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1.
Front Endocrinol (Lausanne) ; 14: 1269334, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37900144

RESUMO

Introduction: Male reproduction is under the control of the hypothalamus-pituitary-gonadal (HPG) axis. The endocannabinoid system (ECS) and the kisspeptin system (KS) are two major signaling systems in the central and peripheral control of reproduction, but their possible interaction has been poorly investigated in mammals. This manuscript analyzes their possible reciprocal modulation in the control of the HPG axis. Materials and methods: Adolescent male rats were treated with kisspeptin-10 (Kp10) and endocannabinoid anandamide (AEA), the latter alone or in combination with the type 1 cannabinoid receptor (CB1) antagonist rimonabant (SR141716A). The hypothalamic KS system and GnRH expression, circulating sex steroids and kisspeptin (Kiss1) levels, and intratesticular KS and ECS were evaluated by immunohistochemical and molecular methods. Non-coding RNAs (i.e., miR145-5p, miR-132-3p, let7a-5p, let7b-5p) were also considered. Results: Circulating hormonal values were not significantly affected by Kp10 or AEA; in the hypothalamus, Kp10 significantly increased GnRH mRNA and aromatase Cyp19, Kiss1, and Kiss1 receptor (Kiss1R) proteins. By contrast, AEA treatment affected the hypothalamic KS at the protein levels, with opposite effects on the ligand and receptor, and SR141716A was capable of attenuating the AEA effects. Among the considered non-coding RNA, only the expression of miR145-5p was positively affected by AEA but not by Kp10 treatment. Localization of Kiss1+/Kiss1R+ neurons in the arcuate nucleus revealed an increase of Kiss1R-expressing neurons in Kp10- and AEA-treated animals associated with enlargement of the lateral ventricles in Kp10-treated animals. In the brain and testis, the selected non-coding RNA was differently modulated by Kp10 or AEA. Lastly, in the testis, AEA treatment affected the KS at the protein levels, whereas Kp10 affected the intragonadal levels of CB1 and FAAH, the main modulator of the AEA tone. Changes in pubertal transition-related miRNAs and the intratesticular distribution of Kiss1, Kiss1R, CB1, and CB2 following KP and AEA treatment corroborate the KS-ECS crosstalk also showing that the CB1 receptor is involved in this interplay. Conclusion: For the first time in mammals, we report the modulation of the KS in both the hypothalamus and testis by AEA and revealed the KP-dependent modulation of CB1 and FAAH in the testis. KP involvement in the progression of spermatogenesis is also suggested.


Assuntos
Kisspeptinas , MicroRNAs , Masculino , Ratos , Animais , Kisspeptinas/genética , Kisspeptinas/metabolismo , Receptores de Kisspeptina-1/genética , Endocanabinoides/farmacologia , Endocanabinoides/metabolismo , Rimonabanto/metabolismo , Rimonabanto/farmacologia , Hipotálamo/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Mamíferos/metabolismo , Reprodução , RNA não Traduzido/metabolismo , MicroRNAs/metabolismo
2.
Pharmacol Res ; 188: 106659, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36646190

RESUMO

Cardiorenal syndrome encompasses a spectrum of disorders involving heart and kidney dysfunction, and sharing common risk factors, such as hypertension and diabetes. Clinical studies have shown that patients with and without diabetes may benefit from using sodium-glucose cotransporter 2 inhibitors to reduce the risk of heart failure and ameliorate renal endpoints. Because the underlying mechanisms remain elusive, we investigated the effects of dapagliflozin on the progression of renal damage, using a model of non-diabetic cardiorenal disease. Dahl salt-sensitive rats were fed a high-salt diet for five weeks and then randomized to dapagliflozin or vehicle for the following six weeks. After treatment with dapagliflozin, renal function resulted ameliorated as shown by decrease of albuminuria and urine albumin-to-creatinine ratio. Functional benefit was accompanied by a decreased accumulation of extracellular matrix and a reduced number of sclerotic glomeruli. Dapagliflozin significantly reduced expression of inflammatory and endothelial activation markers such as NF-κB and e-selectin. Upregulation of pro-oxidant-releasing NADPH oxidases 2 and 4 as well as downregulation of antioxidant enzymes were also counteracted by drug treatment. Our findings also evidenced the modulation of both classic and non-classic renin-angiotensin-aldosterone system (RAAS), and effects of dapagliflozin on gene expression of ion channels/transporters involved in renal homeostasis. Thus, in a non-diabetic model of cardiorenal syndrome, dapagliflozin provides renal protection by modulating inflammatory response, endothelial activation, fibrosis, oxidative stress, local RAAS and ion channels.


