Nitric oxide-dependent activation of CaMKII increases diastolic sarcoplasmic reticulum calcium release in cardiac myocytes in response to adrenergic stimulation.

PubMed

Curran, Jerry; Tang, Lifei; Roof, Steve R; Velmurugan, Sathya; Millard, Ashley; Shonts, Stephen; Wang, Honglan; Santiago, Demetrio; Ahmad, Usama; Perryman, Matthew; Bers, Donald M; Mohler, Peter J; Ziolo, Mark T; Shannon, Thomas R

2014-01-01

Spontaneous calcium waves in cardiac myocytes are caused by diastolic sarcoplasmic reticulum release (SR Ca(2+) leak) through ryanodine receptors. Beta-adrenergic (β-AR) tone is known to increase this leak through the activation of Ca-calmodulin-dependent protein kinase (CaMKII) and the subsequent phosphorylation of the ryanodine receptor. When β-AR drive is chronic, as observed in heart failure, this CaMKII-dependent effect is exaggerated and becomes potentially arrhythmogenic. Recent evidence has indicated that CaMKII activation can be regulated by cellular oxidizing agents, such as reactive oxygen species. Here, we investigate how the cellular second messenger, nitric oxide, mediates CaMKII activity downstream of the adrenergic signaling cascade and promotes the generation of arrhythmogenic spontaneous Ca(2+) waves in intact cardiomyocytes. Both SCaWs and SR Ca(2+) leak were measured in intact rabbit and mouse ventricular myocytes loaded with the Ca-dependent fluorescent dye, fluo-4. CaMKII activity in vitro and immunoblotting for phosphorylated residues on CaMKII, nitric oxide synthase, and Akt were measured to confirm activity of these enzymes as part of the adrenergic cascade. We demonstrate that stimulation of the β-AR pathway by isoproterenol increased the CaMKII-dependent SR Ca(2+) leak. This increased leak was prevented by inhibition of nitric oxide synthase 1 but not nitric oxide synthase 3. In ventricular myocytes isolated from wild-type mice, isoproterenol stimulation also increased the CaMKII-dependent leak. Critically, in myocytes isolated from nitric oxide synthase 1 knock-out mice this effect is ablated. We show that isoproterenol stimulation leads to an increase in nitric oxide production, and nitric oxide alone is sufficient to activate CaMKII and increase SR Ca(2+) leak. Mechanistically, our data links Akt to nitric oxide synthase 1 activation downstream of β-AR stimulation. Collectively, this evidence supports the hypothesis that CaMKII is regulated by nitric oxide as part of the adrenergic cascade leading to arrhythmogenesis.

Nitric oxide synthase generates nitric oxide locally to regulate compartmentalized protein S-nitrosylation and protein trafficking

PubMed Central

Iwakiri, Yasuko; Satoh, Ayano; Chatterjee, Suvro; Toomre, Derek K.; Chalouni, Cecile M.; Fulton, David; Groszmann, Roberto J.; Shah, Vijay H.; Sessa, William C.

2006-01-01

Nitric oxide (NO) is a highly diffusible and short-lived physiological messenger. Despite its diffusible nature, NO modifies thiol groups of specific cysteine residues in target proteins and alters protein function via S-nitrosylation. Although intracellular S-nitrosylation is a specific posttranslational modification, the defined localization of an NO source (nitric oxide synthase, NOS) with protein S-nitrosylation has never been directly demonstrated. Endothelial NOS (eNOS) is localized mainly on the Golgi apparatus and in plasma membrane caveolae. Here, we show by using eNOS targeted to either the Golgi or the nucleus that S-nitrosylation is concentrated at the primary site of eNOS localization. Furthermore, localization of eNOS on the Golgi enhances overall Golgi protein S-nitrosylation, the specific S-nitrosylation of N-ethylmaleimide-sensitive factor and reduces the speed of protein transport from the endoplasmic reticulum to the plasma membrane in a reversible manner. These data indicate that local NOS action generates organelle-specific protein S-nitrosylation reactions that can regulate intracellular transport processes. PMID:17170139

Mild zinc deficiency in male and female rats: early postnatal alterations in renal nitric oxide system and morphology.

PubMed

Tomat, Analia Lorena; Veiras, Luciana Cecilia; Aguirre, Sofía; Fasoli, Héctor; Elesgaray, Rosana; Caniffi, Carolina; Costa, María Ángeles; Arranz, Cristina Teresa

2013-03-01

Fetal and postnatal zinc deficiencies induce an increase in arterial blood pressure and impair renal function in male adult rats. We therefore hypothesized that these renal alterations are present in early stages of life and that there are sexual differences in the adaptations to this nutritional injury. The aim was to study the effects of moderate zinc deficiency during fetal life and lactation on renal morphology, oxidative stress, apoptosis, and the nitric oxide system in male and female rats at 21 d of life. Female Wistar rats received low (8 ppm) or control (30 ppm) zinc diets from the beginning of pregnancy to weaning. Glomerulus number, morphology, oxidative stress, apoptotic cells, nitric oxide synthase activity, and protein expression were evaluated in the kidneys of offspring at 21 d. Zinc deficiency decreased the nephron number, induced glomerular hypertrophy, increased oxidative damage, and decreased nitric oxide synthase activity in the male and female rat kidneys. Nitric oxide synthase activity was not affected by inhibitors of the neuronal or inducible isoforms, so nitric oxide was mainly generated by the endothelial isoenzyme. Gender differences were observed in glomerular areas and antioxidant enzyme activities. Zinc deficiency during fetal life and lactation induces an early decrease in renal functional units, associated with a decrease in nitric oxide activity and an increase in oxidative stress, which would contribute to increased arterial blood pressure and renal dysfunction in adulthood. The sexual differences observed in this model may explain the dissimilar development of hypertension and renal diseases in adult life. Copyright © 2013 Elsevier Inc. All rights reserved.

Nitric oxide-mediated blood flow regulation as affected by smoking and nicotine.

PubMed

Toda, Noboru; Toda, Hiroshi

2010-12-15

Cigarette smoking is a major risk factor for atherosclerosis, cerebral and coronary vascular diseases, hypertension, and diabetes mellitus. Chronic smoking impairs endothelial function by decreasing the formation of nitric oxide and increasing the degradation of nitric oxide via generation of oxygen free radicals. Nitric oxide liberated from efferent nitrergic nerves is also involved in vasodilatation, increased regional blood flow, and hypotension that are impaired through nitric oxide sequestering by smoking-induced factors. Influence of smoking on nitric oxide-induced blood flow regulation is not necessarily the same in all organs and tissues. However, human studies are limited mainly to the forearm blood flow measurement that assesses endothelial function under basal and stimulated conditions and also determination of penile tumescence and erection in response to endothelial and neuronal nitric oxide. Therefore, information about blood flow regulation in other organs, such as the brain and placenta, has been provided mainly from studies on experimental animals. Nicotine, a major constituent of cigarette smoke, acutely dilates cerebral arteries and arterioles through nitric oxide liberated from nitrergic neurons, but chronically interferes with endothelial function in various vasculatures, both being noted in studies on experimental animals. Cigarette smoke constituents other than nicotine also have some vascular actions. Not only active but also passive smoking is undoubtedly harmful for both the smokers themselves and their neighbors, who should bear in mind that they can face serious diseases in the future, which may result in lengthy hospitalization, and a shortened lifespan. Copyright © 2010 Elsevier B.V. All rights reserved.

Nitric Oxide Generating Polymeric Coatings for Subcutaneous Glucose Sensors

DTIC Science & Technology

2007-10-01

primary polymer which was then aminated (2) for attachment of (Boc)3-cyclen-N-acetic acid (1). After the conjugation via EDC coupling chemistry, the Boc...dipping procedure is repeated 5 times. This is the needle-type NO sensor currently used (e.g., Figure 4 device but w/o the SePEI and alginic acid ...Cha, M. E. Meyerhoff, " Polymethacrylates with Covalently Linked Cu(II)-Cyclen Complex for the In-Situ Generation of Nitric Oxide from Nitrosothiols in

Distinct role of nitric oxide and peroxynitrite in mediating oligodendrocyte toxicity in culture and in experimental autoimmune encephalomyelitis.

PubMed

Li, S; Vana, A C; Ribeiro, R; Zhang, Y

2011-06-16

Nitric oxide has been implicated in the pathogenesis of multiple sclerosis. However, it is still unclear whether nitric oxide plays a protective role or is deleterious. We have previously shown that peroxynitrite, a reaction product of nitric oxide and superoxide, is toxic to mature oligodendrocytes (OLs). The toxicity is mediated by intracellular zinc release, phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), activation of 12-lipoxygenase (12-LOX) and the formation of reactive oxygen species (ROS). In this study, we found that the donors of nitric oxide, dipropylenetriamine NONOate (DPT NONOate) and diethylenetriamine NONOate (DETA NONOate), protected OLs from peroxynitrite or zinc-induced toxicity. The protective mechanisms appear to be attributable to their inhibition of peroxynitrite- or zinc-induced ERK1/2 phosphorylation and 12-LOX activation. In cultures of mature OLs exposed to lipopolysaccharide (LPS), induction of inducible nitric oxide synthase (iNOS) generated nitric oxide and rendered OLs resistant to peroxynitrite-induced toxicity. The protection was eliminated when 1400W, a specific inhibitor of iNOS, was co-applied with LPS. Using MOG35-55-induced experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, we found that nitrotyrosine immunoreactivity, an indicator of peroxynitrite formation, was increased in the spinal cord white matter, which correlated with the loss of mature OLs. Targeted gene deletion of the NADPH oxidase component gp91phox reduced clinical scores, the formation of nitrotyrosine and the loss of mature OLs. These results suggest that blocking the formation specifically of peroxynitrite, rather than nitric oxide, may be a protective strategy against oxidative stress induced toxicity to OLs. Published by Elsevier Ltd.

Study of plasma-chemical NO-containing gas flow for treatment of wounds and inflammatory processes.

PubMed

Pekshev, Alexander V; Shekhter, Anatoly B; Vagapov, Andrey B; Sharapov, Nikolay A; Vanin, Anatoly F

2018-02-28

This work is aimed at exhaustive and detailed study of chemical, physical and physico-chemical characteristics of NO-containing gas flow (NO-CGF) generated by a plasma-chemical generator of Plason device, which has been used in medical practice for more than 15 years for effectively healing wound and inflammatory conditions with exogenous nitric oxide (NO-therapy). Data was obtained on spatial structure of the gas flow, and values of its local parameters in axial and radial directions, such as nitric oxide content, velocity, temperature and mass flow density of nitric oxide, providing altogether the effectiveness of treatment by the exogenous NO-therapy method, were determined experimentally and by computations. It was demonstrated that plasma-chemical synthesis of NO from atmospheric air in a low direct current (DC) arc provides a high mass flow of nitric oxide at the level of 1.6-1.8 mg/s, while in the area of impact of NO-CGF on the biological tissue, on its axis, NO content is 400-600 ppm, flow velocity about 5 m/s, nitric oxide mass flow density 0.25-0.40 mg/(s·cm 2 ), temperature 40-60 °C. Tendencies were determined for designing new devices for further experimental biological and medical research in the field of NO-therapy: lowering the temperature of NO-CGF to ambient temperature will enable variation, in experiments, of the affecting flow parameters in a wide range up to their maximum values: NO content up to 2000 ppm, velocity up to 20 m/s, nitric oxide mass flow density up to 2.5 mg/(s·cm 2 ). Copyright © 2017. Published by Elsevier Inc.

Candida albicans Chitin Increases Arginase-1 Activity in Human Macrophages, with an Impact on Macrophage Antimicrobial Functions

PubMed Central

MacCallum, Donna M.; Brown, Gordon D.

2017-01-01

ABSTRACT   The opportunistic human fungal pathogen Candida albicans can cause a variety of diseases, ranging from superficial mucosal infections to life-threatening systemic infections. Phagocytic cells of the innate immune response, such as neutrophils and macrophages, are important first-line responders to an infection and generate reactive oxygen and nitrogen species as part of their protective antimicrobial response. During an infection, host cells generate nitric oxide through the enzyme inducible nitric oxide synthase (iNOS) to kill the invading pathogen. Inside the phagocyte, iNOS competes with the enzyme arginase-1 for a common substrate, the amino acid l-arginine. Several pathogenic species, including bacteria and parasitic protozoans, actively modulate the production of nitric oxide by inducing their own arginases or the host’s arginase activity to prevent the conversion of l-arginine to nitric oxide. We report here that C. albicans blocks nitric oxide production in human-monocyte-derived macrophages by induction of host arginase activity. We further determined that purified chitin (a fungal cell wall polysaccharide) and increased chitin exposure at the fungal cell wall surface induces this host arginase activity. Blocking the C. albicans-induced arginase activity with the arginase-specific substrate inhibitor Nω-hydroxy-nor-arginine (nor-NOHA) or the chitinase inhibitor bisdionin F restored nitric oxide production and increased the efficiency of fungal killing. Moreover, we determined that C. albicans influences macrophage polarization from a classically activated phenotype toward an alternatively activated phenotype, thereby reducing antimicrobial functions and mediating fungal survival. Therefore, C. albicans modulates l-arginine metabolism in macrophages during an infection, potentiating its own survival. PMID:28119468

Direct Reaction of Amides with Nitric Oxide To Form Diazeniumdiolates

PubMed Central

2015-01-01

We report the apparently unprecedented direct reaction of nitric oxide (NO) with amides to generate ions of structure R(C=O)NH–N(O)=NO–, with examples including R = Me (1a) or 3-pyridyl (1b). The sodium salts of both released NO in pH 7.4 buffer, with 37 °C half-lives of 1–3 min. As NO-releasing drug candidates, diazeniumdiolated amides would have the advantage of generating only 1 equiv of base on hydrolyzing exhaustively to NO, in contrast to their amine counterparts, which generate 2 equiv of base. PMID:25210948

Expression of Neuronal and Inducible Nitric Oxide Synthase Isoforms and Generation of Protein Nitrotyrosine in Rat Brain Following Hypobaric Hypoxia

DTIC Science & Technology

2001-06-01

Promoci6n General del Conocimiento , Ministerio de Educaci6n y Cultura. We thank Mr. E. Sfnchez and directors and staff of the Hospital del Aire and CIMA... based mechanism for the neuroprotective and neurodestructive effects of nitric oxide and related nitroso-compounds. Nature 364: 626-632. Lowenstein, C.J

Non-thermal atmospheric pressure HF plasma source: generation of nitric oxide and ozone for bio-medical applications

NASA Astrophysics Data System (ADS)

Kühn, S.; Bibinov, N.; Gesche, R.; Awakowicz, P.

2010-01-01

A new miniature high-frequency (HF) plasma source intended for bio-medical applications is studied using nitrogen/oxygen mixture at atmospheric pressure. This plasma source can be used as an element of a plasma source array for applications in dermatology and surgery. Nitric oxide and ozone which are produced in this plasma source are well-known agents for proliferation of the cells, inhalation therapy for newborn infants, disinfection of wounds and blood ozonation. Using optical emission spectroscopy, microphotography and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined for varied nitrogen/oxygen flows. The influence of the gas flows on the plasma conditions is studied. Ozone and nitric oxide concentrations in the effluent of the plasma source are measured using absorption spectroscopy and electro-chemical NO-detector at variable gas flows. Correlations between plasma parameters and concentrations of the particles in the effluent of the plasma source are discussed. By varying the gas flows, the HF plasma source can be optimized for nitric oxide or ozone production. Maximum concentrations of 2750 ppm and 400 ppm of NO and O3, correspondingly, are generated.

Development of High-Throughput Method for Measurement of Vascular Nitric Oxide Generation in Microplate Reader.

PubMed

Abd El-Hay, Soad S; Colyer, Christa L

2017-01-13

Despite the importance of nitric oxide (NO) in vascular physiology and pathology, a high-throughput method for the quantification of its vascular generation is lacking. By using the fluorescent probe 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM), we have optimized a simple method for the determination of the generation of endothelial nitric oxide in a microplate format. A nitric oxide donor was used (3-morpholinosydnonimine hydrochloride, SIN-1). Different factors affecting the method were studied, such as the effects of dye concentration, different buffers, time of reaction, gain, and number of flashes. Beer's law was linear over a nanomolar range (1-10 nM) of SIN-1 with wavelengths of maximum excitation and emission at 495 and 525 nm; the limit of detection reached 0.897 nM. Under the optimized conditions, the generation of rat aortic endothelial NO was measured by incubating DAF-FM with serial concentrations (10-1000 µM) of acetylcholine (ACh) for 3 min. To confirm specificity, N ω -Nitro-l-arginine methyl ester (l-NAME)-the standard inhibitor of endothelial NO synthase-was found to inhibit the ACh-stimulated generation of NO. In addition, vessels pre-exposed for 1 h to 400 µM of the endothelial damaging agent methyl glyoxal showed inhibited NO generation when compared to the control stimulated by ACh. The capability of the method to measure micro-volume samples makes it convenient for the simultaneous handling of a very large number of samples. Additionally, it allows samples to be run simultaneously with their replicates to ensure identical experimental conditions, thus minimizing the effect of biological variability.

THE ESTROGENS / CHROMIUM INTERACTION IN THE NITRIC OXIDE GENERATION.

PubMed

Sawicka, Ewa; Piwowar, Agnieszka; Musiala, Tomasz; Dlugosz, Anna

2017-05-01

The interaction of estrogens with environmental toxins in free radicals generation: reactive oxygen species (ROS) or reactive nitrogen species (RNS) which participates in cancerogenesis is not yet recognized. Chromium(VI) is widely present in environment. One of its toxicity pathway is free radicals generation. Estrogens have the ability to scavenge free radicals, but may also act as prooxidants. Both chromium(VI) and estrogens are classified by International Agency for Research on Cancer (IARC) as carcinogens, so synergistic effect seems very dangerous. The interaction of chromium and estrogens in ROS generation are partly described but there are no reports on estrogen/chromium interaction on nitric oxide (NO) generation. The aim of the study was to examine the interaction of chromium(VI) and 17-p-estradiol (E2) on NO level in human blood as well as the role of E2 metabolites: 4-hydroxyestradiol (4-OHE2) and 16a-hydroxyestrone (16α-OHE1) in these processes. The NO level was estimated with the diagnostic kit (Nitric Oxide Colorimetric Detection Kit from Arbor Assays) in human blood in vitm. The results showed that Cr(VI) in used concentration (0.5; 1.0 and 5.0 gg/mL) decreases significantly NO level in blood, acting antagonistically to E2 and 4-OHE2. Estrogens (E2, 4-OHE2 and 16α-OHEI) do not protect against inhibiting effect of Cr(VI) on nitric oxide generation in blood because after combined exposure the decreased production of NO in blood was noted. In conclusion, presented results provide the information about the character of estrogen/Cr(VI) interaction in NO level in human blood. It is important knowledge for cardio protected effect e.g., hormone replacement therapy in environmental or occupational exposure to Cr(VI), chromium supplementation, also important for cancer risk evaluation.

Hydrogen peroxide catalytic decomposition

NASA Technical Reports Server (NTRS)

Parrish, Clyde F. (Inventor)

2010-01-01

Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated through the use of concentrated hydrogen peroxide fed as a monopropellant into a catalyzed thruster assembly. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50%-70% by volume, and may be increased in concentration in a continuous process preceding decomposition in the thruster assembly. The exhaust of the thruster assembly, rich in hydroxyl and/or hydroperoxy radicals, may be fed into a stream containing oxidizable components, such as nitric oxide, to facilitate their oxidation.

Modulation of the cyclooxygenase pathway via inhibition of nitric oxide production contributes to the anti-inflammatory activity of kaempferol.

PubMed

Mahat, Mahamad Yunnus A; Kulkarni, Nagaraj M; Vishwakarma, Santosh L; Khan, Farhin R; Thippeswamy, B S; Hebballi, Vijay; Adhyapak, Anjana A; Benade, Vijay S; Ashfaque, Saudagar Mohammad; Tubachi, Suraj; Patil, Basangouda M

2010-09-10

Kaempferol has been reported to inhibit nitric oxide synthase and cyclooxygenase enzymes in animal models. The present study was designed to investigate whether kaempferol modulates the cyclooxygenase pathway via inhibition of nitric oxide production, which in turn contributes to its anti-inflammatory activity. Investigations were performed using carrageenan induced rat air pouch model. Inflammation was assessed by measurement of nitrites (nitrite, a breakdown product of nitric oxide), prostaglandin-E(2) levels and cellular infiltration in the pouch fluid exudates. To assess the anti-inflammatory effect of the extract, rat air pouch linings were examined histologically. The levels of nitrite and prostaglandin-E(2) in pouch fluid were measured by using Griess assay and ELISA respectively. Cell counts and differential counts were performed using a Coulter counter and Wright-Giemsa stain respectively. Kaempferol when administered orally at 50 and 100mg/kg dose showed significant inhibition of carrageenan induced production of nitrite (40.12 and 59.74%, respectively) and prostaglandin-E(2) generation (64.23 and 78.55%, respectively). Infiltration of the cells into the rat granuloma air pouch was also significantly inhibited by kaempferol. Modulation of cyclooxygenase pathway via inhibition of nitric oxide synthesis significantly contributes to kaempferol's anti-inflammatory activity. The present study characterizes the effects and mechanisms of naturally occurring phenolic flavonoid kaempferol, on inducible nitric oxide synthase expression and nitric oxide production. These results partially explain the pharmacological efficacy of flavonoids in general and kaempferol in particular as anti-inflammatory compounds. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Flavone inhibits nitric oxide synthase (NOS) activity, nitric oxide production and protein S-nitrosylation in breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Wenzhen; Yang, Bingwu; Fu, Huiling

As the core structure of flavonoids, flavone has been proved to possess anticancer effects. Flavone's growth inhibitory functions are related to NO. NO is synthesized by nitric oxide synthase (NOS), and generally increased in a variety of cancer cells. NO regulates multiple cellular responses by S-nitrosylation. In this study, we explored flavone-induced regulations on nitric oxide (NO)-related cellular processes in breast cancer cells. Our results showed that, flavone suppresses breast cancer cell proliferation and induces apoptosis. Flavone restrains NO synthesis by does-dependent inhibiting NOS enzymatic activity. The decrease of NO generation was detected by fluorescence microscopy and flow cytometry. Flavone-inducedmore » inhibitory effect on NOS activity is dependent on intact cell structure. For the NO-induced protein modification, flavone treatment significantly down-regulated protein S-nitrosylation, which was detected by “Biotin-switch” method. The present study provides a novel, NO-related mechanism for the anticancer function of flavone. - Highlights: • Flavone inhibits proliferation and induces apoptosis in MCF-7 cells. • Flavone decreases nitric oxide production by inhibiting NOS enzymatic activity in breast cancer cells. • Flavone down-regulates protein S-nitrosylation.« less

Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin.

PubMed Central

Stamler, J S; Jaraki, O; Osborne, J; Simon, D I; Keaney, J; Vita, J; Singel, D; Valeri, C R; Loscalzo, J

1992-01-01

We have recently shown that nitric oxide or authentic endothelium-derived relaxing factor generated in a biologic system reacts in the presence of specific protein thiols to form S-nitrosoprotein derivatives that have endothelium-derived relaxing factor-like properties. The single free cysteine of serum albumin, Cys-34, is particularly reactive toward nitrogen oxides (most likely nitrosonium ion) under physiologic conditions, primarily because of its anomalously low pK; given its abundance in plasma, where it accounts for approximately 0.5 mM thiol, we hypothesized that this plasma protein serves as a reservoir for nitric oxide produced by the endothelial cell. To test this hypothesis, we developed a methodology, which involves UV photolytic cleavage of the S--NO bond before reaction with ozone for chemiluminescence detection, with which to measure free nitric oxide, S-nitrosothiols, and S-nitrosoproteins in biologic systems. We found that human plasma contains approximately 7 microM S-nitrosothiols, of which 96% are S-nitrosoproteins, 82% of which is accounted for by S-nitroso-serum albumin. By contrast, plasma levels of free nitric oxide are only in the 3-nM range. In rabbits, plasma S-nitrosothiols are present at approximately 1 microM; 60 min after administration of NG-monomethyl-L-arginine at 50 mg/ml, a selective and potent inhibitor of nitric oxide synthetases, S-nitrosothiols decreased by approximately 40% (greater than 95% of which were accounted for by S-nitrosoproteins, and approximately 80% of which was S-nitroso-serum albumin); this decrease was accompanied by a concomitant increase in mean arterial blood pressure of 22%. These data suggest that naturally produced nitric oxide circulates in plasma primarily complexed in S-nitrosothiol species, principal among which is S-nitroso-serum albumin. This abundant, relatively long-lived adduct likely serves as a reservoir with which plasma levels of highly reactive, short-lived free nitric oxide can be regulated for the maintenance of vascular tone. PMID:1502182

Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin.

PubMed

Stamler, J S; Jaraki, O; Osborne, J; Simon, D I; Keaney, J; Vita, J; Singel, D; Valeri, C R; Loscalzo, J

1992-08-15

We have recently shown that nitric oxide or authentic endothelium-derived relaxing factor generated in a biologic system reacts in the presence of specific protein thiols to form S-nitrosoprotein derivatives that have endothelium-derived relaxing factor-like properties. The single free cysteine of serum albumin, Cys-34, is particularly reactive toward nitrogen oxides (most likely nitrosonium ion) under physiologic conditions, primarily because of its anomalously low pK; given its abundance in plasma, where it accounts for approximately 0.5 mM thiol, we hypothesized that this plasma protein serves as a reservoir for nitric oxide produced by the endothelial cell. To test this hypothesis, we developed a methodology, which involves UV photolytic cleavage of the S--NO bond before reaction with ozone for chemiluminescence detection, with which to measure free nitric oxide, S-nitrosothiols, and S-nitrosoproteins in biologic systems. We found that human plasma contains approximately 7 microM S-nitrosothiols, of which 96% are S-nitrosoproteins, 82% of which is accounted for by S-nitroso-serum albumin. By contrast, plasma levels of free nitric oxide are only in the 3-nM range. In rabbits, plasma S-nitrosothiols are present at approximately 1 microM; 60 min after administration of NG-monomethyl-L-arginine at 50 mg/ml, a selective and potent inhibitor of nitric oxide synthetases, S-nitrosothiols decreased by approximately 40% (greater than 95% of which were accounted for by S-nitrosoproteins, and approximately 80% of which was S-nitroso-serum albumin); this decrease was accompanied by a concomitant increase in mean arterial blood pressure of 22%. These data suggest that naturally produced nitric oxide circulates in plasma primarily complexed in S-nitrosothiol species, principal among which is S-nitroso-serum albumin. This abundant, relatively long-lived adduct likely serves as a reservoir with which plasma levels of highly reactive, short-lived free nitric oxide can be regulated for the maintenance of vascular tone.

An ethanol extract of Piper betle Linn. mediates its anti-inflammatory activity via down-regulation of nitric oxide.

PubMed

Ganguly, Sudipto; Mula, Soumyaditya; Chattopadhyay, Subrata; Chatterjee, Mitali

2007-05-01

The leaves of Piper betle (locally known as Paan) have long been in use in the Indian indigenous system of medicine for the relief of pain; however, the underlying molecular mechanisms of this effect have not been elucidated. The anti-inflammatory and immunomodulatory effects of an ethanolic extract of the leaves of P. betle (100 mg kg(-1); PB) were demonstrated in a complete Freund's adjuvant-induced model of arthritis in rats with dexamethasone (0.1 mg kg(-1)) as the positive control. At non-toxic concentrations of PB (5-25 microg mL(-1)), a dose-dependent decrease in extracellular production of nitric oxide in murine peritoneal macrophages was measured by the Griess assay and corroborated by flow cytometry using the nitric oxide specific probe, 4,5-diaminofluorescein-2 diacetate. This decreased generation of reactive nitrogen species was mediated by PB progressively down-regulating transcription of inducible nitric oxide synthase in macrophages, and concomitantly causing a dose-dependent decrease in the expression of interleukin-12 p40, indicating the ability of PB to down-regulate T-helper 1 pro-inflammatory responses. Taken together, the anti-inflammatory and anti-arthrotic activity of PB is attributable to its ability to down-regulate the generation of reactive nitrogen species, thus meriting further pharmacological investigation.

Synthesis of nitric oxide in human osteoblasts in response to physiologic stimulation of electrotherapy.

PubMed

Hamed, Ayman; Kim, Paul; Cho, Michael

2006-12-01

Electrotherapy for bone healing, remodeling and wound healing may be mediated by modulation of nitric oxide (NO). Using NO-specific fluorophore (DAF-2), we report here that application of non-invasive, physiologic electrical stimulation induces NO synthesis in human osteoblasts, and that such NO generation is comparable to that induced by estrogen treatment. For example, application of a sinusoidal 1 Hz, 2 V/cm (peak to peak) electrical stimulation (ES) increases NO-bound DAF-2 fluorescence intensity by a 2-fold within 60 min exposure by activating nitric oxide synthase (NOS). Increase in the NO level is found to depend critically on the frequency and strength of ES. While the frequency of 1 Hz ES seems optimal, the ES strength >0.5 V/cm is required to induce significant NO increase, however. Nitric oxide synthesis in response to ES is completely prevented by blocking estrogen receptors using a competitive inhibitor, suggesting that NO generation is likely initiated by activation of estrogen receptors at the cell surface. Based on these findings, physiologic stimulation of electrotherapy appears to represent a potential non-invasive, non-genomic, and novel physical technique that could be used to regulate NO-mediated bone density and facilitate bone remodeling without adverse effects associated with hormone therapy.

Nitric oxide, human diseases and the herbal products that affect the nitric oxide signalling pathway.

PubMed

Achike, Francis I; Kwan, Chiu-Yin

2003-09-01

1. Nitric oxide (NO) is formed enzymatically from l-arginine in the presence of nitric oxide synthase (NOS). Nitric oxide is generated constitutively in endothelial cells via sheer stress and blood-borne substances. Nitric oxide is also generated constitutively in neuronal cells and serves as a neurotransmitter and neuromodulator in non-adrenergic, non-cholinergic nerve endings. Furthermore, NO can also be formed via enzyme induction in many tissues in the presence of cytokines. 2. The ubiquitous presence of NO in the living body suggests that NO plays an important role in the maintenance of health. Being a free radical with vasodilatory properties, NO exerts dual effects on tissues and cells in various biological systems. At low concentrations, NO can dilate the blood vessels and improve the circulation, but at high concentrations it can cause circulatory shock and induce cell death. Thus, diseases can arise in the presence of the extreme ends of the physiological concentrations of NO. 3. The NO signalling pathway has, in recent years, become a target for new drug development. The high level of flavonoids, catechins, tannins and other polyphenolic compounds present in vegetables, fruits, soy, tea and even red wine (from grapes) is believed to contribute to their beneficial health effects. Some of these compounds induce NO formation from the endothelial cells to improve circulation and some suppress the induction of inducible NOS in inflammation and infection. 4. Many botanical medicinal herbs and drugs derived from these herbs have been shown to have effects on the NO signalling pathway. For example, the saponins from ginseng, ginsenosides, have been shown to relax blood vessels (probably contributing to the antifatigue and blood pressure-lowering effects of ginseng) and corpus cavernosum (thus, for the treatment of men suffering from erectile dysfunction; however, the legendary aphrodisiac effect of ginseng may be an overstatement). Many plant extracts or purified drugs derived from Chinese medicinal herbs with proposed actions on NO pathways are also reviewed.

Effect of PDT-treated apoptotic cells on macrophages

NASA Astrophysics Data System (ADS)

Song, Sheng; Xing, Da; Zhou, Fei-fan; Chen, Wei R.

2009-02-01

Recently, the long-term immunological effects of photodynamic therapy have attracted much attention. PDT induced immune response was mainly initiated through necrotic cells and apoptotic cells, as well as immune cells such as macrophages. Nitric oxide (NO) as an important regulatory factor in signal transfer between cells has been wildly studied for generation, development, and metastasis of tumors. NO synthase is a key enzyme in nitric oxide synthesis. However, inducible nitric oxide synthase (iNOS) is usually activated under pathological conditions, such as stress and cancer, which can produce high levels of nitric oxide and contribute to tumor cytotoxicity. In addition, increased NO production by iNOS has been associated with the host immune response and cell apoptosis, which play an important role in many carcinogenesis and anti-carcinoma mechanisms. This study focuses on the NO production in macrophages, induced by mouse breast carcinoma apoptotic cells treated by PDT in vitro, and on the effects of immune response induced by apoptotic cells in tumor cells growth.

Nitric oxide-related species-induced protein oxidation: reversible, irreversible, and protective effects on enzyme function of papain.

PubMed

Väänänen, Antti J; Kankuri, Esko; Rauhala, Pekka

2005-04-15

Protein oxidation, irreversible modification, and inactivation may play key roles in various neurodegenerative disorders. Therefore, we studied the effects of the potentially in vivo occurring nitric oxide-related species on two different markers of protein oxidation: protein carbonyl generation on bovine serum albumine (BSA) and loss of activity of a cysteine-dependent protease, papain, in vitro by using Angeli's salt, papanonoate, SIN-1, and S-nitrosoglutathione (GSNO) as donors of nitroxyl, nitric oxide, peroxynitrite, and nitrosonium ions, respectively. Angeli's salt, SIN-1, and papanonoate (0-1000 microM) all generated a concentration-dependent increase in carbonyl formation on BSA (107, 60, and 45%, respectively). GSNO did not affect carbonyl formation. Papain was inhibited by Angeli's salt, SIN-1, papanonoate, and GSNO with IC50 values of 0.62, 2.3, 54, and 80 microM, respectively. Angeli's salt (3.16 microM)-induced papain inactivation was only partially reversible, while the effects of GSNO (316 microM) and papanonoate (316 microM) were reversible upon addition of excess DTT. The Angeli's salt-mediated DTT-irreversible inhibition of papain was prevented by GSNO or papanonoate pretreatment, hypothetically through mixed disulfide formation or S-nitrosylation of the catalytically critical thiol group of papain. These results, for the first time, compare the generation of carbonyls in proteins by Angeli's salt, papanonoate, and SIN-1. Furthermore, these results suggest that S-nitrosothiols may have a novel function in protecting critical thiols from irreversible oxidative damage.

Applications of plasma sources for nitric oxide medicine

NASA Astrophysics Data System (ADS)

Vasilets, Victor; Shekhter, Anatoly; Pekshev, Alexander

2013-09-01

Nitric oxide (NO) has important roles in the function of many tissues and organs. Wound healing processes are always accompanying by the increase of nitric oxide concentration in wound tissue. These facts suggest a possible therapeutic use of various NO donors for the acceleration of the wound healing and treatment of other diseases. Our previous studies indicated that gaseous NO flow produced by air-plasma generators acts beneficially on the wound healing. This beneficial effect could be caused by the mechanism involving peroxynitrite as an intermediate. As a result of mobilization of various antioxidant reactions more endogenous NO molecules become available as signaling molecules. to regulate the metabolic processes in wound tissue. In this paper different air plasma sources generated therapeutic concentrations of NO are discussed. The concentration of NO and other therapeutically important gas products are estimated by thermodynamic simulation. Synergy effects of NO with other plasma components are discussed as a factor enhancing therapeutic results. Some new medical application of plasma devices are presented. Advanced Plasma Therapies Inc.

Biomedical implications of information processing in chemical systems: non-classical approach to photochemistry of coordination compounds.

PubMed

Szaciłowski, Konrad

2007-01-01

Analogies between photoactive nitric oxide generators and various electronic devices: logic gates and operational amplifiers are presented. These analogies have important biological consequences: application of control parameters allows for better targeting and control of nitric oxide drugs. The same methodology may be applied in the future for other therapeutic strategies and at the same time helps to understand natural regulatory and signaling processes in biological systems.

Superoxide and peroxynitrite generation from inducible nitric oxide synthase in macrophages

PubMed Central

Xia, Yong; Zweier, Jay L.

1997-01-01

Superoxide (O2⨪) and nitric oxide (NO) act to kill invading microbes in phagocytes. In macrophages NO is synthesized by inducible nitric oxide synthase (iNOS, NOS 2) from l-arginine (l-Arg) and oxygen; however, O2⨪ was thought to be produced mainly by NADPH oxidase. Electron paramagnetic resonance (EPR) spin trapping experiments performed in murine macrophages demonstrate a novel pathway of O2⨪ generation. It was observed that depletion of cytosolic l-Arg triggers O2⨪ generation from iNOS. This iNOS-mediated O2⨪ generation was blocked by the NOS inhibitor N-nitro-l-arginine methyl ester or by l-Arg, but not by the noninhibitory enantiomer N-nitro-d-arginine methyl ester. In l-Arg-depleted macrophages iNOS generates both O2⨪ and NO that interact to form the potent oxidant peroxynitrite (ONOO−), which was detected by luminol luminescence and whose formation was blocked by superoxide dismutase, urate, or l-Arg. This iNOS-derived ONOO− resulted in nitrotyrosine formation, and this was inhibited by iNOS blockade. iNOS-mediated O2⨪ and ONOO− increased the antibacterial activity of macrophages. Thus, with reduced l-Arg availability iNOS produces O2⨪ and ONOO− that modulate macrophage function. Due to the existence of l-Arg depletion in inflammation, iNOS-mediated O2⨪ and ONOO− may occur and contribute to cytostatic/cytotoxic actions of macrophages. PMID:9192673

Neural mechanisms in nitric-oxide-deficient hypertension

NASA Technical Reports Server (NTRS)

Sander, M.; Victor, R. G.; Blomqvist, C. G. (Principal Investigator)

1999-01-01

Nitric oxide is hypothesized to be an inhibitory modulator of central sympathetic nervous outflow, and deficient neuronal nitric oxide production to cause sympathetic overactivity, which then contributes to nitric-oxide-deficient hypertension. The biochemical and neuroanatomical basis for this concept revolves around nitric oxide modulation of glutamatergic neurotransmission within brainstem vasomotor centers. The functional consequence of neuronal nitric oxide in blood pressure regulation is, however, marked by an apparent conflict in the literature. On one hand, conscious animal studies using sympathetic blockade suggest a significant role for neuronal nitric oxide deficiency in the development of nitric-oxide-deficient hypertension, and on the other hand, there is evidence against such a role derived from 'knock-out' mice lacking nitric-oxide synthase 1, the major source of neuronal nitric oxide.

