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Involvement of reactive oxygen species during early stages of ectomycorrhiza establishment between Castanea sativa and Pisolithus tinctorius

Baptista, Paula; Martins, Anabela; Pais, Maria Salomé; Tavares, Rui Manuel; Lino-Neto, Teresa
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.01%
Evidence for the participation of reactive oxygen species (ROS) and antioxidant systems in ectomycorrhizal(ECM) establishment is lacking. In this paper, we evaluated ROS production and the activities of superoxide dismutase (SOD) and catalase (CAT) during the early contact of the ECM fungus Pisolithus tinctorius with the roots of Castanea sativa (chestnut tree). Roots were placed in contact with P. tinctorius mycelia, and ROS production was evaluated by determining the levels of H2O2 and O2 I− during the early stages of fungal contact. Three peaks of H2O2 production were detected, the first two coinciding with O2 I− bursts. The first H2O2 production peak coincided with an increase in SOD activity, whereas CAT activity seemed to be implicated in H2O2 scavenging. P. tinctorius growth was evaluated in the presence of P. tinctorius-elicited C. sativa crude extracts prepared during the early stages of fungal contact. Differential hyphal growth that matched the H2O2 production profile with a delay was detected. The result suggests that during theearly stages of ECM establishment, H2O2 results from an inhibition of ROS-scavenging enzymes and plays a role in signalling during symbiotic establishment.

Diphenyleneiodonium inhibits NF-kappaB activation and iNOS expression induced by IL-1beta: involvement of reactive oxygen species

Mendes, A. Ferreira; Carvalho, A. Pato; Caramona, M. Margarida; Lopes, M. Celeste
Fonte: Taylor & Francis Ltd Publicador: Taylor & Francis Ltd
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.09%
AIMS: In this work, we studied the mechanisms by which diphenyleneiodonium chloride (DPI) inhibits nitric oxide (NO) synthesis induced by the proinflammatory cytokine interleukin-1beta (IL-1) in bovine articular chondrocytes. To achieve this, we evaluated the ability of DPI to inhibit the expression and activity of the inducible isoform of the NO synthase (iNOS) induced by IL-1. We also studied the ability of DPI to prevent IL-1-induced NF-kappaB activation and reactive oxygen species (ROS) production. RESULTS: Northern and Western blot analysis, respectively, showed that DPI dose-dependently inhibited IL-1-induced iNOS mRNA and protein synthesis in primary cultures of bovine articular chondrocytes. DPI effectively inhibited NO production (IC50=0.03+/-0.004 microM), as evaluated by the method of Griess. Nuclear factor-kappa B (NF-kappaB) activation, as evaluated by electrophoretic mobility shift assay, was inhibited by DPI (1-10 microM) in a dose-dependent manner. IL-1-induced ROS production, as evaluated by measurement of dichlorofluorescein fluorescence, was inhibited by DPI at concentrations that also prevented NF-kappaB activation and iNOS expression. CONCLUSIONS: DPI inhibits IL-1-induced NO production in chondrocytes by two distinct mechanisms: (i) by inhibiting NOS activity...

Insulin and IGF-1 improve mitochondrial function in a PI-3K/Akt-dependent manner and reduce mitochondrial generation of reactive oxygen species in Huntington’s disease knock-in striatal cells

Ribeiro, Márcio; Rosenstock, Tatiana R.; Oliveira, Ana M.; Oliveira, Catarina R.; Rego, A. Cristina
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.01%
Akt, protein kinase B; ARE, antioxidant response element; Erk, extracellular signal-regulated kinase; CBP, CREB-binding protein; CREB, cAMP response-element (CRE) binding protein; CDK, cyclin-dependent kinase; DHE, dihydroethidium; Drp1, dynamin-related protein 1 or dynamin 1-like (DNM1L); GCL, glutamate-cysteine ligase; GCLc, glutamate-cysteine catalytic subunit; GPx, glutathione peroxidase; GSH, glutathione, reduced form; GSSG, glutathione oxidized form; IGF-1, Insulin-like growth factor 1; IGF1R, insulin-like growth factor 1 receptor; IR, insulin receptor; IRS, insulin receptor substrate; H2DCFDA, 2′,7′-dichlorodihydrofluorescein diacetate; HKII, hexokinase type II; HD, Huntington’s disease; HO-1, heme oxygenase; Hsp60, heat shock 60 kDa protein 1 (chaperonin); mHtt, mutant huntingtin; mtDNA, mitochondrial DNA; MT-COII, mitochondrial-encoded cytochrome c oxidase II; mTOR, mammalian target of rapamycin; NDUFS3, NADH dehydrogenase (ubiquinone) Fe–S protein 3, 30 kDa (NADH-coenzyme Q reductase); NQO1, NAD(P)H dehydrogenase [quinone] 1; Nrf2, nuclear factor (erythroid-derived 2)-like 2; PI-3K, phosphatidylinositol 3-kinase; PGC-1α, peroxisome proliferator-activated receptor-γ coactivator 1α; ROS, reactive oxygen species; SDHA...