Assuntos
Síndrome Cardiorrenal , Diabetes Mellitus , Animais , Ratos , Compostos Benzidrílicos/farmacologia , Compostos Benzidrílicos/uso terapêutico , Síndrome Cardiorrenal/tratamento farmacológico , Síndrome Cardiorrenal/metabolismo , Diabetes Mellitus/tratamento farmacológico , Rim/metabolismo , Ratos Endogâmicos Dahl
3.
Cancers (Basel) ; 16(1)2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38201480

RESUMO

The application of doxorubicin (DOX) is hampered by cardiotoxicity, with diastolic dysfunction as the earliest manifestation. Fibrosis leads to impaired relaxation, but the mechanisms that operate shortly after DOX exposure are not clear. We asked whether the activation of cardiac fibroblasts (CFs) anticipates myocardial dysfunction and evaluated the effects of DOX on CF metabolism. CFs were isolated from the hearts of rats after the first injection of DOX. In another experiment, CFs were exposed to DOX in vitro. Cell phenotype and metabolism were determined. Early effects of DOX consisted of diastolic dysfunction and unchanged ejection fraction. Markers of pro-fibrotic remodeling and evidence of CF transformation were present immediately after treatment completion. Oxygen consumption rate and extracellular acidification revealed an increased metabolic activity of CFs and a switch to glycolytic energy production. These effects were consistent in CFs isolated from the hearts of DOX-treated animals and in naïve CFs exposed to DOX in vitro. The metabolic switch was paralleled with the phenotype change of CFs that upregulated markers of myofibroblast differentiation and the activation of pro-fibrotic signaling. In conclusion, the metabolic switch and activation of CFs anticipate DOX-induced damage and represent a novel target in the early phase of anthracycline cardiomyopathy.

4.
Cent Nerv Syst Agents Med Chem ; 22(3): 160-174, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36177627

RESUMO

BACKGROUND: Neuroinflammation is a key component in the etiopathogenesis of neurological diseases and brain aging. This process involves the brain immune system that modulates synaptic functions and protects neurons from infection or damage. Hence, the knowledge of neuroinflammation related pathways and modulation by drugs or natural compounds is functional to developing therapeutic strategies aimed at preserving, maintaining and restoring brain health. OBJECTIVE: This review article summarizes the basics of neuroinflammation and related signaling pathways, the success of the dietary intervention in clinical practice and the possible development of RNA-based strategies for treating neurological diseases. METHODS: Pubmed search from 2012 to 2022 with the keywords neuroinflammation and molecular mechanisms in combination with diet, miRNA and non-coding RNA. RESULTS: Glial cells-play a crucial role in neuroinflammation, but several pathways can be activated in response to different inflammatory stimuli, inducing cell death by apoptosis, pyroptosis or necroptosis. The dietary intervention has immunomodulatory effects and could limit the inflammatory process induced by microglia and astrocytes. Thus by inhibiting neuroinflammation and improving the symptoms of a variety of neurological diseases, diet exerts pleiotropic neuroprotective effects independently from the spectrum of pathophysiological mechanisms underlying the specific disorder. Furthermore, data from animal models revealed that altered expression of specific noncoding RNAs, in particular microRNAs, contributes to neuroinflammatory diseases; consequently, RNA-based strategies may be promising to alleviate the consequences of neuroinflammation. CONCLUSION: Further studies are needed to identify the molecular pathways and the new pharmacological targets in neuroinflammation to lay the basis for more effective and selective therapies to be applied, in parallel to dietary intervention, in the treatment of neuroinflammation-based diseases.


