SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Silva,J.S.; Aliberti,J.C.S.; Martins,G.A.; Souza,M.A.; Souto,J.T.; Pádua,M.A..

Host resistance to Trypanosoma cruzi infection is dependent on both natural and acquired immune responses. During the early acute phase of infection in mice, natural killer (NK) cell-derived IFN-<FONT FACE="Symbol">g</font> is involved in controlling intracellular parasite replication, mainly through the induction of nitric oxide biosynthesis by activated macrophages. We have shown that IL-12, a powerful inducer of IFN-<FONT FACE="Symbol">g</font> production by NK cells, is synthesized soon after trypomastigote-macrophage interaction. The role of IL-12 in the control of T. cruzi infection in vivo was determined by treating infected mice with anti-IL-12 monoclonal antibody (mAb) and analyzing both parasitemia and mortality during the...

Antimicrobial peptides and nitric oxide production by neutrophils from periodontitis subjects

Palavras-chave: IL-12 Trypanosoma cruzi NK cells IFN-<; FONT FACE=Symbol>; G<; /font>; Nitric oxide.

Ano: 1998

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000100014

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...

Cellular signaling with nitric oxide and cyclic GMP

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

Murad,F..

During the past two decades, nitric oxide signaling has been one of the most rapidly growing areas in biology. This simple free radical gas can regulate an ever growing list of biological processes. In most instances nitric oxide mediates its biological effects by activating guanylyl cyclase and increasing cyclic GMP synthesis. However, the identification of effects of nitric oxide that are independent of cyclic GMP is also growing at a rapid rate. The effects of nitric oxide can mediate important physiological regulatory events in cell regulation, cell-cell communication and signaling. Nitric oxide can function as an intracellular messenger, neurotransmitter and hormone. However, as with any messenger molecule, there can be too much or too little of the...

Antagonic effect of the inhibition of inducible nitric oxide on the mortality of mice acutely infected with Escherichia coli and Bacteroides fragilis

Palavras-chave: Nitric oxide; Nitric oxide synthase; Guanylyl cyclase; Cell signaling.

Ano: 1999

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999001100001

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...

Anticonvulsant and proconvulsant roles of nitric oxide in experimental epilepsy models

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

Del-Bel,E.A.; Oliveira,P.R.; Oliveira,J.A.C.; Mishra,P.K.; Jobe,P.C.; Garcia-Cairasco,N..

The effect of acute (120 mg/kg) and chronic (25 mg/kg, twice a day, for 4 days) intraperitonial injection of the nitric oxide (NO) synthase (NOS) inhibitor NG-nitro-L-arginine (L-NOARG) was evaluated on seizure induction by drugs such as pilocarpine and pentylenetetrazole (PTZ) and by sound stimulation of audiogenic seizure-resistant (R) and audiogenic seizure-susceptible (S) rats. Seizures were elicited by a subconvulsant dose of pilocarpine (100 mg/kg) only after NOS inhibition. NOS inhibition also simultaneously potentiated the severity of PTZ-induced limbic seizures (60 mg/kg) and protected against PTZ-induced tonic seizures (80 mg/kg). The audiogenic seizure susceptibility of S or R rats did not change after similar treatments. In conclusion,...

Mechanisms of endothelial dysfunction in obesity-associated hypertension

Palavras-chave: Experimental epilepsy; Seizures; Forebrain; Brainstem; Pilocarpine; Pentylenetetrazol; Audiogenic seizures; Genetically epilepsy-prone rats; GEPR; Nitric oxide.

Ano: 1997

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000800010

Lobato,N.S.; Filgueira,F.P.; Akamine,E.H.; Tostes,R.C.; Carvalho,M.H.C.; Fortes,Z.B..