The role of mitochondrial DNA damage in the citotoxicity of reactive oxygen species

COSTA, R. A. P.; ROMAGNA, C. D.; PEREIRA, J. L.; SOUZA-PINTO, N. C.
Fonte: SPRINGER/PLENUM PUBLISHERS Publicador: SPRINGER/PLENUM PUBLISHERS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.04%
Mitochondria contain their own genome, a small circular molecule of around 16.5 kbases. The mitochondrial DNA (mtDNA) encodes for only 13 polypeptides, but its integrity is essential for mitochondrial function, as all 13 proteins are regulatory subunits of the oxidative phosphorylation complexes. Nonetheless, the mtDNA is physically associated with the inner mitochondrial membrane, where the majority of the cellular reactive oxygen species are generated. In fact, the mitochondrial DNA accumulates high levels of oxidized lesions, which have been associated with several pathological and degenerative processes. The cellular responses to nuclear DNA damage have been extensively studied, but so far little is known about the functional outcome and cellular responses to mtDNA damage. In this review we will discuss the mechanisms that lead to damage accumulation and the in vitro models we are establishing to dissect the cellular responses to oxidative damage in the mtDNA and to sort out the differential cellular consequences of accumulation of damage in each cellular genome, the nuclear and the mitochondrial genome.; FAPESP; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); CNPq/FAPESP through the Instituto Nacional de Ciencia e Tecnologia (INCT) Processos redox em biomedicina/Redoxoma; CNPq/FAPESP through the Instituto Nacional de Ciencia e Tecnologia (INCT) ""Processos redox em biomedicina/Redoxoma""

The role of reactive oxygen species in the modulation of the contraction induced by angiotensin II in carotid artery from diabetic rat

Pernomian, Larissa; Gomes, Mayara Santos; Araujo Restini, Carolina Baraldi; Zambelli Ramalho, Leandra Naira; Tirapelli, Carlos Renato; Oliveira, Ana Maria de
Fonte: ELSEVIER SCIENCE BV; AMSTERDAM Publicador: ELSEVIER SCIENCE BV; AMSTERDAM
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.09%
The modulation played by reactive oxygen species on the angiotensin II-induced contraction in type I-diabetic rat carotid was investigated. Concentration-response curves for angiotensin II were obtained in endothelium-intact or endothelium-denuded carotid from control or streptozotocin-induced diabetic rats, pre-treated with tiron (superoxide scavenger), PEG-catalase (hydrogen peroxide scavenger), dimethylthiourea (hydroxyl scavenger), apocynin [NAD(P) H oxidase inhibitor], SC560 (cyclooxygenase-1 inhibitor), SC236 (cyclooxygenase-2 inhibitor) or Y-27632 (Rho-kinase inhibitor). Reactive oxygen species were measured by flow cytometry in dihydroethidium (DHE)-loaded endothelial cells. Cyclooxygenase and AT1-receptor expression was assessed by immunohistochemistry. Diabetes increased the angiotensin II-induced contraction but reduced the agonist potency in rat carotid. Endothelium removal, tiron or apocynin restored the angiotensin II-induced contraction in diabetic rat carotid to control levels. PEG-catalase, DMTU or SC560 reduced the angiotensin II-induced contraction in diabetic rat carotid at the same extent. SC236 restored the angiotensin II potency in diabetic rat carotid. Y-27632 reduced the angiotensin II-induced contraction in endothelium-intact or -denuded diabetic rat carotid. Diabetes increased the DHE-fluorescence of carotid endothelial cells. Apocynin reduced the DHE-fluorescence of endothelial cells from diabetic rat carotid to control levels. Diabetes increased the muscular cyclooxygenase-2 expression but reduced the muscular AT1-receptor expression in rat carotid. In summary...