Assuntos
MicroRNAs , Doenças do Sistema Nervoso , Fármacos Neuroprotetores , Animais , Doenças Neuroinflamatórias , Microglia/metabolismo , Microglia/patologia , Astrócitos/metabolismo , Fármacos Neuroprotetores/farmacologia , MicroRNAs/genética , Doenças do Sistema Nervoso/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo
5.
Genes (Basel) ; 13(2)2022 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-35205340

RESUMO

The hypothalamus-pituitary-testis axis controls the production of spermatozoa, and the kisspeptin system, comprising Kiss1 and Kiss1 receptor (Kiss1R), is the main central gatekeeper. The activity of the kisspeptin system also occurs in testis and spermatozoa, but currently the need of peripheral kisspeptin to produce gametes is not fully understood. Hence, we characterized kisspeptin system in rat spermatozoa and epididymis caput and cauda and analyzed the possible presence of Kiss1 in the epididymal fluid. The presence of Kiss1 and Kiss1R in spermatozoa collected from epididymis caput and cauda was evaluated by Western blot; significant high Kiss1 levels in the caput (p < 0.001 vs. cauda) and constant levels of Kiss1R proteins were observed. Immunofluorescence analysis revealed that the localization of Kiss1R in sperm head shifts from the posterior region in the epididymis caput to perforatorium in the epididymis cauda. In spermatozoa-free epididymis, Western blot revealed higher expression of Kiss1 and Kiss1R in caput (p < 0.05 vs. cauda). Moreover, immunohistochemistry revealed that Kiss1 and Kiss1R proteins were mainly localized in the secretory epithelial cell types and in contractile myoid cells, respectively. Finally, both dot blot and Elisa revealed the presence of Kiss1 in the epididymal fluid collected from epididymis cauda and caput, indicating that rat epididymis and spermatozoa possess a complete kisspeptin system. In conclusion, we reported for the first time in rodents Kiss1R trafficking in spermatozoa during the epididymis transit and Kiss1 measure in the epididymal fluid, thus suggesting a possible role for the system in spermatozoa maturation and storage within the epididymis.


Assuntos
Epididimo , Kisspeptinas , Animais , Epididimo/metabolismo , Kisspeptinas/genética , Kisspeptinas/metabolismo , Masculino , Proteínas/metabolismo , Ratos , Receptores de Kisspeptina-1/genética , Receptores de Kisspeptina-1/metabolismo , Maturação do Esperma/genética , Espermatozoides/metabolismo
6.
Int J Mol Sci ; 22(22)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34830483

RESUMO

Glyphosate is widely used worldwide as a potent herbicide. Due to its ubiquitous use, it is detectable in air, water and foodstuffs and can accumulate in human biological fluids and tissues representing a severe human health risk. In plants, glyphosate acts as an inhibitor of the shikimate pathway, which is absent in vertebrates. Due to this, international scientific authorities have long-considered glyphosate as a compound that has no or weak toxicity in humans. However, increasing evidence has highlighted the toxicity of glyphosate and its formulations in animals and human cells and tissues. Thus, despite the extension of the authorization of the use of glyphosate in Europe until 2022, several countries have begun to take precautionary measures to reduce its diffusion. Glyphosate has been detected in urine, blood and maternal milk and has been found to induce the generation of reactive oxygen species (ROS) and several cytotoxic and genotoxic effects in vitro and in animal models directly or indirectly through its metabolite, aminomethylphosphonic acid (AMPA). This review aims to summarize the more relevant findings on the biological effects and underlying molecular mechanisms of glyphosate, with a particular focus on glyphosate's potential to induce inflammation, DNA damage and alterations in gene expression profiles as well as adverse effects on reproduction and development.