Expression of the Nitric Oxide Synthase 2 Gene Is Not Essential for Early Control of Mycobacterium tuberculosis in the Murine Lung

PubMed Central

Cooper, Andrea M.; Pearl, John E.; Brooks, Jason V.; Ehlers, Stefan; Orme, Ian M.

2000-01-01

The interleukin-12 and gamma interferon (IFN-γ) pathway of macrophage activation plays a pivotal role in controlling tuberculosis. In the murine model, the generation of supplementary nitric oxide by the induction of the nitric oxide synthase 2 (NOS2) gene product is considered the principal antimicrobial mechanism of IFN-γ-activated macrophages. Using a low-dose aerosol-mediated infection model in the mouse, we have investigated the role of nitric oxide in controlling Mycobacterium tuberculosis in the lung. In contrast to the consequences of a systemic infection, a low dose of bacteria introduced directly into the lungs of mice lacking the NOS2 gene is controlled almost as well as in intact animals. This is in contrast to the rapid progression of disease in mice lacking IFN-γ or a key member of the IFN signaling pathway, interferon regulatory factor 1. Thus while IFN-γ is pivotal in early control of bacterial growth in the lung, this control does not completely depend upon the expression of the NOS2 gene. The absence of inducible nitric oxide in the lung does, however, result in increased polymorphonuclear cell involvement and eventual necrosis in the pulmonary granulomas of the infected mice lacking the NOS2 gene. PMID:11083808

Chemical generation of nitric oxide in the mouth from the enterosalivary circulation of dietary nitrate.

PubMed

Duncan, C; Dougall, H; Johnston, P; Green, S; Brogan, R; Leifert, C; Smith, L; Golden, M; Benjamin, N

1995-06-01

High concentrations of nitrite present in saliva (derived from dietary nitrate) may, upon acidification, generate nitrogen oxides in the stomach in sufficient amounts to provide protection from swallowed pathogens. We now show that, in the rat, reduction of nitrate to nitrite is confined to a specialized area on the posterior surface of the tongue, which is heavily colonized by bacteria, and that nitrate reduction is absent in germ-free rats. We also show that in humans increased salivary nitrite production resulting from nitrate intake enhances oral nitric oxide production. We propose that the salivary generation of nitrite is accomplished by a symbiotic relationship involving nitrate-reducing bacteria on the tongue surface, which is designed to provide host defence against microbial pathogens in the mouth and lower gut. These results provide further evidence for beneficial effects of dietary nitrate.

Nitric oxide: a physiologic messenger.

PubMed

Lowenstein, C J; Dinerman, J L; Snyder, S H

1994-02-01

To review the physiologic role of nitric oxide, an unusual messenger molecule that mediates blood vessel relaxation, neurotransmission, and pathogen suppression. A MEDLINE search of articles published from 1987 to 1993 that addressed nitric oxide and the enzyme that synthesizes it, nitric oxide synthase. Animal and human studies were selected from 3044 articles to analyze the clinical importance of nitric oxide. Descriptions of the structure and function of nitric oxide synthase were selected to show how nitric oxide acts as a biological messenger molecule. Biochemical and physiologic studies were analyzed if the same results were found by three or more independent observers. Two major classes of nitric oxide synthase enzymes produce nitric oxide. The constitutive isoforms found in endothelial cells and neurons release small amounts of nitric oxide for brief periods to signal adjacent cells, whereas the inducible isoform found in macrophages releases large amounts of nitric oxide continuously to eliminate bacteria and parasites. By diffusing into adjacent cells and binding to enzymes that contain iron, nitric oxide plays many important physiologic roles. It regulates blood pressure, transmits signals between neurons, and suppresses pathogens. Excess amounts, however, can damage host cells, causing neurotoxicity during strokes and causing the hypotension associated with sepsis. Nitric oxide is a simple molecule with many physiologic roles in the cardiovascular, neurologic, and immune systems. Although the general principles of nitric oxide synthesis are known, further research is necessary to determine what role it plays in causing disease.

Electron transfer of Pseudomonas aeruginosa CP1 in electrochemical reduction of nitric oxide.

PubMed

Zhou, Shaofeng; Huang, Shaobin; He, Jiaxin; Li, Han; Zhang, Yongqing

2016-10-01

This study reports catalytic electro-chemical reduction of nitric oxide (NO) enhanced by Pseudomonas aeruginosa strain CP1. The current generated in the presence of bacteria was 4.36times that in the absence of the bacteria. The strain was able to catalyze electro-chemical reduction of NO via indirect electron transfer with an electrode, revealed by a series of cyclic voltammetry experiments. Soluble electron shuttles secreted into solution by live bacteria were responsible for the catalytic effects. The enhancement of NO reduction was also confirmed by detection of nitrous oxide; the level of this intermediate was 46.4% higher in the presence of bacteria than in controls, illustrated that the electron transfer pathway did not directly reduce nitric oxide to N2. The findings of this study may offer a new model for bioelectrochemical research in the field of NO removal by biocatalysts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Consequences of MnSOD interactions with nitric oxide: nitric oxide dismutation and the generation of peroxynitrite and hydrogen peroxide.

PubMed

Filipović, Milos R; Stanić, Dragana; Raicević, Smiljana; Spasić, Mihajlo; Niketić, Vesna

2007-01-01

The present study demonstrates that manganese superoxide dismutase (MnSOD) (Escherichia coli), binds nitric oxide (*NO) and stimulates its decay under both anaerobic and aerobic conditions. The results indicate that previously observed MnSOD-catalyzed *NO disproportionation (dismutation) into nitrosonium (NO+) and nitroxyl (NO-) species under anaerobic conditions is also operative in the presence of molecular oxygen. Upon sustained aerobic exposure to *NO, MnSOD-derived NO- species initiate the formation of peroxynitrite (ONOO-) leading to enzyme tyrosine nitration, oxidation and (partial) inactivation. The results suggest that both ONOO- decomposition and ONOO(-)-dependent tyrosine residue nitration and oxidation are enhanced by metal centre-mediated catalysis. We show that the generation of ONOO- is accompanied by the formation of substantial amounts of H2O2. MnSOD is a critical mitochondrial antioxidant enzyme, which has been found to undergo tyrosine nitration and inactivation in various pathologies associated with the overproduction of *NO. The results of the present study can account for the molecular specificity of MnSOD nitration in vivo. The interaction of *NO with MnSOD may represent a novel mechanism by which MnSOD protects the cell from deleterious effects associated with overproduction of *NO.

Chemical Excitation of Electrons: A Dark Path to Melanoma

PubMed Central

Premi, Sanjay; Brash, Douglas E.

2016-01-01

Sunlight’s ultraviolet wavelengths induce cyclobutane pyrimidine dimers (CPDs), which then cause mutations that lead to melanoma or to cancers of skin keratinocytes. In pigmented melanocytes, we found that CPDs arise both instantaneously and for hours after UV exposure ends. Remarkably, the CPDs arising in the dark originate by a novel pathway that resembles bioluminescence but does not end in light: First, UV activates the enzymes nitric oxide synthase (NOS) and NADPH oxidase (NOX), which generate the radicals nitric oxide (NO•) and superoxide (O2•−); these combine to form the powerful oxidant peroxynitrite (ONOO−). A fragment of the skin pigment melanin is then oxidized, exciting an electron to an energy level so high that it is rarely seen in biology. This process of chemically exciting electrons, termed “chemiexcitation”, is used by fireflies to generate light but it had never been seen in mammalian cells. In melanocytes, the energy transfers radiationlessly to DNA, inducing CPDs. Chemiexcitation is a new source of genome instability, and it calls attention to endogenous mechanisms of genome maintenance that prevent electronic excitation or dissipate the energy of excited states. Chemiexcitation may also trigger pathogenesis in internal tissues because the same chemistry should arise wherever superoxide and nitric oxide arise near cells that contain melanin. PMID:27262612

Chemical excitation of electrons: A dark path to melanoma.

PubMed

Premi, Sanjay; Brash, Douglas E

2016-08-01

Sunlight's ultraviolet wavelengths induce cyclobutane pyrimidine dimers (CPDs), which then cause mutations that lead to melanoma or to cancers of skin keratinocytes. In pigmented melanocytes, we found that CPDs arise both instantaneously and for hours after UV exposure ends. Remarkably, the CPDs arising in the dark originate by a novel pathway that resembles bioluminescence but does not end in light: First, UV activates the enzymes nitric oxide synthase (NOS) and NADPH oxidase (NOX), which generate the radicals nitric oxide (NO) and superoxide (O2(-)); these combine to form the powerful oxidant peroxynitrite (ONOO(-)). A fragment of the skin pigment melanin is then oxidized, exciting an electron to an energy level so high that it is rarely seen in biology. This process of chemically exciting electrons, termed "chemiexcitation", is used by fireflies to generate light but it had never been seen in mammalian cells. In melanocytes, the energy transfers radiationlessly to DNA, inducing CPDs. Chemiexcitation is a new source of genome instability, and it calls attention to endogenous mechanisms of genome maintenance that prevent electronic excitation or dissipate the energy of excited states. Chemiexcitation may also trigger pathogenesis in internal tissues because the same chemistry should arise wherever superoxide and nitric oxide arise near cells that contain melanin. Copyright © 2016 Elsevier B.V. All rights reserved.

Toxicity of chemically generated nitric oxide towards pancreatic islet cells can be prevented by nicotinamide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kallmann, B.; Burkart, V.; Kolb, H.

1992-01-01

Previous studies have indicated that nitric oxide is involved in the lysis of pancreatic islet cells by inflammatory macrophages. Here the authors show that the incubation of islet cells with chemical NO-donors leads to cell lysis in a concentration and time dependent way. Islet cell death could be prevented by nicotinamide and 3-aminobenzamide, which are known to inhibit ADP-ribosylation, while several scavengers of oxygen radicals, N-acetylcysteine, dihydrolipoic acid, dimethylthiourea and citiolone, provided no protection.

Endothelial Barrier Protection by Local Anesthetics: Ropivacaine and Lidocaine Block Tumor Necrosis Factor-α–induced Endothelial Cell Src Activation

PubMed Central

Piegeler, Tobias; Votta-Velis, E. Gina; Bakhshi, Farnaz R.; Mao, Mao; Carnegie, Graeme; Bonini, Marcelo G.; Schwartz, David E.; Borgeat, Alain; Beck-Schimmer, Beatrice; Minshall, Richard D.

2014-01-01

Background Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase–Akt–nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability. Methods Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed. Results Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10−10 M for ropivacaine; IC50 = 5.864 × 10−10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10−10 M for ropivacaine; IC50 = 6.377 × 10−10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated. Conclusions Ropivacaine and lidocaine effectively blocked inflammatory TNFα signaling in endothelial cells by attenuating p85 recruitment to TNF-receptor-1. The resultant decrease in Akt, endothelial nitric oxide synthase, and Src phosphorylation reduced neutrophil adhesion and endothelial hyperpermeability. This novel anti-inflammatory “side-effect” of ropivacaine and lidocaine may provide therapeutic benefit in acute inflammatory disease. PMID:24525631

Endothelial barrier protection by local anesthetics: ropivacaine and lidocaine block tumor necrosis factor-α-induced endothelial cell Src activation.

PubMed

Piegeler, Tobias; Votta-Velis, E Gina; Bakhshi, Farnaz R; Mao, Mao; Carnegie, Graeme; Bonini, Marcelo G; Schwartz, David E; Borgeat, Alain; Beck-Schimmer, Beatrice; Minshall, Richard D

2014-06-01

Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase-Akt-nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability. Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed. Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10 M for ropivacaine; IC50 = 5.864 × 10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10 M for ropivacaine; IC50 = 6.377 × 10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated. Ropivacaine and lidocaine effectively blocked inflammatory TNFα signaling in endothelial cells by attenuating p85 recruitment to TNF-receptor-1. The resultant decrease in Akt, endothelial nitric oxide synthase, and Src phosphorylation reduced neutrophil adhesion and endothelial hyperpermeability. This novel anti-inflammatory "side-effect" of ropivacaine and lidocaine may provide therapeutic benefit in acute inflammatory disease.

Ethanol exposure induces oxidative stress and impairs nitric oxide availability in the human placental villi: a possible mechanism of toxicity.

PubMed

Kay, H H; Grindle, K M; Magness, R R

2000-03-01

We undertook this investigation to explore the effects of ethanol exposure on nitric oxide synthase levels and nitric oxide release. Our hypothesis was that ethanol exposure modifies nitric oxide activity within the placenta as a result of oxidative stress. Four 10-g samples of term normal human placental villous tissue were perifused with nonrecirculating Dulbecco's modified Eagle's medium and 25-mmol/L N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid] with 0-, 50-, 100-, or 200-mmol/L ethanol. After 2 hours of exposure, tissue was removed, fixed, and frozen for analysis. Immunohistochemical analysis was performed for subtype I or neuronal nitric oxide synthase (nNOS), subtype II or inducible nitric oxide synthase (iNOS), and subtype III or endothelial nitric oxide synthase (eNOS) localization. Western blot analysis was performed for eNOS quantitation. Cyclic guanosine monophosphate and copper-zinc superoxide dismutase levels were measured by electroimmunoassay and kinetic assay, respectively. Nitric oxide release was analyzed by a Sievers nitric oxide analyzer. Immunohistochemical examination confirmed that only eNOS was localized to the syncytiotrophoblasts. After ethanol exposure, eNOS protein expression increased 2.5- to 3.0-fold over that of the control. Tissue cyclic guanosine monophosphate content and nitric oxide release into the effluent were decreased, whereas superoxide dismutase levels were increased at higher ethanol levels (P <.05). Ethanol exposure appears to induce oxidative stress, which may account for the decreased nitric oxide release, because nitric oxide may be shunted toward scavenging free radicals. Increased eNOS protein expression may be a response to the increased demand for nitric oxide. Decreased nitric oxide availability could adversely affect placental blood flow regulation, which could, in turn, account for the growth restriction seen in ethanol-exposed fetuses.

Expression and Activity of Nitric Oxide Synthase Isoforms in Methamphetamine-Induced Striatal Dopamine Toxicity

PubMed Central

Friend, Danielle M.; Son, Jong H.; Keefe, Kristen A.

2013-01-01

Nitric oxide is implicated in methamphetamine (METH)-induced neurotoxicity; however, the source of the nitric oxide has not been identified. Previous work has also revealed that animals with partial dopamine loss induced by a neurotoxic regimen of methamphetamine fail to exhibit further decreases in striatal dopamine when re-exposed to methamphetamine 7–30 days later. The current study examined nitric oxide synthase expression and activity and protein nitration in striata of animals administered saline or neurotoxic regimens of methamphetamine at postnatal days 60 and/or 90, resulting in four treatment groups: Saline:Saline, METH:Saline, Saline:METH, and METH:METH. Acute administration of methamphetamine on postnatal day 90 (Saline:METH and METH:METH) increased nitric oxide production, as evidenced by increased protein nitration. Methamphetamine did not, however, change the expression of endothelial or inducible isoforms of nitric oxide synthase, nor did it change the number of cells positive for neuronal nitric oxide synthase mRNA expression or the amount of neuronal nitric oxide synthase mRNA per cell. However, nitric oxide synthase activity in striatal interneurons was increased in the Saline:METH and METH:METH animals. These data suggest that increased nitric oxide production after a neurotoxic regimen of methamphetamine results from increased nitric oxide synthase activity, rather than an induction of mRNA, and that constitutively expressed neuronal nitric oxide synthase is the most likely source of nitric oxide after methamphetamine administration. Of interest, animals rendered resistant to further methamphetamine-induced dopamine depletions still show equivalent degrees of methamphetamine-induced nitric oxide production, suggesting that nitric oxide production alone in response to methamphetamine is not sufficient to induce acute neurotoxic injury. PMID:23230214

BDNF-induced nitric oxide signals in cultured rat hippocampal neurons: time course, mechanism of generation, and effect on neurotrophin secretion.

PubMed

Kolarow, Richard; Kuhlmann, Christoph R W; Munsch, Thomas; Zehendner, Christoph; Brigadski, Tanja; Luhmann, Heiko J; Lessmann, Volkmar

2014-01-01

BDNF and nitric oxide signaling both contribute to plasticity at glutamatergic synapses. However, the role of combined signaling of both pathways at the same synapse is largely unknown. Using NO imaging with diaminofluoresceine in cultured hippocampal neurons we analyzed the time course of neurotrophin-induced NO signals. Application of exogenous BDNF, NT-4, and NT-3 (but not NGF) induced NO signals in the soma and in proximal dendrites of hippocampal neurons that were sensitive to NO synthase activity, TrkB signaling, and intracellular calcium elevation. The effect of NO signaling on neurotrophin secretion was analyzed in BDNF-GFP, and NT-3-GFP transfected hippocampal neurons. Exogenous application of the NO donor sodium-nitroprusside markedly inhibited neurotrophin secretion. However, endogenously generated NO in response to depolarization and neurotrophin stimulation, both did not result in a negative feedback on neurotrophin secretion. These results suggest that a negative feedback of NO signaling on synaptic secretion of neurotrophins operates only at high intracellular levels of nitric oxide that are under physiological conditions not reached by depolarization or BDNF signaling.

BDNF-induced nitric oxide signals in cultured rat hippocampal neurons: time course, mechanism of generation, and effect on neurotrophin secretion

PubMed Central

Kolarow, Richard; Kuhlmann, Christoph R. W.; Munsch, Thomas; Zehendner, Christoph; Brigadski, Tanja; Luhmann, Heiko J.; Lessmann, Volkmar

2014-01-01

BDNF and nitric oxide signaling both contribute to plasticity at glutamatergic synapses. However, the role of combined signaling of both pathways at the same synapse is largely unknown. Using NO imaging with diaminofluoresceine in cultured hippocampal neurons we analyzed the time course of neurotrophin-induced NO signals. Application of exogenous BDNF, NT-4, and NT-3 (but not NGF) induced NO signals in the soma and in proximal dendrites of hippocampal neurons that were sensitive to NO synthase activity, TrkB signaling, and intracellular calcium elevation. The effect of NO signaling on neurotrophin secretion was analyzed in BDNF-GFP, and NT-3-GFP transfected hippocampal neurons. Exogenous application of the NO donor sodium-nitroprusside markedly inhibited neurotrophin secretion. However, endogenously generated NO in response to depolarization and neurotrophin stimulation, both did not result in a negative feedback on neurotrophin secretion. These results suggest that a negative feedback of NO signaling on synaptic secretion of neurotrophins operates only at high intracellular levels of nitric oxide that are under physiological conditions not reached by depolarization or BDNF signaling. PMID:25426021

Unintended inhalation of nitric oxide by contamination of compressed air: physiologic effects and interference with intended nitric oxide inhalation in acute lung injury.

PubMed

Benzing, A; Loop, T; Mols, G; Geiger, K

1999-10-01

Compressed air from a hospital's central gas supply may contain nitric oxide as a result of air pollution. Inhaled nitric oxide may increase arterial oxygen tension and decrease pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. Therefore, the authors wanted to determine whether unintentional nitric oxide inhalation by contamination of compressed air influences arterial oxygen tension and pulmonary vascular resistance and interferes with the therapeutic use of nitric oxide. Nitric oxide concentrations in the compressed air of a university hospital were measured continuously by chemiluminescence during two periods (4 and 2 weeks). The effects of unintended nitric oxide inhalation on arterial oxygen tension (n = 15) and on pulmonary vascular resistance (n = 9) were measured in patients with acute lung injury and acute respiratory distress syndrome by changing the source of compressed air of the ventilator from the hospital's central gas supply to a nitric oxide-free gas tank containing compressed air. In five of these patients, the effects of an additional inhalation of 5 ppm nitric oxide were evaluated. During working days, compressed air of the hospital's central gas supply contained clinically effective nitric oxide concentrations (> 80 parts per billion) during 40% of the time. Change to gas tank-supplied nitric oxide-free compressed air decreased the arterial oxygen tension by 10% and increased pulmonary vascular resistance by 13%. The addition of 5 ppm nitric oxide had a minimal effect on arterial oxygen tension and pulmonary vascular resistance when added to hospital-supplied compressed air but improved both when added to tank-supplied compressed air. Unintended inhalation of nitric oxide increases arterial oxygen tension and decreases pulmonary vascular resistance in patients with acute lung injury and acute respiratory distress syndrome. The unintended nitric oxide inhalation interferes with the therapeutic use of nitric oxide.

UV Induced Oxidation of Nitric Oxide

NASA Technical Reports Server (NTRS)

Parrish, Clyde, F. (Inventor); Luecke, Dale E. (Inventor)

2007-01-01

Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated at least in part using in situ UV radiation sources. The sources of the oxidizing species include oxygen and/or hydrogen peroxide. The oxygen may be a component of the gaseous stream or added to the gaseous stream, preferably near a UV radiation source, and is converted to ozone by the UV irradiation. The hydrogen peroxide is decomposed through a combination of vaporization and UV irradiation. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50% by volume and increased in concentration in a continuous process preceding vaporization within the flow channel of the gaseous stream and in the presence of the UV radiation sources.

Reactive Oxygen and Nitrogen Species Regulate Inducible Nitric Oxide Synthase Function Shifting the Balance of Nitric Oxide and Superoxide Production

PubMed Central

Sun, Jian; Druhan, Lawrence J.; Zweier, Jay L.

2014-01-01

Inducible NOS (iNOS) is induced in diseases associated with inflammation and oxidative stress, and questions remain regarding its regulation. We demonstrate that reactive oxygen / nitrogen species (ROS/RNS) dose-dependently regulate iNOS function. Tetrahydrobiopterin (BH4)-replete iNOS was exposed to increasing concentrations of ROS/RNS and activity was measured with and without subsequent BH4 addition. Peroxynitrite (ONOO−) produced the greatest change in NO generation rate, ~95% decrease, and BH4 only partially restored this loss of activity. Superoxide (O2.−) greatly decreased NO generation, however, BH4 addition restored this activity. Hydroxyl radical (.OH) mildly decreases NO generation in a BH4-dependent manner. iNOS was resistant to H2O2 with only slightly decreased NO generation with up to millimolar concentrations. In contrast to the inhibition of NO generation, ROS enhanced O2.− production from iNOS, while ONOO− had the opposite effect. Thus, ROS promote reversible iNOS uncoupling, while ONOO− induces irreversible enzyme inactivation and decreases both NO and O2.− production. PMID:19932078

Nitric oxide ameliorates the damaging effects of oxidative stress induced by iron deficiency in cyanobacterium Anabaena 7120.

PubMed

Kaushik, Manish Singh; Srivastava, Meenakshi; Srivastava, Alka; Singh, Anumeha; Mishra, Arun Kumar

2016-11-01

In cyanobacterium Anabaena 7120, iron deficiency leads to oxidative stress with unavoidable consequences. Nitric oxide reduces pigment damage and supported the growth of Anabaena 7120 in iron-deficient conditions. Elevation in nitric oxide accumulation and reduced superoxide radical production justified the role of nitric oxide in alleviating oxidative stress in iron deficiency. Increased activities of antioxidative enzymes and higher levels of ROS scavengers (ascorbate, glutathione and thiol) in iron deficiency were also observed in the presence of nitric oxide. Nitric oxide also supported the membrane integrity of Anabaena cells and reduces protein and DNA damage caused by oxidative stress induced by iron deficiency. Results suggested that nitric oxide alleviates the damaging effects of oxidative stress induced by iron deficiency in cyanobacterium Anabaena 7120.

Analytical study of mechanisms for nitric oxide formation during combustion of methane in a jet-stirred combustor

NASA Technical Reports Server (NTRS)

Jachimowski, C. J.

1975-01-01

The role of chemical kinetics in the formation of nitric oxide during the combustion of methane was examined analytically by means of a detailed chemical mechanism for the oxidation of methane, for the reaction between hydrocarbon fragments, and for the formation of nitric oxide. By comparing predicted nitric oxide levels with values reported in the literature from jet-stirred combuster experiments, it was determined that the nitric oxide levels observed in fuel-rich flames cannot be described by a mechanism in which the rate of nitric oxide formation is controlled solely by the kinetics of oxygen atom formation. A proposed mechanism for the formation of nitric oxide in methane-rich flames reproduces the observed levels. The oxidation of hydrogen cyanide appears to be an important factor in nitric oxide formation.

Nitric Oxide Synthase and Cyclooxygenase Pathways: A Complex Interplay in Cellular Signaling.

PubMed

Sorokin, Andrey

2016-01-01

The cellular reaction to external challenges is a tightly regulated process consisting of integrated processes mediated by a variety of signaling molecules, generated as a result of modulation of corresponding biosynthetic systems. Both, nitric oxide synthase (NOS) and cyclooxygenase (COX) systems, consist of constitutive forms (NOS1, NOS3 and COX-1), which are mostly involved in housekeeping tasks, and inducible forms (NOS2 and COX-2), which shape the cellular response to stress and variety of bioactive agents. The complex interplay between NOS and COX pathways can be observed at least at three levels. Firstly, products of NOS and Cox systems can mediate the regulation and the expression of inducible forms (NOS2 and COX-2) in response of similar and dissimilar stimulus. Secondly, the reciprocal modulation of cyclooxygenase activity by nitric oxide and NOS activity by prostaglandins at the posttranslational level has been shown to occur. Mechanisms by which nitric oxide can modulate prostaglandin synthesis include direct S-nitrosylation of COX and inactivation of prostaglandin I synthase by peroxynitrite, product of superoxide reaction with nitric oxide. Prostaglandins, conversely, can promote an increased association of dynein light chain (DLC) (also known as protein inhibitor of neuronal nitric oxide synthase) with NOS1, thereby reducing its activity. The third level of interplay is provided by intracellular crosstalk of signaling pathways stimulated by products of NOS and COX which contributes significantly to the complexity of cellular signaling. Since modulation of COX and NOS pathways was shown to be principally involved in a variety of pathological conditions, the dissection of their complex relationship is needed for better understanding of possible therapeutic strategies. This review focuses on implications of interplay between NOS and COX for cellular function and signal integration.

Mechanisms of lead-induced poisoning.

PubMed

Nemsadze, K; Sanikidze, T; Ratiani, L; Gabunia, L; Sharashenidze, T

2009-01-01

Lead is a ubiquitous environmental toxin that is capable of causing numerous acute and chronic circulatory, neurological, hematological, gastrointestinal, reproductive and immunological pathologies. The mechanism of lead induced toxicity is not fully understood. The prime targets to lead toxicity are the heme synthesis enzymes, thiol-containing antioxidants and enzymes (superoxide dismutase, catalase, glutathione peroxidase, glucose 6-phosphate dehydrogenase and antioxidant molecules like GSH). The low blood lead levels are sufficient to inhibit the activity of these enzymes and induce generation of reactive oxygen species and intensification oxidative stress. Oxidative stress plays important role in pathogenesis of lead-induced toxicity and pathogenesis of coupled disease. The primary target of lead toxicity is the central nervous system. There are different cellular, intracellular and molecular mechanisms of lead neurotoxicity: such as induction of oxidative stress, intensification of apoptosis of neurocites, interfering with Ca(2+) dependent enzyme like nitric oxide synthase. Population studies have demonstrated a link between lead exposure and subsequent development of hypertension and cardiovascular disease. The vascular endothelium is now regarded as the main target organ for the toxic effect of lead. Lead affects the vasoactive function of endothelium through the increased production of reactive oxygen species, inactivation of endogenous nitric oxide and downregulation of soluble guanylate cyclase by reactive oxygen species, leading to a limiting nitric oxide availability, impairing nitric oxide signaling. This review summarizes recent findings of the mechanism of the lead-induced toxicity and possibilities of its prevention.

The production of nitric oxide in the coeliac ganglion modulates the effect of cholinergic neurotransmission on the rat ovary during the preovulatory period.

PubMed

Delsouc, María B; Della Vedova, María C; Ramírez, Darío; Delgado, Silvia M; Casais, Marilina

2018-05-01

The aim of the present work was to investigate whether the nitric oxide produced by the nitric oxide/nitric oxide synthase (NO/NOS) system present in the coeliac ganglion modulates the effects of cholinergic innervation on oxidative status, steroidogenesis and apoptotic mechanisms that take place in the rat ovary during the first proestrous. An ex vivo Coeliac Ganglion- Superior Ovarian Nerve- Ovary (CG-SON-O) system was used. Cholinergic stimulation of the CG was achieved by 10 -6  M Acetylcholine (Ach). Furthermore, 400 μM Aminoguanidine (AG) - an inhibitor of inducible-NOS was added in the CG compartment in absence and presence of Ach. It was found that Ach in the CG compartment promotes apoptosis in ovarian tissue, probably due to the oxidative stress generated. AG in the CG compartment decreases the release of NO and progesterone, and increases the release of estradiol from the ovary. The CG co-treatment with Ach and AG counteracts the effects of the ganglionic cholinergic agonist on ovarian oxidative stress, increases hormone production and decreases Fas mRNA expression. These results suggest that NO is an endogenous modulator of cholinergic neurotransmission in CG, with implication in ovarian steroidogenesis and the apoptotic mechanisms that take place in the ovary during the preovulatory period in rats. Copyright © 2018 Elsevier Inc. All rights reserved.

L-citrulline immunostaining identifies nitric oxide production sites within neurons

NASA Technical Reports Server (NTRS)

Martinelli, G. P. T.; Friedrich, V. L. Jr; Holstein, G. R.

2002-01-01

The cellular and subcellular localization of L-citrulline was analyzed in the adult rat brain and compared with that of traditional markers for the presence of nitric oxide synthase. Light, transmission electron, and confocal laser scanning microscopy were used to study tissue sections processed for immunocytochemistry employing a monoclonal antibody against L-citrulline or polyclonal anti-neuronal nitric oxide synthase sera, and double immunofluorescence to detect neuronal nitric oxide synthase and L-citrulline co-localization. The results demonstrate that the same CNS regions and cell types are labeled by neuronal nitric oxide synthase polyclonal antisera and L-citrulline monoclonal antibodies, using both immunocytochemistry and immunofluorescence. Short-term pretreatment with a nitric oxide synthase inhibitor reduces L-citrulline immunostaining, but does not affect neuronal nitric oxide synthase immunoreactivity. In the vestibular brainstem, double immunofluorescence studies show that many, but not all, neuronal nitric oxide synthase-positive cells co-express L-citrulline, and that local intracellular patches of intense L-citrulline accumulation are present in some neurons. Conversely, all L-citrulline-labeled neurons co-express neuronal nitric oxide synthase. Cells expressing neuronal nitric oxide synthase alone are interpreted as neurons with the potential to produce nitric oxide under other stimulus conditions, and the subcellular foci of enhanced L-citrulline staining are viewed as intracellular sites of nitric oxide production. This interpretation is supported by ultrastructural observations of subcellular foci with enhanced L-citrulline and/or neuronal nitric oxide synthase staining that are located primarily at postsynaptic densities and portions of the endoplasmic reticulum. We conclude that nitric oxide is produced and released at focal sites within neurons that are identifiable using L-citrulline as a marker. Copyright 2002 IBRO.

Sensitivity evaluation of rhodamine B hydrazide towards nitric oxide and its application for macrophage cells imaging.

PubMed

Wu, Chi-Ming; Chen, Yen-Hao; Dayananda, Kasala; Shiue, Tsun-Wei; Hung, Chen-Hsiung; Liaw, Wen-Feng; Chen, Po-Yu; Wang, Yun-Ming

2011-12-05

A colorless and non-fluorescent rhodamine derivative, rhodamine B hydrazide (RH), is applied to detect nitric oxide and form fluorescent rhodamine B (RB). The reaction mechanism of RH with NO is proposed in this study. The probe shows good stability over a broad pH range (pH>4). Furthermore, fluorescence intensity of RH displays an excellent linearity to the NO concentration and the detection limit is as low as 20 nM. A 1000-fold fluorescence turn-on from a dark background was observed. Moreover, the selectivity study indicated that the fluorescence intensity increasing in the presence of NO was significantly higher than those of other reactive oxygen/nitrogen species. In exogenously generated NO detection study, clear intracellular red fluorescence was observed in the presence of S-nitroso-N-acetyl-D,L-penicillamine (SNAP, a kind of NO releasing agent). In endogenously generated NO detection study, increasing incubation time of RH with lipopolysaccharied (LPS) pre-treated cells could obtain a highly fluorescent cell image. These cell imaging results demonstrated that RH can efficiently penetrate into Raw 264.7 cells and be used for detection of exogenously and endogenously generated nitric oxide. Copyright © 2011 Elsevier B.V. All rights reserved.

Nitric oxide mediates alginate oligosaccharides-induced root development in wheat (Triticum aestivum L.).

PubMed

Zhang, Yunhong; Liu, Hang; Yin, Heng; Wang, Wenxia; Zhao, Xiaoming; Du, Yuguang

2013-10-01

Alginate oligosaccharides (AOS), which are marine oligosaccharides, are involved in regulating plant root growth, but the promotion mechanism for AOS remains unclear. Here, AOS (10-80 mg L(-1)) were found to induce the generation of nitric oxide (NO) in the root system of wheat (Triticum aestivum L.), which promoted the formation and elongation of wheat roots in a dose-dependent manner. NO inhibitors suggested that nitrate reductase (NR), rather than nitric oxide synthase (NOS), was essential for AOS-induced root development. Further studies confirmed that AOS-induced NO generation in wheat roots by up-regulating the gene expression and enzyme activity of NR at the post-transcriptional level. The anatomy and RT-PCR results showed that AOS accelerated the division and growth of stele cells, leading to an increase in the ratio of stele area to root transverse area. This could be inhibited by the NR inhibitor, sodium tungstate, which indicated that NO catalyzed by the NR was involved in AOS regulation of root development. Taken together, in the early stage of AOS-induced root development, NO generation was a novel mechanism by which AOS regulated plant growth. The results also showed that this marine resource could be widely used for crop development. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

21 CFR 868.5165 - Nitric oxide administration apparatus.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nitric oxide administration apparatus. 868.5165... apparatus. (a) Identification. The nitric oxide administration apparatus is a device used to add nitric oxide to gases that are to be breathed by a patient. The nitric oxide administration apparatus is to be...

21 CFR 868.5165 - Nitric oxide administration apparatus.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nitric oxide administration apparatus. 868.5165... apparatus. (a) Identification. The nitric oxide administration apparatus is a device used to add nitric oxide to gases that are to be breathed by a patient. The nitric oxide administration apparatus is to be...

Ab initio molecular dynamics simulation of aqueous solution of nitric oxide in different formal oxidation states

NASA Astrophysics Data System (ADS)

Venâncio, Mateus F.; Rocha, Willian R.

2015-10-01

Ab initio molecular dynamics simulations were used to investigate the early chemical events involved in the dynamics of nitric oxide (NOrad), nitrosonium cation (NO+) and nitroxide anion (NO-) in aqueous solution. The NO+ ion is very reactive in aqueous solution having a lifetime of ∼4 × 10-13 s, which is shorter than the value of 3 × 10-10 s predicted experimentally. The NO+ reacts generating the nitrous acid as an intermediate and the NO2- ion as the final product. The dynamics of NOrad revealed the reversibly formation of a transient anion radical species HONOrad -.

Nitric oxide regulation of calcitonin gene-related peptide gene expression in rat trigeminal ganglia neurons

PubMed Central

Bellamy, Jamie; Bowen, Elizabeth J.; Russo, Andrew F.; Durham, Paul L.

2006-01-01

Calcitonin gene-related peptide (CGRP) and nitric oxide are involved in the underlying pathophysiology of migraine and other diseases involving neurogenic inflammation. We have tested the hypothesis that nitric oxide might trigger signaling mechanisms within the trigeminal ganglia neurons that would coordinately stimulate CGRP synthesis and release. Treatment of primary trigeminal ganglia cultures with nitric oxide donors caused a greater than four-fold increase in CGRP release compared with unstimulated cultures. Similarly, CGRP promoter activity was also stimulated by nitric oxide donors and overexpression of inducible nitric oxide synthase (iNOS). Cotreatment with the antimigraine drug sumatriptan greatly repressed nitric oxide stimulation of CGRP promoter activity and secretion. Somewhat surprisingly, the mechanisms of nitric oxide stimulation of CGRP secretion did not require cGMP or PI3-kinase signaling pathways, but rather, nitric oxide action required extracellular calcium and likely involves T-type calcium channels. Furthermore, nitric oxide was shown to increase expression of the active forms of the mitogen-activated protein kinases Jun amino-terminal kinase and p38 but not extracellular signal-related kinase in trigeminal neurons. In summary, our results provide new insight into the cellular mechanisms by which nitric oxide induces CGRP synthesis and secretion from trigeminal neurons. PMID:16630053

Role of Nitric Oxide in the Regulation of Renin and Vasopressin Secretion

NASA Technical Reports Server (NTRS)

Reid, Ian A.

