Navegando por Palavras-chave "Hydrogen peroxide"
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- ItemAcesso aberto (Open Access)17 beta-Estradiol and steady-state concentrations of H2O2: antiapoptotic effect in endometrial cells from patients with endometriosis(Elsevier B.V., 2013-07-01) Andrade, Sheila Siqueira [UNIFESP]; Azevedo, Aline de Cássia [UNIFESP]; Monasterio, Izabel C. G. [UNIFESP]; Paredes-Gamero, Edgar Julian [UNIFESP]; Gonçalves, Giovana Aparecida [UNIFESP]; Bonetti, Tatiana Carvalho de Souza [UNIFESP]; Albertoni, Guilherme Ambrozio [UNIFESP]; Schor, Eduardo [UNIFESP]; Barreto, Jose A.; Oliva, Maria Luiza Vilela [UNIFESP]; Juliano, Luiz [UNIFESP]; Girão, Manoel João Batista Castello [UNIFESP]; Silva, Ismael Dale Cotrim Guerreiro da [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Charitable Assoc Blood CollectIncreased levels of hydrogen peroxide (H2O2) can initiate protective responses to limit or repair oxidative damage. However, H2O2 signals also fine-tune responses to growth factors and cytokines controlling cell division, differentiation, and proliferation. Because 17 beta-estradiol (E-2) also plays important roles in these processes, and is considered a major risk factor in the development and progression of endometriosis, this study evaluated whether E-2 has an antiapoptotic effect on oxidative stress in endometrial cells in combination with steady-state H2O2 levels ([H2O2]ss). Endometrial stromal cells were prepared from the eutopic endometrium of 18 women with and without endometriosis to produce primary cells. These cells were stimulated with E-2 for 20 h, exposed to [H2O2]ss, and examined for cell viability, proliferation, and apoptosis. the endometrial cells from women with endometriosis maintained the steady state for 120 min at high H2O2 concentrations. When they were pretreated with E-2 and exposed to [H2O2]ss, a decrease in apoptosis level was observed compared to the control cells (p < 0.01). the endometrial cells from patients with endometriosis subjected to both E-2 and [H2O2]ss showed increased ERK phosphorylation. These findings suggested that H2O2 is a signaling molecule that downregulates apoptosis in endometrial cells, supporting the fact that endometriosis, albeit a benign disease, shares some features with cancer such as decreased catalase levels. These results link the E-2 effects on [H2O2]ss to resistance to apoptosis and progression of endometriosis. (C) 2013 Elsevier Inc. All rights reserved.
- ItemAcesso aberto (Open Access)Análise do papel do H2O2 na endometriose: regulação da apoptose e perfil de citocinas inflamatórias(Universidade Federal de São Paulo, 2011-11-30) Azevedo, Aline de Cassia [UNIFESP]; Silva, Ismael Dale Cotrim Guerreiro da [UNIFESP]; http://lattes.cnpq.br/7917312029683516; http://lattes.cnpq.br/5965982844300078Antecedentes: Aumentos nos níveis de peróxido de hidrogênio (H2O2) podem iniciar ações protetoras respostas para limitar ou reparar danos oxidativos. No entanto, os sinais de H2O2 também ajustam o respostas a fatores de crescimento e citocinas para controlar a divisão, diferenciação e proliferação. A análise desses processos requer condições que imitem o estado estacionário de H2O2 in vivo. O 17β-Estradiol (E2) desempenha um papel importante nestes processos e, portanto, o E2 é considerado um importante fator de risco no desenvolvimento e progressão da endometriose. Este estudo foi projetado para avaliar se o E2 tem um efeito citoprotetor no estresse oxidativo e concentrações estaduais de H2O2 ([H2O2]ss) nas células endometriais. Metodologia/Principais Resultados: As células estromais endometriais foram preparadas a partir do endométrio eutópico de 18 mulheres com e sem endometriose para produzir células primárias de cada paciente. As células foram estimuladas com E2 por 20 h, expostas a [H2O2]ss., e depois examinado quanto à viabilidade celular, proliferação e apoptose. As células endometriais com endometriose (em estágios variados) foram capazes de manter o estado estacionário por 120 minutos em alta concentrações de H2O2 (60 μM), seguidas por um aumento contínuo da concentração extracelular concentração de H2O2. Quando foram pré-tratados com E2 e expostos a [H2O2]ss, observaram uma diminuição nos níveis de apoptose em comparação com as células controle (p <0,01). Produção de espécies reativas de oxigênio e vias de desintoxicação foram avaliadas, e E2 teve um efeito protetor efeito sobre o estresse oxidativo, induzindo a produção de uma superóxido dismutase. Estresse oxidativo induz a ativação de ERK; em nosso estudo, células endometriais submetidas a E2 e [H2O2]ss mostrou aumento da fosforilação de ERK, como esperado. Conclusões/Significado: Estas descobertas sugerem que o H2O2 é uma molécula sinalizadora que regula a apoptose nas células endometriais. Nossos resultados vinculam os efeitos do E2 no [H2O2]ss à resistência à apoptose e progressão da endometriose.