Obesity is strongly associated with high blood pressure, dyslipidemia, and type 2 diabetes. These conditions synergistically increase the risk of cardiovascular events. A number of central and peripheral abnormalities can explain the development or maintenance of high blood pressure in obesity. Of great interest is endothelial dysfunction, considered to be a primary risk factor in the development of hypertension. Additional mechanisms also related to endothelial dysfunction have been proposed to mediate the development of hypertension in obese individuals. These include: increase in both peripheral vasoconstriction and renal tubular sodium reabsorption, increased sympathetic activity and overactivation of both the renin-angiotensin system and the...

Glutathione and the redox control system trypanothione/trypanothione reductase are involved in the protection of Leishmania spp. against nitrosothiol-induced cytotoxicity

Palavras-chave: Hypertension; Obesity; Endothelial dysfunction; Oxidative stress; Renin-angiotensin system; Nitric oxide.

Ano: 2012

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000500003

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...

Arginine induces GH gene expression by activating NOS/NO signaling in rat isolated hemi-pituitaries

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

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...

Cytotoxicity of chlorhexidine digluconate to murine macrophages and its effect on hydrogen peroxide and nitric oxide induction

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

Bonacorsi,C.; Raddi,M.S.G.; Carlos,I.Z..

Chlorhexidine, even at low concentrations, is toxic for a variety of eukaryotic cells; however, its effects on host immune cells are not well known. We evaluated in vitro chlorhexidine-induced cytotoxicity and its effects on reactive oxygen/nitrogen intermediate induction by murine peritoneal macrophages. Thioglycollate-induced cells were obtained from Swiss mice by peritoneal lavage with 5 ml of 10 mM phosphate-buffered saline, washed twice and resuspended (10(6) cells/ml) in appropriate medium for each test. Cell preparations contained more than 95% macrophages. The cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay and the presence of hydrogen peroxide (H2O2) and nitric oxide (NO) by the horseradish...

Role of non-nitric oxide non-prostaglandin endothelium-derived relaxing factor(s) in bradykinin vasodilation

Palavras-chave: Chlorhexidine; Cytotoxicity; Macrophages; Nitric oxide; Hydrogen peroxide.

Ano: 2004

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000200007

Resende,A.C.; Ballejo,G.; Salgado,M.C.O..

The most conspicuous effect of bradykinin following its administration into the systemic circulation is a transient hypotension due to vasodilation. In the present study most of the available evidence regarding the mechanisms involved in bradykinin-induced arterial vasodilation is reviewed. It has become firmly established that in most species vasodilation in response to bradykinin is mediated by the release of endothelial relaxing factors following the activation of B2-receptors. Although in some cases the action of bradykinin is entirely mediated by the endothelial release of nitric oxide (NO) and/or prostacyclin (PGI2), a large amount of evidence has been accumulated during the last 10 years indicating that a non-NO/PGI2 factor accounts for...

Role of the hypothalamic pituitary adrenal axis in the control of the response to stress and infection

Palavras-chave: Prostaglandin; Bradykinin; Nitric oxide; Cytochrome P450; Potassium channels; Endothelium-dependent vasodilation.

Ano: 1998

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000900017

McCann,S.M.; Antunes-Rodrigues,J.; Franci,C.R.; Anselmo-Franci,J.A.; Karanth,S.; Rettori,V..

The release of adrenocorticotropin (ACTH) from the corticotrophs is controlled principally by vasopressin and corticotropin-releasing hormone (CRH). Oxytocin may augment the release of ACTH under certain conditions, whereas atrial natriuretic peptide acts as a corticotropin release-inhibiting factor to inhibit ACTH release by direct action on the pituitary. Glucocorticoids act on their receptors within the hypothalamus and anterior pituitary gland to suppress the release of vasopressin and CRH and the release of ACTH in response to these neuropeptides. CRH neurons in the paraventricular nucleus also project to the cerebral cortex and subcortical regions and to the locus ceruleus (LC) in the brain stem. Cortical influences via the limbic system and possibly...

Effects of lipopolysaccharide on low- and high-density cultured rabbit vascular smooth muscle cells: differential modulation of nitric oxide release, ERK1/ERK2 MAP kinase activity, protein tyrosine phosphatase activity, and DNA synthesis

Palavras-chave: Corticotropin-releasing hormone (CRH); Vasopressin; Oxytocin; Atrial natriuretic peptide (ANP); ACTH; Cortisol; Norepinephrine; Acetyl choline; Nitric oxide.