1994-01-01

Research during recent years has established nitric oxide as a unique signaling molecule that plays important roles in the regulation of the cardiovascular, nervous, immune, and other systems. Nitric oxide has also been implicated in the control of the secretion of hormones by the pancreas, hypothalamus, and anterior pituitary gland, and evidence is accumulating that it contributes to the regulation of the secretion of renin and vasopressin, hormones that play key roles in the control of sodium and water balance. Several lines of evidence have implicated nitric oxide in the control of renin secretion. The enzyme nitric oxide synthase is present in vascular and tubular elements of the kidney, particularly in cells of the macula densa, a structure that plays an important role in the control of renin secretion. Guanylyl cyclase, a major target for nitric oxide, is also present in the kidney. Drugs that inhibit nitric oxide synthesis generally suppress renin release in vivo and in vitro, suggesting a stimulatory role for the L-arginine/nitric oxide pathway in the control of renin secretion. Under some conditions, however, blockade of nitric oxide synthesis increases renin secretion. Recent studies indicate that nitric oxide not only contributes to the regulation of basal renin secretion, but also participates in the renin secretory responses to activation of the renal baroreceptor, macula densa, and beta adrenoceptor mechanisms that regulate renin secretion. Histochemical and immunocytochemical studies have revealed the presence of nitric oxide synthase in the supraoptic and paraventricular nuclei of the hypothalamus and in the posterior pituitary gland. Colocalization of nitric oxide synthase and vasopressin has been demonstrated in some hypothalamic neurons. Nitric oxide synthase activity in the hypothalamus and pituitary is increased by maneuvers known to stimulate vasopressin secretion, including salt loading and dehydration, Administration of L-arginine and nitric oxide donors in vitro and in vivo has variable effects on vasopressin secretion, but the most common one is inhibition. Blockade of nitric oxide synthesis has been reported to increase vasopressin secretion, but again variable results have been obtained. An attractive working hypothesis is that nitric oxide serves a neuromodulatory role as an inhibitor of vasopressin secretion.

Nitrous-acid-mediated synthesis of iron-nitrosyl-porphyrin: pH-dependent release of nitric oxide.

PubMed

Bhuyan, Jagannath; Sarkar, Sabyasachi

2012-11-01

Two iron-nitrosyl-porphyrins, nitrosyl[meso-tetrakis(3,4,5-trimethoxyphenylporphyrin]iron(II) acetic acid solvate (3) and nitrosyl[meso-tetrakis(4-methoxyphenylporphyrin]iron(II) CH(2)Cl(2) solvate (4), were synthesized in quantitative yield by using a modified procedure with nitrous acid, followed by oxygen-atom abstraction by triphenylphosphine under an argon atmosphere. These nitrosyl porphyrins are in the {FeNO}(7) class. Under an argon atmosphere, these compounds are relatively stable over a broad range of pH values (4-8) but, under aerobic conditions, they release nitric oxide faster at high pH values than that at low pH values. The generated nitric-oxide-free iron(III)-porphyrin can be re-nitrosylated by using nitrous acid and triphenylphosphine. The rapid release of NO from these Fe(II) complexes at high pH values seems to be similar to that in nitrophorin, a nitric-oxide-transport protein, which formally possesses Fe(III). However, because the release of NO occurs from ferrous-nitrosyl-porphyrin under aerobic conditions, these compounds are more closely related to nitrobindin, a recently discovered heme protein. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Green tea polyphenols and tannic acid act as potent inhibitors of phorbol ester-induced nitric oxide generation in rat hepatocytes independent of their antioxidant properties.

PubMed

Srivastava, R C; Husain, M M; Hasan, S K; Athar, M

2000-05-29

The deleterious effects of excessive release of nitric oxide (NO) have been implicated in the tissue damage and inflammation. In this study, the effect of various flavonoids and other oxidant scavenging chemical agents have been studied for their ability to inhibit 12-O-tetradecanoyl phorbol 13-acetate (TPA)-induced NO generation in rat hepatocyte. Hepatocytes activated with TPA (25-200 nM) released NO in a concentration- and time-dependent manner. Green tea polyphenols (GTP) and tannic acid (TA) were most effective in inhibiting TPA-induced NO generation (90%). These agents were also effective in inhibiting NO formation when added 2 h following TPA addition. The other oxidant scavengers, such as L-histidine, sodium azide, vitamin E and sodium benzoate, were not found to be effective even up to 1.0 mM concentration. These results suggest that TA and GTP are potent inhibitors of NOS activity and the inhibition of TPA-induced NO generation by these polyphenols is independent of their antioxidant activity. It is tempting to speculate that these agents could be utilized in the pharmacological manipulations of NO-dependent pathophysiological responses.

Therapeutic strategies to address neuronal nitric oxide synthase deficiency and the loss of nitric oxide bioavailability in Duchenne Muscular Dystrophy.

PubMed

Timpani, Cara A; Hayes, Alan; Rybalka, Emma

2017-05-25

Duchenne Muscular Dystrophy is a rare and fatal neuromuscular disease in which the absence of dystrophin from the muscle membrane induces a secondary loss of neuronal nitric oxide synthase and the muscles capacity for endogenous nitric oxide synthesis. Since nitric oxide is a potent regulator of skeletal muscle metabolism, mass, function and regeneration, the loss of nitric oxide bioavailability is likely a key contributor to the chronic pathological wasting evident in Duchenne Muscular Dystrophy. As such, various therapeutic interventions to re-establish either the neuronal nitric oxide synthase protein deficit or the consequential loss of nitric oxide synthesis and bioavailability have been investigated in both animal models of Duchenne Muscular Dystrophy and in human clinical trials. Notably, the efficacy of these interventions are varied and not always translatable from animal model to human patients, highlighting a complex interplay of factors which determine the downstream modulatory effects of nitric oxide. We review these studies herein.

Interaction between HSP 70 and iNOS in skeletal muscle injury and repair.

PubMed

Kim, Kijeong

2015-10-01

Muscle injuries are frequently occurred in various sports. The biological process and mechanism of muscle repair after injury are well known through the many studies. This study aimed at presenting heat shock protein and nitric oxide synthase are to respond to muscle damage and repair. This section discusses the results obtained through many articles. Heat shock proteins (HSPs) are considered to play an essential role in protecting cells from damage, preparing them to survive on new environmental challenges. In addition, exercise-induced changes such as heat shock, oxidative, metabolic, muscular, and cytokine stress seem to be responsible for the HSP response to exercise. Also, inducible nitric oxide synthase (iNOS) generates nitric oxide (NO) for prolonged period and causes pathophysiological effects. Furthermore, iNOS is involved in processes such as cell injury, wound repair, embryogenesis, tissue differentiation, and suppression of tumorigenesis. In conclusion, the inhibition of HSP 70 on caspase-3 and apoptosis is associated with its inhibition on iNOS that leads to less NO production.

Decreased Arteriolar Tetrahydrobiopterin is Linked to Superoxide Generation from Nitric Oxide Synthase in Mice Fed High Salt

PubMed Central

Nurkiewicz, Timothy R.; Wu, Guoyao; Li, Peng; Boegehold, Matthew A.

2012-01-01

Objective Impaired endothelium-dependent arteriolar dilation in mice fed high salt is due to local oxidation of nitric oxide (NO) by superoxide anion (O2-). We explored the possibility that “uncoupled” endothelial nitric oxide synthase (eNOS) is the source of this O2-. Methods Levels of L-arginine (L-Arg), tetrahydrobiopterin (BH4) and O2- (hydroethidine oxidation) were measured in spinotrapezius muscle arterioles of mice fed normal salt (0.45%, NS) or high salt (4%, HS) diets for 4 weeks, with or without dietary L-Arg supplementation. The contribution of NO to endothelium-dependent dilation was determined from the effect of Nω-nitro-L-arginine methyl ester (L-NAME) on responses to acetylcholine (ACh). Results Arterioles in HS mice had lower [BH4] and higher O2- levels than those in NS mice. ACh further increased arteriolar O2- in HS mice only. L-Arg supplementation prevented the reduction in [BH4] in arterioles of HS mice, and O2- was not elevated in these vessels. Compared to NS mice, arteriolar ACh responses were diminished and insensitive to L-NAME in HS mice, but not in HS mice supplemented with L-Arg. Conclusions These findings suggest that eNOS uncoupling due to low [BH4] is responsible for O2- generation and reduced NO-dependent dilation in arterioles of mice fed a high salt diet. PMID:20163541

Role of excited N2 in the production of nitric oxide

NASA Astrophysics Data System (ADS)

Campbell, L.; Cartwright, D. C.; Brunger, M. J.

2007-08-01

Excited N2 plays a role in a number of atmospheric processes, including auroral and dayglow emissions, chemical reactions, recombination of free electrons, and the production of nitric oxide. Electron impact excitation of N2 is followed by radiative decay through a series of excited states, contributing to auroral and dayglow emissions. These processes are intertwined with various chemical reactions and collisional quenching involving the excited and ground state vibrational levels. Statistical equilibrium and time step atmospheric models are used to predict N2 excited state densities and emissions (as a test against previous models and measurements) and to investigate the role of excited nitrogen in the production of nitric oxide. These calculations predict that inclusion of the reaction N2[A3Σu +] + O, to generate NO, produces an increase by a factor of up to three in the calculated NO density at some altitudes.

Neural crest development and craniofacial morphogenesis is coordinated by nitric oxide and histone acetylation

PubMed Central

Kong, Yawei; Grimaldi, Michael; Curtin, Eugene; Dougherty, Max; Kaufman, Charles; White, Richard M.; Zon, Leonard I.; Liao, Eric C.

2015-01-01

Cranial neural crest (CNC) cells are patterned and coalesce to facial prominences that undergo convergence and extension to generate the craniofacial form. We applied a chemical genetics approach to identify pathways that regulate craniofacial development during embryogenesis. Treatment with the nitric oxide synthase inhibitor TRIM abrogated first pharyngeal arch structures and induced ectopic ceratobranchial formation. TRIM promoted a progenitor CNC fate and inhibited chondrogenic differentiation, which were mediated through impaired nitric oxide (NO) production without appreciable effect on global protein S-nitrosylation. Instead, TRIM perturbed hox gene patterning and caused histone hypoacetylation. Rescue of TRIM phenotype was achieved with over-expression of histone acetyltransferase kat6a, inhibition of histone deacetylase, and complimentary NO. These studies demonstrate that NO signaling and histone acetylation are coordinated mechanisms that regulate CNC patterning, differentiation and convergence during craniofacial morphogenesis. PMID:24684905

Nitric oxide prevents a pathogen-permissive granulocytic inflammation during tuberculosis.

PubMed

Mishra, Bibhuti B; Lovewell, Rustin R; Olive, Andrew J; Zhang, Guoliang; Wang, Wenfei; Eugenin, Eliseo; Smith, Clare M; Phuah, Jia Yao; Long, Jarukit E; Dubuke, Michelle L; Palace, Samantha G; Goguen, Jon D; Baker, Richard E; Nambi, Subhalaxmi; Mishra, Rabinarayan; Booty, Matthew G; Baer, Christina E; Shaffer, Scott A; Dartois, Veronique; McCormick, Beth A; Chen, Xinchun; Sassetti, Christopher M

2017-05-15

Nitric oxide contributes to protection from tuberculosis. It is generally assumed that this protection is due to direct inhibition of Mycobacterium tuberculosis growth, which prevents subsequent pathological inflammation. In contrast, we report that nitric oxide primarily protects mice by repressing an interleukin-1- and 12/15-lipoxygenase-dependent neutrophil recruitment cascade that promotes bacterial replication. Using M. tuberculosis mutants as indicators of the pathogen's environment, we inferred that granulocytic inflammation generates a nutrient-replete niche that supports M. tuberculosis growth. Parallel clinical studies indicate that a similar inflammatory pathway promotes tuberculosis in patients. The human 12/15-lipoxygenase orthologue, ALOX12, is expressed in cavitary tuberculosis lesions; the abundance of its products correlates with the number of airway neutrophils and bacterial burden and a genetic polymorphism that increases ALOX12 expression is associated with tuberculosis risk. These data suggest that M. tuberculosis exploits neutrophilic inflammation to preferentially replicate at sites of tissue damage that promote contagion.

Hydroxychavicol, a Piper betle leaf component, induces apoptosis of CML cells through mitochondrial reactive oxygen species-dependent JNK and endothelial nitric oxide synthase activation and overrides imatinib resistance.

PubMed

Chakraborty, Jayashree B; Mahato, Sanjit K; Joshi, Kalpana; Shinde, Vaibhav; Rakshit, Srabanti; Biswas, Nabendu; Choudhury Mukherjee, Indrani; Mandal, Labanya; Ganguly, Dipyaman; Chowdhury, Avik A; Chaudhuri, Jaydeep; Paul, Kausik; Pal, Bikas C; Vinayagam, Jayaraman; Pal, Churala; Manna, Anirban; Jaisankar, Parasuraman; Chaudhuri, Utpal; Konar, Aditya; Roy, Siddhartha; Bandyopadhyay, Santu

2012-01-01

Alcoholic extract of Piper betle (Piper betle L.) leaves was recently found to induce apoptosis of CML cells expressing wild type and mutated Bcr-Abl with imatinib resistance phenotype. Hydroxy-chavicol (HCH), a constituent of the alcoholic extract of Piper betle leaves, was evaluated for anti-CML activity. Here, we report that HCH and its analogues induce killing of primary cells in CML patients and leukemic cell lines expressing wild type and mutated Bcr-Abl, including the T315I mutation, with minimal toxicity to normal human peripheral blood mononuclear cells. HCH causes early but transient increase of mitochondria-derived reactive oxygen species. Reactive oxygen species-dependent persistent activation of JNK leads to an increase in endothelial nitric oxide synthase-mediated nitric oxide generation. This causes loss of mitochondrial membrane potential, release of cytochrome c from mitochondria, cleavage of caspase 9, 3 and poly-adenosine diphosphate-ribose polymerase leading to apoptosis. One HCH analogue was also effective in vivo in SCID mice against grafts expressing the T315I mutation, although to a lesser extent than grafts expressing wild type Bcr-Abl, without showing significant bodyweight loss. Our data describe the role of JNK-dependent endothelial nitric oxide synthase-mediated nitric oxide for anti-CML activity of HCH and this molecule merits further testing in pre-clinical and clinical settings. © 2011 Japanese Cancer Association.

Study of the nitric oxide system in the rat cerebellum during aging.

PubMed

Blanco, Santos; Molina, Francisco J; Castro, Lourdes; Del Moral, Maria L; Hernandez, Raquel; Jimenez, Ana; Rus, Alma; Martinez-Lara, Esther; Siles, Eva; Peinado, Maria A

2010-06-24

The cerebellum is the neural structure with the highest levels of nitric oxide, a neurotransmitter that has been proposed to play a key role in the brain aging, although knowledge concerning its contribution to cerebellar senescence is still unclear, due mainly to absence of integrative studies that jointly evaluate the main factors involved in its cell production and function. Consequently, in the present study, we investigate the expression, location, and activity of nitric oxide synthase isoenzymes; the protein nitration; and the production of nitric oxide in the cerebellum of adult and old rats. Our results show no variation in the expression of nitric oxide synthase isoforms with aging, although, we have detected some changes in the cellular distribution pattern of the inducible isoform particularly in the cerebellar nuclei. There is also an increase in nitric oxide synthase activity, as well as greater protein-nitration levels, and maintenance of nitrogen oxides (NOx) levels in the senescent cerebellum. The nitric oxide/nitric oxide synthases system suffers from a number of changes, mainly in the inducible nitric oxide synthase distribution and in overall nitric oxide synthases activity in the senescent cerebellum, which result in an increase of the protein nitration. These changes might be related to the oxidative damage detected with aging in the cerebellum.

Nitric oxide-sensing actuators for modulating structure in lipid-based liquid crystalline drug delivery systems.

PubMed

Liu, Qingtao; Hu, Jinming; Whittaker, Michael R; Davis, Thomas P; Boyd, Ben J

2017-12-15

Herein we report on the development of a nitric oxide-sensing lipid-based liquid crystalline (LLC) system specifically designed to release encapsulated drugs on exposure to NO through a stimulated phase change. A series of nitric oxide (NO)-sensing lipids compatible with phytantriol and GMO cubic phases were designed and synthesized, and utilized in enabling nitric oxide-sensing LLC systems. The nitric oxide (NO)-sensing lipids react with nitric oxide, resulting in hydrolysis of these lipids and phase transition of the LLC system. Specifically, the N-3-aminopyridinyl myristylamine (NAPyM)+phytantriol mixture formed a lamellar phase in excess aqueous environment. The NAPyM+phytantriol LLC responded to the nitric oxide gas as a chemical stimulus which triggers a phase transition from lamellar phase to inverse cubic and hexagonal phase. The nitric oxide-triggered phase transition of the LLC accelerated the release of encapsulated model drug from the LLC bulk phase, resulting in a 15-fold increase in the diffusion coefficient compared to the starting lamellar structure. The nitric oxide-sensing LLC system has potential application in the development of smart medicines to treat nitric oxide implicated diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Light-Induced Acid Generation on a Gatekeeper for Smart Nitric Oxide Delivery.

PubMed

Choi, Hyung Woo; Kim, Jihoon; Kim, Jinhwan; Kim, Yonghwi; Song, Hyun Beom; Kim, Jeong Hun; Kim, Kimoon; Kim, Won Jong

2016-04-26

We report herein the design of a light-responsive gatekeeper for smart nitric oxide (NO) delivery. The gatekeeper is composed of a pH-jump reagent as an intermediary of stimulus and a calcium phosphate (CaP) coating as a shielding layer for NO release. The light irradiation and subsequent acid generation are used as triggers for uncapping the gatekeeper and releasing NO. The acids generated from a light-activated pH-jump agent loaded in the mesoporous nanoparticles accelerated the degradation of the CaP-coating layers on the nanoparticles, facilitating the light-responsive NO release from diazeniumdiolate by exposing a NO donor to physiological conditions. Using the combination of the pH-jump reagent and CaP coating, we successfully developed a light-responsive gatekeeper system for spatiotemporal-controlled NO delivery.

Photolytic generation of nitric oxide through a porous glass partitioning membrane.

PubMed

Zhelyaskov, V R; Godwin, D W

1998-01-01

We report a new method of generating nitric oxide that possesses several potential advantages for experimental use. This method consists of a microphotolysis chamber where NO is released by illuminating photolabile NO donors with light from a xenon lamp. NO then diffuses through a porous glass membrane to the experimental preparation. We observed that the rate of NO generation is a linear function of light intensity. Due to a dynamic equilibrium between the mechanisms of NO generation and dissipation (by diffusion or oxidation) the NO concentration in the experimental cuvette can be reversibly and reproducibly controlled. The major potential advantages of this device include its use as a NO point source, and the ability to partition the NO donor compound from the experimental preparation by a porous glass membrane. The diffusion of the caging moiety through the membrane is insignificant as seen by absorption spectroscopy due to its large relative size to NO. In this way, the porous glass membrane protects the preparation from the potential bioactive effects of the caging moiety, which is an important consideration for biological experiments.

HBOC vasoactivity: interplay between nitric oxide scavenging and capacity to generate bioactive nitric oxide species.

PubMed

Cabrales, Pedro; Friedman, Joel M

2013-06-10

Despite many advances in blood substitute research, the development of materials that are effective in maintaining blood volume and oxygen delivery remains a priority for emergency care and trauma. Clinical trials on hemoglobin (Hb)-based oxygen carriers (HBOCs) have not provided information on the mechanism of toxicity, although all commercial formulations have safety concerns. Specifically, it is important to reconcile the different hypotheses of Hb toxicity, such as nitric oxide (NO) depletion and oxidative reactions, to provide a coherent molecular basis for designing a safe HBOC. HBOCs with different sizes often exhibit differences in the degree of HBOC-induced vasoactivity. This has been attributed to differences in the degree of NO scavenging and in the extent of Hb extravasation. Additionally, it is appears that Hb can undergo reactions that compensate for NO scavenging by generating bioactive forms of NO. Engineering modifications to enhance bioactive NO production can result in diminished oxygen delivery by virtue of increased oxygen affinity. This strategy can prevent the HBOC from fulfilling the intended goal on preserving oxygenation; however, the NO production effects will increase perfusion and oxygen transport. Hb modifications influence NO scavenging and the capacity of certain HBOCs to compensate for NO scavenging through nitrite-mediated reactions that generate bioactive NO. Based on the current understanding of these NO-related factors, possible synthetic strategies are presented that address how HBOC formulations can be prepared that: (i) effectively deliver oxygen, (ii) maintain tissue perfusion, and (iii) limit/reverse underlying inflammation within the vasculature.

Combination of nitric oxide therapy, anti-oxidative therapy, low level laser therapy, plasma rich platelet therapy and stem cell therapy as a novel therapeutic application to manage the pain and treat many clinical conditions

NASA Astrophysics Data System (ADS)

Halasa, Salaheldin; Dickinson, Eva

2014-02-01

From hypertension to diabetes, cancer to HIV, stroke to memory loss and learning disorders to septic shock, male impotence to tuberculosis, there is probably no pathological condition where nitric oxide does not play an important role. Nitric oxide is an analgesic, immune-modulator, vasodilator, anti-apoptotic, growth modulator, angiogenetic, anti-thrombotic, anti-inflammatory and neuro-modulator. Because of the above actions of nitric oxide, many clinical conditions associated with abnormal Nitric oxide (NO) production and bioavailability. Our novel therapeutic approach is to restore the homeostasis of nitric oxide and replace the lost cells by combining nitric oxide therapy, anti-oxidative therapy, low level laser therapy, plasma rich platelet therapy and stem cell therapy.

Induction of expression of iNOS by N-nitrosodimethylamine (NDMA) in human leukocytes.

PubMed

Ratajczak-Wrona, Wioletta; Jablonska, Ewa; Jablonski, Jakub; Marcinczyk, Magdalena

2009-01-01

The aim of this study was to assess the influence of N-nitrosodimethylamine (NDMA) on expression of inducible nitric oxide synthase (iNOS), as well as production of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) by human neutrophils (PMN) and peripheral blood mononuclear cells (PBMC), and the participation of the p38 MAPK kinase in this process. Furthermore, the ability of neutrophils to release superoxide anion was determined. The influence of N-nitrosodimethylamine on iNOS expression was determined in isolated PMN and PBMC cells from peripheral blood of healthy individuals. The mononuclear cells showed higher sensitivity to NDMA. Moreover, cytotoxic effect of NDMA can be influenced in some way by the impact of this xenobiotic on nitric oxide and superoxide anion release from human leukocytes. Furthermore, increased generation of these radicals by human leukocytes suggest that neutrophils and mononuclear cells that are exposed to NDMA activity can play a key role in endogenous NDMA generation. However the relationship between iNOS expression and phospho-p38 MAPK in neutrophils and mononuclear cells shows that p38 MAPK pathway participates in induction of iNOS expression in the presence of NDMA.

Effects of endogenous nitric oxide and of DETA NONOate in arteriogenesis.

PubMed

Troidl, Kerstin; Tribulova, Silvia; Cai, Wei-Jun; Rüding, Inka; Apfelbeck, Hanna; Schierling, Wilma; Troidl, Christian; Schmitz-Rixen, Thomas; Schaper, Wolfgang

2010-02-01

Previous studies showed that targeted endothelial nitric oxide synthase (eNOS) disruption in mice with femoral artery occlusion does not impede and transgenic eNOS overexpression does not stimulate collateral artery growth after femoral artery occlusion, suggesting that nitric oxide from eNOS does not play a role in arteriogenesis. However, pharmacologic nitric oxide synthase inhibition with L-NAME markedly blocks arteriogenesis, suggestive of an important role of nitric oxide. To solve the paradox, we studied targeted deletion of eNOS and of inducible nitric oxide synthase (iNOS) in mice and found that only iNOS knockout could partially inhibit arteriogenesis. However, the combination of eNOS knockout and treatment with the iNOS inhibitor L-NIL completely abolished arteriogenesis. mRNA transcription studies (reverse transcriptase-polymerase chain reaction) performed on collateral arteries of rats showed that eNOS and especially iNOS (but not neural nitric oxide synthase) become upregulated in shear stress-stimulated collateral vessels, which supports the hypothesis that nitric oxide is necessary for arteriogenesis but that iNOS plays an important part. This was strengthened by the observation that the nitric oxide donor DETA NONOate strongly stimulated collateral artery growth, activated perivascular monocytes, and increased proliferation markers. Shear stress-induced nitric oxide may activate the innate immune system and activate iNOS. In conclusion, arteriogenesis is completely dependent on the presence of nitric oxide, a large part of it coming from mononuclear cells.

The transport of nitric oxide in the upper atmosphere by planetary waves and the zonal mean circulation

NASA Technical Reports Server (NTRS)

Jones, G. A.; Avery, S. K.

1982-01-01

A time-dependent numerical model was developed and used to study the interaction between planetary waves, the zonal mean circulation, and the trace constituent nitric oxide in the region between 55 km and 120 km. The factors which contribute to the structure of the nitric oxide distribution were examined, and the sensitivity of the distribution to changes in planetary wave amplitude was investigated. Wave-induced changes in the mean nitric oxide concentration were examined as a possible mechanism for the observed winter anomaly. Results indicate that vertically-propagating planetary waves induce a wave-like structure in the nitric oxide distribution and that at certain levels, transports of nitric oxide by planetary waves could significantly affect the mean nitric oxide distribution. The magnitude and direction of these transports at a given level was found to depend not only on the amplitude of the planetary wave, but also on the loss rate of nitric oxide at that level.

Effects of nitric oxide on neuromuscular properties of developing zebrafish embryos.

PubMed

Jay, Michael; Bradley, Sophie; McDearmid, Jonathan Robert

2014-01-01

Nitric oxide is a bioactive signalling molecule that is known to affect a wide range of neurodevelopmental processes. However, its functional relevance to neuromuscular development is not fully understood. Here we have examined developmental roles of nitric oxide during formation and maturation of neuromuscular contacts in zebrafish. Using histochemical approaches we show that elevating nitric oxide levels reduces the number of neuromuscular synapses within the axial swimming muscles whilst inhibition of nitric oxide biosynthesis has the opposite effect. We further show that nitric oxide signalling does not change synapse density, suggesting that the observed effects are a consequence of previously reported changes in motor axon branch formation. Moreover, we have used in vivo patch clamp electrophysiology to examine the effects of nitric oxide on physiological maturation of zebrafish neuromuscular junctions. We show that developmental exposure to nitric oxide affects the kinetics of spontaneous miniature end plate currents and impacts the neuromuscular drive for locomotion. Taken together, our findings implicate nitrergic signalling in the regulation of zebrafish neuromuscular development and locomotor maturation.

Graphene Electronic Device Based Biosensors and Chemical Sensors

NASA Astrophysics Data System (ADS)

Jiang, Shan

Two-dimensional layered materials, such as graphene and MoS2, are emerging as an exciting material system for a new generation of atomically thin electronic devices. With their ultrahigh surface to volume ratio and excellent electrical properties, 2D-layered materials hold the promise for the construction of a generation of chemical and biological sensors with unprecedented sensitivity. In my PhD thesis, I mainly focus on graphene based electronic biosensors and chemical sensors. In the first part of my thesis, I demonstrated the fabrication of graphene nanomesh (GNM), which is a graphene thin film with a periodic array of holes punctuated in it. The periodic holes introduce long periphery active edges that provide a high density of functional groups (e.g. carboxylic groups) to allow for covalent grafting of specific receptor molecules for chemical and biosensor applications. After covalently functionalizing the GNM with glucose oxidase, I managed to make a novel electronic sensor which can detect glucose as well as pH change. In the following part of my thesis I demonstrate the fabrication of graphene-hemin conjugate for nitric oxide detection. The non-covalent functionalization through pi-pi stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. The graphene-hemin nitric oxide sensor is capable of real-time monitoring of nitric oxide concentrations, which is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems, and immune responses. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their practical functionality in complex biological systems. In the last part of my thesis, I demonstrate the construction of few-layer molybdenum disulfide (MoS2) based field-effect transistor (FET) device for highly sensitive detection of Hg2+ ion in aquatic solutions. The detection of mercury in aquatic environment is of great importance because mercury is an environment pollutant with severe toxicity. High binding affinity between mercury and sulfur makes MoS2 a promising candidate for mercury sensing. Our studies demonstrate that MoS2 sensors can selectively respond to Hg2+ ion with a detection limit of 30 pM. This MoS2 FET based mercury sensor promises great potential for highly sensitive, label-free, low-cost, fast and non-aggressive detection of mercury in aquatic environment.

Vascular smooth muscle relaxation mediated by nitric oxide donors: a comparison with acetylcholine, nitric oxide andnitroxyl ion

PubMed Central

Wanstall, Janet C; Jeffery, Trina K; Gambino, Agatha; Lovren, Fina; Triggle, Christopher R

2001-01-01

Vasorelaxant properties of three nitric oxide (NO) donor drugs (glyceryl trinitrate, sodium nitroprusside and spermine NONOate) in mouse aorta (phenylephrine pre-contracted) were compared with those of endothelium-derived NO (generated with acetylcholine), NO free radical (NO·; NO gas solution) and nitroxyl ion (NO−; from Angeli's salt). The soluble guanylate cyclase inhibitor, ODQ (1H-(1,2,4-)oxadiazolo(4,3-a)-quinoxalin-1-one; 0.3, 1 and 10 μM), concentration-dependently inhibited responses to all agents. 10 μM ODQ abolished responses to acetylcholine and glyceryl trinitrate, almost abolished responses to sodium nitroprusside but produced parallel shifts (to a higher concentration range; no depression in maxima) in the concentration-response curves for NO gas solution, Angeli's salt and spermine NONOate. The NO· scavengers, carboxy-PTIO, (2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide; 100 μM) and hydroxocobalamin (100 μM), both inhibited responses to NO gas solution and to the three NO donor drugs, but not Angeli's salt. Hydroxocobalamin, but not carboxy-PTIO, also inhibited responses to acetylcholine. The NO− inhibitor, L-cysteine (3 mM), inhibited responses to Angeli's salt, acetylcholine and the three NO donor drugs, but not NO gas solution. The data suggest that, in mouse aorta, responses to all three NO donors involve (i) activation of soluble guanylate cyclase, but to differing degrees and (ii) generation of both NO· and NO−. Glyceryl trinitrate and sodium nitroprusside, which generate NO following tissue bioactivation, have profiles resembling the profile of endothelium-derived NO more than that of exogenous NO. Spermine NONOate, which generates NO spontaneously outside the tissue, was the drug that most closely resembled (but was not identical to) exogenous NO. PMID:11588100

In vitro antioxidant and anti-inflammatory activities of Jaceosidin from Artemisia princeps Pampanini cv. Sajabal.

PubMed

Kim, Min-Jung; Han, Jong-Min; Jin, Yue-Yan; Baek, Nam-In; Bang, Myun-Ho; Chung, Hae-Gon; Choi, Myung-Sook; Lee, Kyung-Tae; Sok, Dai-Eun; Jeong, Tae-Sook

2008-04-01

Oxidized low-density lipoprotein (oxLDL) plays a key role in the inflammatory processes of atherosclerosis. Jaceosidin isolated from the methanolic extracts of the aerial parts of Artemisia princeps Pampanini cv. Sajabal was tested for antioxidant and anti-inflammatory activities. Jaceosidin inhibited the Cu(2+)-mediated LDL oxidation with IC(50) values of 10.2 microM in the thiobarbituric acid-reactive substances (TBARS) assay as well as the macrophage-mediated LDL oxidation. The antioxidant activities of jaceosidin were exhibited in the conjugated diene production, relative electrophoretic mobility, and apoB-100 fragmentation on copper-mediated LDL oxidation. Jaceosidin also inhibited the generation of reactive oxygen species (ROS) concerning in regulation of NF-kappaB signaling. And jaceosidin inhibited nuclear factor-kappa B (NF-kappaB) activity, nitric oxide (NO) production, and suppressed expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-induced RAW264.7 macrophages.

Nitric oxide is a versatile sensor of low oxygen stress in plants

PubMed Central

Borisjuk, Ljudmilla

2008-01-01

The plant response to low levels of oxygen involves an interplay of transcriptional, translational and post-translational signaling. However, in plants, the sensing mechanism itself remains obscure. The role of nitric oxide (NO) in oxygen sensing and balancing has been extensively explored in our laboratory. We suggest that NO is generated within the mitochondria from nitrite in response to hypoxia, and that this small gaseous molecule can reversibly modify both the respiratory oxygen consumption and the oxygen availability within the seed. We further propose that hemoglobins play a central role in the detoxification of excess NO. PMID:19704575

Altered respiratory responses to hypoxia in mutant mice deficient in neuronal nitric oxide synthase

PubMed Central

Kline, David D; Yang, Tianen; Huang, Paul L; Prabhakar, Nanduri R

1998-01-01

The role of endogenous nitric oxide (NO) generated by neuronal nitric oxide synthase (NOS-1) in the control of respiration during hypoxia and hypercapnia was assessed using mutant mice deficient in NOS-1. Experiments were performed on awake and anaesthetized mutant and wild-type control mice. Respiratory responses to varying levels of inspired oxygen (100, 21 and 12 % O2) and carbon dioxide (3 and 5 % CO2 balanced oxygen) were analysed. In awake animals, respiration was monitored by body plethysmograph along with oxygen consumption (V̇O2), CO2 production (V̇CO2) and body temperature. In anaesthetized, spontaneously breathing mice, integrated efferent phrenic nerve activity was monitored as an index of neural respiration along with arterial blood pressure and blood gases. Cyclic 3′,5′-guanosine monophosphate (cGMP) levels in the brainstem were analysed by radioimmunoassay as an index of nitric oxide generation. Unanaesthetized mutant mice exhibited greater respiratory responses during 21 and 12 % O2 than the wild-type controls. Respiratory responses were associated with significant decreases in oxygen consumption in both groups of mice, and the magnitude of change was greater in mutant than wild-type mice. Changes in CO2 production and body temperature, however, were comparable between both groups of mice. Similar augmentation of respiratory responses during hypoxia was also observed in anaesthetized mutant mice. In addition, five of the fourteen mutant mice displayed periodic oscillations in respiration (brief episodes of increases in respiratory rate and tidal phrenic nerve activity) while breathing 21 and 12 % O2, but not during 100 % O2. The time interval between the episodes decreased by reducing inspired oxygen from 21 to 12 % O2. Changes in arterial blood pressure and arterial blood gases were comparable at any given level of inspired oxygen between both groups of mice, indicating that changes in these variables do not account for the differences in the response to hypoxia. Respiratory responses to brief hyperoxia (Dejours test) and to cyanide, a potent chemoreceptor stimulant, were more pronounced in mutant mice, suggesting augmented peripheral chemoreceptor sensitivity. cGMP levels were elevated in the brainstem during 21 and 12 % O2 in wild-type but not in mutant mice, indicating decreased formation of nitric oxide in mutant mice. The magnitude of respiratory responses to hypercapnia (3 and 5 % CO2 balanced oxygen) was comparable in both groups of mice in the awake and anaesthetized conditions. These observations suggest that the hypoxic responses were selectively augmented in mutant mice deficient in NOS-1. Peripheral as well as central mechanisms contributed to the altered responses to hypoxia. These results support the idea that nitric oxide generated by NOS-1 is an important physiological modulator of respiration during hypoxia. PMID:9679181

Lack of modulation of gastric emptying by dietary nitrate in healthy volunteers.

PubMed

Terai, Shiho; Iijima, Katsunori; Asanuma, Kiyotaka; Ara, Nobuyuki; Uno, Kaname; Abe, Yasuhiko; Koike, Tomoyuki; Imatani, Akira; Ohara, Shuichi; Shimosegawa, Tooru

2009-05-01

Nitric oxide produced endogenously in vagal neurons modulates gastrointestinal motor activity as an important non-adrenergic and non-cholinergic neurotransmitter. Other than through endogenous biosynthesis, a high concentration of nitric oxide also occurs by chemical reactions within the stomach in the presence of gastric acid through the entero-salivary re-circulation of dietary nitrate. Although dietary nitrate can be a potential source of nitric oxide in the human stomach, there has been no report on the effect of dietary nitrate on gastric motor function. The aim of this study is to investigate the effect of dietary nitrate on gastric emptying, one of the major parameters for the gastric motor function. Fifteen healthy volunteers underwent a placebo-controlled (310 mg sodium nitrate or placebo), double-blind, crossover trial. Since a sufficient amount of gastric acid is essential for dietary nitrate-derived nitric oxide generation in the stomach, the same protocol was repeated after 1-week treatment with a proton pump inhibitor, rabeprazole. Gastric emptying was evaluated by (13)C-octanoate breath test. The sodium nitrate ingestion did not affect gastric emptying either prior to or during rabeprazole treatment, although rabeprazole treatment itself significantly delayed gastric emptying, being independent of the dietary nitrate load. Confirmation of the delayed gastric emptying with rabeprazole indicates the sensitivity of the breath test employed in the present study. In conclusion, despite the potential nitrogen source of exogenous nitric oxide, the ingestion of 310 mg sodium nitrate, which is equivalent to the average daily intake of Japanese adults, does not affect gastric emptying in healthy volunteers.

Modulation of opioid actions by nitric oxide signaling.

PubMed

Toda, Noboru; Kishioka, Shiroh; Hatano, Yoshio; Toda, Hiroshi

2009-01-01

Nitric oxide (NO) plays pivotal roles in controlling physiological functions, participates in pathophysiological intervention, and is involved in mechanisms underlying beneficial or untoward actions of therapeutic agents. Endogenous nitric oxide is formed by three isoforms of nitric oxide synthase: endothelial, neurogenic and inducible. The former two are constitutively present mainly in the endothelium and nervous system, respectively, and the latter one is induced by lipopolysaccharides or cytokines mainly in mitochondria and glial cells. Constitutively formed nitric oxide modulates the actions of morphine and related analgesics by either enhancing or reducing antinociception. Tolerance to and dependence on morphine or its withdrawal syndrome are likely prevented by nitric oxide synthase inhibition. Information concerning modulation of morphine actions by nitric oxide is undoubtedly useful in establishing new strategies for efficient antinociceptive treatment and for minimizing noxious and unintended reactions.