- ItemSomente MetadadadosApplications of Europium Tetracycline Complex: A Review(Bentham Science Publ Ltd, 2008-11-01) Courrol, Lilia Coronato [UNIFESP]; Samad, Ricardo E.; Universidade Federal de São Paulo (UNIFESP); IPEN CNEN SPEuropium solutions present low absorption coefficients and, due to the energy transfer between europium ions and the OH vibration of coordinated water molecules, there is a significant non-radiative relaxation and no emission is observed. However, when europium complexes with tetracycline (EuTc), it exhibits and intense and narrow emission band centered on 615 nm, characteristic of the (5)D(0) -> (5)F(2) transition within the lanthanide ion. the tetracycline molecule acts as an antenna or sensitizer, absorbing the excitation light and transferring the energy to the lanthanide ion.A major increase in the luminescence of the EuTc complex was observed in the presence of hydrogen peroxide and also urea hydrogen peroxide. the possibility of quantifying the hydrogen peroxide using luminescence measurements is also promising for the indirect quantification of glucose and cholesterol since enzymatic reactions generate hydrogen peroxide. This principle can be applied to determine, indirectly, concentrations of lactose and galactose, alcohol, catalase, etc.There are also other possibilities of EuTc applications: assay for phosphate, sensing and imaging of malate in aqueous solution, spectrofluorimetric determination of lecithin, heparin, human serum albumin, citrate and other intermediates in the citric acid cycle, low density lipoproteins (LDL), the determination of the activity of phosphorylation, immunoassays, etc.The purpose of this review is to describe and discuss the latest advances in analytical methodologies based in the luminescence properties of EuTc probes.
- ItemAcesso aberto (Open Access)Cardioprotective mechanism of S-nitroso-N-acetylcysteine via S-nitrosated betadrenoceptor-2 in the LDLr-/- mice(Elsevier B.V., 2014-01-30) Wanschel, Amarylis Claudine Bonito Azeredo; Caceres, Viviane de Menezes [UNIFESP]; Moretti, Ana Iochabel Soares; Bruni-Cardoso, Alexandre; Carvalho, Hernandes Faustino de; Souza, Heraldo Possolo de; Laurindo, Francisco Rafael Martins; Spadari, Regina Celia [UNIFESP]; Krieger, Marta Helena; NYU; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)Previous studies from our group have demonstrated the protective effect of S-nitroso-N-acetylcysteine (SNAC) on the cardiovascular system in dyslipidemic LDLr-/- mice that develop atheroma and left ventricular hypertrophy after 15 days on a high fat diet. We have shown that SNAC treatment attenuates plaque development via the suppression of vascular oxidative stress and protects the heart from structural and functional myocardial alterations, such as heart arrhythmia, by reducing cardiomyocyte sensitivity to catecholamines. Here we investigate the ability of SNAC to modulate oxidative stress and cell survival in cardiomyocytes during remodeling and correlation with beta(2)-AR signaling in mediating this protection. Ventricular superoxide (O-2(-)) and hydrogen peroxide (H2O2) generation was measured by HPLC methods to allow quantification of dihydroethidium (DHE) products. Ventricular histological sections were stained using terminal dUTP nick-end labeling (TUNEL) to identify nuclei with DNA degradation (apoptosis) and this was confirmed by Western blot for cleaved caspase-3 and caspase-7 protein expression. the findings show that O-2(-) and H2O2 production and also cell apoptosis were increased during left ventricular hypertrophy (LVH). SNAC treatment reduced oxidative stress during on cardiac remodeling, measured by decreased H2O2 and O-2(-) production (65% and 52%, respectively), and a decrease in the ratio of p-Ser1177 eNOS/total eNOS. Left ventricle (LV) from SNAC-treated mice revealed a 4-fold increase in beta(2)-AR expression associated with coupling change to Gi; beta(2)-ARs-S-nitrosation (beta(2)-AR-SNO) increased 61%, while apoptosis decreased by 70%. These results suggest that the cardio-protective effect of SNAC treatment is primarily through its anti-oxidant role and is associated with beta(2)-ARs overexpression and beta(2)-AR-SNO via an anti-apoptotic pathway. (C) 2013 Elsevier Inc. All rights reserved.
