos de los fármacos , Humanos , Neuroglía/efectos de los fármacos , Neuroglía/metabolismo , Neuroglía/patología , Receptores de Estrógenos/antagonistas & inhibidores , Receptores de Estrógenos/química , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transducción de Señal/efectos de los fármacos , Contaminantes Químicos del Agua/antagonistas & inhibidores , Pez Cebra/embriología , Pez Cebra/genética , Pez Cebra/metabolismo , Proteínas de Pez Cebra/agonistas , Proteínas de Pez Cebra/antagonistas & inhibidores , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo , Cigoto/efectos de los fármacos , Cigoto/metabolismo , Cigoto/patologíaRESUMEN
In zebrafish, the identification of the cells expressing steroidogenic enzymes and their regulators is far from completely fulfilled though it could provide crucial information on the elucidation of the role of these enzymes. The aim of this study was to better characterize the expression pattern of steroidogenic enzymes involved in estrogen and androgen production (Cyp17-I, Cyp11c1, Cyp19a1a and Cyp19a1b) and one of their regulators (Foxl2a) in zebrafish gonads. By using immunohistochemistry, we localized the steroid-producing cells in mature zebrafish gonads and determined different expression patterns between males and females. All these steroidogenic enzymes and Foxl2a were detected both in the testis and ovary. In the testis, they were all localized both in Leydig and germ cells except Cyp19a1b which was only detected in germ cells. In the ovary, Cyp17-I, Cyp19a1a and Foxl2a were immunolocalized in both somatic and germ cells while Cyp19a1b was only detected in germ cells and Cyp11c1 in somatic cells. Moreover, Cyp19a1a and Foxl2a did not display exactly the same patterns of spatial localization but their expressions were correlated suggesting a possible regulation of cyp19a1a gene by Foxl2a in zebrafish. Comparative analysis revealed a dimorphic expression of Cyp11c1, Cyp19a1a, Cyp19a1b and Foxl2a between males and females. Overall, our study provides a detailed description of the expression of proteins involved in the biosynthesis of steroidal hormones at the cellular scale within gonads, which is critical to further elucidating the intimate roles of the enzymes and the use of the zebrafish as a model in the field of endocrinology.
Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Factores de Transcripción Forkhead/metabolismo , Gónadas/metabolismo , Proteínas de Pez Cebra/metabolismo , Pez Cebra/metabolismo , Animales , Aromatasa/metabolismo , Femenino , Proteína Forkhead Box L2 , Gónadas/citología , Inmunohistoquímica , Isoenzimas/metabolismo , Masculino , Microscopía Fluorescente , Ovario/citología , Ovario/metabolismo , Esteroide 11-beta-Hidroxilasa/metabolismo , Esteroide 17-alfa-Hidroxilasa/metabolismo , Testículo/citología , Testículo/metabolismoRESUMEN
Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model) was coupled to an individual based model of zebrafish population dynamics (IBM model). Next, we fitted the DEB model to new experimental data on zebrafish growth and reproduction thus improving existing models. We further analysed the DEB-model and DEB-IBM using a sensitivity analysis. Finally, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding), it can already serve to predict the impact of compounds at the population level.
Asunto(s)
Modelos Teóricos , Dinámica Poblacional , Pez Cebra , Algoritmos , AnimalesRESUMEN
Zebrafish (Danio rerio) is a widely used model for toxicological studies, in particular those related to investigations on endocrine disruption. The development and regulatory use of in vivo and in vitro tests based on this species can be enhanced by toxicokinetic modeling. For this reason, we propose a physiologically based toxicokinetic (PBTK) model for zebrafish describing the uptake and disposition of organic chemicals. The model is based on literature data on zebrafish, other cyprinidae and other fish families, new experimental physiological information (volumes, lipids and water contents) obtained from zebrafish, and chemical-specific parameters predicted by generic models. The relevance of available models predicting the latter parameters was evaluated with respect to gill uptake and partition coefficients in zebrafish. This evaluation benefited from the fact that the influence of confounding factors such as body weight and temperature on ventilation rate was included in our model. The predictions for six chemicals (65 data points) yielded by our PBTK model were compared to available toxicokinetics data for zebrafish and 88% of them were within a factor of 5 of the corresponding experimental values. Sensitivity analysis highlighted that the 1-octanol/water partition coefficient, the metabolism rate, and all the parameters that enable the prediction of assimilation efficiency and partitioning of chemicals need to be precisely determined in order to allow an effective toxicokinetic modeling.