Assuntos
Glicina/análogos & derivados , Herbicidas/efeitos adversos , Inflamação/genética , Neoplasias/genética , Dano ao DNA/efeitos dos fármacos , Europa (Continente) , Regulação da Expressão Gênica/efeitos dos fármacos , Glicina/efeitos adversos , Humanos , Inflamação/induzido quimicamente , Inflamação/patologia , Neoplasias/induzido quimicamente , Neoplasias/patologia , Organofosfonatos/metabolismo , Reprodução/efeitos dos fármacos , Reprodução/genética , Glifosato
7.
Int J Mol Sci ; 22(18)2021 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-34576283

RESUMO

Alongside the well-known central modulatory role, the Kisspeptin system, comprising Kiss1, its cleavage products (Kisspeptins), and Kisspeptin receptor (Kiss1R), was found to regulate gonadal functions in vertebrates; however, its functional role in the male gamete and its localization during maturation have been poorly understood. The present study analyzed Kisspeptin system in dog testis and spermatozoa recovered from different segments of the epididymis, with focus on Kiss1R on sperm surface alongside the maturation during epididymal transit, demonstrated by modification in sperm kinetic, morphology, and protamination. The proteins Kiss1 and Kiss1R were detected in dog testis. The receptor Kiss1R only was detected in total protein extracts from epididymis spermatozoa, whereas dot blot revealed Kiss1 immunoreactivity in the epidydimal fluid. An increase of the Kiss1R protein on sperm surface along the length of the epididymis, with spermatozoa in the tail showing plasma membrane integrity and Kiss1R protein (p < 0.05 vs. epididymis head and body) was observed by flow cytometry and further confirmed by epifluorescence microscopy and Western blot carried on sperm membrane preparations. In parallel, during the transit in the epididymis spermatozoa significantly modified their ability to move and the pattern of motility; a progressive increase in protaminization also occurred. In conclusion, Kisspeptin system was detected in dog testis and spermatozoa. Kiss1R trafficking toward plasma membrane along the length of the epididymis and Kiss1 in epididymal fluid suggested a new functional role of the Kisspeptin system in sperm maturation and storage.


Assuntos
Epididimo/metabolismo , Receptores de Kisspeptina-1/metabolismo , Espermatozoides/metabolismo , Animais , Líquidos Corporais/metabolismo , Contagem de Células , Cães , Epididimo/anatomia & histologia , Cinética , Kisspeptinas/metabolismo , Masculino , Testículo/anatomia & histologia
8.
Int J Mol Sci ; 22(18)2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34575829

RESUMO

Bisphenol A (BPA) is largely used as a monomer in some types of plastics. It accumulates in tissues and fluids and is able to bypass the placental barrier, affecting various organs and systems. Due to huge developmental processes, children, foetuses, and neonates could be more sensitive to BPA-induced toxicity. To investigate the multi-systemic effects of chronic exposure to a low BPA dose (100 µg/L), pregnant Wistar rats were exposed to BPA in drinking water during gestation and lactation. At weaning, newborn rats received the same treatments as dams until sex maturation. Free and conjugated BPA levels were measured in plasma and adipose tissue; the size of cerebral ventricles was analysed in the brain; morpho-functional and molecular analyses were carried out in the liver with a focus on the expression of inflammatory cytokines and Sirtuin 1 (Sirt1). Higher BPA levels were found in plasma and adipose tissue from BPA treated pups (17 PND) but not in weaned animals. Lateral cerebral ventricles were significantly enlarged in lactating and weaned BPA-exposed animals. In addition, apart from microvesicular steatosis, liver morphology did not exhibit any statistically significant difference for morphological signs of inflammation, hypertrophy, or macrovesicular steatosis, but the expression of inflammatory cytokines, Sirt1, its natural antisense long non-coding RNA (Sirt1-AS LncRNA) and histone deacetylase 1 (Hdac1) were affected in exposed animals. In conclusion, chronic exposure to a low BPA dose could increase the risk for disease in adult life as a consequence of higher BPA circulating levels and accumulation in adipose tissue during the neonatal period.


