خيارات البحث
النتائج 1641 - 1650 من 1,966
Surface runoff and nitrogen (N) loss in a bamboo (Phyllostachys pubescens) forest under different fertilization regimes النص الكامل
2013
Zhang, Qichun | Shamsi, Imran Haider | Zhi'an, | Song, Qiujin | Xue, Qiaoyun | Yu, Yan | Lin, Xianyong | Hussain, Sayed
Nitrogen (N) losses from agricultural fields have been extensively studied. In contrast, surface runoff and N losses have rarely been considered for bamboo forests that are widespread in regions such as southern China. The thriving of bamboo industries has led to increasing fertilizer use in bamboo forests. In this study, we evaluated surface runoff and N losses in runoff following different fertilization treatments under field conditions in a bamboo (Phyllostachys pubescens) forest in the catchment of Lake Taihu in Jiangsu, China. Under three different fertilization regimes, i.e., control, site-specific nutrient management (SSNM), and farmer's fertilization practice (FFP), the water runoff rate amounted to 356, 361, and 342 m(3) ha(-1) and accounted for 1.91, 1.98, and 1.85 % of the water input, respectively, from June 2009 to May 2010. The total N losses via surface runoff ranged from 1.2 to 1.8 kg ha(-1). Compared with FFP, the SSNM treatment reduced total nitrogen (TN) and dissolved nitrogen (DN) losses by 31 and 34 %, respectively. The results also showed that variations in N losses depended mainly on runoff fluxes, not N concentrations. Runoff samples collected from all treatments throughout the year showed TN concentrations greater than 0.35 mg L(-1), with the mean TN concentration in the runoff from the FFP treatment reaching 8.97 mg L(-1). The loss of NO3 (-)-N was greater than the loss of NH4 (+)-N. The total loss of dissolved organic nitrogen (DON) reached 23-41 % of the corresponding DN. Therefore, DON is likely the main N species in runoff from bamboo forests and should be emphasized in the assessment and management of N losses in bamboo forest.
اظهر المزيد [+] اقل [-]Multiple biomarkers of pollution effects in Solea solea fish on the Tunisia coastline النص الكامل
2013
Jebali, Jamel | Sabbagh, Marwa | Banni, Mohamed | Kamel, Naouel | Ben-Khedher, Sana | M’hamdi, Naceur | Boussetta, Hamadi
This field study investigates the morphological indices (condition index, hepatosomatic index) and biochemical (catalase (CAT), glutathione S-transferase (GST), acetylcholinesterase (AChE), metallothionein (MT), lipid peroxidation) parameters in liver, gills and kidney of common sole (Solea solea) originating from different sites of the Tunisian coast area impacted by different anthropogenic activities. Differences among sites and tissues for AChE, GST, CAT, MT and TBARS were found and possibly related to known sources of domestic and industrial discharges in the studied sites. Liver, gills and kidney CAT, liver and kidney MT and brain AChE were key biomarkers to discriminate fish of different sites. So, we suggest using these biomarkers in future biomonitoring.
اظهر المزيد [+] اقل [-]Enzymatic synthesis of bromo- and chlorocarbazoles and elucidation of their structures by molecular modeling النص الكامل
2013
Mumbo, John | Lenoir, Dieter | Henkelmann, Bernhard | Schramm, Karl-Werner
3-Chlorocarbazole, 3,6-dichlorocarbazole, dibromocarbazole, and 1,3,6,8-tetrabromocarbazole are emerging environmental contaminants which have been detected recently in water, sediment, and soil samples. However, their sources and occurrence have not been explained. Here, we report an enzymatic synthesis of bromo- and chlorocarbazoles by chloroperoxidase from Caldariomyces fumago in water. Density functional theory (DFT) method was used to predict the most stable products. Carbazole and chloroperoxidase were assayed in vitro in the presence of hydrogen peroxide, bromide, and chloride ions in different substrate ratio treatments against constant and varying enzyme concentrations. Halogenated carbazoles formed were identified by high-resolution gas chromatography coupled to mass spectrometry. In all treatments, bromination and chlorination took place, but the composition and concentration of compounds formed varied from one treatment to another. Mono-, di-, tri-, and tetra-substituted bromo- and chlorocarbazoles which include the reported environmental contaminants were synthesized. 3-Substituted and 3,6-substituted congeners were relatively higher in concentration. Enzyme concentration did not favor preferential formation of any of the compounds synthesized. However, their synthesis was influenced by halide concentration. Congeners with bromine and chlorine at position of C-3, C-3,6, C-1,3,6, and C-1,3,6,8 were calculated as the stable intermediate sigma complexes by DFT method. Regioselectivity in halogenation is discussed and hypothesis of the likely stable products in the environment explained. This study provides evidence that bromo- and chlorocarbazoles reported previously can be formed enzymatically in the environment, demonstrating the need to consider aromatic pollutants transformation and their potential toxicity enhancements in the management of water pollution and contaminated sites.