High temperature decomposition of hydrogen peroxide

NASA Technical Reports Server (NTRS)

Parrish, Clyde F. (Inventor)

2005-01-01

Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

High Temperature Decomposition of Hydrogen Peroxide

NASA Technical Reports Server (NTRS)

Parrish, Clyde F. (Inventor)

2004-01-01

Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydropemxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

Fact and Fiction of Nitrous Oxide Production By Nitrification

NASA Astrophysics Data System (ADS)

Stein, L. Y.; Kozlowski, J.; Stieglmeier, M.; Klotz, M. G.; Schleper, C.

2014-12-01

An accepted dogma in nitrification research is that ammonia-oxidizing bacteria (AOB) produce a modicum of nitrous oxide (N2O) during nitritation via incomplete oxidation of hydroxylamine, and substantially more at low oxygen concentrations via nitrifier denitrification.The nitrifier denitrification pathway involves the reduction of nitrite to N2O via nitric oxide and was thought to require activities of a copper-containing nitrite reductase (NirK) and nitric oxide reductase (NorB); inventory encoded in most, but not all AOB genome sequences. The discovery of nirK genes in ammonia-oxidizing Thaumarchaeota (AOA) resulted in a slew of publications stating that AOA must also perform nitrifier denitrification and, due to their high abundance, must control the majority of nitrification-linked N2O emissions. Prior to a publication by Stieglmeier et al. (2014), which definitively showed a lack of nitrifier denitrification by two axenic AOA cultures, other researchers relied on enrichment cultures, negative data, and heavy inferencing without direct demonstration of either a functional pathway or involvement of specific genes or enzymes. AOA genomes lack recognizable nitric oxide reductases and thermophilic AOA also lack nirK genes. Physiological and microrespirometry experiments with axenic AOB and AOA cultures allowed us to demonstrate that: 1) AOB produce N2O via nitrifier denitrification even though some lack annotated nirK and/or norB genes; 2) nitrifier denitrification by AOB is reliant on nitric oxide but ammonia oxidation is not; 3) ammonia oxidation by AOA is reliant on production of nitric oxide; 4) AOA are incapable of generating N2O via nitrifier denitrification; 5) N2O production by AOA is from chemical interactions between NO and media components, most likely not by enzyme activity. Our results reveal operation of different N oxide transformation pathways in AOB and AOA governed by different environmental controls and involving different mechanisms of N2O production. Critical controls on these mechanisms are levels of oxygen and ammonium. Future calculations of relative contributions of AOB and AOA to N2O emissions must take into account physiological, enzymatic, and environmental differences between these two nitrifying microorganisms.

Role of the recombinant protein of the platelet receptor for type I collagen in the release of nitric oxide during platelet aggregation.

PubMed

Chiang, T M; Wang, Y B; Kang, E S

2000-12-01

Nitric oxide plays an important role in platelet function and platelets possess the endothelial isoform of nitric oxide synthase. Several reports have indicated that nitric oxide is released upon exposure of platelets to collagen. We have reported that a non-integrin platelet protein of 65 kDa is a receptor for type I collagen. By direct measurement of NO release from washed human platelets suspended in Tyrode buffer with a ISO-NO Mark II, World Precision Instruments, Sarasota, FL, USA, p30 sensor, type I collagen, but not ADP and epinephrine, induces the release of NO in a time-dependent manner. The production of NO is inhibited either by preincubation of type I collagen with the platelet type I collagen receptor recombinant protein or by preincubation of platelets with the antibody to the receptor protein, the anti-65 antibody. However, preincubation of platelets with anti-P-selectin and anti-glycoprotein IIb/IIIa did not affect the release of NO by platelets. These results suggest that the 65 kDa platelet receptor for type I collagen is specifically linked to the generation of NO, and that the 65 kDa platelet receptor for type I collagen plays an important new role in platelet function.

Neural nitric oxide gene inactivation affects the release profile of oxytocin into the blood in response to forced swimming.

PubMed

Orlando, G F; Langnaese, K; Landgraf, R; Spina, M G; Wolf, G; Engelmann, M

2007-02-01

This study was undertaken to examine the importance of nitric oxide (NO) generated by the neural isoform of the nitric oxide synthase (nNOS) on the activity of the hypothalamic neurohypophyseal system in neural nitric oxide synthase knock-out (KO) and wild-type (WT) mice under basal conditions and in response to forced swimming. The intensity of the hybridisation signal for vasopressin (AVP) in the hypothalamic supraoptic nucleus (SON) was significantly higher in KO mice when compared with WT, whereas oxytocin (OXT) basal mRNA levels were similar in both groups. Although the basal peripheral release of AVP and OXT was equivalent in both genotypes, we observed in KO mice a significant drop of AVP and OXT plasma values 15 min after stressor onset and a robust increase in the OXT plasma concentration at 60 min. These findings suggest that in the male mouse, NO inhibits AVP gene transcription in magnocellular neurones of the SON and collaborates in maintaining constant AVP and OXT plasma levels following acute stressor exposure, exerting a bimodal regulatory action on OXT secretion. We conclude that NO is involved in the regulation of magnocellular neurones of the SON, and it is preferentially implicated in the attenuation of the peripheral release of OXT induced by acute stressor exposure.

Inducible nitric oxide synthase and apoptosis in murine proximal tubule epithelial cells.

PubMed

Tiwari, Manish M; Messer, Kurt J; Mayeux, Philip R

2006-06-01

Since inducible nitric oxide synthase (iNOS) and proximal tubule injury are known to be critical determinants of lipopolysaccharide (LPS)-induced renal failure, the role of nitric oxide (NO) in proximal tubule cell apoptosis was examined. An 18-h treatment with a combination of LPS (5 microg/ml) and interferon-gamma (IFN-gamma, 100 units/ml) synergistically induced iNOS and produced a 20-fold increase in NO generation in the TKPTS murine proximal tubule cell line. NO generation by LPS + IFN-gamma was blocked by a specific iNOS blocker, L-N6-(1-iminoethyl)-lysine (L-NIL, 1 mM). To assess the role of iNOS-derived NO in proximal tubule cell apoptosis, annexin V- and propidium iodide-labeled cells were analyzed by flow cytometry. Neither the induction of iNOS nor its inhibition produced significant apoptotic cell death in TKPTS cells. Two exogenous NO donors were used to examine the role of NO more directly in proximal tubule apoptosis. Although both sodium nitroprusside (SNP), an iron-containing, nitrosonium cation donor, and S-nitroso-N-acetylpenicillamine (SNAP), a noniron-containing, NO generator, produced a concentration-dependent increase in NO generation, only SNP increased apoptotic cell death in TKPTS cells (5.9 +/- 0.7% in control cells vs. 21.6 +/- 3.8% in SNP [500 microM]-treated cells; n = 4-9; p < 0.01). SNP-mediated tubule cell apoptosis was not dependent on the activation of caspases or p53 but was possibly related to the generation of reactive oxygen species by SNP. Thus, in TKPTS cells induction of iNOS and generation of NO by LPS does not lead to tubular epithelial cell death.

Nitric oxide is cytoprotective to breast cancer spheroids vulnerable to estrogen-induced apoptosis

PubMed Central

Shafran, Yana; Zurgil, Naomi; Ravid-Hermesh, Orit; Sobolev, Maria; Afrimzon, Elena; Hakuk, Yaron; Shainberg, Asher; Deutsch, Mordechai

2017-01-01

Estrogen-induced apoptosis has become a successful treatment for postmenopausal metastatic, estrogen receptor-positive breast cancer. Nitric oxide involvement in the response to this endocrine treatment and its influence upon estrogen receptor-positive breast cancer progression is still unclear. Nitric oxide impact on the MCF7 breast cancer line, before and after estrogen-induced apoptosis, was investigated in 3D culture systems using unique live-cell imaging methodologies. Spheroids were established from MCF7 cells vulnerable to estrogen-induced apoptosis, before and after exposure to estrogen. Spheroids derived from estrogen-treated cells exhibited extensive apoptosis levels with downregulation of estrogen receptor expression, low proliferation rate and reduced metabolic activity, unlike spheroids derived from non-treated cells. In addition to basic phenotypic differences, these two cell cluster types are diverse in their reactions to exogenous nitric oxide. A dual effect of nitric oxide was observed in the breast cancer phenotype sensitive to estrogen-induced apoptosis. Nitric oxide, at the nanomolar level, induced cell proliferation, high metabolic activity, downregulation of estrogen receptor and enhanced collective invasion, contributing to a more aggressive phenotype. Following hormone supplementation, breast cancer 3D clusters were rescued from estrogen-induced apoptosis by these low nitric oxide-donor concentrations, since nitric oxide attenuates cell death levels, upregulates survivin expression and increases metabolic activity. Higher nitric oxide concentrations (100nM) inhibited cell growth, metabolism and promoted apoptosis. These results suggest that nitric oxide, in nanomolar concentrations, may inhibit estrogen-induced apoptosis, playing a major role in hormonal therapy. Inhibiting nitric oxide activity may benefit breast cancer patients and ultimately reduce tumor recurrence. PMID:29312577

Nox control for high nitric oxide concentration flows through combustion-driven reduction

DOEpatents

Yeh, James T.; Ekmann, James M.; Pennline, Henry W.; Drummond, Charles J.

1989-01-01

An improved method for removing nitrogen oxides from concentrated waste gas streams, in which nitrogen oxides are ignited with a carbonaceous material in the presence of substoichiometric quantities of a primary oxidant, such as air. Additionally, reductants may be ignited along with the nitrogen oxides, carbonaceous material and primary oxidant to achieve greater reduction of nitrogen oxides. A scrubber and regeneration system may also be included to generate a concentrated stream of nitrogen oxides from flue gases for reduction using this method.

High temperature decomposition of hydrogen peroxide

NASA Technical Reports Server (NTRS)

Parrish, Clyde F. (Inventor)

2004-01-01

Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

High temperature decomposition of hydrogen peroxide

NASA Technical Reports Server (NTRS)

Parrish, Clyde F. (Inventor)

2011-01-01

Nitric oxide (NO) is oxidized into nitrogen dioxide (NO.sub.2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

Enterocyte protein tyrosine nitration in response to Eimeria infection in broilers

USDA-ARS?s Scientific Manuscript database

Activation of pathogen-sensing mechanisms in intestinal cells initiate the generation of pathway effectors that perturb normal nutritional enterocyte (ETC) functions. Among the conserved pathway mediator molecules generated are nitric oxide (NO) and superoxide anion (SOA) which are known to interac...

A Finite Rate Chemical Analysis of Nitric Oxide Flow Contamination Effects on Scramjet Performance

NASA Technical Reports Server (NTRS)

Cabell, Karen F.; Rock, Kenneth E.

2003-01-01

The level of nitric oxide contamination in the test gas of the Langley Research Center Arc-Heated Scramjet Test Facility and the effect of the contamination on scramjet test engine performance were investigated analytically. A finite rate chemical analysis was performed to determine the levels of nitric oxide produced in the facility at conditions corresponding to Mach 6 to 8 flight simulations. Results indicate that nitric oxide levels range from one to three mole percent, corroborating previously obtained measurements. A three-stream combustor code with finite rate chemistry was used to investigate the effects of nitric oxide on scramjet performance. Results indicate that nitric oxide in the test gas causes a small increase in heat release and thrust performance for the test conditions investigated. However, a rate constant uncertainty analysis suggests that the effect of nitric oxide ranges from no net effect, to an increase of about 10 percent in thrust performance.

Vernonia cinerea L. scavenges free radicals and regulates nitric oxide and proinflammatory cytokines profile in carrageenan induced paw edema model.

PubMed

Kumar, P Pratheesh; Kuttan, Girija

2009-01-01

In this study, we evaluated the anti-oxidant and anti-inflammatory activities of the medicinal plant, Vernonia cinerea L (Asteraceae) using in vitro as well as in vivo models. Methanolic extract of Vernonia cinerea was found to scavenge the hydroxyl radical generated by Fenton reaction (IC(50)130 microg/ml), Superoxide generated by photo reduction of riboflavin (IC(50)190 microg/ml) and inhibited lipid peroxidation significantly (IC(50)130.5 microg/ml). The drug also scavenged nitric oxide (IC(50)210 microg/ml). Intraperitoneal administration of Vernonia cinerea was found to inhibit the PMA induced Superoxide generation in mice peritoneal macrophages. The administration of Vernonia cinerea to mice significantly increased the levels of catalase, superoxide dismutase, glutathione, glutathione peroxidase and glutathione-S transferase in blood and liver, whereas lipid peroxidation activity was significantly decreased. It was also found that Vernonia cinerea extract significantly inhibited carrageenan induced inflammation, compared with control models. Down regulation of pro-inflammatory cytokine level and gene expression were also support the above result.

Effect of endogenous nitric oxide on mitochondrial respiration of rat hepatocytes in vitro and in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadler, J.; Curran, R.D.; Ochoa, J.B.

1991-02-01

Nitric oxide, a highly reactive radical, was recently identified as an intermediate of L-arginine metabolism in mammalian cells. We have shown that nitric oxide synthesis is induced in vitro in cultured hepatocytes by supernatants from activated Kupffer cells or in vivo by injecting rats with nonviable Corynebacterium parvum. In both cases, nitric oxide biosynthesis in hepatocytes was associated with suppression of total protein synthesis. This study attempts to determine the effect of nitric oxide biosynthesis on the activity of specific hepatocytic mitochondrial enzymes and to determine whether inhibition of protein synthesis is caused by suppression of energy metabolism. Exposure ofmore » hepatocytes to supernatants from activated Kupffer cells led to a 30% decrease of aconitase (Krebs cycle) and complex I (mitochondrial electron transport chain) activity. Using NG-monomethyl-L-arginine, an inhibitor of nitric oxide synthesis, we demonstrated that the inhibition of mitochondrial aconitase activity was due, in part, to the action of nitric oxide. In contrast, in vivo nitric oxide synthesis of hepatocytes from Corynebacterium parvum-treated animals had no effect on mitochondrial respiration. This suggests that inhibition of protein synthesis by nitric oxide is not likely to be mediated by inhibition of energy metabolism.« less

Arginase activity and nitric oxide levels in patients with obstructive sleep apnea syndrome

PubMed Central

Yüksel, Meral; Okur, Hacer Kuzu; Pelin, Zerrin; Öğünç, Ayliz Velioğlu; Öztürk, Levent

2014-01-01

OBJECTIVE: Obstructive sleep apnea syndrome is characterized by repetitive obstruction of the upper airways, and it is a risk factor for cardiovascular diseases. There have been several studies demonstrating low levels of nitric oxide in patients with obstructive sleep apnea syndrome compared with healthy controls. In this study, we hypothesized that reduced nitric oxide levels would result in high arginase activity. Arginase reacts with L-arginine and produces urea and L-ornithine, whereas L-arginine is a substrate for nitric oxide synthase, which produces nitric oxide. METHODS: The study group consisted of 51 obstructive sleep apnea syndrome patients (M/F: 43/8; mean age 49±10 years of age) and 15 healthy control subjects (M/F: 13/3; mean age 46±14 years of age). Obstructive sleep apnea syndrome patients were divided into two subgroups based on the presence or absence of cardiovascular disease. Nitric oxide levels and arginase activity were measured via an enzyme-linked immunosorbent assay of serum samples. RESULTS: Serum nitric oxide levels in the control subjects were higher than in the obstructive sleep apnea patients with and without cardiovascular diseases (p<0.05). Arginase activity was significantly higher (p<0.01) in obstructive sleep apnea syndrome patients without cardiovascular diseases compared with the control group. Obstructive sleep apnea syndrome patients with cardiovascular diseases had higher arginase activity than the controls (p<0.001) and the obstructive sleep apnea syndrome patients without cardiovascular diseases (p<0.05). CONCLUSION: Low nitric oxide levels are associated with high arginase activity. The mechanism of nitric oxide depletion in sleep apnea patients suggests that increased arginase activity might reduce the substrate availability of nitric oxide synthase and thus could reduce nitric oxide levels. PMID:24714832

Dysfunctional nitric oxide signalling increases risk of myocardial infarction.

PubMed

Erdmann, Jeanette; Stark, Klaus; Esslinger, Ulrike B; Rumpf, Philipp Moritz; Koesling, Doris; de Wit, Cor; Kaiser, Frank J; Braunholz, Diana; Medack, Anja; Fischer, Marcus; Zimmermann, Martina E; Tennstedt, Stephanie; Graf, Elisabeth; Eck, Sebastian; Aherrahrou, Zouhair; Nahrstaedt, Janja; Willenborg, Christina; Bruse, Petra; Brænne, Ingrid; Nöthen, Markus M; Hofmann, Per; Braund, Peter S; Mergia, Evanthia; Reinhard, Wibke; Burgdorf, Christof; Schreiber, Stefan; Balmforth, Anthony J; Hall, Alistair S; Bertram, Lars; Steinhagen-Thiessen, Elisabeth; Li, Shu-Chen; März, Winfried; Reilly, Muredach; Kathiresan, Sekar; McPherson, Ruth; Walter, Ulrich; Ott, Jurg; Samani, Nilesh J; Strom, Tim M; Meitinger, Thomas; Hengstenberg, Christian; Schunkert, Heribert

2013-12-19

Myocardial infarction, a leading cause of death in the Western world, usually occurs when the fibrous cap overlying an atherosclerotic plaque in a coronary artery ruptures. The resulting exposure of blood to the atherosclerotic material then triggers thrombus formation, which occludes the artery. The importance of genetic predisposition to coronary artery disease and myocardial infarction is best documented by the predictive value of a positive family history. Next-generation sequencing in families with several affected individuals has revolutionized mutation identification. Here we report the segregation of two private, heterozygous mutations in two functionally related genes, GUCY1A3 (p.Leu163Phefs*24) and CCT7 (p.Ser525Leu), in an extended myocardial infarction family. GUCY1A3 encodes the α1 subunit of soluble guanylyl cyclase (α1-sGC), and CCT7 encodes CCTη, a member of the tailless complex polypeptide 1 ring complex, which, among other functions, stabilizes soluble guanylyl cyclase. After stimulation with nitric oxide, soluble guanylyl cyclase generates cGMP, which induces vasodilation and inhibits platelet activation. We demonstrate in vitro that mutations in both GUCY1A3 and CCT7 severely reduce α1-sGC as well as β1-sGC protein content, and impair soluble guanylyl cyclase activity. Moreover, platelets from digenic mutation carriers contained less soluble guanylyl cyclase protein and consequently displayed reduced nitric-oxide-induced cGMP formation. Mice deficient in α1-sGC protein displayed accelerated thrombus formation in the microcirculation after local trauma. Starting with a severely affected family, we have identified a link between impaired soluble-guanylyl-cyclase-dependent nitric oxide signalling and myocardial infarction risk, possibly through accelerated thrombus formation. Reversing this defect may provide a new therapeutic target for reducing the risk of myocardial infarction.

Plasma membrane calcium ATPase 4b inhibits nitric oxide generation through calcium-induced dynamic interaction with neuronal nitric oxide synthase.

PubMed

Duan, Wenjuan; Zhou, Juefei; Li, Wei; Zhou, Teng; Chen, Qianqian; Yang, Fuyu; Wei, Taotao

2013-04-01

The activation and deactivation of Ca(2+)- and calmodulindependent neuronal nitric oxide synthase (nNOS) in the central nervous system must be tightly controlled to prevent excessive nitric oxide (NO) generation. Considering plasma membrane calcium ATPase (PMCA) is a key deactivator of nNOS, the present investigation aims to determine the key events involved in nNOS deactivation of by PMCA in living cells to maintain its cellular context. Using time-resolved Förster resonance energy transfer (FRET), we determined the occurrence of Ca(2+)-induced protein-protein interactions between plasma membrane calcium ATPase 4b (PMCA4b) and nNOS in living cells. PMCA activation significantly decreased the intracellular Ca(2+) concentrations ([Ca(2+)]i), which deactivates nNOS and slowdowns NO synthesis. Under the basal [Ca(2+)]i caused by PMCA activation, no protein-protein interactions were observed between PMCA4b and nNOS. Furthermore, both the PDZ domain of nNOS and the PDZ-binding motif of PMCA4b were essential for the protein-protein interaction. The involvement of lipid raft microdomains on the activity of PMCA4b and nNOS was also investigated. Unlike other PMCA isoforms, PMCA4 was relatively more concentrated in the raft fractions. Disruption of lipid rafts altered the intracellular localization of PMCA4b and affected the interaction between PMCA4b and nNOS, which suggest that the unique lipid raft distribution of PMCA4 may be responsible for its regulation of nNOS activity. In summary, lipid rafts may act as platforms for the PMCA4b regulation of nNOS activity and the transient tethering of nNOS to PMCA4b is responsible for rapid nNOS deactivation.

Post-challenge hyperglycaemia, nitric oxide production and endothelial dysfunction: the putative role of asymmetric dimethylarginine (ADMA).

PubMed

Siervo, M; Corander, M; Stranges, S; Bluck, L

2011-01-01

The endothelium is a thin layer of cells at the internal surface of blood vessels in continuous contact with the circulating fluids. The endothelial cells represent the primary barrier for the transport of glucose from the vascular conduits into the interstitial space. Insulin and nitric oxide have an important role in the regulation of glucose transport and metabolism. Hyperglycaemia is the main criteria for the diagnosis of diabetes and is responsible for the micro- and macro-vascular pathology seen in diabetic patients. Recent evidence suggests that post-challenge hyperglycaemia is a better predictor of cardiovascular risk than fasting glucose. Acute glucose elevations have been associated with a reduced endothelial-dependent flow mediated dilation indicating a decrease in nitric oxide production. Post-prandial hyperglycaemic peaks have been directly associated with increased intima media thickness in type 2 diabetic patients indicative of an increased atherosclerotic risk. The increase in intra-cellular glucose concentrations in the endothelial cells induces a hyper-generation of reactive oxygen species via the activation of different pathways (polyol-sorbitol, hexosamine, advanced glycated end products, activation of PKC, asymmetric dimethylarginine (ADMA)). These mechanisms influence the expression of genes and release of signalling and structural molecules involved in several functions (inflammation, angiogenesis, coagulation, vascular tone and permeability, cellular migration, nutrient metabolism). ADMA is considered as a biomarker of endothelial dysfunction and it has been associated with an increased risk of atherosclerosis and cardiovascular diseases. The increased generation of ADMA and reactive oxygen species in subjects with persistent hyperglycaemia could lead to an impairment of nitric oxide synthesis. Copyright © 2010 Elsevier B.V. All rights reserved.

Flow-dependent regulation of endothelial nitric oxide synthase: role of protein kinases

NASA Technical Reports Server (NTRS)

Boo, Yong Chool; Jo, Hanjoong

2003-01-01

Vascular endothelial cells are directly and continuously exposed to fluid shear stress generated by blood flow. Shear stress regulates endothelial structure and function by controlling expression of mechanosensitive genes and production of vasoactive factors such as nitric oxide (NO). Though it is well known that shear stress stimulates NO production from endothelial nitric oxide synthase (eNOS), the underlying molecular mechanisms remain unclear and controversial. Shear-induced production of NO involves Ca2+/calmodulin-independent mechanisms, including phosphorylation of eNOS at several sites and its interaction with other proteins, including caveolin and heat shock protein-90. There have been conflicting results as to which protein kinases-protein kinase A, protein kinase B (Akt), other Ser/Thr protein kinases, or tyrosine kinases-are responsible for shear-dependent eNOS regulation. The functional significance of each phosphorylation site is still unclear. We have attempted to summarize the current status of understanding in shear-dependent eNOS regulation.

Nitrogen-Based Diazeniumdiolates: Versatile Nitric Oxide-Releasing Compounds for Biomedical Research and Potential Clinical Applications

NASA Astrophysics Data System (ADS)

Saavedra, Joseph E.; Keefer, Larry K.

2002-12-01

Nitric oxide-generating ions of the nitrogen-diazeniumdiolate class with the general structure R1R2N-[N(O)NO]1 have been prepared by exposing primary, secondary, and polyamines to nitric oxide (NO). The resulting complexes regenerate bioactive NO at physiological pH with half-lives ranging from 2 seconds to 20 hours. An important goal in our research is to deliver NO to a specific organ or cell type where it is needed without affecting other NO-sensitive parts of the anatomy. By taking advantage of the remarkable chemical versatility of diazeniumdiolates, we have developed general strategies to prepare either tissue-selective NO donor drugs or materials containing NO delivery agents that can be physically placed near the target sites. Inhibition of blood coagulation, induction of penile erection, relief of pulmonary hypertension, and reversal of cerebral vasospasm are a few examples of their potential clinical applications.

See Featured Molecules.

Efficacy of surface-generated nitric oxide against Candida albicans adhesion and biofilm formation.

PubMed

Privett, Benjamin J; Nutz, Steven T; Schoenfisch, Mark H

2010-11-01

This report details the efficacy of nitric oxide (NO)-releasing xerogel surfaces composed of N-(6-aminohexyl)aminopropyl trimethoxysilane (AHAP3) and isobutyltrimethoxysilane (BTMOS) against Candida albicans adhesion, viability, and biofilm formation. A parallel plate flow cell assay was used to examine the effect of NO on planktonic fungal cells. Nitric oxide fluxes as low as 14 pmol cm(-2) s(-1) were sufficient to reduce fungal adhesion by ∼49% over the controls after 90 min. By utilizing a fluorescence live/dead assay and replicate plating, NO flux was determined to reduce fungal viability in a dose-dependent manner. The formation of C. albicans biofilms on NO-releasing xerogel-coated silicon rubber (SiR) coupons was impeded when compared to control (non-NO-releasing) and bare SiR surfaces. The synergistic efficacy of NO and silver sulfadiazine against adhered fungal cells and biofilms is reported with increased killing and biofilm inhibition over NO alone.

Solubilization and Resolution of the Membrane-Bound Nitrite Reductase from Paracoccus Halodenitrificans into Nitrite and Nitric Oxide Reductases

NASA Technical Reports Server (NTRS)

Grant, Michael A.; Cronin, Sonja E.; Hochstein, Lawrence I.

1984-01-01

Membranes prepared from Paracoccus halodenitrificans reduced nitrite or nitric oxide to nitrous oxide. Extraction of these membranes with the detergent CHAPSO [3-(3-Chlolamidoporopyldimethylammonio)-1-(2- hydroxy-1-propanesulfonate)], followed by ammonium sulfate fractionation of the solubilized proteins, resulted in the separation of nitrite and nitric oxide reductase activities. The fraction containing nitrite reductase activity spectrally resembled a cd-type cytochrome. Several cytochromes were detected in the nitric oxide reductase fraction. Which, if any, of these cytochromes is associated with the reduction of nitric oxide is not clear at this time.

Carboxyhemoglobin formation secondary to nitric oxide therapy in the setting of interstitial lung disease and pulmonary hypertension.

PubMed

Ruisi, Phillip; Ruisi, Michael

2011-01-01

Carbon monoxide (CO) has been widely recognized as an exogenous poison, although endogenous mechanisms for its formation involve heme-oxygenase (HO) isoforms, more specifically HO-1, in the setting of oxidative stress such as acute respiratory distress syndrome, sepsis, trauma, and nitric oxide use have been studied. In patients with refractory hypoxemia, inhaled nitric oxide (iNO) therapy is used to selectively vasodilate the pulmonary vasculature and improve ventilation-perfusion match. Inhaled nitric oxide is rapidly inactivated on binding to hemoglobin in the formation of nitrosyl- and methemoglobin in the pulmonary vasculature. Hence, inhaled nitric oxide has minimal systemic dissemination. Several experimental design studies involving lab rats have demonstrated increased levels of carboxyhemoglobin and exhaled CO as a result of nitric oxide HO-1 induction.

Application of a Chemiluminescence Detector for the Measurement of Total Oxides of Nitrogen and Ammonia in the Atmosphere

NASA Technical Reports Server (NTRS)

Hodgeson, J. A.; Bell, J. P.; Rehme, K. A.; Krost, K. J.; Stevens, R. K.

1971-01-01

By means of the thermal conversion of nitrogen dioxide to the nitric oxide, the chemiluminescent nitric oxide monitor, based on the nitric oxide plus ozone reaction, may be used for monitoring nitrogen dioxide plus nitric oxide (NO(x)). Under conditions previously described, ammonia is also converted to nitric oxide and therefore interferes. A metal surface, gold wool or stainless steel, operated at two different temperatures has been used to convert only nitrogen dioxide or nitrogen dioxide plus ammonia. Quantitative conversion of nitrogen dioxide to nitric oxide has been obtained at temperatures as low as 200 C. Conversion of ammonia is effected at temperatures of 300 C or higher. By the addition of a converter the basic nitric oxide monitor may be used for measuring NO(x) or NO(x) plus ammonia. As an alternate mode, for a fixed high temperature, a specific scrubber is described for removing NH3 without affecting NO2 concentrations.

Influence of vitamin C and vitamin E on redox signaling: Implications for exercise adaptations.

PubMed

Cobley, James N; McHardy, Helen; Morton, James P; Nikolaidis, Michalis G; Close, Graeme L

2015-07-01

The exogenous antioxidants vitamin C (ascorbate) and vitamin E (α-tocopherol) often blunt favorable cell signaling responses to exercise, suggesting that redox signaling contributes to exercise adaptations. Current theories posit that this antioxidant paradigm interferes with redox signaling by attenuating exercise-induced reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation. The well-documented in vitro antioxidant actions of ascorbate and α-tocopherol and characterization of the type and source of the ROS/RNS produced during exercise theoretically enable identification of redox-dependent mechanisms responsible for the blunting of favorable cell signaling responses to exercise. This review aimed to apply this reasoning to determine how the aforementioned antioxidants might attenuate exercise-induced ROS/RNS production. The principal outcomes of this analysis are (1) neither antioxidant is likely to attenuate nitric oxide signaling either directly (reaction with nitric oxide) or indirectly (reaction with derivatives, e.g., peroxynitrite); (2) neither antioxidant reacts appreciably with hydrogen peroxide, a key effector of redox signaling; (3) ascorbate but not α-tocopherol has the capacity to attenuate exercise-induced superoxide generation; and (4) alternate mechanisms, namely pro-oxidant side reactions and/or reduction of bioactive oxidized macromolecule adducts, are unlikely to interfere with exercise-induced redox signaling. Out of all the possibilities considered, ascorbate-mediated suppression of superoxide generation with attendant implications for hydrogen peroxide signaling is arguably the most cogent explanation for blunting of favorable cell signaling responses to exercise. However, this mechanism is dependent on ascorbate accumulating at sites rich in NADPH oxidases, principal contributors to contraction-mediated superoxide generation, and outcompeting nitric oxide and superoxide dismutase isoforms. The major conclusions of this review are: (1) direct evidence for interference of ascorbate and α-tocopherol with exercise-induced ROS/RNS production is lacking; (2) theoretical analysis reveals that both antioxidants are unlikely to have a major impact on exercise-induced redox signaling; and (3) it is worth considering alternate redox-independent mechanisms. Copyright © 2015 Elsevier Inc. All rights reserved.

Transcriptional coupling of synaptic transmission and energy metabolism: role of nuclear respiratory factor 1 in co-regulating neuronal nitric oxide synthase and cytochrome c oxidase genes in neurons.

PubMed

Dhar, Shilpa S; Liang, Huan Ling; Wong-Riley, Margaret T T

2009-10-01

Neuronal activity is highly dependent on energy metabolism; yet, the two processes have traditionally been regarded as independently regulated at the transcriptional level. Recently, we found that the same transcription factor, nuclear respiratory factor 1 (NRF-1) co-regulates an important energy-generating enzyme, cytochrome c oxidase, as well as critical subunits of glutamatergic receptors. The present study tests our hypothesis that the co-regulation extends to the next level of glutamatergic synapses, namely, neuronal nitric oxide synthase, which generates nitric oxide as a downstream signaling molecule. Using in silico analysis, electrophoretic mobility shift assay, chromatin immunoprecipitation, promoter mutations, and NRF-1 silencing, we documented that NRF-1 functionally bound to Nos1, but not Nos2 (inducible) and Nos3 (endothelial) gene promoters. Both COX and Nos1 transcripts were up-regulated by depolarizing KCl treatment and down-regulated by TTX-mediated impulse blockade in neurons. However, NRF-1 silencing blocked the up-regulation of both Nos1 and COX induced by KCl depolarization, and over-expression of NRF-1 rescued both Nos1 and COX transcripts down-regulated by TTX. These findings are consistent with our hypothesis that synaptic neuronal transmission and energy metabolism are tightly coupled at the molecular level.

Statin-induced inhibition of breast cancer proliferation and invasion involves attenuation of iron transport: intermediacy of nitric oxide and antioxidant defence mechanisms.

PubMed

Kanugula, Anantha Koteswararao; Gollavilli, Paradesi Naidu; Vasamsetti, Sathish Babu; Karnewar, Santosh; Gopoju, Raja; Ummanni, Ramesh; Kotamraju, Srigiridhar

2014-08-01

Accumulating evidence from in vitro, in vivo, clinical and epidemiological studies shows promising results for the use of statins against many cancers including breast carcinoma. However, the molecular mechanisms responsible for the anti-proliferative and anti-invasive properties of statins still remain elusive. In this study, we investigated the involvement of nitric oxide, iron homeostasis and antioxidant defence mechanisms in mediating the anti-proliferative and anti-invasive properties of hydrophobic statins in MDA-MB-231, MDA-MB-453 and BT-549 metastatic triple negative breast cancer cells. Fluvastatin and simvastatin significantly increased cytotoxicity which was reversed with mevalonate. Interestingly, fluvastatin downregulated transferrin receptor (TfR1), with a concomitant depletion of intracellular iron levels in these cells. Statin-induced effects were mimicked by geranylgeranyl transferase inhibitor (GGTI-298) but not farnesyl transferase inhibitor (FTI-277). Further, it was observed that TfR1 downregulation is mediated by increased nitric oxide levels via inducible nitric oxide synthase (iNOS) expression. NOS inhibitors (asymmetric dimethylarginine and 1400W) counteracted and sepiapterin, a precursor of tetrahydrobiopterin, exacerbated statin-induced depletion of intracellular iron levels. Notably, fluvastatin increased manganese superoxide dismutase (by repressing the transcription factor DNA damage-binding protein 2), catalase and glutathione which, in turn, diminished H2 O2 levels. Fluvastatin-induced downregulation of TfR1, matrix metalloproteinase-2, -9 and inhibition of invasion were reversed in the presence of aminotriazole, a specific inhibitor of catalase. Finally, we conclude that fluvastatin, by altering iron homeostasis, nitric oxide generation and antioxidant defence mechanisms, induces triple negative breast cancer cell death. © 2014 FEBS.

Polyurethane with Tethered Copper(II)-Cyclen Complex: Preparation, Characterization and Catalytic Generation of Nitric Oxide from S-Nitrosothiols

PubMed Central

Hwang, Sangyeul

2008-01-01

The preparation and characterization of a commercial biomedical grade polyurethane (Tecophilic, SP-93A-100) material possessing covalently linked copper(II)-cyclen moieties as a nitric oxide (NO) generating polymer are described. Chemiluminescence NO measurements demonstrate that the prepared polymer can decompose endogenous S-nitrosothiols (RSNOs) such as S-nitrosoglutathione and S-nitrosocysteine to NO in the presence of thiol reducing agents (RSHs; e.g., glutathione and cysteine) at physiological pH. Since such RSNO and RSH already exist in blood, the proposed polymer is capable of spontaneously generating NO when in contact with fresh blood. This is demonstrated by utilizing the polymer as an outer coating at the distal end of an amperometric NO sensor to create a device that generates response toward the RSNO species in the blood. This polymer possesses the combined benefits of a commercial biomedical grade polyurethane with the ability to generate biologically active NO when on contact with blood, and thus may serve as a useful coating to improve the hemocompatibility of various medical devices. PMID:18314189

[Comparative evaluation of the efficiency of the effect of very high frequency electromagnetic waves on platelet functional activity].

PubMed

Kirichuk, V F; Maĭborodin, A V; Volin, M V; Krenitskiĭ, A P; Tupikin, V D

2001-01-01

A comparative analysis was made of the effect of two kinds of EMI MMD-radiation: EMI MMD-waves, generated by a vehicle "Jav-1 M" (42.2 and 53.5 HHz), and EMI MMD-waves exerting influence with frequencies of molecular spectrum of radiation and nitric oxide absorption (150.176-150.644 HHz), obtained with a specially created generator, with respect to their influence on the functional ability of platelets of unstable angina pectoris patients. It was shown that in vitro EMI MMD-fluctuations with frequencies of molecular spectrum of radiation and nitric oxide absorption exert a stronger inhibiting influence on the functional activity of platelets of unstable angina pectoris patients. Features of the action of various kinds of EMI MMD-effect on the activative-high-speed characteristics of platelet aggregation are shown.

Proinflammatory activation of macrophages by bisphenol A-glycidyl-methacrylate involved NFκB activation via PI3K/Akt pathway.

