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Registros recuperados: 143 | |
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Goldstein,J.; Silberstein,C.; Ibarra,C.. |
Adenylyl cyclase (AC) isoforms catalyze the synthesis of 3',5'-cyclic AMP from ATP. These isoforms are critically involved in the regulation of gene transcription, metabolism, and ion channel activity among others. Nitric oxide (NO) is a gaseous product whose synthesis from L-arginine is catalyzed by the enzyme NO synthase. It has been well established that NO activates the enzyme guanylyl cyclase, but little has been reported on the effects of NO on other important second messengers, such as AC. In the present study, the effects of sodium nitroprusside (SNP), a nitric oxide-releasing compound, on COS-7 cells transfected with plasmids containing AC types I, II, V and VI were evaluated. Total inhibition (~98.5%) of cAMP production was observed in COS-7... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adenylyl cyclase; Nitric oxide; Sodium nitroprusside; Cyclic AMP; COS-7 cells; Signal transduction. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000200002 |
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Astolfi,R.S.; Khouri,D.G.; Brandizzi,L.I.V.; Ávila-Campos,M.J.; Andrade Jr.,H.F. de. |
Sepsis, the leading cause of death in intensive care units, is associated with overproduction of nitric oxide (NO) due to inducible NO synthase (iNOS), responsible for some of the pathologic changes. Aminoguanidine (AG) is a selective iNOS inhibitor with reported inconsistent actions in sepsis. To investigate the influence of iNOS, we studied models of acute bacterial sepsis using acute challenges with aerobic (Escherichia coli) and anaerobic (Bacteroides fragilis) bacteria in the presence of AG. Six-week-old, 23 g, male and female BALB/c and C57Bl/6j mice, in equal proportions, were inoculated (ip) with bacteria in groups of 4 animals for each dose and each experiment in the absence or presence of AG (50 mg/kg, ip, starting 24 h before challenge and daily... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Nitric oxide; Sepsis; Experimental model; Bacterial infections; Escherichia coli; Bacteroides fragilis. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2007000300006 |
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Oliveira,D.M.; Silva-Teixeira,D.N.; Araújo-Filho,R.; Goes,A.M.. |
Nitric oxide (NO) is an extremely important and versatile messenger in biological systems. It has been identified as a cytotoxic factor in the immune system, presenting anti- or pro-inflammatory properties under different circumstances. In murine monocytes and macrophages, stimuli by cytokines or lipopolysaccharide (LPS) are necessary for inducing the immunologic isoform of the enzyme responsible for the high-output production of NO, nitric oxide synthase (iNOS). With respect to human cells, however, LPS seems not to stimulate NO production in the same way. Addressing this issue, we demonstrate here that peripheral blood mononuclear cells (PBMC) obtained from schistosomiasis-infected patients and cultivated with parasite antigens in the in vitro granuloma... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitric oxide; LPS; Schistosomiasis infection; In vitro granuloma. |
Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001100015 |
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Mariano,F.S.; Campanelli,A.P.; Nociti Jr.,F.H.; Mattos-Graner,R.O.; Gonçalves,R.B.. |
Neutrophils play an important role in periodontitis by producing nitric oxide (NO) and antimicrobial peptides, molecules with microbicidal activity via oxygen-dependent and -independent mechanisms, respectively. It is unknown whether variation in the production of antimicrobial peptides such as LL-37, human neutrophil peptides (HNP) 1-3, and NO by neutrophils influences the pathogenesis of periodontal diseases. We compared the production of these peptides and NO by lipopolysaccharide (LPS)-stimulated neutrophils isolated from healthy subjects and from patients with periodontitis. Peripheral blood neutrophils were cultured with or without Aggregatibacter actinomycetemcomitans-LPS (Aa-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and Escherichia coli-LPS... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antimicrobial peptides; Nitric oxide; Neutrophils; Periodontitis; Innate immunity. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001100004 |
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Lopes,L.S.; Marques,R.B.; Pereira,S.S.; Ayres,M.C.C.; Chaves,M.H.; Cavalheiro,A.J.; Vieira Júnior,G.M.; Almeida,F.R.C.. |