اظهر المزيد [+] اقل [-]Challenges with tracing the fate and speciation of mine-derived metals in turbid river systems: implications for bioavailability النص الكامل
2013
Cresswell, Tom | Smith, Ross E. W. | Nugegoda, Dayanthi | Simpson, Stuart L.
The fast-flowing and highly turbid Lagaip River (0.5-10 g/L suspended solids) in the central highlands of Papua New Guinea receives mine-derived metal inputs in both dissolved and particulate forms. Nearest the mine, metal concentrations in suspended solids were 360, 9, 90, 740 and 1,300 mg/kg for As, Cd, Cu, Pb and Zn, while dissolved concentrations were 2.7, 0.6, 3.1, 0.1 and 25 μg/L, respectively. This creates a significant metal exposure source for organisms nearer the mine. However, because the Lagaip River is diluted by a large number of tributaries, the extent to which mine-derived metals may affect biota in the lower catchments is uncertain. To improve our understanding of the forms of potentially bioavailable metals entering the lower river system, we studied the partitioning and speciation of metals within the Lagaip River system. Dissolved and particulate metal concentrations decreased rapidly downstream of the mine due to dilution from tributaries. As a portion of the particulate metal concentrations, the more labile dilute acid-extractable forms typically comprised 10-30 % for As and Pb, 50-75 % for Cu and Zn, and 50-100 % for Cd. Only dissolved Cd, Cu and Zn remained elevated relative to the non-mine-impacted tributaries (<0.03, 0.5 and 0.3 μg/L), but the concentrations did not appreciably change with increasing dilution downriver. This indicated that release of Cd, Cu and Zn was likely occurring from the more labile metal phases of the mine-derived particulates. Chelex-labile metal analyses and speciation modelling indicated that dissolved copper and lead were largely non-labile and likely complexed by naturally occurring organic ligands, while dissolved cadmium and zinc were predominantly present in labile forms. The study confirmed that mine-derived particulates may represent a significant source of dissolved metals in the lower river system; however, comparison with water quality guidelines indicates the low concentrations would not adversely affect aquatic life.
اظهر المزيد [+] اقل [-]Xenobiotics removal by adsorption in the context of tertiary treatment: a mini review النص الكامل
2013
Tahar, Alexandre | Choubert, Jean-Marc | Coquery, Marina
Xenobiotics removal by adsorption in the context of tertiary treatment: a mini review النص الكامل
2013
Tahar, Alexandre | Choubert, Jean-Marc | Coquery, Marina
Many xenobiotics, including several pharmaceuticals and pesticides, are poorly treated in domestic wastewater treatment plants. Adsorption processes, such as with activated carbons, could be a solution to curb their discharge into the aquatic environment. As adsorbent-like activated carbon is known to be expensive, identifying promising alternative adsorbent materials is a key challenge for efficient yet affordable xenobiotic removal from wastewaters. As part of the effort to address this challenge, we surveyed the literature on pharmaceutical and pesticide xenobiotics and built a database compiling data from 38 scientific publications covering 65 xenobiotics and 58 materials. Special focus was given to the relevance and comparability of the data to the characteristics of the adsorbent materials used and to the operating conditions of the batch tests inventoried. This paper gives an in-depth overview of the adsorption capacities of various adsorbents. The little data on alternative adsorbent materials, especially for the adsorption of pharmaceuticals, makes it difficult to single out any one activated carbon alternative capable of adsorbing pesticides and pharmaceuticals at the tertiary stage of treatment. There is a pressing need for further lab-scale experiments to investigate the tertiary treatment of discharged effluents. We conclude with recommendations on how future data should best be used and interpreted.