Ano: 2000

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001000001

Barbosa de Oliveira,L.C.; Rocha Oliveira,C.J.; Fries,D.M.; Stern,A.; Monteiro,H.P..

Previous studies have shown that exogenously generated nitric oxide (NO) inhibits smooth muscle cell proliferation. In the present study, we stimulated rabbit vascular smooth muscle cells (RVSMC) with E. coli lipopolysaccharide (LPS), a known inducer of NO synthase transcription, and established a connection between endogenous NO, phosphorylation/dephosphorylation-mediated signaling pathways, and DNA synthesis. Non-confluent RVSMC were cultured with 0, 5, 10, or 100 ng/ml of the endotoxin. NO release was increased by 86.6% (maximum effect) in low-density cell cultures stimulated with 10 ng/ml LPS as compared to non-stimulated controls. Conversely, LPS (5 to 100 ng/ml) did not lead to enhanced NO production in multilayered (high density) RVSMC. DNA...

Nitric oxide synthesis and biological functions of nitric oxide released from ruthenium compounds

Palavras-chave: Nitric oxide; Lipopolysaccharide; Protein tyrosine phosphatases; Mitogen-activated protein kinases; DNA synthesis; Cell density.

Ano: 2002

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000200006

Pereira,A.C.; Paulo,M.; Araújo,A.V.; Rodrigues,G.J.; Bendhack,L.M..

During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO) as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC) modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP) production, which in turn leads to protein kinase G (PKG) activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca2+ signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could...

Treatment with ascorbic acid and α-tocopherol modulates oxidative-stress markers in the spinal cord of rats with neuropathic pain

Palavras-chave: Nitric oxide; Vasodilatation; Ruthenium complex; NO-synthase; Resistance artery; Conduit vessel.

Ano: 2011

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000900017

Riffel,A.P.K.; Santos,M.C.Q.; de Souza,J.A.; Scheid,T.; Horst,A.; Kolberg,C.; Belló-Klein,A.; Partata,W.A..

Vitamin E (vit. E) and vitamin C (vit. C) are antioxidants that inhibit nociception. The effect of these vitamins on oxidative-stress markers in the spinal cord of rats with chronic constriction injury (CCI) of the sciatic nerve is unknown. This study investigated the effect of intraperitoneal administration of vit. E (15 mg·kg-1·day-1) and vit. C (30 mg·kg-1·day-1), given alone or in combination, on spinal cord oxidative-stress markers in CCI rats. Adult male Wistar rats weighing 200–250 g were divided equally into the following groups: Naive (rats did not undergo surgical manipulation); Sham (rats in which all surgical procedures involved in CCI were used except the ligature), and CCI (rats in which four ligatures were tied loosely around the right...

Nitro-fatty acids: novel anti-inflammatory lipid mediators

Palavras-chave: Total thiol; Superoxide anion generation; Nitric oxide; Lipid hydroperoxides; Hydrogen peroxide; Total antioxidant capacity.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2018000400612

Rubbo,H..

Nitro-fatty acids are formed and detected in human plasma, cell membranes, and tissue, modulating metabolic as well as inflammatory signaling pathways. Here we discuss the mechanisms of nitro-fatty acid formation as well as their key chemical and biochemical properties. The electrophilic properties of nitro-fatty acids to activate anti-inflammatory signaling pathways are discussed in detail. A critical issue is the influence of nitroarachidonic acid on prostaglandin endoperoxide H synthases, redirecting arachidonic acid metabolism and signaling. We also analyze in vivo data supporting nitro-fatty acids as promising pharmacological tools to prevent inflammatory diseases.

Anxiolytic effect of methylene blue microinjected into the dorsal periaqueductal gray matter

Palavras-chave: Nitro-fatty acids; Antioxidants; Nitric oxide; Inflammation.