Asunto(s)
Modelos Biológicos , Compuestos Orgánicos/farmacocinética , Toxicocinética , Contaminantes Químicos del Agua/farmacocinética , Contaminantes Químicos del Agua/toxicidad , Pez Cebra/fisiología , 1-Octanol , Animales , Calibración , Cyprinidae , Disruptores Endocrinos , Femenino , Peces , Branquias/efectos de los fármacos , Masculino , Compuestos Orgánicos/toxicidad , Distribución TisularRESUMEN
The contamination of aquatic systems by endocrine disrupting chemicals (EDCs) is now a widely established fact. Nevertheless, there is still a scarcity of knowledge concerning the source, transport, fate and bioavailability of such active compounds. In the present study we assessed the distribution of estrogenic, (anti-)androgenic, pregnane X receptor-like (PXR) and dioxin-like activities between sediment and water compartments using a polar organic compound integrative sampler (POCIS) and a semi-permeable membrane device (SPMD) passive sampler in a river where sediment has been previously described as highly and multi-contaminated. We first confirmed the contamination pattern of this river sediment between 2004, 2009 and 2010 samples, suggesting that this river is subject to a constant high contamination level. However, we showed a different distribution pattern of these activities between compartments: estrogenic activity was mainly detected in POCIS extracts and to a lesser extent in sediment and SPMD extracts; anti-androgenic activities were mainly detected in SPMD and sediment extracts while no activity was detected in POCIS extracts; PXR-like activity was detected in all three investigated compartments, with POCIS > SPMD > sediment; dioxin-like activity was mainly found in the sediment and the SPMD extracts. Overall, partitioning of the biological activities was in accordance with physicochemical properties (e.g., log K ow) of typical known active chemicals in each bioassay. Furthermore, in order to establish whether the chemicals involved in these activities were similar between the compartments, we fractionated sediment, POCIS and SPMD extracts using a multi-step fractionation procedure. This highlighted differences in the nature of active chemicals between compartments. Altogether, our results support the need to consider different compartments in order to enhance exposure assessment.
Asunto(s)
Dioxinas/análisis , Disruptores Endocrinos/análisis , Monitoreo del Ambiente/instrumentación , Monitoreo del Ambiente/métodos , Sedimentos Geológicos/análisis , Contaminantes Químicos del Agua/análisis , Línea Celular , Fraccionamiento Químico , Cromatografía Líquida de Alta Presión , Dioxinas/metabolismo , Disruptores Endocrinos/metabolismo , Francia , Receptor X de Pregnano , Receptores Androgénicos/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Esteroides/metabolismo , Ríos/química , Extracción en Fase Sólida , Contaminantes Químicos del Agua/metabolismoRESUMEN
The tg(cyp19a1b-GFP) transgenic zebrafish expresses GFP (green fluorescent protein) under the control of the cyp19a1b gene, encoding brain aromatase. This gene has two major characteristics: (i) it is only expressed in radial glial progenitors in the brain of fish and (ii) it is exquisitely sensitive to estrogens. Based on these properties, we demonstrate that natural or synthetic hormones (alone or in binary mixture), including androgens or progestagens, and industrial chemicals induce a concentration-dependent GFP expression in radial glial progenitors. As GFP expression can be quantified by in vivo imaging, this model presents a very powerful tool to screen and characterize compounds potentially acting as estrogen mimics either directly or after metabolization by the zebrafish embryo. This study also shows that radial glial cells that act as stem cells are direct targets for a large panel of endocrine disruptors, calling for more attention regarding the impact of environmental estrogens and/or certain pharmaceuticals on brain development. Altogether these data identify this in vivo bioassay as an interesting alternative to detect estrogen mimics in hazard and risk assessment perspective.