اظهر المزيد [+] اقل [-]Xenobiotics removal by adsorption in the context of tertiary treatment: a mini review النص الكامل
2013
Tahar, A. | Choubert, J.M. | Coquery, Marina | Milieux aquatiques, écologie et pollutions (UR MALY) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [Axe_IRSTEA]TED-SOWASTE [Axe_IRSTEA]TED-EPURE | Many xenobiotics, including several pharmaceuticals and pesticides, are poorly treated in domestic wastewater treatment plants. Adsorption processes, such as with activated carbons, could be a solution to curb their discharge into the aquatic environment. As adsorbent-like activated carbon is known to be expensive, identifying promising alternative adsorbent materials is a key challenge for efficient yet affordable xenobiotic removal from wastewaters. As part of the effort to address this challenge, we surveyed the literature on pharmaceutical and pesticide xenobiotics and built a database compiling data from 38 scientific publications covering 65 xenobiotics and 58 materials. Special focus was given to the relevance and comparability of the data to the characteristics of the adsorbent materials used and to the operating conditions of the batch tests inventoried. This paper gives an in-depth overview of the adsorption capacities of various adsorbents. The little data on alternative adsorbent materials, especially for the adsorption of pharmaceuticals, makes it difficult to single out any one activated carbon alternative capable of adsorbing pesticides and pharmaceuticals at the tertiary stage of treatment. There is a pressing need for further lab-scale experiments to investigate the tertiary treatment of discharged effluents. We conclude with recommendations on how future data should best be used and interpreted.
اظهر المزيد [+] اقل [-]Accumulation of heavy metals and antioxidant responses in Vicia faba plants grown on monometallic contaminated soil النص الكامل
2013
Accumulation of heavy metals and antioxidant responses in Vicia faba plants grown on monometallic contaminated soil النص الكامل
2013
The purpose of this study was to explore the effects of soil contamination by selected metals (cadmium, copper, nickel, lead or zinc) on the antioxidant response of Vicia faba plants. The levels of the antioxidants: glutathione, proline, non-protein thiols, as well as guaiacol peroxidase and catalase activities were measured in the upperparts of plants. Additionally, the potential bioavailability of metals in the soil and their concentrations in V. faba plants were compared. Treatment with metal caused the problem of an elevation in its bioavailability in soil and its concentration in leaves and stems. The most serious problems seemed to be metal elevations in soil, especially Zn and Ni as well as in the aerial parts of V. faba plants. The antioxidant responses appeared to be metal specific. The elevation of guaiacol peroxidase activity in leaves and stems as well as the proline in leaves was the only more general reaction to metal exposure. Upon analysis of the effects of soil metal contamination on V. faba plants, we recommend the use of some measurements such as guaiacol peroxidase activity and proline level as useful tools in biological monitoring.
اظهر المزيد [+] اقل [-]Accumulation of heavy metals and antioxidant responses in Vicia faba plants grown on monometallic contaminated soil النص الكامل
Aleksandra Nagórska-Socha | Alina Kafel | Marta Kandziora-Ciupa | Janina Gospodarek | Agnieszka Zawisza-Raszka
The purpose of this study was to explore the effects of soil contamination by selected metals (cadmium, copper, nickel, lead or zinc) on the antioxidant response of Vicia faba plants. The levels of the antioxidants: glutathione, proline, non-protein thiols, as well as guaiacol peroxidase and catalase activities were measured in the upperparts of plants. Additionally, the potential bioavailability of metals in the soil and their concentrations in V. faba plants were compared. Treatment with metal caused the problem of an elevation in its bioavailability in soil and its concentration in leaves and stems. The most serious problems seemed to be metal elevations in soil, especially Zn and Ni as well as in the aerial parts of V. faba plants. The antioxidant responses appeared to be metal specific. The elevation of guaiacol peroxidase activity in leaves and stems as well as the proline in leaves was the only more general reaction to metal exposure. Upon analysis of the effects of soil metal contamination on V. faba plants, we recommend the use of some measurements such as guaiacol peroxidase activity and proline level as useful tools in biological monitoring. | Antioxidant response, Metal contamination, Vicia faba | 30 | 1124-1134 | 2
اظهر المزيد [+] اقل [-]Seasonal and air mass trajectory effects on dissolved organic matter of bulk deposition at a coastal town in south-western Europe النص الكامل
2013
Santos, Patrícia S. M. | Santos, Eduarda B. H. | Duarte, Armando C.