Major components of energy drinks (caffeine, taurine, and guarana) exert cytotoxic effects on human neuronal SH-SY5Y cells by decreasing reactive oxygen species production

Zeidán-Chuliá, Fares; Gelain, Daniel Pens; Kolling, Eduardo Antônio; Rybarczyk-Filho, José Luiz; Ambrosi, Priscilla; Resende Terra, Silvia; Pires, André Simões; Da Rocha, João Batista Teixeira; Antônio Behr, Guilherme; Fonseca Moreira, José Cláu
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.08%
Scope. To elucidate the morphological and biochemical in vitro effects exerted by caffeine, taurine, and guarana, alone or in combination, since they are major components in energy drinks (EDs). Methods and Results. On human neuronal SH-SY5Y cells, caffeine (0.125-2 mg/mL), taurine (1-16 mg/mL), and guarana (3.125-50 mg/mL) showed concentration-dependent nonenzymatic antioxidant potential, decreased the basal levels of free radical generation, and reduced both superoxide dismutase (SOD) and catalase (CAT) activities, especially when combined together. However, guarana-treated cells developed signs of neurite degeneration in the form of swellings at various segments in a beaded or pearl chain-like appearance and fragmentation of such neurites at concentrations ranging from 12.5 to 50 mg/mL. Swellings, but not neuritic fragmentation, were detected when cells were treated with 0.5 mg/mL (or higher doses) of caffeine, concentrations that are present in EDs. Cells treated with guarana also showed qualitative signs of apoptosis, including membrane blebbing, cell shrinkage, and cleaved caspase-3 positivity. Flow cytometric analysis confirmed that cells treated with 12.5-50 mg/mL of guarana and its combinations with caffeine and/or taurine underwent apoptosis. Conclusion. Excessive removal of intracellular reactive oxygen species...

Capacidade de desativação de espécies reativas de oxigênio por polpas de frutas congeladas; Scavenger capacity of reactive oxygen species by frozen fruit pulps

Lizziane Cynara Vissoto
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 18/10/2012 PT
Relevância na Pesquisa
96.16%
A diversidade de frutas frescas e/ou processadas comercializadas atualmente tem conquistado cada vez mais o mercado consumidor, com destaque para a produção de polpas de frutas congeladas, que além de permitirem o consumo de frutas durante o período não sazonal, possuem diversos compostos bioativos em sua composição. A atenção que as frutas e suas polpas vêm recebendo é devido ao crescente reconhecimento da associação direta entre o consumo de frutas e de vegetais e à prevenção de várias doenças crônico-degenerativas, as quais podem ser provocadas por espécies reativas, incluindo as espécies reativas de oxigênio. Este benefício tem sido atribuído aos compostos com capacidade antioxidante presentes em frutas e vegetais, com destaque para os compostos fenólicos e o ácido ascórbico. Considerando as observações acima e o aumento na comercialização e consumo de polpas de frutas congeladas, os objetivos deste trabalho foram: (1) determinar os teores de compostos fenólicos totais (CFT), flavonoides totais (FT) e ácido ascórbico (AA) nos extratos aquosos de 18 polpas de frutas congeladas, (2) avaliar a capacidade de desativação de algumas espécies reativas de oxigênio (radical peroxila (ROO?), peróxido de hidrogênio (H2O2) e radical hidroxila (?OH) por esses extratos...

