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| Registros recuperados: 33 | |
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| Pedro,M.A.; Augusto,O.; Barbeiro,H.V.; Carvalho,M.H.C.; da-Luz,P.L.; Laurindo,F.R.M.. |
| Methylated arginine analogues are often used as probes of the effect of nitric oxide; however, their specificity is unclear and seems to be frequently overestimated. This study analyzed the effects of NG-methyl-L-arginine (L-NMMA) on the endothelium-dependent release of vascular superoxide radicals triggered by increased flow. Plasma ascorbyl radical signals measured by direct electron paramagnetic resonance spectroscopy in 25 rabbits increased by 3.8 ± 0.7 nmol/l vs baseline (28.7 ± 1.4 nmol/l, P<0.001) in response to papaverine-induced flow increases of 121 ± 12%. In contrast, after similar papaverine-induced flow increases simultaneously with L-NMMA infusions, ascorbyl levels were not significantly changed compared to baseline. Similar results... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Free radicals; Arginine analogues; NG-methyl-L-arginine; NG-methyl-D-arginine; NG-nitro-L-arginine methyl ester. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000600004 |
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| Romão,P.R.T.; Tovar,J.; Fonseca,S.G.; Moraes,R.H.; Cruz,A.K.; Hothersall,J.S.; Noronha-Dutra,A.A.; Ferreira,S.H.; Cunha,F.Q.. |
| Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Leishmania; Glutathione; Trypanothione; Trypanothione reductase; Nitric oxide; Free radicals. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000300006 |
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| Carreira,R.S.; Facundo,H.T.F.; Kowaltowski,A.J.. |
| Mitochondrial ion transport, oxidative phosphorylation, redox balance, and physical integrity are key factors in tissue survival following potentially damaging conditions such as ischemia/reperfusion. Recent research has demonstrated that pharmacologically activated inner mitochondrial membrane ATP-sensitive K+ channels (mitoK ATP) are strongly cardioprotective under these conditions. Furthermore, mitoK ATP are physiologically activated during ischemic preconditioning, a procedure which protects against ischemic damage. In this review, we discuss mechanisms by which mitoK ATP may be activated during preconditioning and the mitochondrial and cellular consequences of this activation, focusing on end-effects which may promote ischemic protection. These... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mitochondria; Potassium; Calcium; Free radicals; Heart; Ischemia. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000300004 |
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| Torres,R.L.; Torres,I.L.S.; Gamaro,G.D.; Fontella,F.U.; Silveira,P.P.; Moreira,J.S.R.; Lacerda,M.; Amoretti,J.R.; Rech,D.; Dalmaz,C.; Belló,A.A.. |
| Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Stress; TBARS; TRAP; Free radicals; Lungs; Oxidative stress. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000200004 |
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| Voces,J.; Cabral de Oliveira,A.C.; Prieto,J.G.; Vila,L.; Perez,A.C.; Duarte,I.D.G.; Alvarez,A.I.. |
| Enzymatic activity was analyzed in the soleus, gastrocnemius (red and white) and plantaris muscles of acutely exercised rats after long-term administration of Panax ginseng extract in order to evaluate the protective role of ginseng against skeletal muscle oxidation. Ginseng extract (3, 10, 100, or 500 mg/kg) was administered orally for three months to male Wistar rats weighing 200 ± 50 g before exercise and to non-exercised rats (N = 8/group). The results showed a membrane stabilizing capacity of the extract since mitochondrial function measured on the basis of citrate synthase and 3-hydroxyacyl-CoA dehydrogenase activities was reduced, on average, by 20% (P < 0.05) after exercise but the activities remained unchanged in animals treated with a ginseng... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Panax ginseng; Exercise; Free radicals; Lipid peroxidation; Glutathione status; Mitochondria. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004001200012 |
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| Belló-Klein,A.; Oliveira,A.R.; Miranda,M.F.S.; Irigoyen,M.C.; Homem-de-Bittencourt Jr.,P.I.; Llesuy,S.; Belló,A.A.. |