Seasonal and air mass trajectory effects on dissolved organic matter of bulk deposition at a coastal town in south-western Europe النص الكامل
2013
Santos, Patrícia S. M. | Santos, Eduarda B. H. | Duarte, Armando C.
Rainwater contains a complex mixture of organic compounds which may influence climate, terrestrial and maritime ecosystems and thus human health. In this work, the characteristics of DOM of bulk deposition at a coastal town on the southwest of Europe were assessed by UV–visible and three-dimensional excitation–emission matrix fluorescence spectroscopies and by dissolved organic carbon (DOC) content. The seasonal and air mass trajectory effects on dissolved organic matter (DOM) of bulk deposition were evaluated. The absorbance at 250 nm (UV₂₅₀ₙₘ) and integrated fluorescence showed to be positively correlated with each other, and they were also positively correlated to the DOC in bulk deposition, which suggest that a constant fraction of DOM is likely to fluoresce. There was more chromophoric dissolved organic matter (CDOM) present in summer and autumn seasons than in winter and spring. Bulk deposition associated with terrestrial air masses contained a higher CDOM content than bulk deposition related to marine air masses, thus highlighting the contribution of terrestrial/anthropogenic sources.
اظهر المزيد [+] اقل [-]Seasonal and air mass trajectory effects on dissolved organic matter of bulk deposition at a coastal town in south-western Europe النص الكامل
2013
Santos, Patrícia S. M. | Santos, Eduarda B. H. | Duarte, Armando C.
Rainwater contains a complex mixture of organic compounds which may influence climate, terrestrial and maritime ecosystems and thus human health. In this work, the characteristics of DOM of bulk deposition at a coastal town on the southwest of Europe were assessed by UV-visible and three-dimensional excitation-emission matrix fluorescence spectroscopies and by dissolved organic carbon (DOC) content. The seasonal and air mass trajectory effects on dissolved organic matter (DOM) of bulk deposition were evaluated. The absorbance at 250 nm (UV(250 nm)) and integrated fluorescence showed to be positively correlated with each other, and they were also positively correlated to the DOC in bulk deposition, which suggest that a constant fraction of DOM is likely to fluoresce. There was more chromophoric dissolved organic matter (CDOM) present in summer and autumn seasons than in winter and spring. Bulk deposition associated with terrestrial air masses contained a higher CDOM content than bulk deposition related to marine air masses, thus highlighting the contribution of terrestrial/anthropogenic sources. | Authors acknowledge funding from the Portuguese FCT (Foundation for Science and Technology) to CESAM (Centre for Environmental and Marine Studies). The FCT fellowship given to P.S.M. Santos (Ref. SFRH/BPD/75350/2010) is also acknowledged. Authors would like to gratefully thank the Group of Organic Chemistry of University of Aveiro for making available to us the use of their Fluoromax 3 equipment of molecular fluorescence spectrophotometer. TOC analyses were carried out at the “Administração Regional de Saúde” (Aveiro) and authors wish to here express their gratitude to this Centre and especially to Dra. Ana Maria Félix and Dra. Rosário Figueiredo. The authors also wish to thank Professor Maria Dolores Orgaz from the Department of Physics at the University of Aveiro for meteorological information support. | published
اظهر المزيد [+] اقل [-]Metal extractability patterns to evaluate (potentially) mobile fractions in periurban calcareous agricultural soils in the Mediterranean area—analytical and mineralogical approaches النص الكامل
2013
de Santiago-Martín, Ana | Valverde-Asenjo, Inmaculada | Quintana, Jose R. | Vázquez, Antonio | Lafuente, Antonio L. | González-Huecas, Concepción
Metal extractability patterns to evaluate (potentially) mobile fractions in periurban calcareous agricultural soils in the Mediterranean area—analytical and mineralogical approaches النص الكامل
2013