PubMed

Kuan, Yu-Hsiang; Huang, Fu-Mei; Li, Yi-Ching; Chang, Yu-Chao

2012-11-01

Bisphenol A-glycidyl-methacrylate (BisGMA), a dental composite resin and dentin bonding agent, might prompt inflammatory effects to adjacent tissues. Macrophages are a major cellular component of the inflammatory sites. Little is known about the mechanisms of BisGMA on macrophages activation. The aim of this study was to evaluate BisGMA on proinflammatory mediators generation of murine macrophage RAW264.7 cells. IL-1β and IL-6 were analyzed by enzyme-linked immunosorbent assay. Nitric oxide, extracellular superoxide anion, and intracellular reaction oxygen species were measured by Griess assay, ferricytochrome c, and 2',7'-dichlorofluorescein assay, respectively. Expression of iNOS, p-p65, IκB, and p-Akt was analyzed by Western blotting. BisGMA augmented the generation of IL-1β, IL-6, nitric oxide and the expression of iNOS in a time- and dose-dependent manner (p<0.05). BisGMA enhanced the generation of intracellular and extracellular ROS in a dose-dependent manner (p<0.05). The levels of p65 phosphorylation, IκB degradation, and Akt phosphorylation were found to be increased in a time- and dose-dependent manner (p<0.05). These results indicate that BisGMA could induce nitric oxide, ROS, and inflammatory cytokines in macrophages. In addition, BisGMA may active macrophage via NF-κB activation, IκB degradation, and p-Akt activation. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

[Dinitrosyl iron complexes are endogenous signaling agents in animal and human cells and tissues (a hypothesis)].

PubMed

Vanin, A F

2004-01-01

The hypothesis was advanced that dinitrosyl iron complexes generated in animal and human cells and tissues producing nitric oxide can function as endogenous universal regulators of biochemical and physiological processes. This function is realized by the ability of dinitrosyl iron complexes to act as donors of free nitric oxide molecules interacting with the heme groups of proteins, nitrosonium ions, or Fe+(NO+)2 interacting with the thiol groups of proteins. The effect of dinitrosyl iron complexes on the activity of some enzymes and the expression of the genome at the translation and transcription levels was considered.

Nitric oxide in plants: an assessment of the current state of knowledge

PubMed Central

Mur, Luis A. J.; Mandon, Julien; Persijn, Stefan; Cristescu, Simona M.; Moshkov, Igor E.; Novikova, Galina V.; Hall, Michael A.; Harren, Frans J. M.; Hebelstrup, Kim H.; Gupta, Kapuganti J.

2012-01-01

Background and aims After a series of seminal works during the last decade of the 20th century, nitric oxide (NO) is now firmly placed in the pantheon of plant signals. Nitric oxide acts in plant–microbe interactions, responses to abiotic stress, stomatal regulation and a range of developmental processes. By considering the recent advances in plant NO biology, this review will highlight certain key aspects that require further attention. Scope and conclusions The following questions will be considered. While cytosolic nitrate reductase is an important source of NO, the contributions of other mechanisms, including a poorly defined arginine oxidizing activity, need to be characterized at the molecular level. Other oxidative pathways utilizing polyamine and hydroxylamine also need further attention. Nitric oxide action is dependent on its concentration and spatial generation patterns. However, no single technology currently available is able to provide accurate in planta measurements of spatio-temporal patterns of NO production. It is also the case that pharmaceutical NO donors are used in studies, sometimes with little consideration of the kinetics of NO production. We here include in planta assessments of NO production from diethylamine nitric oxide, S-nitrosoglutathione and sodium nitroprusside following infiltration of tobacco leaves, which could aid workers in their experiments. Further, based on current data it is difficult to define a bespoke plant NO signalling pathway, but rather NO appears to act as a modifier of other signalling pathways. Thus, early reports that NO signalling involves cGMP—as in animal systems—require revisiting. Finally, as plants are exposed to NO from a number of external sources, investigations into the control of NO scavenging by such as non-symbiotic haemoglobins and other sinks for NO should feature more highly. By crystallizing these questions the authors encourage their resolution through the concerted efforts of the plant NO community. PMID:23372921

Impaired Arginine Metabolism Coupled to a Defective Redox Conduit Contributes to Low Plasma Nitric Oxide in Polycystic Ovary Syndrome.

PubMed

Krishna, Meera B; Joseph, Annu; Thomas, Philip Litto; Dsilva, Belinda; Pillai, Sathy M; Laloraya, Malini

2017-01-01

Though oxidative stress is associated with Polycystic Ovary Syndrome (PCOS), the status of nitric oxide is still unclear. Nitric Oxide (NO) plays pivotal roles in many physiological functions which are compromised in PCOS. Our recent study reveals lowered T-regulatory cells (Tregs) in PCOS, and Treg generation is known to be regulated by NO levels. However concrete evidences are lacking on mechanisms modulating NO levels under PCOS. This is a retrospective case-control cohort study, comprised of PCOS women (N=29) and normal menstruating women as controls (N=20). We analysed NOx (nitrite+nitrate) and hydrogen peroxide (H2O2) concentrations, transcript levels of endothelial nitric oxide synthase (eNOS)/inducible nitric oxide synthase (iNOS) and arginine modulators, hydrogen peroxide regulators in the cohort. PCOS women showed reduced plasma NOx(nitrate+nitrite) and H2O2 compared to controls. We report reduction in transcript levels of iNOS/NOS2 and eNOS/NOS3 in PCOS peripheral blood. The transcripts involved in arginine bioavailability: Argininosuccinate lyase (ASL), Solute Carrier Family1, member 7 (SLC7A1) and Arginase 1 (ARG1) and Asymmetric Dimethyl Arginine (ADMA) metabolism: Protein arginine methyltransferase 1 (PRMT1) and Dimethylarginine dimethylaminohydrolase 2 (DDAH2) also showed differential expression. H2O2 concentration in PCOS women was also found to be reduced. The reduction can be attributed to increase in catalase levels as a consequence of the body's effort to alleviate the oxidative burden in the system. Our study advocates that PCOS women have lowered NO due to reduced iNOS/eNOS expression, low H2O2, high ADMA synthesis and reduced arginine bioavailability. An in-depth analysis of redox biology of PCOS to open up potential therapeutic strategies is highly recommended. © 2017 The Author(s). Published by S. Karger AG, Basel.

Real-time electrical detection of nitric oxide in biological systems with sub-nanomolar sensitivity

NASA Astrophysics Data System (ADS)

Jiang, Shan; Cheng, Rui; Wang, Xiang; Xue, Teng; Liu, Yuan; Nel, Andre; Huang, Yu; Duan, Xiangfeng

2013-07-01

Real-time monitoring of nitric oxide concentrations is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems and immune responses. Here we report a new design of nitric oxide sensors based on hemin-functionalized graphene field-effect transistors. With its single atom thickness and the highest carrier mobility among all materials, graphene holds the promise for unprecedented sensitivity for molecular sensing. The non-covalent functionalization through π-π stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with a sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their practical functionality in complex biological systems.

Molecular Dynamics Simulations Reveal Proton Transfer Pathways in Cytochrome C-Dependent Nitric Oxide Reductase

PubMed Central

Pisliakov, Andrei V.; Hino, Tomoya; Shiro, Yoshitsugu; Sugita, Yuji

2012-01-01

Nitric oxide reductases (NORs) are membrane proteins that catalyze the reduction of nitric oxide (NO) to nitrous oxide (N2O), which is a critical step of the nitrate respiration process in denitrifying bacteria. Using the recently determined first crystal structure of the cytochrome c-dependent NOR (cNOR) [Hino T, Matsumoto Y, Nagano S, Sugimoto H, Fukumori Y, et al. (2010) Structural basis of biological N2O generation by bacterial nitric oxide reductase. Science 330: 1666–70.], we performed extensive all-atom molecular dynamics (MD) simulations of cNOR within an explicit membrane/solvent environment to fully characterize water distribution and dynamics as well as hydrogen-bonded networks inside the protein, yielding the atomic details of functionally important proton channels. Simulations reveal two possible proton transfer pathways leading from the periplasm to the active site, while no pathways from the cytoplasmic side were found, consistently with the experimental observations that cNOR is not a proton pump. One of the pathways, which was newly identified in the MD simulation, is blocked in the crystal structure and requires small structural rearrangements to allow for water channel formation. That pathway is equivalent to the functional periplasmic cavity postulated in cbb 3 oxidase, which illustrates that the two enzymes share some elements of the proton transfer mechanisms and confirms a close evolutionary relation between NORs and C-type oxidases. Several mechanisms of the critical proton transfer steps near the catalytic center are proposed. PMID:22956904

Nitric Oxide Homeostasis in Neurodegenerative Diseases.

PubMed

Hannibal, Luciana

2016-01-01

The role of nitric oxide in the pathogenesis and progression of neurodegenerative illnesses such as Parkinson's and Alzheimer's diseases has become prominent over the years. Increased activity of the enzymes that produce reactive oxygen species, decreased activity of antioxidant enzymes and imbalances in glutathione pools mediate and mark the neurodegenerative process. Much of the oxidative damage of proteins is brought about by the overproduction of nitric oxide by nitric oxide synthases (NOS) and its subsequent reactivity with reactive oxygen species. Proteomic methods have advanced the field tremendously, by facilitating the quantitative assessment of differential expression patterns and oxidative modifications of proteins and alongside, mapping their non-canonical functions. As a signaling molecule involved in multiple biochemical pathways, the level of nitric oxide is subject to tight regulation. All three NOS isoforms display aberrant patterns of expression in Alzheimer's disease, altering intracellular signaling and routing oxidative stress in directions that are uncompounded. This review discusses the prime factors that control nitric oxide biosynthesis, reactivity footprints and ensuing effects in the development of neurodegenerative diseases.

Perchlorate and Halogen-Free High Energy Dense Oxidizers (HEDO)

DTIC Science & Technology

2011-06-01

nitric acid indicate that the covalent oxalic acid dinitrate ester should be more stable than the ionic dinitronium oxalate . The following three...synthetic strategies were developed to generate compound 11 (Scheme 17). Strategy I is the nitration of anhydrous oxalic acid with nitric acid (100...temperatures (25 to –30 °C) and in all dry solvents used. Scheme 17: Synthetic strategies for the production of oxalic acid dinitrate ester (11

Mechanisms of neptunium redox reactions in nitric acid solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chatterjee, Sayandev; Bryan, Samuel A.; Casella, Amanda J.

First transuranium element neptunium (Np) exhibits complicated behavior in acidic solutions because it can adopt wide range of oxidation states typically from +3 to +6 and coordinate large variety of ligands. In particular, accurate determination of Np redox potentials in nitric acid solutions is challenging due to overlapping chemical and electrochemical reactions leading to significant experimental uncertainties. Furthermore, over past decades spectrophotometry has been extensively applied to identify and characterize Np solution species in different oxidation states. However, relevant spectral database of Np in nitric acid solutions that can serve for the reference purposes has yet to be established duemore » to the experimental difficulty to isolate and stabilize Np species in pure oxidation states without compromising solution optical properties. This work demonstrates that combination of voltammetry and controlled-potential in situ thin-layer spectropotentiometry overcomes these challenges so that Np species in pure +3, +4, +5, or +6 oxidation states were electrochemically generated in the systematically varied 0.1 – 5 M nitric acid solutions, and corresponding vis-NIR spectral signatures were obtained. In situ optical monitoring of the interconversion between adjacent Np oxidation states resulted in elucidation of the mechanisms of the involved redox reactions, in-depth understanding of the relative stability of the Np oxidation states, and allowed benchmarking of the redox potentials of the NpO22+/NpO2+, NpO2+/Np4+ and Np4+/Np3+ couples. Notably, the NpO2+/Np4+ couple was distinguished from the proximal Np4+/Np3+ process overcoming previous concerns and challenges encountered in accurate determination of the respective potentials.« less

Temperature and Nitric Oxide Generation in a Pulsed Arc Discharge Plasma

NASA Astrophysics Data System (ADS)

Namihira, T.; Sakai, S.; Matsuda, M.; D., Wang; Kiyan, T.; Akiyama, H.; Okamoto, K.; Toda, K.

2007-12-01

Nitric oxide (NO) is increasingly being used in medical treatments of high blood pressure, acute respiratory distress syndrome and other illnesses related to the lungs. Currently a NO inhalation system consists of a gas cylinder of N2 mixed with a high concentration of NO. This arrangement is potentially risky due to the possibility of an accidental leak of NO from the cylinder. The presence of NO in the air leads to the formation of nitric dioxide (NO2), which is toxic to the lungs. Therefore, an on-site generator of NO would be highly desirable for medical doctors to use with patients with lung disease. To develop the NO inhalation system without a gas cylinder, which would include a high concentration of NO, NAMIHIRA et al have recently reported on the production of NO from room air using a pulsed arc discharge. In the present work, the temperature of the pulsed arc discharge plasma used to generate NO was measured to optimize the discharge condition. The results of the temperature measurements showed the temperature of the pulsed arc discharge plasma reached about 10,000 K immediately after discharge initiation and gradually decreased over tens of microseconds. In addition, it was found that NO was formed in a discharge plasma having temperatures higher than 9,000 K and a smaller input energy into the discharge plasma generates NO more efficiently than a larger one.

Experimental and analytical study of nitric oxide formation during combustion of propane in a jet-stirred combustor

NASA Technical Reports Server (NTRS)

Wakelyn, N. T.; Jachimowski, C. J.; Wilson, C. H.

1978-01-01

A jet-stirred combustor, constructed of castable zirconia and with an Inconel injector, was used to study nitric oxide formation in propane-air combustion with residence times in the range from 3.2 to 3.3 msec and equivalence ratios varying from 0.7 to 1.4. Measurements were made of combustor operating temperature and of nitric oxide concentration. Maximum nitric oxide concentrations of the order of 55 ppm were found in the range of equivalence ratio from 1.0 to 1.1. A finite-rate chemical kinetic mechanism for propane combustion and nitric oxide formation was assembled by coupling an existing propane oxidation mechanism with the Zeldovich reactions and reactions of molecular nitrogen with hydrocarbon fragments. Analytical studies using this mechanism in a computer simulation of the experimental conditions revealed that the hydrocarbon-fragment-nitrogen reactions play a significant role in nitric oxide formation during fuel-rich combustion.

An Abnormal Nitric Oxide Metabolism Contributes to Brain Oxidative Stress in the Mouse Model for the Fragile X Syndrome, a Possible Role in Intellectual Disability

PubMed Central

Lima-Cabello, Elena; Garcia-Guirado, Francisco; Calvo-Medina, Rocio; el Bekay, Rajaa; Perez-Costillas, Lucia; Quintero-Navarro, Carolina; Sanchez-Salido, Lourdes

2016-01-01

Background. Fragile X syndrome is the most common genetic cause of mental disability. Although many research has been performed, the mechanism underlying the pathogenesis is unclear and needs further investigation. Oxidative stress played major roles in the syndrome. The aim was to investigate the nitric oxide metabolism, protein nitration level, the expression of NOS isoforms, and furthermore the activation of the nuclear factor NF-κB-p65 subunit in different brain areas on the fragile X mouse model. Methods. This study involved adult male Fmr1-knockout and wild-type mice as controls. We detected nitric oxide metabolism and the activation of the nuclear factor NF-κBp65 subunit, comparing the mRNA expression and protein content of the three NOS isoforms in different brain areas. Results. Fmr1-KO mice showed an abnormal nitric oxide metabolism and increased levels of protein tyrosine nitrosylation. Besides that, nuclear factor NF-κB-p65 and inducible nitric oxide synthase appeared significantly increased in the Fmr1-knockout mice. mRNA and protein levels of the neuronal nitric oxide synthase appeared significantly decreased in the knockout mice. However, the epithelial nitric oxide synthase isoform displayed no significant changes. Conclusions. These data suggest the potential involvement of an abnormal nitric oxide metabolism in the pathogenesis of the fragile X syndrome. PMID:26788253

Effect of placental tissue on inhibition of uterine contraction by nitric oxide donors.

PubMed

Syal, A; Okawa, T; Vedernikov, Y; Chwalisz, K; Saade, G R; Garfield, R E

1999-08-01

Our purpose was to test the hypothesis that placental tissue modulates the effect of nitric oxide on spontaneous uterine contractility in pregnant rats. Rings (approximately 4 mm) of uterus taken from rats on day 14 (midpregnancy, n = 6), day 18 (late pregnancy, n = 4), and day 22 (term, n = 4) of gestation were placed in organ chambers filled with Krebs-bicarbonate buffer bubbled with 5% carbon dioxide in air (37 degrees C, pH approximately 7.4) for isometric tension recording. In some rings a piece of placenta was left attached to the uterine wall. In the other rings the fetuses, placentas, and membranes were removed completely. Change of spontaneous contractions of the rings (percentage change of basal integral activity for 10 minutes) in response to cumulative concentrations of the nitric oxide donors diethylamine-nitric oxide and nitroglycerin (10(-6) mol/L to 10(-4) mol/L) were compared between rings with and without placenta. Diethylamine-nitric oxide and nitroglycerin inhibited spontaneous uterine contractions in rings from midpregnancy, in both the absence and the presence of placenta. In rings from midpregnancy, the maximal inhibition of contractions by diethylamine-nitric oxide but not by nitroglycerin was significantly (P <.05) higher in the presence (26.7% +/- 3.5% of basal activity) than in the absence (39. 6% +/- 3.3%) of placenta. Inhibition of contraction by nitric oxide donors in rings from late and term pregnancy was less than in midpregnancy, and the presence of placental tissue did not influence the responses. The presence of placental tissue enhances inhibition of uterine contractility by agents that spontaneously release nitric oxide, such as diethylamine-nitric oxide, but not by nitroglycerin, which requires metabolic transformation for nitric oxide to be released. Refractoriness to nitric oxide near or at term does not depend on the presence or absence of placental tissue.

Influence of nanosecond pulsed plasma on the non-enzymatic pathway for the generation of nitric oxide from L-arginine and the modification of graphite oxide to increase the solar cell efficiency.

PubMed

Attri, Pankaj; Park, Ji Hoon; Gaur, Jitender; Kumar, Naresh; Park, Dae Hoon; Jeon, Su Nam; Park, Bong Sang; Chand, Suresh; Uhm, Han Sup; Choi, Eun Ha

2014-09-14

In this work, we demonstrated the action of nanosecond pulsed plasma (NPP) on the generation of nitric oxide (NO) from the non-enzymatic pathway and on the modification of graphite oxide (GO) sheets to increase polymer solar cells (PSCs) efficiency. NO is an important signal and an effector molecule in animals, which is generated from the enzyme-catalyzed oxidation of L-arginine to NO and L-citrulline. Hence, L-arginine is an important biological precursor for NO formation. Therefore, we developed a new non-enzymatic pathway for the formation of NO and L-citrulline using NPP and characterized the pathway using NO detection kit, NMR, liquid chromatography/capillary electrophoresis-mass spectrometry (LC/CE-MS) for both quantitative and qualitative bioanalysis. We then synthesized and modified the functional groups of GO using NPP, and it was characterised by X-ray photoelectron spectroscopy (XPS), confocal Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) imaging, cathodoluminescence (CL) and work function using γ-FIB. Further, we also tested the power conversion efficiency of the PSCs devices with modified GO that is similar to the one obtained with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) as HTL. This work is perceived to have great implications for inexpensive and efficient methodology for NO generation and modification of GO, which are applicable in materials from nanomaterials to biomolecules.

Elevated nitric oxide in recurrent vulvovaginal candidiasis - association with clinical findings.

PubMed

Alvendal, Cathrin; Ehrström, Sophia; Brauner, Annelie; Lundberg, Jon O; Bohm-Starke, Nina

2017-03-01

Recurrent vulvovaginal candidiasis is defined as having three to four episodes per year and causes substantial suffering. Little is known about the mechanisms leading to relapses in otherwise healthy women. Nitric oxide is part of the nonspecific host defense and is increased during inflammation. Nitric oxide levels were measured and the expression of inducible nitric oxide synthase was analyzed in the vagina during an acute episode of recurrent vulvovaginal candidiasis and after treatment with fluconazole. Twenty-eight women with symptoms of recurrent vulvovaginal candidiasis were enrolled together with 31 healthy controls. Nitric oxide was measured with an air-filled 25-mL silicon catheter balloon incubated in the vagina for five minutes and then analyzed by chemiluminescence technique. Vaginal biopsies were analyzed for the expression of inducible nitric oxide synthase. Symptoms and clinical findings were surveyed using a scoring system. The measurements and biopsies were repeated in patients after six weeks of fluconazole treatment. Nitric oxide levels were increased during acute infection (median 352 ppb) compared with controls (median 6 ppb), p < 0.0001. The levels decreased after treatment (median 18 ppb) but were still higher than in controls. Increased expression of inducible nitric oxide synthase was observed in the epithelial basal layer in patients before and after treatment compared with controls. Before treatment, there were positive correlations between nitric oxide and symptom (r s  = 0.644) and examination scores (r s  = 0.677), p < 0.001. Nitric oxide is significantly elevated in patients with recurrent vulvovaginal candidiasis during acute episodes of infection and decreases after antifungal treatment. The results illustrate the pronounced inflammatory response in recurrent vulvovaginal candidiasis correlating to symptoms of pain and discomfort. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

The effect of brain death in rat steatotic and non-steatotic liver transplantation with previous ischemic preconditioning.

PubMed

Jiménez-Castro, Mónica B; Meroño, Noelia; Mendes-Braz, Mariana; Gracia-Sancho, Jordi; Martínez-Carreres, Laia; Cornide-Petronio, Maria Eugenia; Casillas-Ramirez, Araní; Rodés, Juan; Peralta, Carmen

2015-01-01

Most liver grafts undergoing transplantation derive from brain dead donors, which may also show hepatic steatosis, being both characteristic risk factors in liver transplantation. Ischemic preconditioning shows benefits when applied in non-brain dead clinical situations like hepatectomies, whereas it has been less promising in the transplantation from brain dead patients. This study examined how brain death affects preconditioned steatotic and non-steatotic liver grafts undergoing transplantation. Steatotic and non-steatotic grafts from non-brain dead and brain dead-donors were cold stored for 6h and then transplanted. After 2, 4, and 16 h of reperfusion, hepatic damage was analysed. In addition, two therapeutic strategies, ischemic preconditioning and/or acetylcholine pre-treatment, and their underlying mechanisms were characterized. Preconditioning benefits in non-brain dead donors were associated with nitric oxide and acetylcholine generation. In brain dead donors, preconditioning generated nitric oxide but did not promote acetylcholine upregulation, and this resulted in inflammation and damage. Acetylcholine treatment in brain dead donors, through PKC, increased antioxidants and reduced lipid peroxidation, nitrotyrosines and neutrophil accumulation, altogether protecting against damage. The combination of acetylcholine and preconditioning conferred stronger protection against damage, oxidative stress and neutrophil accumulation than acetylcholine treatment alone. These superior beneficial effects were due to a selective preconditioning-mediated generation of nitric oxide and regulation of PPAR and TLR4 pathways, which were not observed when acetylcholine was administered alone. Our findings propose the combination of acetylcholine+preconditioning as a feasible and highly protective strategy to reduce the adverse effects of brain death and to ultimately improve liver graft quality. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

HBOC Vasoactivity: Interplay Between Nitric Oxide Scavenging and Capacity to Generate Bioactive Nitric Oxide Species

PubMed Central

Friedman, Joel M.

2013-01-01

Abstract Significance: Despite many advances in blood substitute research, the development of materials that are effective in maintaining blood volume and oxygen delivery remains a priority for emergency care and trauma. Clinical trials on hemoglobin (Hb)-based oxygen carriers (HBOCs) have not provided information on the mechanism of toxicity, although all commercial formulations have safety concerns. Specifically, it is important to reconcile the different hypotheses of Hb toxicity, such as nitric oxide (NO) depletion and oxidative reactions, to provide a coherent molecular basis for designing a safe HBOC. Recent Advances: HBOCs with different sizes often exhibit differences in the degree of HBOC-induced vasoactivity. This has been attributed to differences in the degree of NO scavenging and in the extent of Hb extravasation. Additionally, it is appears that Hb can undergo reactions that compensate for NO scavenging by generating bioactive forms of NO. Critical Issues: Engineering modifications to enhance bioactive NO production can result in diminished oxygen delivery by virtue of increased oxygen affinity. This strategy can prevent the HBOC from fulfilling the intended goal on preserving oxygenation; however, the NO production effects will increase perfusion and oxygen transport. Future Directions: Hb modifications influence NO scavenging and the capacity of certain HBOCs to compensate for NO scavenging through nitrite-mediated reactions that generate bioactive NO. Based on the current understanding of these NO-related factors, possible synthetic strategies are presented that address how HBOC formulations can be prepared that: (i) effectively deliver oxygen, (ii) maintain tissue perfusion, and (iii) limit/reverse underlying inflammation within the vasculature. Antioxid. Redox Signal. 18, 2284–2297. PMID:23249305

Nitric oxide induced by Indian ginseng root extract inhibits Infectious Bursal Disease virus in chicken embryo fibroblasts in vitro.

PubMed

Ganguly, Bhaskar; Umapathi, Vijaypillai; Rastogi, Sunil Kumar

2018-01-01

Infectious Bursal Disease is a severe viral disease of chicken responsible for serious economic losses to poultry farmers. The causative agent, Infectious Bursal Disease virus, is inhibited by nitric oxide. Root extract of the Indian ginseng, Withania somnifera , inhibits Infectious Bursal Disease virus in vitro. Also, Withania somnifera root extract is known to induce nitric oxide production in vitro. Therefore, the present study was undertaken to determine if the inhibitory activity of Withania somnifera against Infectious Bursal Disease virus was based on the production of nitric oxide. We show that besides other mechanisms, the inhibition of Infectious Bursal Disease virus by Withania somnifera involves the production of nitric oxide. Our results also highlight the paradoxical role of nitric oxide in the pathogenesis of Infectious Bursal Disease.

SOIL NITROUS OXIDE, NITRIC OXIDE, AND AMMONIA EMISSIONS FROM A RECOVERING RIPARIAN ECOSYSTEM IN SOUTHERN APPALACHIA

EPA Science Inventory

The paper presents two years of seasonal nitric oxide, ammonia, and nitrous oxide trace gas fluxes measured in a recovering riparian zone with cattle excluded and in an adjacent riparian zone grazed by cattle. In the recovering riparian zone, average nitric oxide, ammonia, and ni...

Mitochondrial dysfunction associated with nitric oxide pathways in glutamate neurotoxicity.

PubMed

Manucha, Walter

Multiple mechanisms underlying glutamate-induced neurotoxicity have recently been discussed. Likewise, a clear deregulation of the mitochondrial respiratory mechanism has been described in patients with neurodegeneration, oxidative stress, and inflammation. This article highlights nitric oxide, an atypical neurotransmitter synthesized and released on demand by the post-synaptic neurons, and has many important implications for nerve cell survival and differentiation. Consequently, synaptogenesis, synapse elimination, and neurotransmitter release, are nitric oxide-modulated. Interesting, an emergent role of nitric oxide pathways has been discussed as regards neurotoxicity from glutamate-induced apoptosis. These findings suggest that nitric oxide pathways modulation could prevent oxidative damage to neurons through apoptosis inhibition. This review aims to highlight the emergent aspects of nitric oxide-mediated signaling in the brain, and how they can be related to neurotoxicity, as well as the development of neurodegenerative diseases development. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

A sub-nanomolar real-time nitric oxide probe: in vivo nitric oxide release in heart.

PubMed

Mantione, Kirk J; Stefano, George B

2004-04-01

Amperometric nitric oxide probes are critical in evaluating real-time nitric oxide levels. This valuable tool enables one to measure spontaneous baseline levels of nitric oxide as well as 'puffs' of the gaseous signal molecule that may last for only seconds to minutes. However, in the past, many probes suffered from a lack of sensitivity, durability and reliability, causing investigators to design numerous controls to support their data. Our laboratory evaluated the new ISO-NOPF100 NO probe manufactured by World Precision Instruments of Sarasota, Florida. An invertebrate in vivo heart preparation was used, which presents a high degree of difficuly in obtaining nitric oxide measurements due to space limitations, resulting in physical contact of the probe with tissues. Additionally, we used in vitro invertebrate ganglionic preparations as a comparison since this tissue releases spontaneous and low levels of NO. Calibration of the new probe demonstrated high linearity and sensitivity. The detection limit for this new probe was determined to be approximately two times lower than probes previously used in our laboratory. Basal nitric oxide fluctuations in Mytilus edulis heart and excised ganglia were able to be resolved in the sub-nanomolar range. The ISO-NOPF100 NO probe represents a significant advancement for measuring nitric oxide in real-time.

Nitric Oxide as a Mediator of Oxidant Lung Injury Due to Paraquat

NASA Astrophysics Data System (ADS)

Berisha, Hasan I.; Pakbaz, Hedayatollah; Absood, Afaf; Said, Sami I.

1994-08-01

At low concentrations, nitric oxide is a physiological transmitter, but in excessive concentrations it may cause cell and tissue injury. We report that in acute oxidant injury induced by the herbicide paraquat in isolated guinea pig lungs, nitric oxide synthesis was markedly stimulated, as evidenced by increased levels of cyclic GMP in lung perfusate and of nitrite and L-citrulline production in lung tissue. All signs of injury, including increased airway and perfusion pressures, pulmonary edema, and protein leakage into the airspaces, were dose-dependently attenuated or totally prevented by either N^G-nitro-L-arginine methyl ester or N^ω-nitro-L-arginine, selective and competitive inhibitors of nitric oxide synthase. Protection was reversed by excess L-arginine but not by its enantiomer D-arginine. When blood was added to the lung perfusate, the paraquat injury was moderated or delayed as it was when paraquat was given to anesthetized guinea pigs. The rapid onset of injury and its failure to occur in the absence of Ca2+ suggest that constitutive rather than inducible nitric oxide synthase was responsible for the stimulated nitric oxide synthesis. The findings indicate that nitric oxide plays a critical role in the production of lung tissue injury due to paraquat, and it may be a pathogenetic factor in other forms of oxidant tissue injury.

iNOS-derived nitric oxide promotes glycolysis by inducing pyruvate kinase M2 nuclear translocation in ovarian cancer.

PubMed

Li, Linlin; Zhu, Lingqun; Hao, Bingtao; Gao, Wenwen; Wang, Qianli; Li, Keyi; Wang, Meng; Huang, Mengqiu; Liu, Zhengjun; Yang, Qiaohong; Li, Xiqing; Zhong, Zhuo; Huang, Wenhua; Xiao, Guanghui; Xu, Yang; Yao, Kaitai; Liu, Qiuzhen

2017-05-16

Aerobic glycolysis is essential for tumor growth and survival. Activation of multiple carcinogenic signals contributes to metabolism reprogramming during malignant transformation of cancer. Recently nitric oxide has been noted to promote glycolysis but the mechanism remains elusive. We report here the dual role of nitric oxide in glycolysis: low/physiological nitric oxide (≤ 100 nM) promotes glycolysis for ATP production, oxidative defense and cell proliferation of ovary cancer cells, whereas excess nitric oxide (≥ 500 nM) inhibits it. Nitric oxide has a positive effect on glycolysis by inducing PKM2 nuclear translocation in an EGFR/ERK2 signaling-dependent manner. Moreover, iNOS induced by mild inflammatory stimulation increased glycolysis and cell proliferation by producing low doses of nitric oxide, while hyper inflammation induced iNOS inhibited it by producing excess nitric oxide. Finally, iNOS expression is abnormally increased in ovarian cancer tissues and is correlated with PKM2 expression. Overexpression of iNOS is associated with aggressive phenotype and poor survival outcome in ovarian cancer patients. Our study indicated that iNOS/NO play a dual role of in tumor glycolysis and progression, and established a bridge between iNOS/NO signaling pathway and EGFR/ERK2/PKM2 signaling pathway, suggesting that interfering glycolysis by targeting the iNOS/NO/PKM2 axis may be a valuable new therapeutic approach of treating ovarian cancer.

Nitric oxide/cGMP pathway signaling actively down-regulates α4β1-integrin affinity: an unexpected mechanism for inducing cell de-adhesion.

PubMed

Chigaev, Alexandre; Smagley, Yelena; Sklar, Larry A

2011-05-17

Integrin activation in response to inside-out signaling serves as the basis for rapid leukocyte arrest on endothelium, migration, and mobilization of immune cells. Integrin-dependent adhesion is controlled by the conformational state of the molecule, which is regulated by seven-transmembrane Guanine nucleotide binding Protein-Coupled Receptors (GPCRs). α4β1-integrin (CD49d/CD29, Very Late Antigen-4, VLA-4) is expressed on leukocytes, hematopoietic progenitors, stem cells, hematopoietic cancer cells, and others. VLA-4 conformation is rapidly up-regulated by inside-out signaling through Gαi-coupled GPCRs and down-regulated by Gαs-coupled GPCRs. However, other signaling pathways, which include nitric oxide-dependent signaling, have been implicated in the regulation of cell adhesion. The goal of the current report was to study the effect of nitric oxide/cGMP signaling pathway on VLA-4 conformational regulation. Using fluorescent ligand binding to evaluate the integrin activation state on live cells in real-time, we show that several small molecules, which specifically modulate nitric oxide/cGMP signaling pathway, as well as a cell permeable cGMP analog, can rapidly down-modulate binding of a VLA-4 specific ligand on cells pre-activated through three Gαi-coupled receptors: wild type CXCR4, CXCR2 (IL-8RB), and a non-desensitizing mutant of formyl peptide receptor (FPR ΔST). Upon signaling, we detected rapid changes in the ligand dissociation rate. The dissociation rate after inside-out integrin de-activation was similar to the rate for resting cells. In a VLA-4/VCAM-1-specific myeloid cell adhesion system, inhibition of the VLA-4 affinity change by nitric oxide had a statistically significant effect on real-time cell aggregation. We conclude that nitric oxide/cGMP signaling pathway can rapidly down-modulate the affinity state of the VLA-4 binding pocket, especially under the condition of sustained Gαi-coupled GPCR signaling, generated by a non-desensitizing receptor mutant. This suggests a fundamental role of this pathway in de-activation of integrin-dependent cell adhesion.

Nitric oxide synthase-I containing cortical interneurons co-express antioxidative enzymes and anti-apoptotic Bcl-2 following focal ischemia: evidence for direct and indirect mechanisms towards their resistance to neuropathology.

PubMed

Bidmon, H J; Emde, B; Kowalski, T; Schmitt, M; Mayer, B; Kato, K; Asayama, K; Witte, O W; Zilles, K

2001-09-01

Neuronal nitric oxide-I is constitutively expressed in approximately 2% of cortical interneurons and is co-localized with gamma-amino butric acid, somatostatin or neuropeptide Y. These interneurons additionally express high amounts of glutamate receptors which mediate the glutamate-induced hyperexcitation following cerebral injury, under these conditions nitric oxide production increases contributing to a potentiation of oxidative stress. However, perilesional nitric oxide synthase-I containing neurons are known to be resistant to ischemic and excitotoxic injury. In vitro studies show that nitrosonium and nitroxyl ions inactivate N-methyl-D-aspartate receptors, resulting in neuroprotection. The question remains of how these cells are protected against their own high intracellular nitric oxide production after activation. In this study, we investigated immunocytochemically nitric oxide synthase-I containing cortical neurons in rats after unilateral, cortical photothrombosis. In this model of focal ischemia, perilesional, constitutively nitric oxide synthase-I containing neurons survived and co-expressed antioxidative enzymes, such as manganese- and copper-zinc-dependent superoxide dismutases, heme oxygenase-2 and cytosolic glutathione peroxidase. This enhanced antioxidant expression was accompanied by a strong perinuclear presence of the antiapoptotic Bcl-2 protein. No colocalization was detectable with upregulated heme oxygenase-1 in glia and the superoxide and prostaglandin G(2)-producing cyclooxygenase-2 in neurons. These results suggest that nitric oxide synthase-I containing interneurons are protected against intracellular oxidative damage and apoptosis by Bcl-2 and several potent antioxidative enzymes. Since nitric oxide synthase-I positive neurons do not express superoxide-producing enzymes such as cyclooxygenase-1, xanthine oxidase and cyclooxygenase-2 in response to injury, this may additionally contribute to their resistance by reducing their internal peroxynitrite, H(2)O(2)-formation and caspase activation.

Peroxisomal plant metabolism - an update on nitric oxide, Ca2+ and the NADPH recycling network.

PubMed

Corpas, Francisco J; Barroso, Juan B

2018-01-29

Plant peroxisomes are recognized organelles that - with their capacity to generate greater amounts of H 2 O 2 than other subcellular compartments - have a remarkable oxidative metabolism. However, over the last 15 years, new information has shown that plant peroxisomes contain other important molecules and enzymes, including nitric oxide (NO), peroxynitrite, a NADPH-recycling system, Ca 2+ and lipid-derived signals, such as jasmonic acid (JA) and nitro-fatty acid (NO 2 -FA). This highlights the potential for complex interactions within the peroxisomal nitro-oxidative metabolism, which also affects the status of the cell and consequently its physiological processes. In this review, we provide an update on the peroxisomal interactions between all these molecules. Particular emphasis will be placed on the generation of the free-radical NO, which requires the presence of Ca 2+ , calmodulin and NADPH redox power. Peroxisomes possess several NADPH regeneration mechanisms, such as those mediated by glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) proteins, which are involved in the oxidative phase of the pentose phosphate pathway, as well as that mediated by NADP-isocitrate dehydrogenase (ICDH). The generated NADPH is also an essential cofactor across other peroxisomal pathways, including the antioxidant ascorbate-glutathione cycle and unsaturated fatty acid β-oxidation, the latter being a source of powerful signaling molecules such as JA and NO 2 -FA. © 2018. Published by The Company of Biologists Ltd.

Nitric oxide synthesis in patients with advanced HIV infection.

PubMed Central

Evans, T G; Rasmussen, K; Wiebke, G; Hibbs, J B

1994-01-01

The discovery that humans produce nitric oxide and that this molecule plays an important role in cell communication, host resistance to infection, and perhaps in host defence to neoplastic disease, has created much interest in further research on its function in the body. A cytokine-inducible high output L-arginine/nitric oxide pathway was recently detected in patients with advanced malignancy treated with IL-2. The production of nitric oxide was thus examined in patients with advanced HIV infection and in intensive care unit control patients. Extrinsic nitrate and nitrite consumption were carefully controlled in the diet or through the use of total parenteral nutrition. Seven of eight HIV+ patients were placed into positive nitrogen balance. Nitric oxide synthesis was found to be within the normal human range. In contrast, nitric oxide synthesis in extremely ill intensive care unit patients was low normal to depressed. PMID:8033424

Nitric oxide coupling to generate N2O promoted by a single-heme system as examined by density functional theory.