- ItemSomente MetadadadosChanges in the pro-inflammatory cytokine production and peritoneal macrophage function in rats with chronic heart failure(Elsevier B.V., 2006-06-01) Batista, M. L.; Santos, Ronaldo Vagner Thomatieli dos [UNIFESP]; Cunha, L. M.; Mattos, K.; Oliveira, E. M.; Seelaender, M. C. L.; Rosa, L. F. B. P. Costa; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Chronic heart failure (CHF) is a state of immune activation, and pro-inflammatory cytokines play an important role in its development and progression. Macrophages (M phi s), when activated, are the main source of pro-inflammatory cytokines. We measured interjeukin-6 (IL-6), interleukin (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) production after lipopolysaccharide (LPS)-stimulation, as well as peritoneal M phi s migration, phagocytic capacity, chemotaxis index, and hydrogen peroxide production, in an attempt to clarify the role of this cell in an animal model of CHF. Ligature of the left coronary artery or sham operation was performed in adult Wistar rats. After 12 weeks, resident and total cell number, phagocytic capacity, chemotaxis index, and hydrogen peroxide production in M phi s were significantly higher in CHF than in control rats. the production of IL-6 and TNF-alpha was similarly significantly enhanced in CHF as compared with controls. M phi s obtained from CHF rats were more responsive to LPS, suggesting the existence, in vivo, of possible factor(s) modulating the production of pro-inflammatory cytokines. the results demonstrated that there is modification of peritoneal M phi s function along CHF development, possibly contributing to the pathophysiological process in the establishment of CHF. (c) 2006 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Efeito do peróxido de hidrogênio (H2O2) no íleo(Universidade Federal de São Paulo (UNIFESP), 2017-07-31) Cesário, Thalyta Aparecida Munhóz [UNIFESP]; Smith, Ricardo Luiz [UNIFESP]; http://lattes.cnpq.br/2039545891941644; http://lattes.cnpq.br/1091529937004985; Universidade Federal de São Paulo (UNIFESP)The study of reactive oxygen species becomes interesting due to production by normal cellular metabolism, in the presence of diseases and the ability to oxidize biological macromolecules. H2O2 included in the ROS class is often studied, but the effects are quite variable depending on the tissue, organ and the animal species studied. In general, H2O2 has a dual effect on biological systems, depending on concentration range, acting deleteriously at high concentrations (range of μM to mM) or as a cell marker at lower concentrations (nM range). Thus, the objective of this study was to investigate the effect of exogenous H2O2 administration in ileum isolated from mice to evaluate possible changes in morphology, redox state and antioxidant defense to further deepen the understanding of the effects of induced oxidative stress in ileum. The following results were observed: the exogenous administration of H2O2 for 20 minutes promoted changes depending on the concentration: at 100 nM concentration, was observed an increase in the thickness of the longitudinal and circular layer, with a moderate alteration of the intestinal mucosa, but an increase in lipid peroxidation. At concentrations of 100 μM and 1 mM were observed total villus destruction of the intestinal mucosa and reduction of the muscular layer. In relation to the redox state, there was a decrease in the activity of the antioxidant enzyme catalase (CAT), but of activation of the enzyme superoxide dismutase (SOD) and maintenance of levels of lipid peroxidation at concentrations of 100 μM and 1 mM. These data are indicative of the similarity of mouse ileum results as described in other animal species, that is, ileum is extremely sensitive to exogenous H2O2 administration and this compound acts positively or negatively on the structural and functional integrity of the organ.