de Santiago-Martín, Ana | Valverde-Asenjo, Inmaculada | Quintana, Jose R. | Vázquez, Antonio | Lafuente, Antonio L. | González-Huecas, Concepción
A set of periurban calcareous agricultural Mediterranean soils was spiked with a mixture of Cd, Cu, Pb and Zn at two levels within the limit values proposed by current European legislation, incubated for up to 12 months, and subjected to various one-step extraction procedures to estimate mobile (neutral salts) and potentially mobile metal fractions (complexing and acidic extraction methods). The results obtained were used to study metal extractability patterns according to the soil characteristics. The analytical data were coupled with mineralogical investigations and speciation modelling using the Visual Minteq model. The formation of soluble metal-complexes in the complexing extracts (predicted by the Visual Minteq calculations) led to the highest extraction efficiency with complexing extractants. Metal extractability patterns were related to both content and composition of carbonate, organic matter, Fe oxide and clay fractions. Potentially mobile metal fractions were mainly affected by the finest soil fractions (recalcitrant organic matter, active lime and clay minerals). In the case of Pb, scarce correlations between extractable Pb and soil constituents were obtained which was attributed to high Pb retention due to the formation of 4PbCO3·3PbO (corroborated by X-ray diffraction). In summary, the high metal proportion extracted with complexing agents highlighted the high but finite capacity to store potentially mobilizable metals and the possible vulnerability of these soils against environmental impact from metal accumulation.
اظهر المزيد [+] اقل [-]Metal extractability patterns to evaluate (potentially) mobile fractions in periurban calcareous agricultural soils in the Mediterranean area-analytical and mineralogical approaches النص الكامل
2013
de Santiago-Martín, A. | Valverde-Asenjo, I. | Quintana, J. R. | Vázquez, Antonio | Lafuente, A. L. | González-Huecas, C.
A set of periurban calcareous agricultural Mediterranean soils was spiked with a mixture of Cd, Cu, Pb and Zn at two levels within the limit values proposed by current European legislation, incubated for up to 12 months, and subjected to various one-step extraction procedures to estimate mobile (neutral salts) and potentially mobile metal fractions (complexing and acidic extraction methods). The results obtained were used to study metal extractability patterns according to the soil characteristics. The analytical data were coupled with mineralogical investigations and speciation modelling using the Visual Minteq model. The formation of soluble metal-complexes in the complexing extracts (predicted by the Visual Minteq calculations) led to the highest extraction efficiency with complexing extractants. Metal extractability patterns were related to both content and composition of carbonate, organic matter, Fe oxide and clay fractions. Potentially mobile metal fractions were mainly affected by the finest soil fractions (recalcitrant organic matter, active lime and clay minerals). In the case of Pb, scarce correlations between extractable Pb and soil constituents were obtained which was attributed to high Pb retention due to the formation of 4PbCO3·3PbO (corroborated by X-ray diffraction). In summary, the high metal proportion extracted with complexing agents highlighted the high but finite capacity to store potentially mobilizable metals and the possible vulnerability of these soils against environmental impact from metal accumulation. © 2013 Springer-Verlag Berlin Heidelberg.
اظهر المزيد [+] اقل [-]The role of transboundary air pollution over Galicia and North Portugal area النص الكامل
2013
Borrego, C. | Souto, J. A. | Monteiro, A. | Dios, M. | Fernandez, Aurelio Rodriguez | Ferreira, J. | Saavedra, S. | Casares, J. J. | Miranda, A. I.
The role of transboundary air pollution over Galicia and North Portugal area النص الكامل
2013
Borrego, C. | Souto, J. A. | Monteiro, A. | Dios, M. | Fernandez, Aurelio Rodriguez | Ferreira, J. | Saavedra, S. | Casares, J. J. | Miranda, A. I.