Ano: 2013

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000900728

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)...

Increased expression of p38 mitogen- activated protein kinase is related to the acute renal lesions induced by gentamicin

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

Volpini,R.A.; Balbi,A.P.C.; Costa,R.S.; Coimbra,T.M..

Mitogen-activated protein kinases (MAPK) may be involved in the pathogenesis of acute renal failure. This study investigated the expression of p-p38 MAPK and nuclear factor kappa B (NF-kappaB) in the renal cortex of rats treated with gentamicin. Twenty rats were injected with gentamicin, 40 mg/kg, im, twice a day for 9 days, 20 with gentamicin + pyrrolidine dithiocarbamate (PDTC, an NF-kappaB inhibitor), 14 with 0.15 M NaCl, im, twice a day for 9 days, and 14 with 0.15 M NaCl , im, twice a day for 9 days and PDTC, 50 mg kg-1 day-1, ip, twice a day for 15 days. The animals were killed 5 and 30 days after the last of the injections and the kidneys were removed for histological, immunohistochemical and Western blot analysis and for nitrate determination. The...

Role of nitric oxide and superoxide in Giardia lamblia killing

Palavras-chave: P38 mitogen-activated protein kinase; Nuclear factor-kappaB; Inflammation; Renal fibrosis; Gentamicin-induced acute tubular necrosis; Nitric oxide.

Ano: 2006

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000600016

Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites). This effect was inhibited (>90%) by an NO synthase inhibitor (200 µM) and unaffected by superoxide dismutase (SOD, 300 U/ml). Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP) and sodium nitroprusside (SNP) in a dose-dependent manner (LD50 300 and 50 µM, respectively). A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1), did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml)...

Antagonism by hemoglobin of effects induced by L-arginine in neuromuscular preparations from rats

Palavras-chave: Nitric oxide; Macrophage; Peroxynitrite; Giardia lamblia; Cytotoxicity; Superoxide.

Ano: 1997

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000100015

Ambiel,C.R.; Alves-Do-Prado,Wilson.

Nitric oxide (NO)-synthase is present in diaphragm, phrenic nerve and vascular smooth muscle. It has been shown that the NO precursor L-arginine (L-Arg) at the presynaptic level increases the amplitude of muscular contraction (AMC) and induces tetanic fade when the muscle is indirectly stimulated at low and high frequencies, respectively. However, the precursor in muscle reduces AMC and maximal tetanic fade when the preparations are stimulated directly. In the present study the importance of NO synthesized in different tissues for the L-Arg-induced neuromuscular effects was investigated. Hemoglobin (50 nM) did not produce any neuromuscular effect, but antagonized the increase in AMC and tetanic fade induced by L-Arg (9.4 mM) in rat phrenic nerve-diaphragm...

Local inhibition of nitrergic activity in tenotomized rats accelerates muscle regeneration by increasing fiber area and decreasing central core lesions

Palavras-chave: Skeletal muscle; Nitric oxide; Tetanic fade; L-arginine; D-arginine; Hemoglobin.

Ano: 2001

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000400017

Seabra,A.D.; Moraes,S.A.S.; Batista,E.J.O.; Garcia,T.B.; Souza,M.C.; Oliveira,K.R.M.; Herculano,A.M..

Muscular atrophy is a progressive degeneration characterized by muscular proteolysis, loss of mass and decrease in fiber area. Tendon rupture induces muscular atrophy due to an intrinsic functional connection. Local inhibition of nitric oxide synthase (NOS) by Nω-nitro-L-arginine methyl ester (L-NAME) accelerates tendon histological recovery and induces functional improvement. Here we evaluate the effects of such local nitrergic inhibition on the pattern of soleus muscle regeneration after tenotomy. Adult male Wistar rats (240 to 280 g) were divided into four experimental groups: control (n=4), tenotomized (n=6), vehicle (n=6), and L-NAME (n=6). Muscular atrophy was induced by calcaneal tendon rupture in rats. Changes in muscle wet weight and total protein...