- ItemSomente MetadadadosEffect of fish or soybean oil-rich diets on bradykinin, kallikrein, nitric oxide, leptin, corticosterone and macrophages in carrageenan stimulated rats(Springer, 2005-04-01) Wohlers, Marta [UNIFESP]; Xavier, Roberta Araújo Navarro [UNIFESP]; Oyama, Lila Missae [UNIFESP]; Ribeiro, Eliane Beraldi [UNIFESP]; Nascimento, Claudia Maria da Penha Oller do [UNIFESP]; Casarini, Dulce Elena [UNIFESP]; Silveira, Vera Lucia Flor [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)We have previously demonstrated that both n-3 and n-6 polyunsaturated fatty acids (PUFA)-rich diets decrease the acute inflammatory response partially explained by the high corticosterone basal levels. the present study aimed to determine the effect of hyperlipidic diets (PUFA n-3 or n-6) on phagocytosis, hydrogen peroxide (H2O2) and nitric oxide (NO) release by macrophages, bradykinin (BK) and NO release in the paw inflammatory perfusate and Kallikrein (KK), corticosterone and leptin blood levels. Hyperlipidic diets decreased H2O2 release from macrophages stimulated by carrageenan or phorbol-miristate-acetate (PMA), NO release from macrophage stimulated by carrageenan, BK and NO release in the edema perfusate, KK plasma levels and the increase of serum leptin after carrageenan stimulus. These data show that both fish and soybean oil-rich diets promote similar alterations on inflammatory mediators of carrageenan edema and a causal association with the anti-inflammatory effect of these diets.
- ItemAcesso aberto (Open Access)Hydrogen peroxide (H2O2) induces leukemic but not normal hematopoietic cell death in a dose-dependent manner(Biomed Central Ltd, 2013-12-23) Nogueira-Pedro, Amanda [UNIFESP]; Cesario, Thalyta Aparecida Munhoz [UNIFESP]; Dias, Carolina Carvalho [UNIFESP]; Origassa, Clarice Silvia Taemi [UNIFESP]; Eça, Lilian Piñero Marcolin; Paredes-Gamero, Edgar Julian [UNIFESP]; Ferreira, Alice Teixeira [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); IPCTRON Stem Cell Res InstOver the last few years, studies have suggested that oxidative stress plays a role in the regulation of hematopoietic cell homeostasis. in particular, the effects of hydrogen peroxide (H2O2) range from hematopoietic cell proliferation to cell death, depending on its concentration in the intracellular milieu. in this work, we evaluated the effects of an oxidative environment on normal and leukemic hematopoietic cells by stimulating normal human (umbilical cord blood) and murine (bone marrow) hematopoietic cells, as well as human myeloid leukemic cells (HL-60 lineage), upon H2O2 stimulus. Total cell populations and primitive subsets were evaluated for each cell type. H2O2 stimulus induces HL-60 cell death, whereas the viability of human and murine normal cells was not affected. the effects of H2O2 stimulus on hematopoietic stem/progenitor cell subsets were examined and the normal primitive cells were found to be unaffected; however, the percentage of leukemic stem cells (LSC) increased in response to H2O2, while clonogenic ability of these cells to generate myeloid clones was inhibited. in addition, H2O2 stimulus caused a decrease in the levels of p-AKT in HL-60 cells, which most likely mediates the observed decrease of viability. in summary, we found that at low concentrations, H2O2 preferentially affects both the LSC subset and total HL-60 cells without damage normal cells.