In summer, high levels of ozone (O₃) are frequently measured at both Galicia and Northern Portugal air quality monitoring stations, even exceeding the limit values imposed by legislation. This work aims to investigate the origin of these high O₃ concentrations by the application of a chemical transport modelling system over the northwestern area of the Iberian Peninsula. The WRF–CHIMERE modelling system was applied with high resolution to simulate the selected air pollution episodes that occurred simultaneously in Galicia and North Portugal and in order to study both the contribution of local emission sources and the influence of transboundary pollution. Emission inputs have been prepared based on the development of the Portuguese and Galician emission inventories. The obtained results for O₃ have been evaluated and validated against observations. Modelling results show possible contribution of the transboundary transport over the border of two neighbour regions/countries, indicating that the O₃ episode starts over the urban and industrialised area of North coast of Portugal, reaching the maximum peaks over this region; at the same time, O₃ levels increased over Galicia region, where lower concentrations, but still high, were observed. These results pointed out that air quality management should not be driven by political boundaries and highlight the importance of joining efforts between neighbouring countries.
اظهر المزيد [+] اقل [-]The role of transboundary air pollution over Galicia and North Portugal area النص الكامل
2013
Borrego, C. | Souto, J. A. | Monteiro, A. | Dios, M. | Rodríguez, A. | Ferreira, J. | Saavedra, S. | Casares, J. J. | Miranda, A. I.
Insummer,highlevelsofozone(O3)arefrequently measured at both Galicia and Northern Portugal air quality monitoring stations, even exceeding the limit values imposed by legislation. This work aims to investigate the origin of these high O3 concentrations by the application of a chemical transport modelling system over the northwestern area of the Iberian Peninsula. The WRF–CHIMERE modelling system was applied with high resolution to simulate the selected air pollutionepisodesthatoccurredsimultaneouslyinGaliciaand North Portugal and in order to study both the contribution of local emission sources and the influence of transboundary pollution. Emission inputs have been prepared based on the development of the Portuguese and Galician emission inventories. The obtained results for O3 have been evaluated and validated against observations. Modelling results show possiblecontributionofthetransboundarytransportovertheborder of two neighbour regions/countries, indicating that the O3 episode starts over the urban and industrialised area of North coast of Portugal, reaching the maximum peaks over this region; at the same time, O3 levels increased over Galicia region, where lower concentrations, but still high, were observed. These results pointed out that air quality management should not be driven by political boundaries and high light the importance of joining efforts between neigh bouring countries. | TheauthorsacknowledgethePortugueseEnvironmental Protection Agency, MeteoGalicia, Laboratorio de Medio Ambiente de Galicia (Xunta de Galicia) and As Pontes Power Plant (Endesa) for the observational dataset support. The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (http://www.arl. noaa.gov/ready.php) used in this publication. Thanks are extended to the Portuguese Ministério da Ciência, da Tecnologia e do Ensino Superior for the post-doctoral grants of A. Monteiro (SFRH/BPD/63796/2009) and J. Ferreira (SFRH/BPD/40620/2007). PhD grants of A. Rodríguez and M. Dios (‘María Barbeito’ Programme) and the research stay abroad grant of M.Dios(09.02.561B.444.0) at the University of Aveiro were supported by Xunta de Galicia regional government. This work was developed as part of the project ‘XIMERE/FUXIMERE’ (10MDS009E), also with support of Endesa Generación, S.A. (‘Characterization of ozone episodes’) and Troposfera S.C. (‘Collaboration in air quality modeling over Galicia’). | published
اظهر المزيد [+] اقل [-]Effects of mono-(2-ethylhexyl) phthalate (MEHP) on chicken germ cells cultured in vitro النص الكامل
2013
Guibert, Edith | Prieur, Bérénice | Cariou, Ronan | Courant, Frédérique | Antignac, Jean Philippe | Pain, Bertrand | Brillard, Jean Pierre | Froment, Pascal
Effects of mono-(2-ethylhexyl) phthalate (MEHP) on chicken germ cells cultured in vitro النص الكامل
2013
