Search results for "NITRIC OXIDE SYNTHASE"
showing 10 items of 531 documents
Nitric oxide synthase activity is inducible in rat, but not rabbit alveolar macrophages, with a concomitant reduction in arginase activity
1995
Alveolar macrophages were obtained by broncho-alveolar lavage of isolated rat and rabbit lungs and cultured (2.5 × 106 cells/dish) for 18 h in the absence or presence of bacterial lipopolysaccharides (LPS) alone or in combination with cytokines. Thereafter, accumulation of 3H-citrulline (NO synthase activity) and 3H-ornithine (arginase activity) were determined. During incubation of rat alveolar macrophages with 3H-arginine clear amounts of 3H-citrulline and 3H-ornithine (3.8 and 4.6% of the added 3H-arginine, respectively) were formed and most of these metabolites appeared in the incubation medium (ratios extra-/intracellular of 17 and 70 for 3H-citrulline and 3H-ornithine, respectively). …
Responses of retinal arterioles and ciliary arteries in pigs with acute respiratory distress syndrome (ARDS)
2019
Abstract Acute respiratory distress syndrome (ARDS) is a clinical syndrome of acute lung failure in critically sick patients, which severely compromises the function of multiple organs, including the brain. Although, the optic nerve and the retina are a part of the central nervous system, the effects of ARDS on these ocular structures are completely unknown. Thus, the major goal of this study was to test the hypothesis that ARDS affects vascular function in the eye. ARDS was induced in anesthetized pigs by intratracheal injection of lipopolysaccharide (LPS). Sham-treated animals served as controls. Pigs were monitored for 8 h and then sacrificed. Subsequently, retinal arterioles and short p…
Highly efficient liposome-mediated gene transfer of inducible nitric oxide synthase in vivo and in vitro in vascular smooth muscle cells.
2000
Objective: The efficient introduction of regulatory genes into vascular smooth muscle cells (SMCs) is one of the most promising options for gene therapy of cardiovascular diseases. Cationic liposome-mediated gene transfer may become a favorable transfection technique with regard to patient’s safety for in vivo administration. However, this method until now has its limitation in a low transfection efficiency. Therefore, the present study was designed to improve cationic liposome-mediated transfection of rabbit vascular SMCs in vitro and in vivo, in order to enhance transfection efficiency and present an optimized system which may offer a potential therapeutic benefit for in vivo application.…
Beta-MSH inhibits brain inflammation via MC(3)/(4) receptors and impaired NF-kappaB signaling.
2005
The anti-inflammatory effects of melanocortin peptides have been demonstrated in different inflammation models. This is the first report describing the molecular mechanisms for the beta-MSH-induced suppression of bacterial lipopolisaccharide (LPS)-caused brain inflammation. We found that beta-MSH suppresses LPS-induced nuclear translocation of the transcription factor NF-kappaB, and inhibits the expression of inducible nitric oxide synthase, and the following nitric oxide overproduction in the brain, in vivo. Moreover, administering the preferentially MC(4) receptor selective antagonist HS014 blocked completely these effects, suggesting a tentative MC(4) receptor mediated mechanism of actio…
Transcriptional up-regulation of nNOS in the dorsal vagal complex during low endotoxemia
2005
The present study analyses the expression and distribution of neuronal nitric oxide synthase (nNOS) in the brainstem of animals pre-treated with Escherichia coli or Helicobacter pylori LPS, at doses that modulate gastric motor function. Systemic administration of H. pylori LPS prevented in a dose-dependent manner (5, 40 and 100 microg kg(-1), i.v.) the increase in intragastric pressure induced by 2-deoxy-D-glucose (200 mg kg(-1), i.v.) in urethane-anaesthetized rats. Quantitative analysis showed a significant increase in the amount of nNOS mRNA induced by E. coli or H. pylori LPS (2 h later), in a segment of the brainstem containing the dorsal vagal complex (DVC). Immunohistochemical studie…
ttCH, a selective inhibitor of inducible nitric oxide synthase expression with antiarthritic properties
2003
In a previous work, we investigated the effects of a series of dimethoxy- and trimethoxychalcone derivatives, with various patterns of fluorination, on nitric oxide production in lipopolysaccharide-stimulated murine RAW 264.7 cells. The present study was designed to determine if 2,4,6-trimethoxy-2'-trifluoromethylchalcone (ttCH) could modulate the production of nitric oxide (NO) and/or prostaglandins in vitro and in vivo. On the mouse macrophage cell line RAW 264.7, ttCH inhibited dose-dependently NO and prostaglandin E(2) production, with IC(50) in the micromolar range. This compound had no direct inhibitory effect on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 activities. …
Interaction of dicaffeoylquinic derivatives with peroxynitrite and other reactive nitrogen species.