PubMed

Yi, Jun; Campbell, Adam L O; Richter-Addo, George B

2016-11-30

Bacteria utilize a heme/non-heme enzyme system to detoxify nitric oxide (NO) to N 2 O. In order to probe the capacity of a single-heme system to mediate this NO-to-N 2 O transformation, various scenarios for addition of electrons, protons, and a second NO molecule to a heme nitrosyl to generate N 2 O were explored by density functional theory calculations. We describe, utilizing this single-heme system, several stepwise intermediates along pathways that enable the critical N-N bond formation step yielding the desired Fe-N 2 O product. We also report a hitherto unreported directional second protonation that results in either productive N 2 O formation with loss of water, or formation of a non-productive hyponitrous acid adduct Fe{HONNOH}. Copyright © 2016 Elsevier Inc. All rights reserved.

Reduced Fluoresceinamine as a Fluorescent Sensor for Nitric Oxide

PubMed Central

Duarte, Abel J.; Esteves da Silva, Joaquim C.G.

2010-01-01

A new fluorescent sensor for nitric oxide (NO) is presented that is based on its reaction with a non fluorescent substance, reduced fluoresceinamine, producing the highly fluorescent fluoresceinamine. Using a portable homemade stabilized light source consisting of 450 nm LED and fiber optics to guide the light, the sensor responds linearly within seconds in the NO concentration range between about 10–750 μM with a limit of detection (LOD) of about 1 μM. The system generated precise intensity readings, with a relative standard deviation of less than 1%. The suitability of the sensor was assessed by monitoring the NO generated by either the nitrous acid decomposition reaction or from a NO-releasing compound. Using relatively high incubation times, the sensor also responds quantitatively to hydrogen peroxide and potassium superoxide, however, using transient signal measurements results in no interfering species. PMID:22294892

Nitric Oxide Synthase and Neuronal NADPH Diaphorase are Identical in Brain and Peripheral Tissues

NASA Astrophysics Data System (ADS)

Dawson, Ted M.; Bredt, David S.; Fotuhi, Majid; Hwang, Paul M.; Snyder, Solomon H.

1991-09-01

NADPH diaphorase staining neurons, uniquely resistant to toxic insults and neurodegenerative disorders, have been colocalized with neurons in the brain and peripheral tissue containing nitric oxide synthase (EC 1.14.23.-), which generates nitric oxide (NO), a recently identified neuronal messenger molecule. In the corpus striatum and cerebral cortex, NO synthase immunoreactivity and NADPH diaphorase staining are colocalized in medium to large aspiny neurons. These same neurons colocalize with somatostatin and neuropeptide Y immunoreactivity. NO synthase immunoreactivity and NADPH diaphorase staining are colocalized in the pedunculopontine nucleus with choline acetyltransferase-containing cells and are also colocalized in amacrine cells of the inner nuclear layer and ganglion cells of the retina, myenteric plexus neurons of the intestine, and ganglion cells of the adrenal medulla. Transfection of human kidney cells with NO synthase cDNA elicits NADPH diaphorase staining. The ratio of NO synthase to NADPH diaphorase staining in the transfected cells is the same as in neurons, indicating that NO synthase fully accounts for observed NADPH staining. The identity of neuronal NO synthase and NADPH diaphorase suggests a role for NO in modulating neurotoxicity.

[Ultrasound induced the formation of nitric oxide and nitrosonium ions in water and aqueous solutions].

PubMed

Stepuro, I I; Adamchuk, R I; Stepuro, V I

2004-01-01

Nitric oxide, nitrosonium ions, nitrites, and nitrates are formed in water saturated with air under the action of ultrasound. Nitrosonium ions react with water and hydrogen peroxide to form nitrites and nitrates in sonicated solution, correspondingly. Nitric oxide is practically completely released from sonicated water into the atmosphere and reacts with air oxygen, forming NOx compounds. The oxidation of nitric oxide in aqueous medium by hydroxyl radicals and dissolved oxygen is a minor route of the formation of nitrites and nitrates in ultrasonic field.

Arginine supplementation induces myoblast fusion via augmentation of nitric oxide production.

PubMed

Long, Jodi H D; Lira, Vitor A; Soltow, Quinlyn A; Betters, Jenna L; Sellman, Jeff E; Criswell, David S

2006-01-01

The semi-essential amino acid, L-arginine (L-Arg), is the substrate for endogenous synthesis of nitric oxide, a molecule that is involved in myoblast proliferation and fusion. Since L-Arg supply may limit nitric oxide synthase (NOS) activity in endothelial cells, we examined L-Arg supplementation in differentiating mouse myoblasts and tested the hypothesis that L-Arg exerts direct effects on myoblast fusion via augmentation of endogenous nitric oxide production. C(2)C(12) myoblasts in differentiation media received one of the following treatments for 120 h: 1 mM L-Arg, 0.1 mM N-nitro-L-arginine methyl ester (L-NAME), L-Arg + L-NAME, 10 mM L-Lysine, or no supplement (Control). Cultures were fixed and stained with hematoxylin and eosin for microphotometric image analysis of myotube density, nuclear density, and fusion index (% of total nuclei in myotubes). Endogenous production of nitric oxide during the treatment period peaked between 24 and 48 h. L-Arg amplified nitric oxide production between 0 and 24 h and increased myotube density, total nuclei number, and nuclear fusion index. These L-Arg effects were prevented by the NOS inhibitor, L-NAME. Further, L-Lysine, a competitive inhibitor of L-Arg uptake, repressed nitric oxide production and reduced myotube density and fusion index. In summary, L-Arg augments myotube formation and increases nitric oxide production in a process limited by cellular L-Arg uptake.

Stimulation of nitric oxide synthesis by the aqueous extract of Panax ginseng root in RAW 264.7 cells

PubMed Central

Friedl, Roswitha; Moeslinger, Thomas; Kopp, Brigitte; Spieckermann, Paul Gerhard

2001-01-01

In this study, we investigated the effect of Panax ginseng root aqueous extracts upon inducible nitric oxide synthesis in RAW 264.7 cells. Panax ginseng root extract has been used in the Asian world for centuries as a traditional herb to enhance physical strength and resistance and is becoming more and more popular in Europe and North America. Incubation of murine macrophages (RAW 264.7 cells) with increasing amounts of aqueous extracts of Panax ginseng (0.05 – 0.8 μg μl−1) showed a dose dependent stimulation of inducible nitric oxide synthesis. Polysaccharides isolated from Panax ginseng showed strong stimulation of inducible nitric oxide synthesis, whereas a triterpene-enriched fraction from an aqueous extract of Panax ginseng did not show any stimulation. Inducible nitric oxide synthase protein expression was enhanced in a dose dependent manner as revealed by immunoblotting when cells were incubated with increasing amounts of Panax ginseng extract. This was associated with an incline in inducible nitric oxide synthase mRNA-levels as determined by semiquantitative polymerase chain reaction and electromobility shift assay studies indicated enhanced nuclear factor-κB DNA binding activity. As nitric oxide plays an important role in immune function, Panax ginseng treatment could modulate several aspects of host defense mechanisms due to stimulation of the inducible nitric oxide synthase. PMID:11739242

Molecular analysis of erection regulatory factors in sickle cell disease associated priapism in the human penis.

PubMed

Lagoda, Gwen; Sezen, Sena F; Cabrini, Marcelo R; Musicki, Biljana; Burnett, Arthur L

2013-02-01

Priapism is a vasculopathy that occurs in approximately 40% of patients with sickle cell disease. Mouse models suggest that dysregulated nitric oxide synthase and RhoA/ROCK signaling as well as increased oxidative stress may contribute to the mechanisms of sickle cell disease associated priapism. We examined changes in the protein expression of nitric oxide synthase and ROCK signaling pathways, and a source of oxidative stress, NADPH oxidase, in penile erectile tissue from patients with a priapism history etiologically related and unrelated to sickle cell disease. Human penile erectile tissue was obtained from 5 patients with sickle cell disease associated priapism and from 6 with priapism of other etiologies during nonemergent penile prosthesis surgery for erectile dysfunction or priapism management and urethroplasty. Tissue was also obtained from 5 control patients without a priapism history during penectomy for penile cancer. Samples were collected, immediately placed in cold buffer and then frozen in liquid nitrogen. The expression of phosphodiesterase 5, endothelial nitric oxide synthase, neuronal nitric oxide synthase, inducible nitric oxide synthase, RhoA, ROCK1, ROCK2, p47(phox), p67(phox), gp91(phox) and β-actin were determined by Western blot analysis. Nitric oxide was measured using the Griess reaction. In the sickle cell disease group phosphodiesterase 5 (p <0.05), endothelial nitric oxide synthase (p <0.01) and RhoA (p <0.01) expression was significantly decreased, while gp91(phox) expression (p <0.05) was significantly increased compared to control values. In the nonsickle cell disease group endothelial nitric oxide synthase, ROCK1 and p47(phox) expression (each p <0.05) was significantly decreased compared to control values. Total nitric oxide levels were not significantly different between the study groups. Mechanisms of sickle cell disease associated priapism in the human penis may involve dysfunctional nitric oxide synthase and ROCK signaling, and increased oxidative stress associated with NADPH oxidase mediated signaling. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Separate Nitrite, Nitric Oxide, and Nitrous Oxide Reducing Fractions from Pseudomonas perfectomarinus

PubMed Central

Payne, W. J.; Riley, P. S.; Cox, C. D.

1971-01-01

Pseudomonas perfectomarinus was found to grow anaerobically at the expense of nitrate, nitrite, or nitrous oxide but not chlorate or nitric oxide. In several repetitive experiments, anaerobic incubation in culture media containing nitrate revealed that an average of 82% of the cells in aerobically grown populations were converted to the capacity for respiration of nitrate. Although they did not form colonies under these conditions, the bacteria synthesized the denitrifying enzymes within 3 hr in the absence of oxygen or another acceptable inorganic oxidant. This was demonstrated by the ability, after anaerobic incubation, of cells and of extracts to reduce nitrite, nitric oxide, and nitrous oxide to nitrogen. From crude extracts of cells grown on nitrate, nitrite, or nitrous oxide, separate complex fractions were obtained that utilized reduced nicotinamide adenine dinucleotide as the source of electrons for the reduction of (i) nitrite to nitric oxide, (ii) nitric oxide to nitrous oxide, and (iii) nitrous oxide to nitrogen. Gas chromatographic analyses revealed that each of these fractions reduced only one of the nitrogenous oxides. PMID:4324803

Doxorubicin-induced nitrosative stress is mitigated by vitamin C via the modulation of nitric oxide synthases.

PubMed

Akolkar, Gauri; Bagchi, Ashim K; Ayyappan, Prathapan; Jassal, Davinder S; Singal, Pawan K

2017-04-01

An increase in oxidative stress is suggested to be the main cause in Doxorubicin (Dox)-induced cardiotoxicity. However, there is now evidence that activation of inducible nitric oxide synthase (iNOS) and nitrosative stress are also involved. The role of vitamin C (Vit C) in the regulation of nitric oxide synthase (NOS) and reduction of nitrosative stress in Dox-induced cardiotoxicity is unknown. The present study investigated the effects of Vit C in the mitigation of Dox-induced changes in the levels of nitric oxide (NO), NOS activity, protein expression of NOS isoforms, and nitrosative stress as well as cytokines TNF-α and IL-10 in isolated cardiomyocytes. Cardiomyocytes isolated from adult Sprague-Dawley rats were segregated into four groups: 1 ) control, 2 ) Vit C (25 µM), 3 ) Dox (10 µM), and 4 ) Vit C + Dox. Dox caused a significant increase in the generation of superoxide radical (O 2 ·- ), peroxynitrite, and NO, and these effects of Dox were blunted by Vit C. Dox increased the expression of iNOS and altered protein expression as well as activation of endothelial NOS (eNOS). These changes were prevented by Vit C. Dox induced an increase in the ratio of monomeric/dimeric eNOS, promoting the production of O 2 ·- , which was prevented by Vit C by increasing the stability of the dimeric form of eNOS. Vit C protected against the Dox-induced increase in TNFα as well as a reduction in IL-10. These results suggest that Vit C provides cardioprotection by reducing oxidative/nitrosative stress and inflammation via a modulation of Dox-induced increase in the NO levels and NOS activity. Copyright © 2017 the American Physiological Society.

iNOS-derived nitric oxide promotes glycolysis by inducing pyruvate kinase M2 nuclear translocation in ovarian cancer

PubMed Central

Hao, Bingtao; Gao, Wenwen; Wang, Qianli; Li, Keyi; Wang, Meng; Huang, Mengqiu; Liu, Zhengjun; Yang, Qiaohong; Li, Xiqing; Zhong, Zhuo; Huang, Wenhua; Xiao, Guanghui; Xu, Yang; Yao, Kaitai; Liu, Qiuzhen

2017-01-01

Aerobic glycolysis is essential for tumor growth and survival. Activation of multiple carcinogenic signals contributes to metabolism reprogramming during malignant transformation of cancer. Recently nitric oxide has been noted to promote glycolysis but the mechanism remains elusive. We report here the dual role of nitric oxide in glycolysis: low/physiological nitric oxide (≤ 100 nM) promotes glycolysis for ATP production, oxidative defense and cell proliferation of ovary cancer cells, whereas excess nitric oxide (≥ 500 nM) inhibits it. Nitric oxide has a positive effect on glycolysis by inducing PKM2 nuclear translocation in an EGFR/ERK2 signaling-dependent manner. Moreover, iNOS induced by mild inflammatory stimulation increased glycolysis and cell proliferation by producing low doses of nitric oxide, while hyper inflammation induced iNOS inhibited it by producing excess nitric oxide. Finally, iNOS expression is abnormally increased in ovarian cancer tissues and is correlated with PKM2 expression. Overexpression of iNOS is associated with aggressive phenotype and poor survival outcome in ovarian cancer patients. Our study indicated that iNOS/NO play a dual role of in tumor glycolysis and progression, and established a bridge between iNOS/NO signaling pathway and EGFR/ERK2/PKM2 signaling pathway, suggesting that interfering glycolysis by targeting the iNOS/NO/PKM2 axis may be a valuable new therapeutic approach of treating ovarian cancer. PMID:28380434

HSP70 protects rats and hippocampal neurons from central nervous system oxygen toxicity by suppression of NO production and NF-κB activation.

PubMed

Yi, Hongjie; Huang, Guoyang; Zhang, Kun; Liu, Shulin; Xu, Weigang

2018-05-01

During diving, central nervous system oxygen toxicity may cause drowning or barotrauma, which has dramatically limited the working benefits of hyperbaric oxygen in underwater operations and clinical applications. The aim of this study is to understand the effects and the underlying mechanism of heat shock protein 70 on central nervous system oxygen toxicity and its mechanisms in vivo and in vitro. Rats were given geranylgeranylacetone (800 mg/kg) orally to induce hippocampal expression of heat shock protein 70 and then treated with hyperbaric oxygen. The time course of hippocampal heat shock protein 70 expression after geranylgeranylacetone administration was measured. Seizure latency and first electrical discharge were recorded to evaluate the effects of HSP70 on central nervous system oxygen toxicity. Effects of inhibitors of nitric oxide synthase and nuclear factor-κB on the seizure latencies and changes in nitric oxide, nitric oxide synthase, and nuclear factor-κB levels in the hippocampus tissues were examined. In cell experiments, hippocampal neurons were transfected with a virus vector carrying the heat shock protein 70 gene (H3445) before hyperbaric oxygen treatment. Cell viability, heat shock protein 70 expression, nitric oxide, nitric oxide synthase, and NF-κB levels in neurons were measured. The results showed that heat shock protein 70 expression significantly increased and peaked at 48 h after geranylgeranylacetone was given. Geranylgeranylacetone prolonged the first electrical discharge and seizure latencies, which was reversed by neuronal nitric oxide synthase, inducible nitric oxide synthase and NF-κB inhibitors. Nitric oxide, nitric oxide synthase, and inducible nitric oxide synthase levels in the hippocampus were significantly increased after hyperbaric oxygen exposure, but reversed by geranylgeranylacetone, while heat shock protein 70 inhibitor quercetin could inhibit this effect of geranylgeranylacetone. In the in vitro study, heat shock protein 70-overexpression decreased the nitric oxide, nitric oxide synthase, and inducible nitric oxide synthase levels as well as the cytoplasm/nucleus ratio of nuclear factor-κB and protected neurons from hyperbaric oxygen-induced cell injury. In conclusion, overexpression of heat shock protein 70 in hippocampal neurons may protect rats from central nervous system oxygen toxicity by suppression of neuronal nitric oxide synthase and inducible nitric oxide synthase-mediated nitric oxide production and translocation of nuclear factor-κB to nucleus. Impact statement Because the pathogenesis of central nervous system oxygen toxicity (CNS-OT) remains unclear, there are few interventions available. To develop an efficient strategy against CNS-OT, it is necessary to understand its pathogenesis and in particular, the relevant key factors involved. This study examined the protective effects of heat shock protein 70 (HSP70) on CNS-OT via in vivo and in vitro experiments. Our results indicated that overexpression of HSP70 in hippocampal neurons may protect rats from CNS-OT by suppression of nNOS and iNOS-mediated NO production and the activation of NF-κB. These findings contribute to clarification of the role of HSP70 in CNS-OT and provide us a potential novel target to prevent CNS-OT. Clarification of the involvement of NO, NOS and NF-κB provides new insights into the mechanism of CNS-OT and may help us to develop new approach against it by interfering these molecules.

Methanolic extract of leaves of Jasminum grandiflorum Linn modulates oxidative stress and inflammatory mediators.

PubMed

Chaturvedi, Adya Prasad; Tripathi, Yamini Bhusan

2011-10-01

The leaves of Jasminum grandiflorum (JG) are in clinical use in Ayurveda for wound management. Since, oxidative stress and inflammation are the primary causes in delayed wound healing, so here its antioxidant and anti-inflammatory activities have been investigated using in vitro as well as in vivo models. The solvent-free methanolic extract of dried leaves of JG were tested for its trapping capacity toward pre-generated ABTS•+ radicals, instantly generated superoxide and hydroxyl radicals, along with metal chelation property, reducing power and total phenolic content. Further, it was tested on LPS-induced nitric oxide and cell viability, on primary culture of rat peritoneal macrophages. Its anti-inflammatory property was also tested on carrageenan-induced paw edema in rats. This extract significantly inhibited iron-induced lipid peroxidation and trapped ABTS•+, superoxide and OH radicals. It significantly inhibited nitric oxide (NO) release, without affecting the cell viability at 800 μg/ml concentration and reduced the formation of paw edema in rats. Thus, it could be suggested that the aforesaid anti-inflammatory properties of JG leaves are associated to its high phenolic content (2.25±0.105 mg/l of gallic acid equivalent), reducing power and its free radical-scavenging property.

Effect of selective inhibition of renal inducible nitric oxide synthase on renal blood flow and function in experimental hyperdynamic sepsis.

PubMed

Ishikawa, Ken; Calzavacca, Paolo; Bellomo, Rinaldo; Bailey, Michael; May, Clive N

2012-08-01

Nitric oxide plays an important role in the control of renal blood flow and renal function. In sepsis, increased levels of inducible nitric oxide synthase produce excessive nitric oxide, which may contribute to the development of acute kidney injury. We, therefore, examined the effects of intrarenal infusion of selective inducible nitric oxide synthase inhibitors in a large animal model of hyperdynamic sepsis in which acute kidney injury occurs in the presence of increased renal blood flow. Prospective crossover randomized controlled interventional studies. University-affiliated research institute. Twelve unilaterally nephrectomized Merino ewes. Infusion of a selective (1400W) and a partially selective inducible nitric oxide synthase inhibitor (aminoguanidine) into the renal artery for 2 hrs after the induction of sepsis, and comparison with a nonselective inhibitor (Nω-nitro-L-arginine methyl ester). In sheep with nonhypotensive hyperdynamic sepsis, creatinine clearance halved (32 to 16 mL/min, ratio [95% confidence interval] 0.51 [0.28-0.92]) despite increased renal blood flow (241 to 343 mL/min, difference [95% confidence interval] 102 [78-126]). Infusion of 1400W did not change renal blood flow, urine output, or creatinine clearance, whereas infusion of Nω-nitro-L-arginine methyl ester and a high dose of aminoguanidine normalized renal blood flow, but did not alter creatinine clearance. In hyperdynamic sepsis, intrarenal infusion of a highly selective inducible nitric oxide synthase inhibitor did not reduce the elevated renal blood flow or improve renal function. In contrast, renal blood flow was reduced by infusion of a nonselective NOS inhibitor or a high dose of a partially selective inducible nitric oxide synthase inhibitor. The renal vasodilatation in septic acute kidney injury may be due to nitric oxide derived from the endothelial and neural isoforms of nitric oxide synthase, but their blockade did not restore renal function.

Increased Contextual Fear Conditioning in iNOS Knockout Mice: Additional Evidence for the Involvement of Nitric Oxide in Stress-Related Disorders and Contribution of the Endocannabinoid System

PubMed Central

Gomes, Felipe V.; Silva, Andréia L.; Uliana, Daniela L.; Camargo, Laura H. A.; Guimarães, Francisco S.; Cunha, Fernando Q.; Joca, Sâmia R. L.; Resstel, Leonardo B. M.

2015-01-01

Background: Inducible or neuronal nitric oxide synthase gene deletion increases or decreases anxiety-like behavior in mice, respectively. Since nitric oxide and endocannabinoids interact to modulate defensive behavior, the former effect could involve a compensatory increase in basal brain nitric oxide synthase activity and/or changes in the endocannabinoid system. Thus, we investigated the expression and extinction of contextual fear conditioning of inducible nitric oxide knockout mice and possible involvement of endocannabinoids in these responses. Methods: We evaluated the effects of a preferential neuronal nitric oxide synthase inhibitor, 7-nitroindazol, nitric oxide synthase activity, and mRNA changes of nitrergic and endocannabinoid systems components in the medial prefrontal cortex and hippocampus of wild-type and knockout mice. The effects of URB597, an inhibitor of the fatty acid amide hydrolase enzyme, which metabolizes the endocannabinoid anandamide, WIN55,212-2, a nonselective cannabinoid agonist, and AM281, a selective CB1 antagonist, on contextual fear conditioning were also evaluated. Results: Contextual fear conditioning expression was similar in wild-type and knockout mice, but the latter presented extinction deficits and increased basal nitric oxide synthase activity in the medial prefrontal cortex. 7-Nitroindazol decreased fear expression and facilitated extinction in wild-type and knockout mice. URB597 decreased fear expression in wild-type and facilitated extinction in knockout mice, whereas WIN55,212-2 and AM281 increased it in wild-type mice. Nonconditioned knockout mice showed changes in the mRNA expression of nitrergic and endocannabinoid system components in the medial prefrontal cortex and hippocampus that were modified by fear conditioning. Conclusion: These data reinforce the involvement of the nitric oxide and endocannabinoids (anandamide) in stress-related disorders and point to a deregulation of the endocannabinoid system in situations where nitric oxide signaling is increased. PMID:25618404

Agmatine enhances the anticonvulsant effect of lithium chloride on pentylenetetrazole-induced seizures in mice: Involvement of L-arginine/nitric oxide pathway.

PubMed

Bahremand, Arash; Ziai, Pouya; Khodadad, Tina Kabiri; Payandemehr, Borna; Rahimian, Reza; Ghasemi, Abbas; Ghasemi, Mehdi; Hedayat, Tina; Dehpour, Ahmad Reza

2010-07-01

After nearly 60years, lithium is still the mainstay in the treatment of mood disorders. In addition to its antimanic and antidepressant effects, lithium also has anticonvulsant properties. Similar to lithium, agmatine plays a protective role in the central nervous system against seizures and has been reported to enhance the effect of different antiepileptic agents. Moreover, both agmatine and lithium have modulatory effects on the L-arginine/nitric oxide pathway. This study was designed to investigate: (1) whether agmatine and lithium exert a synergistic effect against clonic seizures induced by pentylenetetrazole and (2) whether or not this synergistic effect is mediated through inhibition of the L-arginine/nitric oxide pathway. In our study, acute administration of a single potent dose of lithium chloride (30mg/kg ip) increased seizure threshold, whereas pretreatment with a low and independently noneffective dose of agmatine (3mg/kg) potentiated a subeffective dose of lithium (10mg/kg). N(G)-L-arginine methyl ester (L-NAME, nonspecific nitric oxide synthase inhibitor) at 1 and 5mg/kg and 7-nitroindazole (7-NI, preferential neuronal nitric oxide synthase inhibitor) at 15 and 30mg/kg augmented the anticonvulsant effect of the noneffective combination of lithium (10mg/kg ip) and agmatine (1mg/kg), whereas several doses (20 and 40mg/kg) of aminoguanidine (inducible nitric oxide synthase inhibitor) failed to alter the seizure threshold of the same combination. Furthermore, pretreatment with independently noneffective doses (30 and 60mg/kg) of L-arginine (substrate for nitric oxide synthase) inhibited the potentiating effect of agmatine (3mg/kg) on lithium (10mg/kg). Our findings demonstrate that agmatine and lithium chloride have synergistic anticonvulsant properties that may be mediated through the L-arginine/nitric oxide pathway. In addition, the role of constitutive nitric oxide synthase versus inducible nitric oxide synthase is prominent in this phenomenon. Copyright 2010 Elsevier Inc. All rights reserved.

Increased Contextual Fear Conditioning in iNOS Knockout Mice: Additional Evidence for the Involvement of Nitric Oxide in Stress-Related Disorders and Contribution of the Endocannabinoid System.

PubMed

Lisboa, Sabrina F; Gomes, Felipe V; Silva, Andréia L; Uliana, Daniela L; Camargo, Laura H A; Guimarães, Francisco S; Cunha, Fernando Q; Joca, Sâmia R L; Resstel, Leonardo B M

2015-01-24

Inducible or neuronal nitric oxide synthase gene deletion increases or decreases anxiety-like behavior in mice, respectively. Since nitric oxide and endocannabinoids interact to modulate defensive behavior, the former effect could involve a compensatory increase in basal brain nitric oxide synthase activity and/or changes in the endocannabinoid system. Thus, we investigated the expression and extinction of contextual fear conditioning of inducible nitric oxide knockout mice and possible involvement of endocannabinoids in these responses. We evaluated the effects of a preferential neuronal nitric oxide synthase inhibitor, 7-nitroindazol, nitric oxide synthase activity, and mRNA changes of nitrergic and endocannabinoid systems components in the medial prefrontal cortex and hippocampus of wild-type and knockout mice. The effects of URB597, an inhibitor of the fatty acid amide hydrolase enzyme, which metabolizes the endocannabinoid anandamide, WIN55,212-2, a nonselective cannabinoid agonist, and AM281, a selective CB1 antagonist, on contextual fear conditioning were also evaluated. Contextual fear conditioning expression was similar in wild-type and knockout mice, but the latter presented extinction deficits and increased basal nitric oxide synthase activity in the medial prefrontal cortex. 7-Nitroindazol decreased fear expression and facilitated extinction in wild-type and knockout mice. URB597 decreased fear expression in wild-type and facilitated extinction in knockout mice, whereas WIN55,212-2 and AM281 increased it in wild-type mice. Nonconditioned knockout mice showed changes in the mRNA expression of nitrergic and endocannabinoid system components in the medial prefrontal cortex and hippocampus that were modified by fear conditioning. These data reinforce the involvement of the nitric oxide and endocannabinoids (anandamide) in stress-related disorders and point to a deregulation of the endocannabinoid system in situations where nitric oxide signaling is increased. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Inhibitory effects of indole α-lipoic acid derivatives on nitric oxide production in LPS/IFNγ activated RAW 264.7 macrophages.

PubMed

Karabay, Arzu Zeynep; Koc, Aslı; Gurkan-Alp, A Selen; Buyukbingol, Zeliha; Buyukbingol, Erdem

2015-04-01

Alpha-lipoic acid (α-lipoic acid) is a potent antioxidant compound that has been shown to possess anti-inflammatory effects. RAW 264.7 macrophages produce various inflammatory mediators such as nitric oxide, IL-1β, IL-6 and TNF-alpha upon activation with LPS (Lipopolysaccharide) and IFNγ (interferon gamma). In this study, the effect of 12 synthetic indole α-lipoic acid derivatives on nitric oxide production and iNOS (inducible nitric oxide synthase) protein expression in LPS/IFNγ activated RAW 264.7 macrophages was determined. Cell proliferation, nitric oxide levels and iNOS protein expression were examined with thiazolyl blue tetrazolium blue test, griess assay and western blot, respectively. Our results showed that all of the indole α-lipoic acid derivatives showed significant inhibitory effects on nitric oxide production and iNOS protein levels (p < 0.05). The most active compounds were identified as compound I-4b, I-4e and II-3b. In conclusion, these indole α-lipoic acid derivatives may have the potential for treatment of inflammatory conditions related with high nitric oxide production. Copyright © 2015 John Wiley & Sons, Ltd.

The Expression of Type-1 and Type-2 Nitric Oxide Synthase in Selected Tissues of the Gastrointestinal Tract during Mixed Mycotoxicosis

PubMed Central

Gajęcka, Magdalena; Stopa, Ewa; Tarasiuk, Michał; Zielonka, Łukasz; Gajęcki, Maciej

2013-01-01

The aim of the study was to verify the hypothesis that intoxication with low doses of mycotoxins leads to changes in the mRNA expression levels of nitric oxide synthase-1 and nitric oxide synthase-2 genes in tissues of the gastrointestinal tract and the liver. The experiment involved four groups of immature gilts (with body weight of up to 25 kg) which were orally administered zearalenone in a daily dose of 40 μg/kg BW (group Z, n = 18), deoxynivalenol at 12 μg/kg BW (group D, n = 18), zearalenone and deoxynivalenol (group M, n = 18) or placebo (group C, n = 21) over a period of 42 days. The lowest mRNA expression levels of nitric oxide synthase-1 and nitric oxide synthase-2 genes were noted in the sixth week of the study, in particular in group M. Our results suggest that the presence of low mycotoxin doses in feed slows down the mRNA expression of both nitric oxide synthase isomers, which probably lowers the concentrations of nitric oxide, a common precursor of inflammation. PMID:24284830

Laser absorption of nitric oxide for thermometry in high-enthalpy air

NASA Astrophysics Data System (ADS)

Spearrin, R. M.; Schultz, I. A.; Jeffries, J. B.; Hanson, R. K.

2014-12-01

The design and demonstration of a laser absorption sensor for thermometry in high-enthalpy air is presented. The sensor exploits the highly temperature-sensitive and largely pressure-independent concentration of nitric oxide in air at chemical equilibrium. Temperature is thus inferred from an in situ measurement of nascent nitric oxide. The strategy is developed by utilizing a quantum cascade laser source for access to the strong fundamental absorption band in the mid-infrared spectrum of nitric oxide. Room temperature measurements in a high-pressure static cell validate the suitability of the Voigt lineshape model to the nitric oxide spectra at high gas densities. Shock-tube experiments enable calibration of a collision-broadening model for temperatures between 1200-3000 K. Finally, sensor performance is demonstrated in a high-pressure shock tube by measuring temperature behind reflected shock waves for both fixed-chemistry experiments where nitric oxide is seeded, and for experiments involving nitric oxide formation in shock-heated mixtures of N2 and O2. Results show excellent performance of the sensor across a wide range of operating conditions from 1100-2950 K and at pressures up to 140 atm.

The antiplatelet effects of nitrates: is it of clinical significance in patients with cardiovascular disease?

PubMed

Zhou, Rui-Hai; Frishman, William H

2010-01-01

Organic nitrates have been used for over a century in cardiovascular therapy and are still widely used in the treatment of acute coronary syndromes, chronic angina pectoris, and congestive heart failure. Nitrates, together with sodium nitroprusside, generally referred to as nitrovasodilators, exert their biologic effects via the release of nitric oxide. They are also known as nitric oxide donors. The mechanism of action of these drugs is traditionally believed to lie in their arterial vasodilation and venodilation effects, resulting in an improvement of coronary artery blood supply and/or reduction of cardiac workload in the treatment of coronary artery disease and congestive heart failure. Recently it has been recognized that these drugs also have intrinsic antiplatelet and antithrombotic effects, demonstrated both in vitro and in vivo, which would add further rationale for the use of these drugs in atherothrombotic diseases. Research has shown that nitrovasodilators can nonselectively inhibit platelet aggregation induced by multiple stimuli. However, clinical trials have yielded conflicting results regarding clinical outcome, especially with long-term nitrate use. The potentially beneficial effects of nitrates could be negated by the development of tolerance and the generation of deleterious oxidative stress causing endothelial dysfunction during continuous nitrate administration. Much progress has been made in the development of new nitric oxide donors devoid of oxidant-generating properties. Novel combination therapies with nitrovasodilators plus antioxidants or agents with antioxidant properties have shown promise in reducing or reversing tolerance, potentiating antiplatelet effects, and improving clinical outcome. It is expected that clinical introduction of novel nitrovasodilator regimens will provide a new approach to the prevention and treatment of atherothrombotic diseases. Large-scale clinical trials will ultimately provide the evidence-based answers.

Redefining Nitric Oxide Production in Legume Nodules through Complementary Insights from Electron Paramagnetic Resonance Spectroscopy and Specific Fluorescent Probes.

PubMed

Calvo-Begueria, Laura; Rubio, Maria C; Martínez, Jesús I; Pérez-Rontomé, Carmen; Delgado, Maria J; Bedmar, Eulogio J; Becana, Manuel

2018-04-26

Nitric oxide (NO) is a signaling molecule with multiple functions in plants. Given its critical importance and reactivity as a gaseous free radical, we have examined NO production in legume nodules using electron paramagnetic resonance (EPR) spectroscopy and the specific fluorescent dye 4,5-diaminofluorescein diacetate. Also, in this context, we critically assess previous and current views of NO production and detection in nodules. EPR of intact nodules revealed that nitrosyl-leghemoglobin (Lb2+NO) was absent from bean or soybean nodules regardless of nitrate supply, but accumulated in soybean nodules treated with nitrate that were defective in nitrite or nitric oxide reductases or that were exposed to ambient temperature. Consequently, bacteroids are a major source of NO, denitrification enzymes are required for NO homeostasis, and Lb2+NO is not responsible for the inhibition of nitrogen fixation by nitrate. Further, we noted that Lb2+NO is artifactually generated in nodule extracts or in intact nodules not analyzed immediately after detachment. The fluorescent probe detected NO formation in bean and soybean nodule infected cells and in soybean nodule parenchyma. The NO signal was slightly decreased by inhibitors of nitrate reductase but not of nitric oxide synthase, which could indicate a minor contribution of plant nitrate reductase and supports the existence of nitrate- and arginine-independent pathways for NO production. Collectively, our data indicate that EPR and fluorometric methods are complementary to draw reliable conclusions about NO production in plants.

Piper sarmentosum increases nitric oxide production in oxidative stress: a study on human umbilical vein endothelial cells.

PubMed

Ugusman, Azizah; Zakaria, Zaiton; Hui, Chua Kien; Nordin, Nor Anita Megat Mohd

2010-07-01

Nitric oxide produced by endothelial nitric oxide synthase (eNOS) possesses multiple anti-atherosclerotic properties. Hence, enhanced expression of eNOS and increased Nitric oxide levels may protect against the development of atherosclerosis. Piper sarmentosum is a tropical plant with antioxidant and anti-inflammatory activities. This study aimed to investigate the effects of Piper sarmentosum on the eNOS and Nitric oxide pathway in cultured human umbilical vein endothelial cells (HUVECs). HUVECS WERE DIVIDED INTO FOUR GROUPS: control, treatment with 180 microM hydrogen peroxide (H(2)O(2)), treatment with 150 microg/mL aqueous extract of Piper sarmentosum, and concomitant treatment with aqueous extract of PS and H(2)O(2) for 24 hours. Subsequently, HUVECs were harvested and eNOS mRNA expression was determined using qPCR. The eNOS protein level was measured using ELISA, and the eNOS activity and Nitric oxide level were determined by the Griess reaction. Human umbilical vein endothelial cells treated with aqueous extract of Piper sarmentosum showed a marked induction of Nitric oxide. Treatment with PS also resulted in increased eNOS mRNA expression, eNOS protein level and eNOS activity in HUVECs. Aqueous extract of Piper sarmentosum may improve endothelial function by promoting NO production in HUVECs.

A Role of Fluoride on Free Radical Generation and Oxidative Stress in BV-2 Microglia Cells

PubMed Central

Shuhua, Xi; Ziyou, Liu; Ling, Yan; Fei, Wang; Sun, Guifan

2012-01-01

The generation of ROS and lipid peroxidation has been considered to play an important role in the pathogenesis of chronic fluoride toxicity. In the present study, we observed that fluoride activated BV-2 microglia cell line by observing OX-42 expression in immunocytochemistry. Intracellular superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS), superoxide anions (O2 ∙−), nitric oxide synthase (NOS), nitrotyrosine (NT) and nitric oxide (NO), NOS in cell medium were determined for oxidative stress assessment. Our study found that NaF of concentration from 5 to 20 mg/L can stimuli BV-2 cells to change into activated microglia displaying upregulated OX-42 expression. SOD activities significantly decreased in fluoride-treated BV-2 cells as compared with control, and MDA concentrations and contents of ROS and O2 ∙− increased in NaF-treated cells. Activities of NOS in cells and medium significantly increased with fluoride concentrations in a dose-dependent manner. NT concentrations also increased significantly in 10 and 50 mg/L NaF-treated cells compared with the control cells. Our present study demonstrated that toxic effects of fluoride on the central nervous system possibly partly ascribed to activiting of microglia, which enhanced oxidative stress induced by ROS and reactive nitrogen species. PMID:22933830

Interference of oxygen, carbon dioxide, and water vapor on the analysis for oxides of nitrogen by chemiluminescence

NASA Technical Reports Server (NTRS)

Maahs, H. G.