Guibert, Edith | Prieur, Bérénice | Cariou, Ronan | Courant, Frédérique | Antignac, Jean Philippe | Pain, Bertrand | Brillard, Jean Pierre | Froment, Pascal
In recent decades, many toxicological tests based on in vivo or in vitro models, mainly from mammalian (rat–mouse) and fish species, were used to assess the risks raised by contact or ingestion of molecules of pharmaceutical, agricultural, or natural origin. But no, or few, in vitro tests using other non-mammalian models such as bird have been explored despite their advantages: the embryonic gonads of birds have a high plasticity of development sensitive to estrogen, and sperm production is nearly two times faster than in rodents. Hence, we have established an in vitro culture of germ cells and somatic cells from chicken post-natal testis, and we have evaluated the sensitivity against the endocrine disruptor compound mono-(2-ethylhexyl) phthalate (MEHP) in comparison to previous studies using rodent and human models. After 96 h of exposure in presence of 10 μM MEHP, chicken seminiferous tubules cultures present a structural alteration, a reduction in cell proliferation and in germ cells population. Apoptosis of germ and somatic cells increases in presence of 1 μM MEHP. Furthermore, MEHP does not affect inhibin B and lactate production by Sertoli cells. These results are in accordance with previous studies using rat, mice, or human culture of testicular cells and in similar range of exposures or even better sensitivity for some “end-points” (biological parameters). In conclusion, the establishment of this postnatal testicular cells culture could be considered as an alternative method to in vivo experiments frequently used for evaluating the impact on the terrestrial wildlife species. This method could be also complementary to mammal model due to the limiting number of animals used and its elevated sensitivity.
اظهر المزيد [+] اقل [-]Effects of mono-(2-ethylhexyl) phthalate (MEHP) on chicken germ cells cultured in vitro النص الكامل
2013
Guibert, Edith | Prieur, Bérénice | Cariou, Ronan | Courant, Frédérique | Antignac, Jean-Philippe | Pain, Bertrand | Brillard, Jean Pierre | Froment, Pascal | Physiologie de la reproduction et des comportements [Nouzilly] (PRC) ; Institut National de la Recherche Agronomique (INRA)-Institut Français du Cheval et de l'Equitation [Saumur] (IFCE)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS) | Laboratoire d'étude des Résidus et Contaminants dans les Aliments (LABERCA) ; École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Institut cellule souche et cerveau (SBRI) ; Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM) | Fertilité et Reproduction Avicole (FERTIL'AVI) | Institut National de la Recherche Agronomique, French Ministry of Environment LOLF 189
In recent decades, many toxicological tests based on in vivo or in vitro models, mainly from mammalian (rat-mouse) and fish species, were used to assess the risks raised by contact or ingestion of molecules of pharmaceutical, agricultural, or natural origin. But no, or few, in vitro tests using other non-mammalian models such as bird have been explored despite their advantages: the embryonic gonads of birds have a high plasticity of development sensitive to estrogen, and sperm production is nearly two times faster than in rodents. Hence, we have established an in vitro culture of germ cells and somatic cells from chicken post-natal testis, and we have evaluated the sensitivity against the endocrine disruptor compound mono-(2-ethylhexyl) phthalate (MEHP) in comparison to previous studies using rodent and human models. After 96 h of exposure in presence of 10 μM MEHP, chicken seminiferous tubules cultures present a structural alteration, a reduction in cell proliferation and in germ cells population. Apoptosis of germ and somatic cells increases in presence of 1 μM MEHP. Furthermore, MEHP does not affect inhibin B and lactate production by Sertoli cells. These results are in accordance with previous studies using rat, mice, or human culture of testicular cells and in similar range of exposures or even better sensitivity for some "end-points" (biological parameters). In conclusion, the establishment of this postnatal testicular cells culture could be considered as an alternative method to in vivo experiments frequently used for evaluating the impact on the terrestrial wildlife species. This method could be also complementary to mammal model due to the limiting number of animals used and its elevated sensitivity.
اظهر المزيد [+] اقل [-]