Assuntos
Compostos Benzidrílicos/efeitos adversos , Água Potável/química , Exposição Ambiental/efeitos adversos , Avaliação do Impacto na Saúde , Fenóis/efeitos adversos , Poluentes Químicos da Água/efeitos adversos , Tecido Adiposo/metabolismo , Animais , Modelos Animais de Doenças , Água Potável/análise , Feminino , Imuno-Histoquímica , Inflamação/etiologia , Inflamação/metabolismo , Inflamação/patologia , Lactação/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , NAD/metabolismo , Estresse Oxidativo , Gravidez , Ratos , Sirtuína 1/metabolismo , Poluentes Químicos da Água/administração & dosagem , Desmame
9.
Artigo em Inglês | MEDLINE | ID: mdl-33573212

RESUMO

Diet deeply impacts brain functions like synaptic plasticity and cognitive processes, neuroendocrine functions, reproduction and behaviour, with detrimental or protective effects on neuronal physiology and therefore consequences for health. In this respect, the activity of metabolic sensors within the brain is critical for the maintenance of health status and represents a possible therapeutic target for some diseases. This review summarizes the main activity of Sirtuin1 (Sirt1), a metabolic sensor within the brain with a focus on the link between the central control of energy homeostasis and reproduction. The possible modulation of Sirt1 by natural phytochemical compounds like polyphenols is also discussed.


Assuntos
Reprodução , Sirtuína 1 , Encéfalo/metabolismo , Metabolismo Energético , Homeostase , Plasticidade Neuronal , Sirtuína 1/metabolismo
10.
Int J Mol Sci ; 22(2)2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33478092

RESUMO

The endocannabinoid system (ECS) is a lipid cell signaling system involved in the physiology and homeostasis of the brain and peripheral tissues. Synaptic plasticity, neuroendocrine functions, reproduction, and immune response among others all require the activity of functional ECS, with the onset of disease in case of ECS impairment. Estrogens, classically considered as female steroid hormones, regulate growth, differentiation, and many other functions in a broad range of target tissues and both sexes through the activation of nuclear and membrane estrogen receptors (ERs), which leads to genomic and non-genomic cell responses. Since ECS function overlaps or integrates with many other cell signaling systems, this review aims at updating the knowledge about the possible crosstalk between ECS and estrogen system (ES) at both central and peripheral level, with focuses on the central nervous system, reproduction, and cancer.


Assuntos
Sistema Nervoso Central/metabolismo , Endocanabinoides/fisiologia , Estrogênios/fisiologia , Animais , Sistema Nervoso Central/efeitos dos fármacos , Endocanabinoides/farmacologia , Estrogênios/metabolismo , Estrogênios/farmacologia , Feminino , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Plasticidade Neuronal/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Reprodução/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
11.
Int J Mol Sci ; 21(12)2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32545547

RESUMO

DNA oxidative damage is one of the main concerns being implicated in severe cell alterations, promoting different types of human disorders and diseases. For their characteristics, male gametes are the most sensitive cells to the accumulation of damaged DNA. We have recently reported the relevance of arginine residues in the Cu(II)-induced DNA breakage of sperm H1 histones. In this work, we have extended our previous findings investigating the involvement of human sperm nuclear basic proteins on DNA oxidative damage in healthy males presenting copper and chromium excess in their semen. We found in 84% of those males an altered protamines/histones ratio and a different DNA binding mode even for those presenting a canonical protamines/histones ratio. Furthermore, all the sperm nuclear basic proteins from these samples that resulted were involved in DNA oxidative damage, supporting the idea that these proteins could promote the Fenton reaction in DNA proximity by increasing the availability of these metals near the binding surface of DNA. In conclusion, our study reveals a new and unexpected behavior of human sperm nuclear basic proteins in oxidative DNA damage, providing new insights for understanding the mechanisms related to processes in which oxidative DNA damage is implicated.