| Hydrogen peroxide (H2O2) perfused into the aorta of the isolated rat heart induces a positive inotropic effect, with cardiac arrhythmia such as extrasystolic potentiation or cardiac contractures, depending on the dose. The last effect is similar to the "stone heart" observed in reperfusion injury and may be ascribed to lipoperoxidation (LPO) of the membrane lipids, to protein damage, to reduction of the ATP level, to enzymatic alterations and to cardioactive compounds liberated by LPO. These effects may result in calcium overload of the cardiac fibers and contracture ("stone heart"). Hearts from male Wistar rats (300-350 g) were perfused at 31oC with Tyrode, 0.2 mM trolox C, 256 mM H2O2 or trolox C + H2O2. Cardiac contractures (baseline elevation of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Trolox C; "stone heart"; Free radicals; Hydrogen peroxide. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001100013 |
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| Dolganova,A.; Sharonov,B.P.. |
| We determined the effect of the antioxidants superoxide dismutase, desferrioxamine and allopurinol on the survival of male CBA mice infected intranasally with 2-5 LD50 lung influenza virus A/Aichi/2/68. Survival for at least 20 days was observed for 45% of the mice that received 1000 U/day superoxide dismutase prepared from red blood cells on days 5, 6, 7 and 8 after infection, and 75% survival was observed for mice that received the same dose on days 4, 5, 6, 7 and 8. Desferrioxamine, 25 mg/kg per day and 100 mg/kg per day injected subcutaneously, resulted in survival rates of 5 and 0%, respectively, compared to 10% survival observed for saline-injected controls. Allopurinol at doses of 5 to 50 mg/kg per day had no effect on mouse survival. These data... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Free radicals; Influenza; Antioxidant; Desferrioxamine; Superoxide dismutase; Allopurinol. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001100012 |
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| Vellosa,José Carlos Rebuglio; Khalil,Najeh Maissar; Gutierres,Vânia Ortega; Santos,Vânia Aparecida de Freitas Formenton Macedo dos; Furlan,Maysa; Brunetti,Iguatemy Lourenço; Oliveira,Olga Maria Mascarenhas de Faria. |
| Reactive oxygen species (ROS) and free radical species have been implicated in initiating or accompanying many diseases in living organisms; there is thus, a continual need for antioxidants molecules to inactivate ROS/free radicals. Many studies of plants crude extracts have demonstrated free-radical scavenging and antioxidant action. Salacia species have long been used, in several countries, as traditional medicines against certain diseases and for their anti-inflammatory properties. In this study, Salacia campestris Walp (Hippocrateaceae) root bark ethanol extract (ScEtOH) was assessed for its ability to scavenge free radicals and reactive oxygen species; the results were expressed as percentage inhibition of the active species. ScEtOH was efficient... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Salacia campestris Walp/antioxidant properties; Hippocrateaceae; Myeloperoxidase; Reactive oxygen species; Antioxidants; Free radicals. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502009000100012 |
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| Lira,Giselda Macena; Lopez,Ana Maria Queijeiro; Firmino,Guilherme Oliveira; Santos,Suzan Diniz; Bezerra,Ranilson de Souza. |
| ABSTRACT Shrimps are sources of carotenoids, astaxanthin is the predominant, responsible for their special and desirable properties, as well as for their instability under heat treatment during the domestic preparation, industrial processing or storage under freezing. These can cause discoloration and reduce the beneficial health properties. This study aimed to evaluate the effect of heat treatment and storage under freezing (0, 45 and 90 days) on the levels of total carotenoids and stability of the antioxidant activity of ethanolic extracts of fillets and shells, raw and cooked, of the white shrimp (“Vila Franca”) Litopenaeus schmitti (Burkenroad, 1938). The antioxidant ability of the extracts was evaluated using the radicals DPPH•... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Free radicals; Functional food; Biomolecules oxidation. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000100094 |
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| Registros recuperados: 33 | |
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