Asunto(s)
Aromatasa , Congéneres del Estradiol/farmacología , Estradiol , Neuroglía , Proteínas de Pez Cebra , Pez Cebra , Animales , Animales Modificados Genéticamente , Aromatasa/genética , Aromatasa/metabolismo , Desarrollo Embrionario/genética , Estradiol/análogos & derivados , Estradiol/farmacología , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Imitación Molecular , Neuroglía/citología , Neuroglía/metabolismo , Pez Cebra/embriología , Pez Cebra/genética , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismoRESUMEN
A set of biochemical and histological responses was measured in wild gudgeon collected upstream and downstream of urban and pharmaceutical manufacture effluents. These individual end-points were associated to fish assemblage characterisation. Responses of biotransformation enzymes, neurotoxicity and endocrine disruption biomarkers revealed contamination of investigated stream by a mixture of pollutants. Fish from sampled sites downstream of the industrial effluent exhibited also strong signs of endocrine disruption including vitellogenin induction, intersex and male-biased sex-ratio. These individual effects were associated to a decrease of density and a lack of sensitive fish species. This evidence supports the hypothesis that pharmaceutical compounds discharged in stream are involved in recorded endocrine disruption effects and fish population disturbances and threaten disappearance of resident fish species. Overall, this study gives argument for the utilisation of an effect-based monitoring approach to assess impacts of pharmaceutical manufacture discharges on wild fish populations.
Asunto(s)
Cyprinidae/fisiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Contaminantes Químicos del Agua/toxicidad , Animales , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP3A/metabolismo , Trastornos del Desarrollo Sexual/inducido químicamente , Trastornos del Desarrollo Sexual/epidemiología , Industria Farmacéutica , Disruptores Endocrinos/toxicidad , Femenino , Glutatión Transferasa/metabolismo , Gónadas/efectos de los fármacos , Gónadas/metabolismo , Gónadas/patología , Masculino , Preparaciones Farmacéuticas/análisis , Ríos/química , Razón de Masculinidad , Vitelogeninas/metabolismo , Contaminantes Químicos del Agua/análisisRESUMEN
The usefulness of fish biomarkers for freshwater biomonitoring is now well recognized, but they still pose several questions to ecotoxicology researchers. The present study, designed to assess the effects of a small city located in an agricultural river basin watershed on sticklebacks living in an adjacent river, underlines the importance of reference selection. Two reference systems were used to analyse responses of a set of biomarkers, including biotransformation enzymes, oxidative stress parameters, neurotoxicity and endocrine disruption end-points, measured in wild sticklebacks electrofished in a contaminated stream. The results showed that the investigated urban pressure disturbed CYP3A activity but also induced hepatic lipoperoxidation and circulating vitellogenine but this result is strongly influenced by the selected reference system. This work therefore demonstrates the need for further research to identify a robust reference system for stickleback biomarker analysis.
Asunto(s)
Biomarcadores , Ecotoxicología/métodos , Exposición a Riesgos Ambientales , Smegmamorpha , Contaminación del Agua , Animales , Agua Dulce , Estadística como AsuntoRESUMEN
The aim of this study was to assess endocrine disruptive effects in wild population of fish in five French rivers selected to represent different pollution contexts at two seasons (summer and fall). For that purpose, a panel of biometrical parameters (length, weight, and gonado-somatic index: GSI) and biochemical (ethoxyresorufin-O-deethylase: EROD, vitellogenin: VTG, and brain aromatase) and histological biomarkers (gonads histology) were used in chub (Leuciscus cephalus), a common cyprinid fish species. In fish from the reference site, EROD activity and VTG levels were low at the two seasons. Brain aromatase activities (AAs) were similar to other species and increased with increasing GSI and gonad maturation. Among the four contaminated sites, the Jalle d'Eysines River was the most impacted site. At this site, fish were exposed to estrogenic substances as demonstrated by the VTG induction in males and the arrest of development of the gonads that led to lower brain AA compared to fish from the reference site. In fish from other contaminated sites, EROD activity was induced as compared to fish from the reference site and some males had elevated concentrations of VTG. Moreover, the presence of aromatase-inhibiting compounds was demonstrated in the sediments of three contaminated sites, even if the precise nature of contaminants is not known. This study provides new data concerning endocrine disruption in wild fish populations inhabiting French rivers and demonstrates that measurements of in vivo and in vitro aromatase could be used as biomarkers of endocrine disruption in field studies.