Assuntos
Arginina/análise , Cobre/análise , DNA/genética , Proteínas Nucleares/metabolismo , Estresse Oxidativo , Espermatozoides/química , DNA/metabolismo , Poluição Ambiental/efeitos adversos , Regulação da Expressão Gênica , Voluntários Saudáveis , Histonas/metabolismo , Humanos , Itália , Masculino , Protaminas/metabolismo , Ligação Proteica , Espermatozoides/metabolismo , Adulto Jovem
12.
Mol Reprod Dev ; 86(6): 650-660, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30938011

RESUMO

Salinity represents a critical environmental and an ecological factor in the reproduction of marine species. As global climate changes and anthropogenic factors affect salinity, in this study, we have analyzed the responses of Mytilus galloprovincialis spermatozoa to hyposaline stress. We exposed mussels, in laboratory tanks, for 24 hr at 18°C to control (35.9 psu) and three hyposaline (17.1, 22.6, and 26.2 psu) conditions, and evaluated the expression of sperm hsp70 and protamine-like proteins genes. Further we analyzed the electrophoretic pattern, the DNA binding and the release from sperm nuclei of protamine-like proteins. For all experimental approaches used, the results obtained at 17.1 psu condition were very similar to those obtained in the control condition, while alterations were always recorded at 22.6 and 26.2 psu conditions. Particularly, at 22.6 and 26.2 psu, was observed: 42.5- and 17.1-fold increase in hsp70 expression, respectively, and hypoexpression of PL-II/PLIV protamine-like proteins genes. Further, electrophoretic mobility shift assays and salt-induced release of nuclear proteins from sperm nuclei, revealed alterations in the PL proteins/DNA binding, in these two hyposaline conditions. The similarity between the results obtained in control and in the more severe hyposaline condition (17.1 psu) could indicate a phenomenon of fertility preservation strategy due to gamete plasticity.


Assuntos
Regulação da Expressão Gênica , Proteínas de Choque Térmico HSP70/biossíntese , Mytilus/metabolismo , Pressão Osmótica , Protaminas/metabolismo , Espermatozoides/metabolismo , Animais , Masculino , Mytilus/citologia , Espermatozoides/citologia
13.
PLoS One ; 10(10): e0141041, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26484667

RESUMO

In the root apoplasm, V(V) and V(IV) toxicity can be alleviated through redox and complexation reactions involving phenolic substances and the polyuronic components. In such context we report the role of polygalacturonic acid (PGA) on the reducing activity of caffeic acid (CAF) towards V(V). The redox reaction was particularly effective at pH 2.8 leading to the formation of oxidation products with redox activity towards V(V). An o-quinone was identified as the first product of the reaction which is further involved in the formation of CAF dimers. At pH ≥ 3.6 the redox activity decreased and a yield in V(IV) equal to 38, 31, 21 and 14% was found at pH 3.6, 4.0. 5.0 and 6.0 respectively compared with that obtained at pH 2.8. The redox reaction was faster in the presence of PGA and a higher yield of V(IV) was found in the 4.0-6.0 pH range with respect to the CAF-V(V) binary system. The higher efficiency of the redox reaction in the presence of PGA was related with the ability of PGA to bind V(IV). The biological significance of the redox reaction between CAF and V(V), as well as the role of PGA in such reaction, was established "in vivo" using triticale plants. Results showed that PGA reduced significantly the phytotoxic effects of the V(V)-CAF system.