The role of mitochondrial DNA damage in the citotoxicity of reactive oxygen species

COSTA, R. A. P.; ROMAGNA, C. D.; PEREIRA, J. L.; SOUZA-PINTO, N. C.
Fonte: SPRINGER/PLENUM PUBLISHERS Publicador: SPRINGER/PLENUM PUBLISHERS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.04%
Mitochondria contain their own genome, a small circular molecule of around 16.5 kbases. The mitochondrial DNA (mtDNA) encodes for only 13 polypeptides, but its integrity is essential for mitochondrial function, as all 13 proteins are regulatory subunits of the oxidative phosphorylation complexes. Nonetheless, the mtDNA is physically associated with the inner mitochondrial membrane, where the majority of the cellular reactive oxygen species are generated. In fact, the mitochondrial DNA accumulates high levels of oxidized lesions, which have been associated with several pathological and degenerative processes. The cellular responses to nuclear DNA damage have been extensively studied, but so far little is known about the functional outcome and cellular responses to mtDNA damage. In this review we will discuss the mechanisms that lead to damage accumulation and the in vitro models we are establishing to dissect the cellular responses to oxidative damage in the mtDNA and to sort out the differential cellular consequences of accumulation of damage in each cellular genome, the nuclear and the mitochondrial genome.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The antioxidant action of Polypodium leucotomos extract and kojic acid: reactions with reactive oxygen species

Gomes,A.J.; Lunardi,C.N.; Gonzalez,S.; Tedesco,A.C.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2001 EN
Relevância na Pesquisa
96.1%
Two natural products Polypodium leucotomos extract (PL) and kojic acid (KA) were tested for their ability to scavenge reactive oxygen species (·OH, ·O2-, H2O2, ¹O2) in phosphate buffer. Hydroxyl radicals were generated by the Fenton reaction, and the rate constants of scavenging were 1.6 x 10(9) M-1 s-1 for KA and 1.0 x 10(9) M-1 s-1 for PL, similar to that of ethanol (1.4 x 10(9) M-1 s-1). With superoxide anions generated by the xanthine/hypoxanthine system, KA and PL (0.2-1.0 mg/ml) inhibited ·O2-dependent reduction of nitroblue tetrazolium by up to 30 and 31%, respectively. In the detection of ¹O2 by rose bengal irradiation, PL at 1.0 mg/ml quenched singlet oxygen by 43% relative to azide and KA by 36%. The present study demonstrates that PL showed an antioxidant effect, scavenging three of four reactive oxygen species tested here. Unlike KA, PL did not significantly scavenge hydrogen peroxide.

Identification of male factor infertility using a novel semen quality score and reactive oxygen species levels

Nallella,Kiran P.; Sharma,Rakesh K.; Allamaneni,Shyam S. R.; Agarwal,Ashok
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2005 EN
Relevância na Pesquisa
96.26%
PURPOSE: To determine whether patients with male factor infertility can be accurately identified by calculating a novel semen quality score and measuring levels of reactive oxygen species during routine infertility screening. METHODS: Semen samples from 133 patients and 91 healthy donors were evaluated with manual and computer-assisted semen analysis. A principal component analysis model was employed to calculate a semen quality score. In brief, this score was calculated by base 10 logarithms multiplied by varying weights given to 9 sperm parameters. Reactive oxygen species levels were measured using chemiluminescence assay. RESULTS: The semen quality score had a sensitivity of 80.45% and accuracy of 77% at a cutoff of 93.1 in identifying patients with male factor infertility. The area under the receiver operating characteristic curves for the semen quality score was 84.28% (95% CI: 65.22%-100%). Reactive oxygen species levels [log10 (reactive oxygen species +1)] were significantly higher in male factor infertility patients. Reactive oxygen species had a sensitivity of 83.47% and specificity of 60.52% with an accuracy of 75% at a cutoff of 1.25 in identifying male factor infertility patients. The area under the receiver operating characteristic curve for reactive oxygen species levels was 78.92% (95% CI: 72.60%-85.23%). semen quality scores were significantly and negatively correlated with reactive oxygen species levels in the donors and the male factor infertility patients. CONCLUSIONS: The semen quality score and reactive oxygen species levels in semen samples appear to be strongly associated with male factor infertility. Because both of these parameters are more sensitive than individual sperm parameters in identifying male factor infertility...