Asunto(s)
Cyprinidae/fisiología , Disruptores Endocrinos/toxicidad , Monitoreo del Ambiente/métodos , Agua Dulce/química , Contaminantes Químicos del Agua/toxicidad , Animales , Animales Salvajes , Aromatasa/efectos de los fármacos , Aromatasa/metabolismo , Biomarcadores/metabolismo , Biometría , Peso Corporal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Cyprinidae/anatomía & histología , Citocromo P-450 CYP1A1/efectos de los fármacos , Citocromo P-450 CYP1A1/metabolismo , Disruptores Endocrinos/análisis , Femenino , Francia , Sedimentos Geológicos/química , Masculino , Ovario/efectos de los fármacos , Ovario/crecimiento & desarrollo , Ovario/patología , Estaciones del Año , Testículo/efectos de los fármacos , Testículo/crecimiento & desarrollo , Testículo/patología , Vitelogeninas/efectos de los fármacos , Vitelogeninas/metabolismo , Contaminantes Químicos del Agua/análisisRESUMEN
In this study, wild three-spined sticklebacks were sampled every six weeks, between April and October, in a low contaminated stream. For all fish, physiological indexes, such as condition factor, hepato-, gonado- and nephro-somatic index were calculated to determine fish condition and reproductive status. Moreover, a set of biomarkers including biotransformation enzymes, oxidative stress parameters, neurotoxicity and endocrine disruption markers was measured. The results allowed to determine biomarker variability due to fish gender or sampling season. For example, 7-ethoxyresorufin-O-deethylase activity, glutathione peroxidase as well as vitellogenin and spiggin exhibited strong gender differences. Conversely, lipoperoxidation and acethylcholinesterase activity were characterised by a lack of gender and seasonal variation, and can be considered as more robust parameters for a field application. The present work allowed to establish practical guideline for biomarker measurements in wild sticklebacks and to define a reference system which can be used to analyze variations in future monitoring studies.
Asunto(s)
Biomarcadores/metabolismo , Monitoreo del Ambiente/métodos , Estaciones del Año , Smegmamorpha/metabolismo , Contaminación del Agua/efectos adversos , Acetilcolinesterasa/metabolismo , Animales , Citocromo P-450 CYP1A1/metabolismo , Disruptores Endocrinos/metabolismo , Femenino , Proteínas de Peces/metabolismo , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Transferasa/metabolismo , Peroxidación de Lípido , Masculino , Estrés Oxidativo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Vitelogeninas/metabolismo , Xenobióticos/metabolismoRESUMEN
The aim of this study was to characterize biomarker responses in three-spined sticklebacks exposed to prochloraz (Pcz). For this purpose, adult sticklebacks were exposed for 2 weeks to prochloraz at 0, 10, 50, 100 and 500 microg/L prior to one week of depuration in clean water. At days 7, 14 and 21, several hepatic biomarkers were measured including 7-ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST), glutathione peroxidase (GPx), catalase (CAT), total glutathione (GSH) content and thiobarbituric acid reactive substances (TBARS). Pcz induced a transient increase of antioxidant enzymes and a depletion of glutathione content during the first 7 days of exposure. This study showed that EROD activity and antioxidants were disrupted in a transient manner. GST was rapidly induced in a dose-dependent manner and this induction was persistent and observed also after depuration. GST appeared as a valuable biomarker to assess the exposure to Pcz.
Asunto(s)
Fungicidas Industriales/toxicidad , Imidazoles/toxicidad , Hígado/enzimología , Estrés Oxidativo/efectos de los fármacos , Smegmamorpha/crecimiento & desarrollo , Animales , Biomarcadores/análisis , Biomarcadores/metabolismo , Catalasa/análisis , Catalasa/metabolismo , Citocromo P-450 CYP1A1/análisis , Citocromo P-450 CYP1A1/metabolismo , Relación Dosis-Respuesta a Droga , Monitoreo del Ambiente/métodos , Glutatión/análisis , Glutatión/metabolismo , Glutatión Peroxidasa/análisis , Glutatión Peroxidasa/metabolismo , Glutatión Transferasa/análisis , Glutatión Transferasa/metabolismo , Hígado/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Factores de Tiempo , Contaminantes Químicos del Agua/toxicidadRESUMEN
The biochemical response of wild sticklebacks collected in Autumn 2005 at seven stations in the North of France was studied using a set of complementary biomarkers. Here, data on biotransformation of xenobiotics, oxidative stress exposure and damages, neurotoxicity and endocrine disruption are provided. All the sites are characterized by a specific response pattern that allows distinguishing sampling locations. Moreover, these responses are in accordance with data on existing environmental pressures and the chemical analysis of metals performed in surface water. The assessment of individual responses is completed by fish population disturbance monitoring. Based on these measurements, the investigated sites are characterized by different levels of disturbance. This study argues for a multi-parametric approach of aquatic ecosystem contamination based on association between chemical, biochemical and ecological endpoints and provides a testimony of the usefulness of stickleback for this purpose.