Assuntos
Poluentes Ambientais/toxicidade , Pectinas/metabolismo , Raízes de Plantas/metabolismo , Vanadatos/metabolismo , Vanadatos/toxicidade , Ácidos Cafeicos/química , Poluentes Ambientais/metabolismo , Poluição Ambiental/efeitos adversos , Inativação Metabólica , Oxirredução , Plantas/efeitos dos fármacos
14.
Environ Sci Technol ; 49(22): 13501-9, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26457447

RESUMO

This study aimed to assess and compare the in vitro and in vivo bioaccessibility/bioavailability of As and Pb in a mining contaminated soil (As, 2267 mg kg(-1); Pb, 1126 mg kg(-1)), after the addition of conventional (phosphoric acid), opportunistic [water treatment residues (WTRs)], and engineered [nano- and microscale zero valent iron (ZVI)] amendments. Phosphoric acid was the only amendment that could significantly decrease Pb bioaccessibility with respect to untreated soil (41 and 47% in the gastric phase and 2.1 and 8.1% in the intestinal phases, respectively), giving treatment effect ratios (TERs, the bioaccessibility in the amended soil divided by the bioaccessibility in the untreated soil) of 0.25 and 0.87 in the gastric and intestinal phase, respectively. The in vivo bioavailability of Pb decreased in the phosphate treatment relative to the untreated soil (6 and 24%, respectively), and also in the Fe WTR 2% (12%) and nZVI-2 (13%) treatments. The ZVI amendments caused a decrease in As bioaccessibility, with the greatest decrease in the nZVI2-treated soil (TERs of 0.59 and 0.64 in the gastric and intestinal phases, respectively). Arsenic X-ray absorption near-edge spectroscopy analysis indicated that most of the As in the untreated soil was present as As(V) associated with Fe mineral phases, whereas in the treated soil, the proportion of arsenosiderite increased. Arsenite was present only as a minor species (3-5%) in the treated soils, with the exception of an nZVI treatment [∼14% of As(III)], suggesting a partial reduction of As(V) to As(III) caused by nZVI oxidation.


Assuntos
Arsênio/farmacocinética , Recuperação e Remediação Ambiental/métodos , Chumbo/farmacocinética , Poluentes do Solo/farmacocinética , Animais , Arsênio/análise , Disponibilidade Biológica , Ferro/química , Ferro/farmacocinética , Itália , Chumbo/análise , Masculino , Camundongos Endogâmicos BALB C , Minerais/química , Mineração , Fosfatos/química , Solo/química , Poluentes do Solo/análise , Espectroscopia por Absorção de Raios X
15.
J Environ Manage ; 139: 146-53, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24685456

RESUMO

Four iron and aluminium-based products, including red mud (RM), hematite (Fe2O3), an iron-rich water treatment residual (Fe-WTR) and amorphous Al hydroxide (Al-OH), were evaluated for their effectiveness at stabilising As and heavy metals (i.e. Cd, Cu, Pb, Zn) in a circumneutral contaminated soil [As (2105 mg kg(-1)), Cd (18 mg kg(-1)), Cu (264 mg kg(-1)), Pb (710 mg kg(-1)), Zn (522 mg kg(-1))]. Treatment impacts on soil microbial and biochemical features (i.e. microbial biomass-C, microbial counts, 16S rRNA PCR-TTGE of culturable bacteria, dehydrogenase, urease and ß-glucosidase activity, Biolog derived parameters-AWCD and richness) as well as bean (Phaseolus vulgaris) and wheat (Triticum vulgare) growth were also assessed. After 6 months equilibration, all the amendments (application rate 3% w/w) but RM reduced labile As while only Al-OH reduced the concentration of water-soluble heavy metals. Despite the highest bioavailability of contaminants, most of the soil microbial and biochemical features monitored (i.e. microbial biomass-C, total bacterial counts, dehydrogenase activity and AWCD) were significantly higher in the RM-soil. Bean germination was completely inhibited in RM-soil while wheat growth was similar to that of the control. The Al-OH treatment was best overall, promoting microbial abundance, diversity and activity while increasing bean and wheat growth and reducing As accumulated in plant shoots. Results suggest that Al-OH is a suitable candidate for field evaluations while the use of RM in the remediation of circumneutral or subalkaline contaminated soils should be reconsidered.