Previous studies on Combretum leprosum, a tree growing in the Northeastern states of Brazil, have shown antinociceptive effects of the ethanol extract of its leaves and bark, but studies examining its constituents are rare. The objective of this study was to evaluate the antinociceptive effect of the hydroalcoholic fraction (HF) of one of its constituents, the flavonoid (-) epicatechin (EPI), administered orally to mice (20-30 g) in models of chemical nociception, and the possible mechanisms involved. Different doses of HF (62.5 to 500 mg/kg) and EPI (12.5 to 50 mg/kg) were evaluated in models of abdominal writhing, glutamate, capsaicin, and formalin in animals pretreated with different antagonists: naloxone, ondansetron, yohimbine, ketanserin, pindolol,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Combretum leprosum; Epicatechin; Antinociceptive; Serotonin; Nitric oxide. |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010001200008 |
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de-Oliveira,R.W.; Guimarães,F.S.. |
The dorsal periaqueductal gray (DPAG) has been implicated in the behavioral and autonomic expression of defensive reactions. Several results suggest that, along with GABA, glutamate and serotonin, nitric oxide (NO) may play a role in defense reactions mediated by this region. To further investigate this possibility we microinjected methylene blue (MB; 10, 30 or 100 nmol/0.5 µl) into the DPAG of rats submitted to the elevated plus-maze test, an animal model of anxiety. MB has been used as an inhibitor of soluble guanylate cyclase (sGC) to demonstrate cGMP-mediated processes, and there is evidence that NO may exert its biological effects by binding to the heme part of guanylate cyclase, causing an increase in cGMP levels. The results showed that MB (30 nmol)... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Anxiety; Elevated plus-maze; Nitric oxide; Animal model. |
Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001200012 |
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Olinto,S.C.F.; Adrião,M.G.; Castro-Barbosa,T.; Goulart-Silva,F.; Nunes,M.T.. |
The amino acid arginine (Arg) is a recognized secretagogue of growth hormone (GH), and has been shown to induce GH gene expression. Arg is the natural precursor of nitric oxide (NO), which is known to mediate many of the effects of Arg, such as GH secretion. Arg was also shown to increase calcium influx in pituitary cells, which might contribute to its effects on GH secretion. Although the mechanisms involved in the effects of Arg on GH secretion are well established, little is known about them regarding the control of GH gene expression. We investigated whether the NO pathway and/or calcium are involved in the effects of Arg on GH gene expression in rat isolated pituitaries. To this end, pituitaries from approximately 170 male Wistar rats (~250 g) were... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Arginine; GH mRNA expression; Nitric oxide; Calcium (Ca2+); Cyclic guanosine monophosphate. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001100011 |
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Fernandes, Jovanir Inês Müller; Universidade Federal do Paraná; Murakami, Alice Eiko; UEM. |
Due to the lack of a complete urea cycle, uricotelic species, such as broilers, are not able to synthesize de novo arginine (Arg), thus depending exclusively on dietary Arg. High levels of dietary lysine (Lys) increase the demand for Arg because of the antagonistic relationship between these amino acids. The Arg-Lys antagonism promotes an expressive increase in the renal Arg activity and consequently induces the degradation of Arg and the decrease in the activity of glycine amidinotransferase, an enzyme that uses Arg in the synthesis of muscle creatin. Arg is considered an important modulator of immunological and physiological processes. The degradation of Arg produces ornithine, a precursor of polyamines that are key to cell division, DNA synthesis, and... |
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Palavras-chave: Carbamoyl phosphatase synthetase; Creatine; Immune system; Nitric oxide; Polyamines; Urea cycle carbamoyl phosphatase synthetase; Creatine; Immune system; Nitric oxide; Polyamines; Urea cycle. |
Ano: 2010 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/10990 |
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Registros recuperados: 143 | |
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