2008
Plant phenolic antioxidants, among them catechins and hydroxycinnamoyl conjugates, constitute a well defined class of inhibitors of reactive nitrogen species (RNS). To gain deeper insight in this field, we examined the effects of 3,5-di-O-caffeoylquinic acid (DCA), its methyl ester (DCE) and epigallocatechin gallate (EGCG) in nitrative and oxidative processes. These compounds were found to be strong inhibitors of the nitration of tyrosine residues induced by ONOO- in bovine seroalbumin, with their IC50 values (10-40 microM) notably decreasing in the presence of bicarbonate. When studied on the intracellular protein tyrosine nitration induced by ONOO- in cultured murine fibroblasts as well a…
Colocalization but differential regulation of neuronal NO synthase and nicotinic acetylcholine receptor in C2C12 myotubes.
2003
In mammalian skeletal muscle, neuronal-type nitric oxide synthase (nNOS) is found to be enriched at neuromuscular endplates. Here we demonstrate the colocalization of the nicotinic acetylcholine receptor (nAChR, stained with α-bungarotoxin) and nNOS (stained with a specific antibody) in murine C2C12myotubes. However, coimmunoprecipitation experiments demonstrated no evidence for a direct protein-protein association between the nAChR and nNOS in C2C12myotubes. An antibody to the α1-subunit of the nAChR did not coprecipitate nNOS, and an nNOS-specific antibody did not precipitate the α1-subunit of the nAChR. Treatment of mice with bacterial LPS downregulated the expression of nNOS in skeletal…
Inhibition of leukocyte functions by the alkaloid isaindigotone from Isatis indigotica and some new synthetic derivatives.
2001
The alkaloid isaindigotone (1a) and seven derivatives have been synthesized to study their influence on several leukocyte functions and the generation of inflammatory mediators. Isaindigotone (1a) was found to be a scavenger of superoxide generated either by the hypoxanthine/xanthine oxidase system or stimulated human neutrophils. Isaindigotone (1a) and its acetylated derivative (1b) also inhibited 5-lipoxygenase activity and leukotriene B(4) production in these cells, whereas none of the compounds affected degranulation. In RAW 264.7 macrophages stimulated with lipopolysaccharide, synthetic derivatives exerted higher inhibitory effects on prostaglandin E(2) (PGE(2)) and nitric oxide (NO) g…
Prostaglandin E2 regulates inducible nitric oxide synthase in the murine macrophage cell line J774.
1995
We have evaluated the role of prostaglandin E2 (PGE2) in the synthesis of nitric oxide (NO) by the activation of the inducible form of nitric oxide synthase (NOS) in the murine macrophage cell line, J774, stimulated with different doses of lipopolysaccharide (LPS). The stimulation of the J774 line with suboptimal doses of LPS (0.1 microgram/mL) caused a production of endogenous PGE2 that was capable of stimulating NOS activity inducing an increase in the NO synthesis, as attested by the fact that cyclooxygenase enzyme inhibitor, indomethacin, significantly reduced NO secretion. On the contrary, a higher dose of LPS (1 microgram/mL) produced high levels of PGE2 that reduced the levels of NOS…