Transcriptomic Footprints Disclose Specificity of Reactive Oxygen Species Signaling in Arabidopsis1[W]

Gadjev, Ilya; Vanderauwera, Sandy; Gechev, Tsanko S.; Laloi, Christophe; Minkov, Ivan N.; Shulaev, Vladimir; Apel, Klaus; Inzé, Dirk; Mittler, Ron; Van Breusegem, Frank
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /06/2006 EN
Relevância na Pesquisa
96.05%
Reactive oxygen species (ROS) are key players in the regulation of plant development, stress responses, and programmed cell death. Previous studies indicated that depending on the type of ROS (hydrogen peroxide, superoxide, or singlet oxygen) or its subcellular production site (plastidic, cytosolic, peroxisomal, or apoplastic), a different physiological, biochemical, and molecular response is provoked. We used transcriptome data generated from ROS-related microarray experiments to assess the specificity of ROS-driven transcript expression. Data sets obtained by exogenous application of oxidative stress-causing agents (methyl viologen, Alternaria alternata toxin, 3-aminotriazole, and ozone) and from a mutant (fluorescent) and transgenic plants, in which the activity of an individual antioxidant enzyme was perturbed (catalase, cytosolic ascorbate peroxidase, and copper/zinc superoxide dismutase), were compared. In total, the abundance of nearly 26,000 transcripts of Arabidopsis (Arabidopsis thaliana) was monitored in response to different ROS. Overall, 8,056, 5,312, and 3,925 transcripts showed at least a 3-, 4-, or 5-fold change in expression, respectively. In addition to marker transcripts that were specifically regulated by hydrogen peroxide...

Metabolic rate and reactive oxygen species production in different genotypes of GH-transgenic zebrafish

Rosa, Carlos Eduardo da; Figueiredo, Márcio de Azevedo; Lanes, Carlos Frederico Ceccon; Almeida, Daniela Volcan; Monserrat, José María; Marins, Luis Fernando Fernandes
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.12%
Growth hormone overexpression increases growth and consequently increases the metabolic rate in fishes. Therefore, the objective of this study was to evaluate the effects of growth hormone overexpression in zebrafish Danio rerio in terms of growth, oxygen consumption, reactive oxygen species production, lipid hydroperoxide content, antioxidant enzyme activity and glutamate-cysteine ligase catalytic subunit gene expression. The employed models were wild type and transgenic (hemizygous and homozygous) zebrafish expressing the Odonthestes argentinensis growth hormone gene directed by the Cyprinus carpio beta-actin promoter. Higher growth parameters were observed in the hemizygous group. The homozygous group possessed higher oxygen consumption and reactive oxygen species production. Growth hormone transgenesis causes a decrease in glutamate-cysteine ligase catalytic subunit expression, an enzyme responsible for glutathione synthesis. Although the lipid hydroperoxide content was similar between groups, we demonstrate that growth hormone overexpression has the potential to generate oxidative stress in fishes.

Reactive Oxygen Species Mediate Lead Effects in the Genesis of Osteoarthritis

Holz, Jonathan D. ; Puzas, J. Edward
Fonte: Universidade de Rochester Publicador: Universidade de Rochester
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
96.09%
Thesis (Ph.D.)--University of Rochester. School of Medicine and Dentistry. Dept. of Environmental Medicine, 2011.; Virtually all organ systems evaluated have proven susceptible to lead intoxication. Effects on the diarthrodial joint, however, remain an unexplored aspect of lead toxicity. Intriguingly, case-study analysis and experimental observations correlate lead exposure with joint pain and degeneration. The importance of exploring deleterious lead effects in the joint is bespoken by the magnitude and persistence of lead in the environment and the immense scope of degenerative joint diseases. Over the course of this project our goal has been to identify and describe lead effects on articular chondrocytes and the underlying mechanisms responsible for these effects. Examination of articular chondrocytes revealed that lead treatment resulted in an osteoarthritis-like phenotype. Caspase activity, type X collagen, MMPs, and oxygen consumption were all elevated while type 2 collagen was decreased. TGF-β signaling is requisite to the maintenance of normal articular chondrocyte phenotype. Interestingly, upon lead treatment TGF-β signaling intermediates, phosphoSmads2/3, were depressed and endogenous negative regulators, Smurf2 and ski...