1975-01-01

The interference of small concentrations (less than 4 percent by volume) of oxygen, carbon dioxide, and water vapor on the analysis for oxides of nitrogen by chemiluminescence was measured. The sample gas consisted primarily of nitrogen, with less than 100 parts per million concentration of nitric oxide, and with small concentrations of oxygen, carbon dioxide, and water vapor added. Results obtained under these conditions indicate that although oxygen does not measurably affect the analysis for nitric oxide, the presence of carbon dioxide and water vapor causes the indicated nitric oxide concentration to be too low. An interference factor - defined as the percentage change in indicated nitric oxide concentration (relative to the true nitric oxide concentration) divided by the percent interfering gas present - was determined for carbon dioxide to be -0.60 + or - 0.04 and for water vapor to be -2.1 + or - 0.3.

Prevention of vascular dysfunction and arterial hypertension in mice generated by assisted reproductive technologies by addition of melatonin to culture media.

PubMed

Rexhaj, Emrush; Pireva, Agim; Paoloni-Giacobino, Ariane; Allemann, Yves; Cerny, David; Dessen, Pierre; Sartori, Claudio; Scherrer, Urs; Rimoldi, Stefano F

2015-10-01

Assisted reproductive technologies (ART) induce vascular dysfunction in humans and mice. In mice, ART-induced vascular dysfunction is related to epigenetic alteration of the endothelial nitric oxide synthase (eNOS) gene, resulting in decreased vascular eNOS expression and nitrite/nitrate synthesis. Melatonin is involved in epigenetic regulation, and its administration to sterile women improves the success rate of ART. We hypothesized that addition of melatonin to culture media may prevent ART-induced epigenetic and cardiovascular alterations in mice. We, therefore, assessed mesenteric-artery responses to acetylcholine and arterial blood pressure, together with DNA methylation of the eNOS gene promoter in vascular tissue and nitric oxide plasma concentration in 12-wk-old ART mice generated with and without addition of melatonin to culture media and in control mice. As expected, acetylcholine-induced mesenteric-artery dilation was impaired (P = 0.008 vs. control) and mean arterial blood pressure increased (109.5 ± 3.8 vs. 104.0 ± 4.7 mmHg, P = 0.002, ART vs. control) in ART compared with control mice. These alterations were associated with altered DNA methylation of the eNOS gene promoter (P < 0.001 vs. control) and decreased plasma nitric oxide concentration (10.1 ± 11.1 vs. 29.5 ± 8.0 μM) (P < 0.001 ART vs. control). Addition of melatonin (10(-6) M) to culture media prevented eNOS dysmethylation (P = 0.005, vs. ART + vehicle), normalized nitric oxide plasma concentration (23.1 ± 14.6 μM, P = 0.002 vs. ART + vehicle) and mesentery-artery responsiveness to acetylcholine (P < 0.008 vs. ART + vehicle), and prevented arterial hypertension (104.6 ± 3.4 mmHg, P < 0.003 vs. ART + vehicle). These findings provide proof of principle that modification of culture media prevents ART-induced vascular dysfunction. We speculate that this approach will also allow preventing ART-induced premature atherosclerosis in humans. Copyright © 2015 the American Physiological Society.

Nitric oxide scavengers differentially inhibit ammonia oxidation in ammonia-oxidizing archaea and bacteria.

PubMed

Sauder, Laura A; Ross, Ashley A; Neufeld, Josh D

2016-04-01

Differential inhibitors are important for measuring the relative contributions of microbial groups, such as ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), to biogeochemical processes in environmental samples. In particular, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) represents a nitric oxide scavenger used for the specific inhibition of AOA, implicating nitric oxide as an intermediate of thaumarchaeotal ammonia oxidation. This study investigated four alternative nitric oxide scavengers for their ability to differentially inhibit AOA and AOB in comparison to PTIO. Caffeic acid, curcumin, methylene blue hydrate and trolox were tested onNitrosopumilus maritimus, two unpublished AOA representatives (AOA-6f and AOA-G6) as well as the AOB representative Nitrosomonas europaea All four scavengers inhibited ammonia oxidation by AOA at lower concentrations than for AOB. In particular, differential inhibition of AOA and AOB by caffeic acid (100 μM) and methylene blue hydrate (3 μM) was comparable to carboxy-PTIO (100 μM) in pure and enrichment culture incubations. However, when added to aquarium sponge biofilm microcosms, both scavengers were unable to inhibit ammonia oxidation consistently, likely due to degradation of the inhibitors themselves. This study provides evidence that a variety of nitric oxide scavengers result in differential inhibition of ammonia oxidation in AOA and AOB, and provides support to the proposed role of nitric oxide as a key intermediate in the thaumarchaeotal ammonia oxidation pathway. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Microbial removal of no.sub.x from gases

DOEpatents

Sublette, Kerry L.

1991-01-01

Disclosed is a process by which a gas containing nitric oxide is contacted with an anaerobic microbial culture of denitrifying bacteria to effect the chemical reduction of the nitric oxide to elemental nitrogen. The process is particularly suited to the removal of nitric oxide from flue gas streams and gas streams from nitric acid plants. Thiobacillus dentrificians as well as other bacteria are disclosed for use in the process.

Inhibition of Cryptococcus neoformans replication by nitrogen oxides supports the role of these molecules as effectors of macrophage-mediated cytostasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alspaugh, J.A.; Granger, D.L.

Activated macrophages are able to inhibit the replication of intracellular microbes and tumor cells. In the murine system, this cytostatic effect is associated with the oxidation of L-arginine to L-citrulline, nitrite, and nitrate and is thought to be mediated by an intermediate of this reaction, possibly nitric oxide (NO.). By exposing replicating Cryptococcus neoformans cells to conditions under which NO. is chemically generated, we have observed a cytostatic effect similar to that caused by activated murine macrophages. Nitric oxide is formed as a decomposition product of nitrite salts in acidic, aqueous solutions. Although C. neoformans replicates well in the presencemore » of high nitrite concentrations at physiologic pH, its growth in acidic media can be inhibited by the addition of low concentrations of sodium nitrite. The degree of cytostasis is dependent on both the pH and the nitrite concentration of the NO. generating solution. The cytostatic effector molecule appears to be a gas since, in addition to inhibiting C. neoformans replication in solution, it is able to exert its inhibitory effect across a gas-permeable but ion-impermeable membrane. At high nitrite concentrations, a fungicidal effect occurs. We propose that the growth inhibition of C. neoformans upon exposure to chemically generated NO. or some related oxide of nitrogen represents a cell-free system simulating the cytostatic effect of activated murine macrophages.« less

21 CFR 868.5165 - Nitric oxide administration apparatus.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nitric oxide administration apparatus. 868.5165 Section 868.5165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5165 Nitric oxide administration...

21 CFR 868.5165 - Nitric oxide administration apparatus.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nitric oxide administration apparatus. 868.5165 Section 868.5165 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5165 Nitric oxide administration...

Endothelial function and vascular oxidative stress in long-lived GH/IGF-deficient Ames dwarf mice

PubMed Central

Csiszar, Anna; Labinskyy, Nazar; Perez, Viviana; Recchia, Fabio A.; Podlutsky, Andrej; Mukhopadhyay, Partha; Losonczy, Gyorgy; Pacher, Pal; Austad, Steven N.; Bartke, Andrzej; Ungvari, Zoltan

2008-01-01

Hypopituitary Ames dwarf mice have low circulating growth hormone (GH)/IGF-I levels, and they have extended longevity and exhibit many symptoms of delayed aging. To elucidate the vascular consequences of Ames dwarfism we compared endothelial O2•− and H2O2 production, mitochondrial reactive oxygen species (ROS) generation, expression of antioxidant enzymes, and nitric oxide (NO) production in aortas of Ames dwarf and wild-type control mice. In Ames dwarf aortas endothelial O2•− and H2O2 production and ROS generation by mitochondria were enhanced compared with those in vessels of wild-type mice. In Ames dwarf aortas there was a less abundant expression of Mn-SOD, Cu,Zn-SOD, glutathione peroxidase (GPx)-1, and endothelial nitric oxide synthase (eNOS). NO production and acetylcholine-induced relaxation were also decreased in aortas of Ames dwarf mice. In cultured wild-type mouse aortas and in human coronary arterial endothelial cells treatment with GH and IGF significantly reduced cellular O2•− and H2O2 production and ROS generation by mitochondria and upregulated expression of Mn-SOD, Cu,Zn-SOD, GPx-1, and eNOS. Thus GH and IGF-I promote antioxidant phenotypic changes in the endothelial cells, whereas Ames dwarfism leads to vascular oxidative stress. PMID:18757483

Nitric oxide fumigation for postharvest pest control

USDA-ARS?s Scientific Manuscript database

Nitric oxide fumigation is effective against all arthropod pests at various life stages tested. Nine insect pests at various life stages and bulb mites were subjected to nitric oxide fumigation treatments under ultralow oxygen conditions of =50 ppm O2 in 1.9L glass jars as fumigation chambers. The ...

Effect of soy isoflavone supplementation on nitric oxide metabolism and blood pressure in menopausal women

USDA-ARS?s Scientific Manuscript database

Isoflavones, having chemical structures similar to estrogens, are believed to stimulate nitric oxide production and thus lower blood pressure. The efficacy of soy isoflavone supplementation to stimulate nitric oxide production and lower blood pressure in menopausal women with high normal blood press...

Nitric-oxide supplementation for treatment of long-term complications in argininosuccinic aciduria

USDA-ARS?s Scientific Manuscript database

Argininosuccinate lyase (ASL) is required for the synthesis and channeling of L-arginine to nitric oxide synthase (NOS) for nitric oxide (NO) production. Congenital ASL deficiency causes argininosuccinic aciduria (ASA), the second most common urea cycle disorder, and leads to deficiency of both urea...

Recent developments in nitric oxide donor drugs

PubMed Central

Miller, M R; Megson, I L

2007-01-01

During the 1980s, the free radical, nitric oxide (NO), was discovered to be a crucial signalling molecule, with wide-ranging functions in the cardiovascular, nervous and immune systems. Aside from providing a credible explanation for the actions of organic nitrates and sodium nitroprusside that have long been used in the treatment of angina and hypertensive crises respectively, the discovery generated great hopes for new NO-based treatments for a wide variety of ailments. Decades later, however, we are still awaiting novel licensed agents in this arena, despite an enormous research effort to this end. This review explores some of the most promising recent advances in NO donor drug development and addresses the challenges associated with NO as a therapeutic agent. PMID:17401442

Calibration-free self-absorption model for measuring nitric oxide concentration in a pulsed corona discharge.

PubMed

Du, Yanjun; Ding, Yanjun; Liu, Yufeng; Lan, Lijuan; Peng, Zhimin

2014-08-01

The effect of self-absorption on emission intensity distributions can be used for species concentration measurements. A calculation model is developed based on the Beer-Lambert law to quantify this effect. And then, a calibration-free measurement method is proposed on the basis of this model by establishing the relationship between gas concentration and absorption strength. The effect of collision parameters and rotational temperature on the method is also discussed. The proposed method is verified by investigating the nitric oxide emission bands (A²Σ⁺→X²∏) that are generated by a pulsed corona discharge at various gas concentrations. Experiment results coincide well with the expectations, thus confirming the precision and accuracy of the proposed measurement method.

Novel nitric oxide generating compound glycidyl nitrate enhances the therapeutic efficacy of chemotherapy and radiotherapy.

PubMed

Ning, Shoucheng; Bednarski, Mark; Oronsky, Bryan; Scicinski, Jan; Knox, Susan J

2014-05-09

Selective release of nitric oxide (NO) in tumors could improve the tumor blood flow and drug delivery for chemotherapeutic agents and radiotherapy, thereby increasing the therapeutic index. Glycidyl nitrate (GLYN) is a NO generating small molecule, and has ability to release NO on bioactivation in SCC VII tumor cells. GLYN-induced intracellular NO generation was significantly attenuated by NO scavenger carboxy-PTIO (cPTIO) and NAC. GLYN significantly increases tumor blood flow, but has no effect on the blood flow of normal tissues in tumor-bearing mice. When used with cisplatin, GLYN significantly increased the tumor growth inhibition effect of cisplatin. GLYN also had a modest radiosensitizing effect in vitro and in vivo. GLYN was well tolerated and there were no acute toxicities found at its effective therapeutic doses in preclinical studies. These results suggest that GLYN is a promising new drug for use with chemotherapy and radiotherapy, and provide a compelling rationale for future studies of GLYN and related compounds. Copyright © 2014 Elsevier Inc. All rights reserved.

Protein kinase G–regulated production of H2S governs oxygen sensing

PubMed Central

Yuan, Guoxiang; Vasavda, Chirag; Peng, Ying-Jie; Makarenko, Vladislav V.; Raghuraman, Gayatri; Nanduri, Jayasri; Gadalla, Moataz M.; Semenza, Gregg L.; Kumar, Ganesh K.; Snyder, Solomon H.; Prabhakar, Nanduri R.

2015-01-01

Reflexes initiated by the carotid body, the principal O2-sensing organ, are critical for maintaining cardio-respiratory homeostasis during hypoxia. O2 sensing by the carotid body requires carbon monoxide (CO) generation by heme oxygenase-2 (HO-2) and hydrogen sulfide (H2S) synthesis by cystathionine-γ-lyase (CSE). We report that O2 stimulated the generation of CO, but not that of H2S, and required two cysteine residues in the heme regulatory motif (Cys265 and Cys282) of HO-2. CO stimulated protein kinase G (PKG)–dependent phosphorylation of Ser377 of CSE, inhibiting the production of H2S. Hypoxia decreased the inhibition of CSE by reducing CO generation resulting in increased H2S, which stimulated carotid body neural activity. In carotid bodies from mice lacking HO-2, compensatory increased abundance of nNOS (neuronal nitric oxide synthase) mediated O2 sensing through PKG-dependent regulation of H2S by nitric oxide. These results provide a mechanism for how three gases work in concert in the carotid body to regulate breathing. PMID:25900831

A Translational Pathway Toward a Clinical Trial Using the Second-Generation AAV Micro-Dystrophin Vector

DTIC Science & Technology

responsible for restoring neuronal nitric oxide synthase (nNOS).Failure to restore nNOS significantly contributes to the initiation and progression...model. Our findings have provided the foundation for the recent initiation of human trials.

Exhaled nitric oxide levels in exacerbations of asthma, chronic obstructive pulmonary disease and pneumonia.

PubMed

Al-Ali, M K; Howarth, P H

2001-03-01

Nitric oxide is known to be present in the exhaled air of normal subjects and at higher concentrations in asthmatics. The aim of this study was to measure exhaled nitric oxide levels in patients admitted to hospital with acute exacerbations of asthma, or chronic obstructive pulmonary disease, or with pneumonia. Within 24 hours of admission exhaled nitric oxide levels were measured by a chemiluminescent analyzer in 11 patients with acute sever asthma, 19 patients with acute exacerbation of chronic obstructive pulmonary disease, and in 12 patients with pneumonia. In asthmatics measurements were made on 3 occasions, at day 1, 4, and 28 and were related to changes in peak expiratory flow rate. On admission median exhaled nitric oxide levels (range) were significantly higher in asthmatics 22 (9.3-74) parts per billion in comparison to patients with chronic obstructive pulmonary disease 10.3 (2.7-34) parts per billion; p < 0.01, pneumonia 7 (4-17) parts per billion; p<0.001, and normal subjects 8.7 (5-13.3) parts per billion; p < 0.001. Following treatment the asthmatics had a significant reduction in their exhaled nitric oxide levels from 22 (9.3-74) parts per billion on day 1 to 9.7 (5.7-18.3) parts per billion on day 28; p = 0.005. Peak expiratory flow rate measurements increased from 200 (120-280) l/min on day 1 to 280 (150-475) l/min on day 4; p < 0.05 and to 390 (150-530) l/min on day 28; p < 0.01. A strong negative correlation existed between peak expiratory flow rate measurements and exhaled nitric oxide levels in asthmatics on day 28 (r = -0.70; p = 0.017). Acute exacerbations of asthma are associated with increased levels of exhaled nitric oxide in contrast to exacerbations of chronic obstructive pulmonary disease and acute pneumonia. Exhaled nitric oxide may be a useful indirect marker of asthmatic airway inflammation. The differing time course of response of nitric oxide to peak flow measures suggests that these two measures are reflecting differing airway events.

Inhibition of neuronal nitric oxide synthase in ovine model of acute lung injury*

PubMed Central

Enkhbaatar, Perenlei; Connelly, Rhykka; Wang, Jianpu; Nakano, Yoshimitsu; Lange, Matthias; Hamahata, Atsumori; Horvath, Eszter; Szabo, Csaba; Jaroch, Stefan; Hölscher, Peter; Hillmann, Margrit; Traber, Lillian D.; Schmalstieg, Frank C.; Herndon, David N.; Traber, Daniel L.

2013-01-01

Objective Acute respiratory distress syndrome/acute lung injury is a serious complication of burn patients with concomitant smoke inhalation injury. Nitric oxide has been shown to play a major role in pulmonary dysfunction from thermal damage. In this study, we have tested the hypothesis that inhibition of neuronal nitric oxide synthase could ameliorate the severity of acute lung injury using our well-established ovine model of cutaneous burn and smoke inhalation. Design Prospective, randomized, controlled, experimental animals study. Setting Investigational intensive care unit at university hospital. Subjects Adult female sheep Interventions Female sheep (n = 16) were surgically prepared for the study. Seven days after surgery, all sheep were randomly allocated into three study groups: sham (noninjured, nontreated, n = 6); control (injured, treated with saline, n = 6); and neuronal nitric oxide synthase (injured, treated with specific neuronal nitric oxide synthase inhibitor, ZK 234238 (n = 4). Control and neuronal nitric oxide synthase groups were given a cutaneous burn (40% of total body surface, third degree) and insufflated with cotton smoke (48 breaths, <40°C) under halothane anesthesia. Animals in sham group received fake injury also under halothane anesthesia. After injury or fake injury procedure, all sheep were placed on ventilators and resuscitated with lactated Ringer's solution. Neuronal nitric oxide synthase group was administered with continuous infusion of ZK 234238 started 1 hr postinjury with a dose of 100 μg/kg/hr. Sham and control groups received same amount of saline. Measurements and Main Results Cardiopulmonary hemodynamics monitored during the 24-hr experimental time period was stable in the sham group. Control sheep developed multiple signs of acute lung injury. This pathophysiology included decreased pulmonary gas exchange and lung compliance, increased pulmonary edema, and inflammatory indices, such as interleukin-8. Treatment of injured sheep with neuronal nitric oxide synthase inhibitor attenuated all the observed pulmonary pathophysiology. Conclusions The results provide definitive evidence that inhibition of neuronal nitric oxide synthase-derived excessive nitric oxide may be a novel and beneficial treatment strategy for pulmonary pathology in burn victims with smoke inhalation injury. PMID:19050603

Remote sensing of nitric oxide emissions from planes, trains and automobiles

NASA Astrophysics Data System (ADS)

Popp, Peter John

Remote sensing has been proven as an effective method for measuring in-use mobile source emissions. This document describes the development of a remote sensor for mobile source nitric oxide, based on an instrument previously developed at the University of Denver for measuring carbon monoxide and hydrocarbon emissions. The new remote sensor makes use of a high-speed ultraviolet spectrometer to quantify nitric oxide by absorption spectroscopy at 226 nm in the ultraviolet region. The high-speed spectrometer is coupled to an existing FEAT remote sensor, for the simultaneous measurement of CO, CO2 and hydrocarbons by non-dispersive infrared absorption spectroscopy. The utility of the instrument was demonstrated in the measurement of nitric oxide emissions from automobiles, commercial aircraft, and railroad locomotives. The remote sensor was used to measure nitric oxide emissions from motor vehicles in Chicago in 1997 and 1998, as part of a five-year study to characterize motor vehicle emissions and deterioration in that city. Emissions data were collected for over 19,000 vehicles in 1997 and almost 23,000 vehicles in 1998. All of these records contained valid measurements for carbon monoxide and hydrocarbons, in addition to nitric oxide. In September of 1997, a study was conducted with the cooperation of British Airways and the British Airports Authority to demonstrate the capability of the remote sensor in measuring nitric oxide emissions from in-use commercial aircraft. In two days of sampling at London Heathrow Airport, a total of 122 measurements were made of 90 different aircraft, ranging in size from Gulfstream executive jets to Boeing 747-400s. The measured nitric oxide emission indices were not inconsistent with commercial aircraft emission indices published by the International Civil Aviation Organization. The utility of the remote sensor in measuring nitric oxide emissions from railroad locomotives was demonstrated in January of 1999, in a study conducted with the cooperation of the Burlington Northern Santa Fe Railway. Nitric oxide emissions measured from freight locomotives in a controlled test at a switchyard agreed with previously published values. Measurements of in-use locomotives hauling coal trains revealed higher NO emissions than those measured from similar locomotives in the controlled test.

Nitric oxide signals are interlinked with calcium signals in normal pancreatic stellate cells upon oxidative stress and inflammation.

PubMed

Jakubowska, Monika A; Ferdek, Pawel E; Gerasimenko, Oleg V; Gerasimenko, Julia V; Petersen, Ole H

2016-08-01

The mammalian diffuse stellate cell system comprises retinoid-storing cells capable of remarkable transformations from a quiescent to an activated myofibroblast-like phenotype. Activated pancreatic stellate cells (PSCs) attract attention owing to the pivotal role they play in development of tissue fibrosis in chronic pancreatitis and pancreatic cancer. However, little is known about the actual role of PSCs in the normal pancreas. These enigmatic cells have recently been shown to respond to physiological stimuli in a manner that is markedly different from their neighbouring pancreatic acinar cells (PACs). Here, we demonstrate the capacity of PSCs to generate nitric oxide (NO), a free radical messenger mediating, for example, inflammation and vasodilatation. We show that production of cytosolic NO in PSCs is unambiguously related to cytosolic Ca(2+) signals. Only stimuli that evoke Ca(2+) signals in the PSCs elicit consequent NO generation. We provide fresh evidence for the striking difference between signalling pathways in PSCs and adjacent PACs, because PSCs, in contrast to PACs, generate substantial Ca(2+)-mediated and NOS-dependent NO signals. We also show that inhibition of NO generation protects both PSCs and PACs from necrosis. Our results highlight the interplay between Ca(2+) and NO signalling pathways in cell-cell communication, and also identify a potential therapeutic target for anti-inflammatory therapies. © 2016 The Authors.

Nitrate, nitrite and nitric oxide reductases: from the last universal common ancestor to modern bacterial pathogens

PubMed Central

Vázquez-Torres, Andrés; Bäumler, Andreas

2016-01-01

The electrochemical gradient that ensues from the enzymatic activity of cytochromes such as nitrate reductase, nitric oxide reductase, and quinol oxidase contributes to the bioenergetics of the bacterial cell. Reduction of nitrogen oxides by bacterial pathogens can, however, be uncoupled from proton translocation and biosynthesis of ATP or NH4+, but still linked to quinol and NADH oxidation. Ancestral nitric oxide reductases, as well as cytochrome coxidases and quinol bo oxidases evolved from the former, are capable of binding and detoxifying nitric oxide to nitrous oxide. The NO-metabolizing activity associated with these cytochromes can be a sizable source of antinitrosative defense in bacteria during their associations with host cells. Nitrosylation of terminal cytochromes arrests respiration, reprograms bacterial metabolism, stimulates antioxidant defenses and alters antibiotic cytotoxicity. Collectively, the bioenergetics and regulation of redox homeostasis that accompanies the utilization of nitrogen oxides and detoxification of nitric oxide by cytochromes of the electron transport chain increases fitness of many Gram-positive and –negative pathogens during their associations with invertebrate and vertebrate hosts. PMID:26426528

Prolonged exposure of resveratrol induces reactive superoxide species-independent apoptosis in murine prostate cells.

PubMed

Kumar, Sanjay; Stokes, James; Singh, Udai P; Scissum-Gunn, Karyn; Singh, Rajesh; Manne, Upender; Mishra, Manoj K

2017-10-01

Nitric oxide, a signaling molecule, inhibits mitochondrial respiration by binding with cytochrome c oxidase, resulting in elevated production of reactive superoxide species (reactive oxygen and nitrogen) in the mitochondria and increased susceptibility to cell death. Generation of mitochondrial superoxide species can be suppressed by natural compounds such as resveratrol, a dietary polyphenol found in the skin of red fruits. In various cancer cells, resveratrol shows anti-oxidant and cancer preventive properties. Since, the effect of resveratrol on reactive superoxide species-independent apoptosis in prostate cancer cells is not well illustrated; therefore, we investigated this phenomenon in TRAMP murine prostate cancer cells. To accomplish this, TRAMP cells were incubated with resveratrol, resveratrol + DETA-NONOate, DETA-NONOate (nitric oxide donor), resveratrol + L-NMMA, or L-NMMA (nitric oxide inhibitor) for 48 h, and reactive superoxide species in the mitochondria and culture supernatant were measured. In addition, the mitochondrial membrane potential, cell viability, expression of apoptotic markers (Bax and Bcl2), γ-H2A.x, p53, and caspase-3 was determined. We found that resveratrol suppressed reactive superoxide species such as reactive oxygen species in the mitochondria and nitric oxide in culture supernatant when compared to the DETA-NONOate treatment and disrupted the mitochondrial membrane potential. Resveratrol also reduced cell viability, altered the expression of apoptotic markers (Bax and Bcl2), and increased expression of γ-H2A.x (indicative marker of DNA fragmentation) and p53 (a critical DNA damage response protein). However, there was no appreciable modulation of the caspase-3. Therefore, our data suggest that resveratrol induces superoxide species-independent apoptosis and may act as a therapeutic agent against prostate cancer.

Prevention of the pulmonary vasoconstrictor effects of HBOC-201 in awake lambs by continuously breathing nitric oxide.

PubMed

Yu, Binglan; Volpato, Gian Paolo; Chang, Keqin; Bloch, Kenneth D; Zapol, Warren M

2009-01-01

Hemoglobin-based oxygen-carrying solutions (HBOC) provide emergency alternatives to blood transfusion to carry oxygen to tissues without the risks of disease transmission or transfusion reaction. Two primary concerns hampering the clinical acceptance of acellular HBOC are the occurrence of systemic and pulmonary vasoconstriction and the maintenance of the heme-iron in the reduced state (Fe2+). We recently demonstrated that pretreatment with inhaled nitric oxide prevents the systemic hypertension induced by HBOC-201 (polymerized bovine hemoglobin) infusion in awake mice and sheep without causing methemoglobinemia. However, the impact of HBOC-201 infusion with or without inhaled nitric oxide on pulmonary vascular tone has not yet been examined. The pulmonary and systemic hemodynamic effects of breathing nitric oxide both before and after the administration of HBOC-201 were determined in healthy, awake lambs. Intravenous administration of HBOC-201 (12 ml/kg) induced prolonged systemic and pulmonary vasoconstriction. Pretreatment with inhaled nitric oxide (80 parts per million [ppm] for 1 h) prevented the HBOC-201--induced increase in mean arterial pressure but not the increase of pulmonary arterial pressure, systemic vascular resistance, or pulmonary vascular resistance. Pretreatment with inhaled nitric oxide (80 ppm for 1 h) followed by breathing a lower concentration of nitric oxide (5 ppm) during and after HBOC-201 infusion prevented systemic and pulmonary vasoconstriction without increasing methemoglobin levels. These findings demonstrate that pretreatment with inhaled nitric oxide followed by breathing a lower concentration of the gas during and after administration of HBOC-201 may enable administration of an acellular hemoglobin substitute without vasoconstriction while preserving its oxygen-carrying capacity.

Purafil-filtration prevents the development of ozone-induced frost injury: A potential role for nitric oxide

NASA Astrophysics Data System (ADS)

Neighbour, E. A.; Pearson, M.; Mehlhorn, H.

The relationship between exposure to ozone in the summer and the subsequent development of frost hardiness in the autumn was evaluated in recent experiments with red spruce ( Picea rubens Sarg. Syn. P. rubra). When O 3 was added to air filtered only through charcoal (contaminated with nitric oxide (NO)), frost sensitivity in late autumn was increased as measured by conductivity from electrocyte leakage. However, when O 3 was added to air filtered through charcoal and Purafil (no NO), no enhancement of frost sensitivity was found. A possible explanation of this difference, involving the chain-propagating property of NO in the O 3-initiated oxidation of unsaturated hydrocarbons (HCs), is proposed and discussed. N 2O 5, which was found to be generated at approximately 0.02 moles per mole of O 3 in the first year's experiment, only marginally modified O 3 toxicity.

Melatonin and its precursors scavenge nitric oxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noda, Y.; Mori, A.; Liburdy, R.

Nitric oxide (NO) scavenging activity of melatonin, N-acetyl-5-hydroxytryptamine, serotonin, 5-hydroxytryptophan and L-tryptophan was examined by the Griess reaction using flow injection analysis. 1-Hydroxy-2-oxo-3-(N-methyl-3-aminopropyl)-3-methyl-1-triazene(NOC-7) was used as NO generator. The Griess reagent stoichiometrically reacts with NO2-, which was converted by a cadmium-copper reduction column from the stable end products of NO oxidation. Except for tryptophan, all the compounds examined scavenged NO in a dose-dependent manner. Melatonin, which has a methoxy group in the 5-position and an acetyl side chain, exhibited the most potent scavenging activity among the compounds tested. Serotonin, N-acetyl-5-hydroxytryptamine, and 5-hydroxytryptophan, respectively, showed moderate scavenging activity compared to melatonin.more » Tryptophan, which has neither a methoxy nor a hydroxyl group in the 5-position, exhibited the least NO scavenging activity.« less

Influences of the heme-lysine crosslink in cytochrome P460 over redox catalysis and nitric oxide sensitivity† †Electronic supplementary information (ESI) available: Experimental materials and methods, and supplementary figures and tables. See DOI: 10.1039/c7sc03450d

PubMed Central

Vilbert, Avery C.; Caranto, Jonathan D.

2017-01-01

Ammonia (NH3)-oxidizing bacteria (AOB) derive total energy for life from the multi-electron oxidation of NH3 to nitrite (NO2–). One obligate intermediate of this metabolism is hydroxylamine (NH2OH), which can be oxidized to the potent greenhouse agent nitrous oxide (N2O) by the AOB enzyme cytochrome (cyt) P460. We have now spectroscopically characterized a 6-coordinate (6c) {FeNO}7 intermediate on the NH2OH oxidation pathway of cyt P460. This species has two fates: it can either be oxidized to the {FeNO}6 that then undergoes attack by NH2OH to ultimately generate N2O, or it can lose its axial His ligand, thus generating a stable, off-pathway 5-coordinate (5c) {FeNO}7 species. We show that the wild type (WT) cyt P460 exhibits a slow nitric oxide (NO)-independent conversion (kHis-off = 2.90 × 10–3 s–1), whereas a cross-link-deficient Lys70Tyr cyt P460 mutant protein underwent His dissociation via both a NO-independent (kHis-off = 3.8 × 10–4 s–1) and a NO-dependent pathway [kHis-off(NO) = 790 M–1 s–1]. Eyring analyses of the NO-independent pathways for these two proteins revealed a significantly larger (ca. 27 cal mol–1 K–1) activation entropy (ΔS‡) in the cross-link-deficient mutant. Our results suggest that the Lys–heme cross-link confers rigidity to the positioning of the heme P460 cofactor to avoid the fast NO-dependent His dissociation pathway and subsequent formation of the off-pathway 5c {FeNO}7 species. The relevance of these findings to NO signaling proteins such as heme-nitric oxide/oxygen binding (H-NOX) is also discussed. PMID:29629106

Nitric oxide fumigation for control of bulb mites on flower bulbs and tubers

USDA-ARS?s Scientific Manuscript database

Nitric oxide fumigation was studied for efficacy to control bulb mites in the genus Rhizoglyphus and effects on germination and growth of flower bulbs and tubers. Bulb mites on infested peanuts were fumigated with nitric oxide at different concentrations under ultralow oxygen conditions in 1.9L jar...

The light-induced reduction of horizontal cell receptive field size in the goldfish retina involves nitric oxide.

PubMed

Daniels, Bryan A; Baldridge, William H

2011-03-01

Horizontal cells of the vertebrate retina have large receptive fields as a result of extensive gap junction coupling. Increased ambient illumination reduces horizontal cell receptive field size. Using the isolated goldfish retina, we have assessed the contribution of nitric oxide to the light-dependent reduction of horizontal cell receptive field size. Horizontal cell receptive field size was assessed by comparing the responses to centered spot and annulus stimuli and from the responses to translated slit stimuli. A period of steady illumination decreased the receptive field size of horizontal cells, as did treatment with the nitric oxide donor (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (100 μM). Blocking the endogenous production of nitric oxide with the nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester (1 mM), decreased the light-induced reduction of horizontal cell receptive field size. These findings suggest that nitric oxide is involved in light-induced reduction of horizontal cell receptive field size. Copyright © Cambridge University Press, 2011

Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation

PubMed Central

Nguyen, Minh Cong; Park, Jong Taek; Jeon, Yeong Gwan; Jeon, Byeong Hwa; Hoe, Kwang Lae; Kim, Young Myeong

2016-01-01

Purpose Peroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism. Materials and Methods Human umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured. eNOS activation was evaluated via Western blot and dimer blot analysis. We also tested nitric oxide (NO) and reactive oxygen species (ROS) production and performed a vascular tension assay. Results SIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. NG-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition. Conclusion These findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions. PMID:27593859

Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation.

PubMed

Nguyen, Minh Cong; Park, Jong Taek; Jeon, Yeong Gwan; Jeon, Byeong Hwa; Hoe, Kwang Lae; Kim, Young Myeong; Lim, Hyun Kyo; Ryoo, Sungwoo

2016-11-01

Peroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism. Human umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured. eNOS activation was evaluated via Western blot and dimer blot analysis. We also tested nitric oxide (NO) and reactive oxygen species (ROS) production and performed a vascular tension assay. SIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. N(G)-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition. These findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions.

Novel device for continuous spatial control and temporal delivery of nitric oxide for in vitro cell culture☆

PubMed Central

Romanowicz, Genevieve E.; He, Weilue; Nielsen, Matthew; Frost, Megan C.

2013-01-01

Nitric oxide (NO) is an ubiquitous signaling molecule of intense interest in many physiological processes. Nitric oxide is a highly reactive free radical gas that is difficult to deliver with precise control over the level and timing that cells actually experience. We describe and characterize a device that allows tunable fluxes and patterns of NO to be generated across the surface upon which cells are cultured. The system is based on a quartz microscope slide that allows for controlled light levels to be applied to a previously described photosensitive NO-releasing polydimethylsiloxane (PDMS). Cells are cultured in separate wells that are either NO-releasing or a chemically similar PDMS that does not release NO. Both wells are then top coated with DowCorning RTV-3140 PDMS and a polydopamine/gelatin layer to allow cells to grow in the culture wells. When the waveguide is illuminated, the surface of the quartz slide propagates light such that the photosensitive polymer is evenly irradiated and generates NO across the surface of the cell culture well and no light penetrates into the volume of the wells where cells are growing. Mouse smooth muscle cells (MOVAS) were grown in the system in a proof of principle experiment, whereby 60% of the cells were present in the NO-releasing well compared to control wells after 17 h. The compelling advantage of illuminating the NO-releasing polymers with the waveguide system is that light can be used to tunably control NO release while avoiding exposing cells to optical radiation. This device provides means to quantitatively control the surface flux, timing and duration of NO cells experience and allows for systematic study of cellular response to NO generated at the cell/surface interface in a wide variety of studies. PMID:24024168

The Semireduced Mechanism for Nitric Oxide Reduction by Non-Heme Diiron Complexes: Modeling Flavodiiron Nitric Oxide Reductases.

PubMed

White, Corey J; Speelman, Amy L; Kupper, Claudia; Demeshko, Serhiy; Meyer, Franc; Shanahan, James P; Alp, E Ercan; Hu, Michael; Zhao, Jiyong; Lehnert, Nicolai

2018-02-21

Flavodiiron nitric oxide reductases (FNORs) are a subclass of flavodiiron proteins (FDPs) capable of preferential binding and subsequent reduction of NO to N 2 O. FNORs are found in certain pathogenic bacteria, equipping them with resistance to nitrosative stress, generated as a part of the immune defense in humans, and allowing them to proliferate. Here, we report the spectroscopic characterization and detailed reactivity studies of the diiron dinitrosyl model complex [Fe 2 (BPMP)(OPr)(NO) 2 ](OTf) 2 for the FNOR active site that is capable of reducing NO to N 2 O [Zheng et al., J. Am. Chem. Soc. 2013, 135, 4902-4905]. Using UV-vis spectroscopy, cyclic voltammetry, and spectro-electrochemistry, we show that one reductive equivalent is in fact sufficient for the quantitative generation of N 2 O, following a semireduced reaction mechanism. This reaction is very efficient and produces N 2 O with a first-order rate constant k > 10 2 s -1 . Further isotope labeling studies confirm an intramolecular N-N coupling mechanism, consistent with the rapid time scale of the reduction and a very low barrier for N-N bond formation. Accordingly, the reaction proceeds at -80 °C, allowing for the direct observation of the mixed-valent product of the reaction. At higher temperatures, the initial reaction product is unstable and decays, ultimately generating the diferrous complex [Fe 2 (BPMP)(OPr) 2 ](OTf) and an unidentified ferric product. These results combined offer deep insight into the mechanism of NO reduction by the relevant model complex [Fe 2 (BPMP)(OPr)(NO) 2 ] 2+ and provide direct evidence that the semireduced mechanism would constitute a highly efficient pathway to accomplish NO reduction to N 2 O in FNORs and in synthetic catalysts.