- ItemAcesso aberto (Open Access)Increased exhalation of hydrogen peroxide in healthy subjects following cigarette consumption(Associação Paulista de Medicina - APM, 2000-07-06) Guatura, Sandra Baltazar [UNIFESP]; Martinez, José Antônio Baddini [UNIFESP]; Bueno, Patricia Cincotto dos Santos [UNIFESP]; Santos, Manuel Lopes dos [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); University of São Paulo Medical School of Ribeirão Preto Department of MedicineCONTEXT: Increased hydrogen peroxide has been described in the expired breath condensate (H2O2-E) of several lung conditions, such as acute respiratory distress syndrome, chronic obstructive pulmonary disease and asthma. This technique has been advocated as being a simple method for documenting airway inflammation. OBJECTIVE: To evaluate H2O2-E in healthy cigarette smokers, and to determine the acute effects of the consumption of one cigarette on H2O2-E levels. TYPE OF STUDY: Prospective, controlled trial. SETTING: A pulmonary function laboratory in a University Hospital. PARTICIPANTS: Two groups of healthy volunteers: individuals who had never smoked (NS; n=10; 4 men; age = 30.6 ± 6.2 years) and current cigarette smokers (S; n=12; 7 men; age = 38.7 ± 9.8). None of the volunteers had respiratory symptoms and all showed normal spirometric tests. INTERVENTION: Expired air was collected from all volunteers through a face mask and a plastic collecting system leading into a flask with dry ice and pure ethanol. Samples from the group S were collected twice, before and half an hour after the combustion of one cigarette. MAIN MEASUREMENTS: Expired hydrogen peroxide using the Gallati and Pracht method. RESULTS: The S and NS groups showed comparable levels of H2O2-E at basal conditions [NS = 0.74 muM (DP 0.24) vs. S = 0.75 muM (DP 0.31)]. The smokers showed a significant increase in H2O2-E levels half an hour after the consumption of only one cigarette [0.75 muM (DP 0.31) vs. 0.95 muM (DP 0.22)]. CONCLUSION: The present results are consistent with the concept that smokers increase oxidative stress with elevated production of reactive oxygen species, contributing to the development of smoking-related disorders.
- ItemSomente MetadadadosOptical Properties of Metacycline, Oxytetracycline and Chlortetracycline Europium Complexes in the Presence of Hydrogen Peroxide(Springer, 2009-07-01) Grasso, Andrea Nastri; Teixeira, Luciane dos Santos; Vieira, Nilson Dias; Courrol, Lilia Coronato [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); IPEN CNEN SPTetracycline possesses a great tendency to form complexes with a number of chemical species, particularly with Eu(3+) ions. in this work we investigate the europium optical properties of three tetracyclines europium complexes: Metacycline (MTc), Oxytetracycline (OTc), and Chlortetracycline (CTc), in the presence and absence of hydrogen peroxide (HP). the results show that the emission band of EuOTc have enhancement in the presence of hydrogen peroxide. A calibration curve was shown for this complex with the best molar ratio obtained.