Role of reactive oxygen species in the response of barley to necrotrophic pathogens

Able, A.
Fonte: Springer-Verlag Wien Publicador: Springer-Verlag Wien
Tipo: Artigo de Revista Científica
Publicado em //2003 EN
Relevância na Pesquisa
96.09%
The interactions between Hordeum vulgare (barley) and two fungal necrotrophs, Rhynchosporium secalis and Pyrenophora teres (causal agents of barley leaf scald and net blotch), were investigated in a detached-leaf system. An early oxidative burst specific to epidermal cells was observed in both the susceptible and resistant responses to R. secalis, and later on, a second susceptiblespecific burst was observed. Time points of the first and the second burst correlated closely with pathogen contact to the plasma membrane and subsequent cell death, respectively. HO2 •/O2 - levels in resistant and susceptible responses to P. teres were limited in comparison. During later stages, HO2 •/O2 - was only detected in 2 to 3 epidermal cells immediately adjacent to phenolic browning and cell death observed during the susceptible response. However, H2O2 was detected in the majority of mesophyll cells adjacent to the observed lesion caused by P. teres. In contrast to observations during challenge with R. secalis, no direct contact between P. teres and the plasma membrane at sites of reactive oxygen species production was evident. Preinfiltration of leaves with antioxidants prior to challenge with either pathogen had no effect on resistance responses but did limit the growth of the pathogens and inhibit the extent of cell death during susceptible responses. These results suggest a possible role for reactive oxygen species in the induction of cell death during the challenge of a susceptible plant cell with a necrotrophic fungal leaf pathogen.; http://link.springer.com/article/10.1007%2Fs00709-002-0064-1; The original publication can be found at www.springerlink.com

Reactive oxygen species and sperm function - In sickness and in health

Aitken, R.; Jones, K.; Robertson, S.
Fonte: Amer Soc Andrology Inc Publicador: Amer Soc Andrology Inc
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
96.03%
The ability of spermatozoa to generate reactive oxygen species (ROS) has been appreciated since the 1940s. It is a universal property of mature spermatozoa from all mammalian species and a major contributor to the oxidative stress responsible for defective sperm function. The mechanisms by which oxidative stress limits the functional competence of mammalian spermatozoa involve the peroxidation of lipids, the induction of oxidative DNA damage, and the formation of protein adducts. ROS production in these cells involves electron leakage from the sperm mitochondria, triggered by a multitude of factors that impede electron flow along the electron transport chain. The net result of mitochondrial ROS generation is to damage these organelles and initiate an intrinsic apoptotic cascade, as a consequence of which spermatozoa lose their motility, DNA integrity, and vitality. This pathway of programmed senescence also results in the exteriorization of phosphatidylserine, which may facilitate the silent phagocytosis of these cells in the aftermath of insemination, in turn influencing the female tract immune response to sperm antigens and future fertility. Despite the vulnerability of sperm to oxidative stress, it is also clear that normal sperm function depends on low levels of ROS generation in order to promote the signal transduction pathways associated with capacitation. Modulators of ROS generation by spermatozoa may therefore have clinical utility in regulating the fertilizing capacity of these cells and preventing the development of antisperm immunity. Achievement of these objectives will require a systematic evaluation of pro- and antioxidant strategies in vivo and in vitro.; http://www.ncbi.nlm.nih.gov/pubmed/22879525; R. J. Aitken...

INVESTIGATING THE ROLE OF REACTIVE OXYGEN SPECIES IN BENZOQUINONE-MEDIATED DNA DAMAGE AND RECOMBINATION IN FETAL HEMATOPOIETIC CELLS

MacDonald, Katharine Dawn Dawson
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
96.14%
Benzene is a ubiquitous environmental pollutant and a known human leukemogen. Early-life exposure to environmental carcinogens, including benzene, may lead to genomic instability in the fetus, ultimately leading to an increased risk for the development of childhood cancers including leukemia. It is possible that exposure to benzene results in DNA damage that may either be left unrepaired or be repaired erroneously causing genotoxicity. The first objective of this study was to determine if exposure of fetal hematopoietic cells to p-benzoquinone, a known toxic metabolite of benzene, increased DNA recombination in the pKZ1 model of mutagenesis. A significant increase in recombination was observed following exposure to 25 μM and 50 μM p-benzoquinone for 2, 4, 8, and 24 hours. A significant increase in recombination was also observed following exposure to 25 μM p-benzoquinone for 30 min, 45 min, and 1 hour, but not 15 min as compared to vehicle alone. Secondly, this study determined if exposure of fetal hematopoietic cells to p-benzoquinone resulted in DNA damage using γ-H2A.X as a marker for DNA double strand breaks and 8-hydroxy-2’-deoxyguanosine as a marker of oxidative DNA damage. A significant increase in γ-H2A.X foci formation was observed following exposure to 25 μM p-benzoquinone for 30 min...