Assuntos
Hidróxido de Alumínio/química , Arsênio/química , Compostos Férricos/química , Ferro/química , Metais Pesados/química , Poluentes do Solo/química , Hidróxido de Alumínio/toxicidade , Carga Bacteriana , Biomassa , Compostos Férricos/toxicidade , Ferro/toxicidade , Phaseolus/efeitos dos fármacos , Phaseolus/crescimento & desenvolvimento , RNA Ribossômico 16S/análise , Microbiologia do Solo , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento
16.
J Hazard Mater ; 264: 144-52, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24295765

RESUMO

Here we report a survey addressed to determine, at different pH values (pH 4.0, 7.0 and 9.0), the ability of two different water treatment residues, a Fe-based (Fe-WTR) and an Al-based (Al-WTR), to accumulate arsenate and phosphate anions from an aqueous solution and to define the mechanism which regulate the sorption of these anions. Fe-WTR showed a greater As(V) and P(V) sorption capacity respect to Al-WTR at all the pH values investigated, in particular at pH 4.0. The greater capacity of the Fe-WTR to accumulate phosphate at pH 4.0 seems to be linked to the higher content of manganese ions compared to Al-WTR, which can give rise, with phosphate ions, to the formation of MnHPO4 precipitates. Sequential extraction of As(V)- or P(V)-WTRs suggested that the main mechanism governing the sorption of both two anions likely involve the formation of inner-sphere surface complexes [Fe/Al-O-As(P)]. Such a coordination mode was supported by the FT-IR spectra that exhibit well resolved band at 865cm(-1) and 1040cm(-1) attributable to ν(As-O) or ν(P-O) stretching vibration, respectively.


Assuntos
Arseniatos/isolamento & purificação , Fosfatos/isolamento & purificação , Purificação da Água , Adsorção , Precipitação Química , Solo/química , Espectroscopia de Infravermelho com Transformada de Fourier
17.
J Environ Qual ; 42(3): 774-81, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23673944

RESUMO

The mobility and bioavailability of As in the soil-plant system can be affected by a number of organic acids that originate from the activity of plants and microorganisms. In this study we evaluated the ability of citrate and malate anions to mobilize As in a polluted subacidic soil (UP soil) treated with red mud (RM soil). Both anions promoted the mobilization of As from UP and RM soils, with citrate being more effective than malate. The RM treatment induced a greater mobility of As. The amounts of As released in RM and UP soils treated with 3.0 mmol L citric acid solution were 2.78 and 1.83 µmol g respectively, whereas an amount equal to 1.73 and 1.06 µmol g was found after the treatment with a 3.0 mmol L malic acid solution. The release of As in both soils increased with increasing concentration of organic acids, and the co-release of Al and Fe in solution also increased. The sequential extraction showed that Fe/Al (oxi)hydroxides in RM were the main phases involved in As binding in RM soil. Two possible mechanisms could be responsible for As solubilization: (i) competition of the organic anions for As adsorption sites and (ii) partial dissolution of the adsorbents (e.g., dissolution of iron and aluminum oxi-hydroxides) induced by citrate or malate and formation of complexes between dissolved Fe and Al and organic anions. This is the first report on the effect of malate and citrate on the As mobility in a polluted soil treated with RM.


Assuntos
Arsênio , Ácido Cítrico , Adsorção , Citratos , Concentração de Íons de Hidrogênio , Malatos , Solo/química , Poluentes do Solo/química
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