- ItemSomente MetadadadosRelação entre o exercício aeróbio moderado e o estresse oxidativo induzido pelo peróxido de hidrogênio(H2O2) sobre a resposta contrátil de íleo isolado de camundongo(Universidade Federal de São Paulo (UNIFESP), 2004) Vancini, Rodrigo Luiz [UNIFESP]; Nouailhetas, Viviane Louise Andreé [UNIFESP]Introdução: Sabe-se que diferentes concentrações de H202 e exercícios de diferentes intensidades interferem no status oxidativo de tecidos e órgãos. Recentemente, demonstramos que a administração exógena de H202 e o exercício aeróbio moderado prejudicam a reatividade a diversos agentes estimulantes em íleo de cobaia e de camundongos C57BL/6, respectivamente. Objetivos: Neste trabalho, investigamos se os eventuais efeitos deletérios da administração exógena de H202 sobre a reatividade intestinal de camundongos C57BL/6 estariam relacionados ao nível de estresse oxidativo induzido por este peróxido, e se um programa de exercício aeróbio moderado protegeria este tecido dos eventuais efeitos deletérios da administração exógena de H202. Metodologia: Camundongos machos, com 3 meses de idade, foram subdivididos em grupos SED, EX 55 e NC, após uma semana de adaptação à corrida em esteira. O programa de exercício aeróbio moderado consistiu de uma sessão de 60 min/dia, 5 vezes/semana, durante 55 dias. Os parâmetros estudados foram a velocidade máxima atingida em um teste de velocidade incremental; a relação peso úmido do coração/peso corporal; o nível de estresse oxidativo dos músculos gastrocnêmio, masseter e do íleo, quantificado pela medida da reação dos produtos da peroxidação lipídica (PL) da membrana com o TBARs; a análise microscópica de cortes histológicos das fibras dos músculos gastrocnêmio, masseter e do íleo corados com hematoxilina/eosina. A reatividade foi estudada pelo registro da resposta contrátil isométrica disparada pelo KCI (acoplamento eletromecânico) ou CCh (acoplamento farmacomecânico) do íleo isolado banhado em solução de Tyrode, pH 7,4, borbulhados com ar e equilibrados a 37°C. A potência e a eficácia foram estudadas a partir de curvas concentrações-resposta aos agentes estimulantes (1,5 min de contato e 5 min de intervalo entre as concentrações), determinando-se os valores de CE50 (concentração do estimulante que provoca 50 por cento da resposta contrátil máxima) e da resposta máxima (Emáx). Os efeitos do H202 sobre a reatividade intestinal foram avaliados através de alterações dos valores de CE50 e do Emáx ao KCI e CCh de curvas concentrações-resposta feitas após o contato de 20 min com H202 0,012, 0,03 e 0,3 mM, seguida de lavagem exaustiva durante 10 min…(au).
- ItemAcesso aberto (Open Access)Vitamina C no Estresse Oxidativo induzido pelo H2O2 em Fibroblastos Humanos Cultivados(Universidade Federal de São Paulo (UNIFESP), 2010-04-28) Manuel, Jorge [UNIFESP]; Gragnani, Alfredo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introdução: EROs são produzidas durante o metabolismo normal das células, tendo funções fisiológicas importantes como a sinalização celular. Porém, em uma situação que leve o organismo a uma produção exagerada de EROs, temos o chamado estresse oxidativo, que tem ação deletéria às células, podendo levar à apoptose ou à senescência celular . A vitamina C é um dos principais agentes antioxidantes do organismo, atuando em todas as formas de estresse oxidativo. Objetivo: O presente estudo teve como objetivo verificar o efeito da vitamina C em cultura de fibroblastos humanos dérmicos submetida ao estresse oxidativo pelo peróxido de hidrogênio. Método: O método constitui-se no isolamento e cultivo de fibroblastos humanos dérmico em seis grupos: controle, Vitamina C+, Vitamina C -, H2O2, Vitamina C + H2O2, Vitamina C - H2O2. Os fibroblastos foram submetidos ao estresse oxidativo pela suplementação de H2O2 ao meio de cultura por 2 horas. Foram avaliados a proliferação pelo MTT, a senescência celular pela marcação da enzima beta-galoctosidase, a apoptose celular e a liberação de EROs pela citometria de fluxo. Resultados: Os resultados demonstraram que o peróxido de hidrogênio aumentou significantemente a senescência celular e a apoptose nos fibroblastos. A vitamina C diminuiu significantemente a indução da senescência celular somente no estado intracelular. Conclusão: Concluiu-se que a vitamina C não protegeu os fibroblastos humanos dérmicos cultivados contra o estresse oxidativo induzido pelo H2O2 e que a Vitamina C intracelular levou a uma diminuição da indução da senescência celular.