Protective effect of flavonoids against reactive oxygen species production in sickle cell anemia patients treated with hydroxyurea

Henneberg,Railson; Otuki,Michel Fleith; Furman,Aline Emmer Ferreira; Hermann,Priscila; Nascimento,Aguinaldo José do; Leonart,Maria Suely Soares
Fonte: Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular Publicador: Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
96.21%
OBJECTIVE: The aim of this study was to evaluate the protective effects of quercetin, rutin, hesperidin and myricetin against reactive oxygen species production with the oxidizing action of tert-butylhydroperoxide in erythrocytes from normal subjects and sickle cell anemia carriers treated with hydroxyurea. METHODS: Detection of intracellular reactive oxygen species was carried out using a liposoluble probe, 2',7'-dichlorfluorescein-diacetate (DCFH-DA). A 10% erythrocyte suspension was incubated with flavonoids (quercetin, rutin, hesperidin or myricetin; 30, 50, and 100 µmol/L), and then incubated withtert-butylhydroperoxide (75 µmol/L). Untreated samples were used as controls. RESULTS: Red blood cell exposure to tert-butylhydroperoxide resulted in significant increases in the generation of intracellular reactive oxygen species compared to basal levels. Reactive oxygen species production was significantly inhibited when red blood cells were pre-incubated with flavonoids, both in normal individuals and in patients with sickle cell anemia. Quercetin and rutin had the highest antioxidant activity, followed by myricetin and hesperidin. CONCLUSION: Flavonoids, in particular quercetin and rutin, showed better antioxidant effects against damage caused by excess reactive oxygen species characteristic of sickle cell anemia. Results obtained with patients under treatment with hydroxyurea suggest an additional protective effect when associated with the use of flavonoids.

ESPÉCIES REATIVAS DE OXIGÊNIO NO CONTROLE NEUROVEGETATIVO DA PRESSÃO ARTERIAL; REACTIVE OXYGEN SPECIES IN THE AUTONOMIC CONTROL OF THE BLOOD PRESSURE

Cardoso, Leonardo M.; Colombari, Débora S A; Menani, José V.; Paula, Patrícia M.; Chianca-Junior, Deoclécio A.; Colombari, Eduardo
Fonte: Universidade de São Paulo. Faculdade de Medicina de Ribeirão Preto Publicador: Universidade de São Paulo. Faculdade de Medicina de Ribeirão Preto
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 30/03/2006 POR
Relevância na Pesquisa
96.15%
Existem evidências de que a atividade neuronal pode ser modulada pelo estado redox (balanço entre espécies químicas oxidantes e redutoras) das células, influenciando, assim, as diferentes funções biológicas que são controladas pelo sistema nervoso. Essa modulação pode ocorrer por meio de diferentes mecanismos e um deles é a modulação da transmissão sináptica no sistema nervoso central (SNC). As descargas autonômicas que são controladas por mecanismos localizados em diferentes áreas do SNC são fundamentais para o controle da pressão arterial. Um importante neurotransmissor que participa dos mecanismos centrais de controle cardiovascular é o glutamato e a transmissão glutamatérgica pode ser extensamente afetada por espécies reativas de oxigênio, oxidantes que parecem ter um importante papel em processos fisiológicos e patológicos. No presente artigo são apresentados os principais achados experimentais que suportam a hipótese de que as espécies reativas de oxigênio podem modular as funções cardiovasculares por produzir alterações nos mecanismos centrais de controle dos sistemas simpático e parassimpático. Logo, desequilíbrios na sinalização mediada por espécies reativas de oxigênios podem contribuir para o desenvolvimento de doenças cardiovasculares como a hipertensão.; The control of the blood pressure depends on the activity of select groups of neurons present in the central nervous system. Evidence has demonstrated that the redox state (a balance between oxidizing and reducing species) is involved in the control of neuronal activity...

Identificação de pacientes portadores do fator de infertilidade masculina através do cálculo de um novo escore de qualidade de sêmen e pela medida de espécies reativas de oxigênio; Identification of male factor infertility using a novel semen quality score and reactive oxygen species levels

Nallella, Kiran P.; Sharma, Rakesh K.; Allamaneni, Shyam S. R.; Agarwal, Ashok
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/08/2005 ENG
Relevância na Pesquisa
96.26%
OBJETIVO: Determinar se pacientes portadores do fator de infertilidade masculina podem ser precisamente identificados através do cálculo de um novo escore de qualidade de sêmen e pela medida de espécies reativas de oxigênio durante uma avaliação rotineira de infertilidade. MÉTODOS: Amostras de sêmen de 133 pacientes e de 91 doadores saudáveis foram avaliadas através de análise manual e computadorizada de sêmen. Um modelo de análise do componente principal foi empregado para calcular o escore de qualidade de sêmen, utilizando logaritmos base 10, multiplicados por ponderações variáveis de 9 parâmetros espermáticos. Os níveis de espécies reativas de oxigênio foram medidos através de testes de quimiluminescência. RESULTADOS: O escore de qualidade de sêmen apresentou sensibilidade de 80.45% e precisão de 77% para um "cutoff" de 93.1 na identificação do fator de infertilidade masculina. A área sob a curva "receiver operating characteristic" para o escore de qualidade de sêmen foi de 84.28% (95% intervalo de confiança: 65.22%-100%). Os níveis de espécies reativas de oxigênio [log10 (espécies reativas de oxigênio +1)] foram siginificativamente mais elevados nos pacientes portadores de fator de infertilidade masculina. A medica de espécies reativas de oxigênio apresentou sensibilidade de 83.47% e especificidade de 60.52% com uma precisão (definida como pacientes portadores do fator de infertilidade masculina com diagnóstico positivo e doadores corretamente excluídos) de 75% para um "cutoff" de 1.25 na identificação de pacientes portadores do fator de infertilidade masculina. A área sob a curva "receiver operating characteristic" para níveis de espécies reativas de oxigênio foi de 78.92% (95% intervalo de confiança: 72.60%-85.23%). Os escores de qualidade de sêmen correlacionaram negativamente com os níveis de espécies reativas de oxigênio tanto nos doadores e nos pacientes portadores do fator de infertilidade masculina. CONCLUSÕES: O escore de qualidade de sêmen e os níveis espécies reativas de oxigênio nas amostras de sêmen parecem associar-se fortemente com o fator de infertilidade masculina. Na medida em que os dois parâmetros mostraram-se mais sensíveis que parâmetros espermáticos individuais na identificação do fator de infertilidade masculina...

Reactive oxygen species in bovine embryo in vitro production

Dalvit,G.C.; Cetica,P.D.; Pintos,L.N.; Beconi,M.T.
Fonte: Biocell Publicador: Biocell
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2005 EN
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Oxidative modifications of cell components due to the action of reactive oxygen species (ROS) is one of the most potentially damaging processes for proper cell function. However, in the last few years it has been observed that ROS participate in physiological processes. The aim of this work was to determine ROS generation during in vitro production of bovine embryos. Cumulus-oocyte complexes were recovered by aspiration of antral follicles from ovaries obtained from slaughtered cows and cultured in medium 199 for 22 h at 39ºC in 5% CO2: 95% humidified air. In vitro fertilization was carried out in IVF-mSOF with frozenthawed semen in the same culture conditions and embryo in vitro culture in IVC-mSOF at 90% N2: 5% CO2: 5% O2. ROS was determined in denuded oocytes and embryos at successive stages of development by the 2´,7´-dichlorodihydrofluorescein diacetate fluorescent assay. ROS production was not modified during oocyte maturation. However, a gradual increase in ROS production was observed up to the late morula stage during embryo in vitro culture (P<0.05). In expanded blastocysts, ROS level decreased to reach values similar to the corresponding in oocytes. In the bovine species, the variation in ROS level during the complete process of embryo in vitro production was determined for the first time.