Investigation on oxidative stress of nitric oxide synthase interacting protein from Clonorchis sinensis.

PubMed

Bian, Meng; Xu, Qingxia; Xu, Yanquan; Li, Shan; Wang, Xiaoyun; Sheng, Jiahe; Wu, Zhongdao; Huang, Yan; Yu, Xinbing

2016-01-01

Numerous evidences indicate that excretory-secretory products (ESPs) from liver flukes trigger the generation of free radicals that are associated with the initial pathophysiological responses in host cells. In this study, we first constructed a Clonorchis sinensis (C. sinensis, Cs)-infected BALB/c mouse model and examined relative results respectively at 3, 5, 7, and 9 weeks postinfection (p.i.). Quantitative reverse transcription (RT)-PCR indicated that the transcriptional level of both endothelial nitric oxide synthase (eNOS) and superoxide dismutase (SOD) gradually decreased with lastingness of infection, while the transcriptional level of inducible NOS (iNOS) significantly increased. The level of malondialdehyde (MDA) in sera of infected mouse significantly increased versus the healthy control group. These results showed that the liver of C. sinensis-infected mouse was in a state with elevated levels of oxidation stress. Previously, C. sinensis NOS interacting protein coding gene (named CsNOSIP) has been isolated and recombinant CsNOSIP (rCsNOSIP) has been expressed in Escherichia coli, which has been confirmed to be a component present in CsESPs and confirmed to play important roles in immune regulation of the host. In the present paper, we investigated the effects of rCsNOSIP on the lipopolysaccharide (LPS)-induced activated RAW264.7, a murine macrophage cell line. We found that endotoxin-free rCsNOSIP significantly promoted the levels of nitric oxide (NO) and reactive oxygen species (ROS) after pretreated with rCsNOSIP, while the level of SOD decreased. Furthermore, rCsNOSIP could also increase the level of lipid peroxidation MDA. Taken together, these results suggested that CsNOSIP was a key molecule which was involved in the production of nitric oxide (NO) and its reactive intermediates, and played an important role in oxidative stress during C. sinensis infection.

Coupling Between the Thermosphere and the Stratosphere: the Role of Nitric Oxide

NASA Technical Reports Server (NTRS)

Brasseur, G.

1984-01-01

In order to understand the lower ionosphere and its probable control by dynamical processes, the behavior of nitric oxide below 100 km was investigated. A two dimensional model with coupled chemical and dynamical processes was constructed. Calculations based on the model reveal that the chemical conditions at the stratopause are related to the state of the thermosphere. This coupling mechanism can be partly explained by the downward transport of nitric oxide during the winter season, and consequently depends on the dynamical conditions in the mesosphere and in the lower thermosphere (mean circulation and waves). In summer, the photodissociation of nitric oxide plays an important role and the thermospheric NO abundance modulates the radiation field reaching the upper stratosphere. Perturbations in the nitric oxide concentration above the mesopause could therefore have an impact in the vicinity of the stratopause.

A redox-based mechanism for the neuroprotective and neurodestructive effects of nitric oxide and related nitroso-compounds.

PubMed

Lipton, S A; Choi, Y B; Pan, Z H; Lei, S Z; Chen, H S; Sucher, N J; Loscalzo, J; Singel, D J; Stamler, J S

1993-08-12

Congeners of nitrogen monoxide (NO) are neuroprotective and neurodestructive. To address this apparent paradox, we considered the effects on neurons of compounds characterized by alternative redox states of NO: nitric oxide (NO.) and nitrosonium ion (NO+). Nitric oxide, generated from NO. donors or synthesized endogenously after NMDA (N-methyl-D-aspartate) receptor activation, can lead to neurotoxicity. Here, we report that NO.- mediated neurotoxicity is engendered, at least in part, by reaction with superoxide anion (O2.-), apparently leading to formation of peroxynitrite (ONOO-), and not by NO. alone. In contrast, the neuroprotective effects of NO result from downregulation of NMDA-receptor activity by reaction with thiol group(s) of the receptor's redox modulatory site. This reaction is not mediated by NO. itself, but occurs under conditions supporting S-nitrosylation of NMDA receptor thiol (reaction or transfer of NO+). Moreover, the redox versatility of NO allows for its interconversion from neuroprotective to neurotoxic species by a change in the ambient redox milieu. The details of this complex redox chemistry of NO may provide a mechanism for harnessing neuroprotective effects and avoiding neurotoxicity in the central nervous system.

Hydrogen sulfide facilities production of nitric oxide via the Akt/endothelial nitric oxide synthases signaling pathway to protect human umbilical vein endothelial cells from injury by angiotensin II.

PubMed

Cui, Jiasen; Zhuang, Shunjiu; Qi, Shaohong; Li, Li; Zhou, Junwen; Zhang, Wan; Zhao, Yun; Qi, Ning; Yin, Yangjun; Huang, Lu

2017-11-01

Angiotensin II (Ang II) has been reported as key in inducing endothelial cell injury, and endothelial cells may produce nitric oxide (NO) to protect themselves. However, the underlying mechanism remains elusive. Human umbilical vein endothelial cells (HUVECs) were divided into five treatment groups as follows: Normal control, Ang II, Ang II + sodium hydrosulfide [NaHS; hydrogen sulfide (H2S) donor], Ang II + Akt inhibitors + NaHS, and Ang II + endothelial nitric oxide synthases (eNOS) inhibitors + NaHS. Subsequently, cell viability, apoptosis, migration, proliferation and adhesion ability were determined. In addition, tubular structure formation was observed, and the NO and phosphorylation levels of Akt and eNOS were evaluated. Compared with the normal control group, Ang II treatment reduced the viability of HUVECs and increased the level of cell apoptosis (P<0.05). Furthermore, Ang II treatment inhibited the phosphorylation level of eNOS and Akt, as well as the generation of NO (P<0.05). H2S reversed the above‑mentioned effects significantly and increased cell proliferation, adhesion ability and promoted tubular structure formation (P<0.05); however, H2S did not reverse the impact of eNOS and Akt phosphorylation levels after being processed with Akt and eNOS inhibitors, which indicates that H2S is capable of protecting HUVECs via the eNOS/Akt signaling pathway (P<0.05). Thus, H2S stimulates the production of NO and protects HUVECs via inducing the Akt/eNOS signaling pathway.

Effect of Thymoquinone on Reproductive Parameter in Morphine-treated Male Mice

PubMed Central

Salahshoor, Mohammad Reza; Haghjoo, Mojdeh; Roshankhah, Shiva; Makalani, Fatemeh; Jalili, Cyrus

2018-01-01

Background: Thymoquinone as the main active component of Nigella sativa might have a various pharmacological effects such as antiapoptotic and antioxidant. Morphine is commonly used for the treatment of severe pain that can increase the generation of free radicals and affects the spermatogenesis. This study was designed to evaluate protective effects of thymoquinone against morphine-induced damages, sperm viability, count, motility, morphology and testis histology, and nitric oxide and testosterone hormone of the mice. Materials and Methods: In this experimental study, we divided 48 mice into eight groups (n = 6); various doses of thymoquinone (2, 10, and 20 mg/kg) and morphine (20 mg/kg) plus thymoquinone (2, 10, and 20 mg/kg) were administered intraperitoneally to 48 male mice for 30 consequent days. Male reproductive parameters including testis weight, testosterone hormone, serum nitric oxide, germinal thickness, sperm morphology, count, viability, and motility were analyzed and compared. Results: The results indicated that morphine administration significantly decreased germinal thickness, testis weight, testosterone level, viability, morphology, count, and motility of sperm and increased nitric oxide as compared to saline group (P < 0.05). However, increasing the dose of thymoquinone in the thymoquinone and thymoquinone plus morphine groups significantly decreases nitric oxide level (P < 0.05) while significantly boosted motility, morphology, count, viability of sperm cells, germinal thickness, and testosterone hormone in all groups as compared to morphine group (P < 0.05). Conclusion: It seems that thymoquinone administration could increase the quality some of spermatozoa and improves morphine-induced adverse effects on reproductive parameters in male mice PMID:29456989

Nitric oxide is a potential down-regulating molecule in autoimmune disease: inhibition of nitric oxide production renders PVG rats highly susceptible to EAE.

PubMed

Cowden, W B; Cullen, F A; Staykova, M A; Willenborg, D O

1998-08-01

Rat strains vary in their susceptibility to experimental autoimmune encephalomyelitis (EAE) and in many cases, factors other than MHC antigens are thought to play a role in this. We found that PVG rats, which have a very low susceptibility to EAE, were rendered highly susceptible to clinical disease when treated with N-methylarginine (NMA) an inhibitor of nitric oxide synthase (NOS). The clinical course of the ensuing disease in NMA-treated PVG rats was in most cases fulminating in nature and accompanied by some mortality. Following immunisation with myelin basic protein (MBP)-complete Freund's adjuvant (CFA), PVG rats developed higher serum levels of the surrogate markers of nitric oxide production, reactive nitrogen intermediates (RNI; nitrite and nitrate), than did their Lewis counterparts. This in vivo finding was reflected in vitro, where the levels of RNI produced in 24, 48 and 72 h IFN-gamma-stimulated spleen cell cultures for PVG rats were significantly higher than those for Lewis rats. A mechanism by which increased NO production might protect PVG rats against clinical EAE was suggested by the finding that lymph node cells, isolated from NMA-treated MBP-immunised PVG rats, proliferated in response to MBP at a rate approximately 3 x greater than those from MBP-immunised, saline treated rats. Thus, the greater number of MBP-specific T cells generated in the NOS inhibitor-treated vs. untreated rats could account for their increased susceptibility to developing clinical EAE. The findings in this study suggest that NO plays a role in protecting PVG rats against developing EAE.

The reduction of nitric oxide by ammonia over polycrystalline platinum model catalysts in the presence of oxygen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katona, T.; Guczi, L.; Somorjai, G.A.

1992-06-01

The reaction system of nitric oxide, ammonia, and oxygen was studied using batch-mode measurements in partial pressure ranges of 65-1000 Pa (0.5-7.6 Torr) on polycrystalline Pt foils over the temperature range 423-598 K. Under these conditions the oxidation of nitric oxide was not detectable. The ammonia oxidation reaction, using dioxygen, occurred in the temperature range 423-493 K, producing nitrogen and water as the only products. The activation energy of the nitrogen formation was found to be 86 kJ/mol. Above this temperature range, flow-mode measurements showed the formation of both nitrous oxide and nitric oxide. The reaction rate between ammonia andmore » oxygen was greatly decreased (about a factor of 10) by nitric oxide, while the reaction rate between nitric oxide and ammonia was accelerated (about 10-fold) due to the presence of oxygen. Nitric oxide reduction by ammonia in the presence of oxygen occurred in the temperature range 423-598 K. The products of the reaction were nitrogen, oxygen nitrous oxide, and water. The Arrhenius plot of the reaction showed a break near 523 K. Below this temperature the activation energy of the reaction was 13 kJ/mol, and in the higher-temperature range it was 62 kJ/mol. At 473 K, the N[sub 2]/N[sub 2]O ratio was about 0.6 and O[sub 2] formation was also monitored. At 573 K, the N[sub 2]N[sub 2]O ratio was approximately 2 and oxygen was consumed in the course of the reaction as well.« less

Intracellular redox state determines whether nitric oxide is toxic or protective to rat oligodendrocytes in culture.

PubMed

Rosenberg, P A; Li, Y; Ali, S; Altiok, N; Back, S A; Volpe, J J

1999-08-01

We found that several nitric oxide donors had similar potency in killing mature and immature forms of oligodendrocytes (OLs). Because of the possibility of interaction of nitric oxide with intracellular thiols, we tested the effect of the nitrosonium ion donor S-nitrosylglutathione (SNOG) in OL cultures in the setting of cystine deprivation, which has been shown to cause intracellular glutathione depletion. Surprisingly, the presence of 200 microM SNOG completely protected OLs against the toxicity of cystine depletion. This protection appeared to be due to nitric oxide, because it could be blocked by hemoglobin and potentiated by inclusion of superoxide dismutase. We tested the effect of three additional NO* donors and found that protection was not seen with diethylamine NONOate, a donor with a half-life measured in minutes, but was seen with dipropylenetriamine NONOate and diethylaminetriamine NONOate, donors with half-lives measured in hours. This need for donors with longer half-lives for the protective effect suggested that NO* was required when intracellular thiol concentrations were falling, a process evolving over hours in medium depleted of cystine. These studies suggest a novel protective role for nitric oxide in oxidative stress injury and raise the possibility that intracerebral nitric oxide production might be a mechanism of defense against oxidative stress injury in OLs.

Effects of Isoprene- and Toluene-Generated Smog on Allergic Inflammation in Mice

EPA Science Inventory

Reactions of organic compounds with nitric oxide (NO) and sunlight produce complex mixtures of pollutants including secondary organic aerosol (SOA), ozone (O3), nitrogen dioxide (NO2), and reactive aldehydes. The health effects of these photochemical smog mixtures in susceptible ...

Serine 1179 phosphorylation of endothelial nitric oxide synthase caused by 2,4,6-trinitrotoluene through PI3K/Akt signaling in endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun Yang; Sumi, Daigo; Kumagai, Yoshito

2006-07-01

Although 2,4,6-trinitrotoluene (TNT) has been found to uncouple nitric oxide synthase (NOS), thereby leading to reactive oxygen species (ROS), cellular response against TNT still remains unclear. Exposure of bovine aortic endothelial cells (BAECs) to TNT (100 {mu}M) resulted in serine 1179 phosphorylation of endothelial NOS (eNOS). With specific inhibitors (wortmannin and LY294002), we found that PI3K/Akt signaling participated in the eNOS phosphorylation caused by TNT, whereas the ERK pathway did not. ROS were generated following exposure of BAECs to TNT. However, TNT-mediated phosphorylation of either eNOS or Akt was drastically blocked by NAC and PEG-CAT. Interestingly, pretreatment with apocynin, amore » specific inhibitor for NADPH oxidase, diminished the phosphorylation of eNOS and Akt. These results suggest that TNT affects NADPH oxidase, thereby generating hydrogen peroxide, which is capable of activating PI3K/Akt signaling associated with eNOS Ser 1179 phosphorylation.« less

pH-Responsive mineralized nanoparticles as stable nanocarriers for intracellular nitric oxide delivery.

PubMed

Lee, Hong Jae; Kim, Da Eun; Park, Dong Jin; Choi, Gi Hyun; Yang, Dal-Nim; Heo, Jung Sun; Lee, Sang Cheon

2016-10-01

We describe a calcium carbonate (CaCO3) mineralization approach to generate pH-responsive nanocarriers that can stably load S-nitrosoglutathione (GSNO) and dissolve at acidic endosomes to trigger intracellular release of nitric oxide (NO). GSNO-loaded CaCO3-mineralized nanoparticles (GSNO-MNPs) were prepared by an anionic block copolymer (PEG-Poly(l-aspartic acid))-templated mineralization. Ionic GSNO could be loaded in situ inside the CaCO3 core during the mineralization process. The stability of GSNO shielded within the crystalline CaCO3 core was greatly enhanced. The GSNO-MNPs triggered NO release at endosomal pH and an intracellular ascorbic acid level. Confocal microscopy demonstrated that the GSNO-MNPs could be dissolved at endosomal environments to release GSNO and sequentially generate NO through the GSNO reduction in the cytosol. In vitro cell experiments demonstrated that NO release by the GSNO-MNPs efficiently improved therapeutic activity of doxorubicin (DOX). Copyright © 2016 Elsevier B.V. All rights reserved.

Sustained generation of nitric oxide and control of mycobacterial infection requires argininosuccinate synthase 1

PubMed Central

Qualls, Joseph E.; Subramanian, Chitra; Rafi, Wasiulla; Smith, Amber M.; Balouzian, Liza; DeFreitas, Ashley A.; Shirey, Kari Ann; Reutterer, Benjamin; Kernbauer, Elisabeth; Stockinger, Silvia; Decker, Thomas; Miyairi, Isao; Vogel, Stefanie N.; Salgame, Padmini; Rock, Charles O.; Murray, Peter J.

2012-01-01

Nitric oxide (NO) defends against intracellular pathogens but its synthesis must be regulated due to cell and tissue toxicity. During infection, macrophages import extracellular arginine to synthesize NO, generating the byproduct citrulline. Accumulated intracellular citrulline is thought to fuel arginine synthesis catalyzed by argininosuccinate synthase (Ass1) and argininosuccinate lyase (Asl), which would lead to abundant NO production. Instead, we find that citrulline is exported from macrophages during early stages of NO production with < 2% retained for recycling via the Ass1-Asl pathway. Later, extracellular arginine is depleted, and Ass1 expression allows macrophages to synthesize arginine from imported citrulline to sustain NO output. Ass1-deficient macrophages fail to salvage citrulline in arginine-scarce conditions, leading to their inability to control mycobacteria infection. Thus, extracellular arginine fuels rapid NO production in activated macrophages, and citrulline recycling via Ass1 and Asl is a fail-safe system that sustains optimum NO production. PMID:22980328

S-nitrosothiols regulate nitric oxide production and storage in plants through the nitrogen assimilation pathway

PubMed Central

Frungillo, Lucas; Skelly, Michael J.; Loake, Gary J.; Spoel, Steven H.; Salgado, Ione

2014-01-01

Nitrogen assimilation plays a vital role in plant metabolism. Assimilation of nitrate, the primary source of nitrogen in soil, is linked to generation of the redox signal nitric oxide (NO). An important mechanism by which NO regulates plant development and stress responses is through S-nitrosylation, i.e. covalent attachment of NO to cysteines to form S-nitrosothiols (SNO). Despite the importance of nitrogen assimilation and NO signalling, it remains largely unknown how these pathways are interconnected. Here we show that SNO signalling suppresses both nitrate uptake and reduction by transporters and reductases, respectively, to fine-tune nitrate homeostasis. Moreover, NO derived from nitrate assimilation suppresses the redox enzyme S-nitrosoglutathione Reductase 1 (GSNOR1) by S-nitrosylation, preventing scavenging of S-nitrosoglutathione, a major cellular bio-reservoir of NO. Hence, our data demonstrates that (S)NO controls its own generation and scavenging by modulating nitrate assimilation and GSNOR1 activity. PMID:25384398

Efficient photochemical generation of peroxycarboxylic nitric anhydrides with ultraviolet light emitting diodes

NASA Astrophysics Data System (ADS)

Rider, N. D.; Taha, Y. M.; Odame-Ankrah, C. A.; Huo, J. A.; Tokarek, T. W.; Cairns, E.; Moussa, S. G.; Liggio, J.; Osthoff, H. D.

2015-01-01

Photochemical sources of peroxycarboxylic nitric anhydrides (PANs) are utilized in many atmospheric measurement techniques for calibration or to deliver an internal standard. Conventionally, such sources rely on phosphor-coated low-pressure mercury (Hg) lamps to generate the UV light necessary to photo-dissociate a dialkyl ketone (usually acetone) in the presence of a calibrated amount of nitric oxide (NO) and oxygen (O2). In this manuscript, a photochemical PAN source in which the Hg lamp has been replaced by arrays of ultraviolet light-emitting diodes (UV-LEDs) is described. The output of the UV-LED source was analyzed by gas chromatography (PAN-GC) and thermal dissociation cavity ring-down spectroscopy (TD-CRDS). Using acetone, diethyl ketone (DIEK), diisopropyl ketone (DIPK), or di-n-propyl ketone (DNPK), respectively, the source produces peroxyacetic (PAN), peroxypropionic (PPN), peroxyisobutanoic (PiBN), or peroxy-n-butanoic nitric anhydride (PnBN) from NO in high yield (> 90%). Box model simulations with a subset of the Master Chemical Mechanism (MCM) were carried out to rationalize products yields and to identify side products. The use of UV-LED arrays offers many advantages over conventional Hg lamp setups, including greater light output over a narrower wavelength range, lower power consumption, and minimal generation of heat.

Mangiferin induces cell death against rhabdomyosarcoma through sustained oxidative stress.

PubMed

Padma, Vishwanadha Vijaya; Kalaiselvi, Palanisamy; Yuvaraj, Rangasamy; Rabeeth, M

2015-06-01

Embryonic rhabdomyosarcoma (RD) is the most prevalent type of cancer among children. The present study aimed to investigate cell death induced by mangiferin in RD cells. The Inhibitory concentration (IC 50 ) value of mangiferin was determined by an MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay. Cell death induced by mangiferin against RD cells was determined through lactate dehydrogenase and nitric oxide release, intracellular calcium levels, reactive oxygen species generation, antioxidant status, mitochondrial calcium level, and mitochondrial membrane potential. Furthermore, acridine orange/ethidium bromide staining was performed to determine early/late apoptotic event. Mangiferin induced cell death in RD cells with an IC 50 value of 70 μM. The cytotoxic effect was reflected in a dose-dependent increase in lactate dehydrogenase leakage and nitric oxide release during mangiferin treatment. Mangiferin caused dose dependent increase in reactive oxygen species generation, intracellular calcium levels with subsequent decrease in antioxidant status (catalase, superoxide dismutase, glutathione-S-transferase, and glutathione) and loss of mitochondrial membrane potential in RD cells. Further data from fluorescence microscopy suggest that mangiferin caused cell shrinkage and nuclear condensation along with the occurrence of a late event of apoptosis. Results of the present study shows that mangiferin can act as a promising chemopreventive agent against RD by inducing sustained oxidative stress.

Smoking, COPD and 3-Nitrotyrosine Levels of Plasma Proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Hongjun; Webb-Robertson, Bobbie-Jo M.; Peterson, Elena S.

BACKGROUND: Nitric oxide is a physiologically regulator of endothelial function and hemodynamics. Oxidized products of nitric oxide can form nitrotyrosine, which is a marker of nitrative stress. Cigarette smoking decreases exhaled nitric oxide, and the underlying mechanism may be important in the cardiovascular toxicity of cigarette smoke, although it is not clear if this effect results from decreased nitric oxide production or oxidation of nitric oxide to reactive, nitrating, species. These processes would be expected to have opposite effects on nitrotyrosine levels, a marker of nitrative stress. OBJECTIVE: In this study, we determine the effects of smoking and chronic obstructivemore » pulmonary disease (COPD) on circulating levels of nitrotyrosine, and thereby gain insight into the processes regulating nitrotyrosine formation. METHODS: A custom antibody microarray platform was used to analyze the levels of 3-nitrotyrosine modifications on 24 proteins in plasma. Plasma samples from 458 individuals were analyzed. RESULTS: Nitrotyrosine levels in circulating proteins were uniformly reduced in smokers but increased in COPD patients. We also observed a persistent suppression of nitrotyrosine in former smokers. CONCLUSIONS: Smoking broadly suppresses the levels of 3-nitrotyrosine in plasma proteins, suggesting that cigarette smoke suppresses endothelial nitric oxide production. In contrast, the increase in nitrotyrosine levels in COPD patients most likely results from inflammatory processes. This study provides the first evidence that smoking has irreversible effects on endothelial production of nitric oxide, and provides insight into how smoking could induce a loss of elasticity in the vasculature and a long-term increase in the risk of cardiovascular disease.« less

Involvement of nitric oxide in anticompulsive-like effect of agmatine on marble-burying behaviour in mice.

PubMed

Gawali, Nitin B; Chowdhury, Amrita A; Kothavade, Pankaj S; Bulani, Vipin D; Nagmoti, Dnyaneshwar M; Juvekar, Archana R

2016-01-05

In view of the reports that nitric oxide modulates the neurotransmitters implicated in obsessive-compulsive disorder (OCD), patients with OCD exhibit higher plasma nitrate levels, and drugs useful in OCD influence nitric oxide. Agmatine is a polyamine and widely distributed in mammalian brain which interacts with nitrergic systems. Hence, the present study was carried out to understand the involvement of nitrergic systems in the anticompulsive-like effect of agmatine. We used marble-burying behaviour (MBB) of mice as the animal model of OCD, and nitric oxide levels in hippocampus (HC) and cortex homogenate were measured. Results revealed that, agmatine (20 and 40mg/kg, i.p) significantly inhibited the MBB. Intraperitoneal administration of nitric oxide enhancers viz. nitric oxide precursor - l-arginine (l-ARG) (400mg/kg and 800mg/kg) increased MBB as well as brain nitrites levels, whereas treatment with N(G)-nitro-l-arginine methyl ester (l-NAME) neuronal nitric oxide synthase inhibitor (30mg/kg and 50mg/kg, i.p.) and 7-nitroindazole (7-NI) (20mg/kg and 40mg/kg) attenuated MBB and nitrites levels in brain. Further, in combination studies, the anticompulsive-like effect of agmatine (20mg/kg, ip) was exacerbated by prior administration of l-ARG (400mg/kg) and conversely l-NAME (15mg/kg) or 7-NI (10.0mg/kg) attenuated OCD-like behaviour with HC and cortex changes in the levels of NO. None of the above treatment had any significant influence on locomotor activity. In conclusion, Agmatine is effective in ameliorating the compulsive-like behaviour in mice which appears to be related to nitric oxide in brain. Copyright © 2015 Elsevier B.V. All rights reserved.

Role of Heat Shock Protein 90 and Endothelial Nitric Oxide Synthase during Early Anesthetic and Ischemic Preconditioning

PubMed Central

Amour, Julien; Brzezinska, Anna K.; Weihrauch, Dorothee; Billstrom, Amie R.; Zielonka, Jacek; Krolikowski, John G.; Bienengraeber, Martin W.; Warltier, David C.; Pratt, Philip F.; Kersten, Judy R.

2009-01-01

Background Nitric oxide is known to be essential for early anesthetic (APC) and ischemic (IPC) preconditioning of myocardium. Heat shock protein 90 (Hsp90) regulates endothelial nitric oxide synthase (eNOS) activity. In this study, we tested the hypothesis that Hsp90-eNOS interactions modulate APC and IPC. Methods Myocardial infarct size was measured in rabbits after coronary occlusion and reperfusion in the absence or presence of preconditioning with 30 min of isoflurane (APC) or 5 min of coronary artery occlusion (IPC), and with or without pre-treatment with geldanamycin or radicicol, two chemically distinct Hsp90 inhibitors, or NG-nitro-L-arginine methylester, a non-specific NOS inhibitor. Isoflurane-dependent nitric oxide production was measured (ozone chemiluminescence) in human coronary artery endothelial cells or mouse cardiomyocytes, in the absence or presence of Hsp90 inhibitors or NG-nitro-L-arginine methylester. Interactions between Hsp90 and eNOS, and eNOS activation were assessed with immunoprecipitation, immunoblotting, and confocal microscopy. Results APC and IPC decreased infarct size (50% and 59%, respectively) and this action was abolished by Hsp90 inhibitors. NG-nitro-L-arginine methylester blocked APC but not IPC. Isoflurane increased nitric oxide production in human coronary artery endothelial cells, concomitantly with an increase in Hsp90-eNOS interaction (immunoprecipitation, immunoblotting, and immunohistochemistry). Pretreatment with Hsp90 inhibitors abolished isoflurane-dependent nitric oxide production and decreased Hsp90-eNOS interactions. Isoflurane did not increase nitric oxide production in mouse cardiomyocytes and eNOS was below the level of detection. Conclusion The results indicate that Hsp90 plays a critical role in mediating APC and IPC through protein-protein interactions, and suggest that endothelial cells are important contributors to nitric oxide-mediated signalling during APC. PMID:19194158

Pharmacology and potential therapeutic applications of nitric oxide-releasing non-steroidal anti-inflammatory and related nitric oxide-donating drugs

PubMed Central

Keeble, J E; Moore, P K

2002-01-01

This review examines the biological significance, therapeutic potential and mechanism(s) of action of a range of nitric oxide-releasing non-steroidal anti-inflammatory drugs (NO-NSAID) and related nitric oxide-releasing donating drugs (NODD). The slow release of nitric oxide (NO) from these compounds leads to subtle changes in the profile of pharmacological activity of the parent, non-steroidal anti-inflammatory drugs (NSAID). For example, compared with NSAID, NO-NSAID cause markedly diminished gastrointestinal toxicity and improved anti-inflammatory and anti-nociceptive efficacy. In addition, nitroparacetamol exhibits hepatoprotection as opposed to the hepatotoxic activity of paracetamol. The possibility that NO-NSAID or NODD may be of therapeutic benefit in a wide variety of disease states including pain and inflammation, thrombosis and restenosis, neurodegenerative diseases of the central nervous system, colitis, cancer, urinary incontinence, liver disease, impotence, bronchial asthma and osteoporosis is discussed. PMID:12237248

NOpiates: Novel Dual Action Neuronal Nitric Oxide Synthase Inhibitors with μ-Opioid Agonist Activity

PubMed Central

2012-01-01

A novel series of benzimidazole designed multiple ligands (DMLs) with activity at the neuronal nitric oxide synthase (nNOS) enzyme and the μ-opioid receptor was developed. Targeting of the structurally dissimilar heme-containing enzyme and the μ-opioid GPCR was predicated on the modulatory role of nitric oxide on μ-opioid receptor function. Structure–activity relationship studies yielded lead compound 24 with excellent nNOS inhibitory activity (IC50 = 0.44 μM), selectivity over both endothelial nitric oxide synthase (10-fold) and inducible nitric oxide synthase (125-fold), and potent μ-opioid binding affinity, Ki = 5.4 nM. The functional activity as measured in the cyclic adenosine monosphospate secondary messenger assay resulted in full agonist activity (EC50 = 0.34 μM). This work represents a novel approach in the development of new analgesics for the treatment of pain. PMID:24900459

NOpiates: Novel Dual Action Neuronal Nitric Oxide Synthase Inhibitors with μ-Opioid Agonist Activity.

PubMed

Renton, Paul; Green, Brenda; Maddaford, Shawn; Rakhit, Suman; Andrews, John S

2012-03-08

A novel series of benzimidazole designed multiple ligands (DMLs) with activity at the neuronal nitric oxide synthase (nNOS) enzyme and the μ-opioid receptor was developed. Targeting of the structurally dissimilar heme-containing enzyme and the μ-opioid GPCR was predicated on the modulatory role of nitric oxide on μ-opioid receptor function. Structure-activity relationship studies yielded lead compound 24 with excellent nNOS inhibitory activity (IC50 = 0.44 μM), selectivity over both endothelial nitric oxide synthase (10-fold) and inducible nitric oxide synthase (125-fold), and potent μ-opioid binding affinity, K i = 5.4 nM. The functional activity as measured in the cyclic adenosine monosphospate secondary messenger assay resulted in full agonist activity (EC50 = 0.34 μM). This work represents a novel approach in the development of new analgesics for the treatment of pain.

Inhaled Nitric Oxide Therapy for Pulmonary Disorders of the Term and Preterm Infant

PubMed Central

Sokol, Gregory M.; Konduri, G. Ganesh; Van Meurs, Krisa P.

2016-01-01

The 21st century began with the FDA approval of inhaled nitric oxide therapy for the treatment of neonatal hypoxic respiratory failure associated with pulmonary hypertension in recognition of the two randomized clinical trials demostrating a significant reduction in the need for extracorporeal support in the term and near-term infant. Inhaled nitric oxide is one of only a few therapeutic agents approved for use through clinical investigations primarily in the neonate. This article provides an overview of the pertinent biology and chemistry of nitric oxide, discusses potential toxicities, and reviews the results of pertinent clinical investigations and large randomized clinical trials including neurodevelopmental follow-up in term and preterm neonates. The clinical investigations conducted by the Eunice Kennedy Shriver NICHD Neonatal Research Network will be discussed and placed in context with other pertinent clinical investigations exploring the efficacy of inhaled nitric oxide therapy in neonatal hypoxic respiratory failure. PMID:27480246

Nitric Oxide Mediates Biofilm Formation and Symbiosis in Silicibacter sp. Strain TrichCH4B.

PubMed

Rao, Minxi; Smith, Brian C; Marletta, Michael A

2015-05-05

Nitric oxide (NO) plays an important signaling role in all domains of life. Many bacteria contain a heme-nitric oxide/oxygen binding (H-NOX) protein that selectively binds NO. These H-NOX proteins often act as sensors that regulate histidine kinase (HK) activity, forming part of a bacterial two-component signaling system that also involves one or more response regulators. In several organisms, NO binding to the H-NOX protein governs bacterial biofilm formation; however, the source of NO exposure for these bacteria is unknown. In mammals, NO is generated by the enzyme nitric oxide synthase (NOS) and signals through binding the H-NOX domain of soluble guanylate cyclase. Recently, several bacterial NOS proteins have also been reported, but the corresponding bacteria do not also encode an H-NOX protein. Here, we report the first characterization of a bacterium that encodes both a NOS and H-NOX, thus resembling the mammalian system capable of both synthesizing and sensing NO. We characterized the NO signaling pathway of the marine alphaproteobacterium Silicibacter sp. strain TrichCH4B, determining that the NOS is activated by an algal symbiont, Trichodesmium erythraeum. NO signaling through a histidine kinase-response regulator two-component signaling pathway results in increased concentrations of cyclic diguanosine monophosphate, a key bacterial second messenger molecule that controls cellular adhesion and biofilm formation. Silicibacter sp. TrichCH4B biofilm formation, activated by T. erythraeum, may be an important mechanism for symbiosis between the two organisms, revealing that NO plays a previously unknown key role in bacterial communication and symbiosis. Bacterial nitric oxide (NO) signaling via heme-nitric oxide/oxygen binding (H-NOX) proteins regulates biofilm formation, playing an important role in protecting bacteria from oxidative stress and other environmental stresses. Biofilms are also an important part of symbiosis, allowing the organism to remain in a nutrient-rich environment. In this study, we show that in Silicibacter sp. strain TrichCH4B, NO mediates symbiosis with the alga Trichodesmium erythraeum, a major marine diazotroph. In addition, Silicibacter sp. TrichCH4B is the first characterized bacteria to harbor both the NOS and H-NOX proteins, making it uniquely capable of both synthesizing and sensing NO, analogous to mammalian NO signaling. Our study expands current understanding of the role of NO in bacterial signaling, providing a novel role for NO in bacterial communication and symbiosis. Copyright © 2015 Rao et al.

The Moraxella catarrhalis nitric oxide reductase is essential for nitric oxide detoxification.

PubMed

Wang, Wei; Kinkel, Traci; Martens-Habbena, Willm; Stahl, David A; Fang, Ferric C; Hansen, Eric J

2011-06-01

Moraxella catarrhalis is a Gram-negative obligate aerobe that is an important cause of human respiratory tract infections. The M. catarrhalis genome encodes a predicted truncated denitrification pathway that reduces nitrate to nitrous oxide. We have previously shown that expression of both the M. catarrhalis aniA (encoding a nitrite reductase) and norB (encoding a putative nitric oxide reductase) genes is repressed by the transcriptional regulator NsrR under aerobic conditions and that M. catarrhalis O35E nsrR mutants are unable to grow in the presence of low concentrations of nitrite (W. Wang, et al., J. Bacteriol. 190:7762-7772, 2008). In this study, we constructed an M. catarrhalis norB mutant and showed that planktonic growth of this mutant is inhibited by low levels of nitrite, whether or not an nsrR mutation is present. To determine the importance of NorB in this truncated denitrification pathway, we analyzed the metabolism of nitrogen oxides by norB, aniA norB, and nsrR norB mutants. We found that norB mutants are unable to reduce nitric oxide and produce little or no nitrous oxide from nitrite. Furthermore, nitric oxide produced from nitrite by the AniA protein is bactericidal for a Moraxella catarrhalis O35E norB mutant but not for wild-type O35E bacteria under aerobic growth conditions in vitro, suggesting that nitric oxide catabolism in M. catarrhalis is accomplished primarily by the norB gene product. Measurement of bacterial protein S-nitrosylation directly implicates nitrosative stress resulting from AniA-dependent nitric oxide formation as a cause of the growth inhibition of norB and nsrR mutants by nitrite.

Polymer-Based Nitric Oxide Therapies: Recent Insights for Biomedical Applications

PubMed Central

Jen, Michele C.; Serrano, María C.; van Lith, Robert

2014-01-01

Since the discovery of nitric oxide (NO) in the 1980s, this cellular messenger has been shown to participate in diverse biological processes such as cardiovascular homeostasis, immune response, wound healing, bone metabolism, and neurotransmission. Its beneficial effects have prompted increased research in the past two decades, with a focus on the development of materials that can locally release NO. However, significant limitations arise when applying these materials to biomedical applications. This Feature Article focuses on the development of NO-releasing and NO-generating polymeric materials (2006–2011) with emphasis on recent in vivo applications. Results are compared and discussed in terms of NO dose, release kinetics, and biological effects, in order to provide a foundation to design and evaluate new NO therapies. PMID:25067935

Nitric Oxide-GAPDH Transcriptional Signaling Mediates Behavioral Actions of Cocaine.

PubMed

Harraz, Maged M; Snyder, Solomon H

2015-01-01

Psychotropic actions of cocaine are generally thought to involve its blockade of monoamine transporters leading to increased synaptic levels of monoamines, especially dopamine. Subsequent intracellular events have been less well characterized. We describe a signaling system wherein lower behavioral stimulant doses of cocaine, as well as higher neurotoxic doses, activate a cascade wherein nitric oxide nitrosylates glyceraldehyde-3-phosphate dehydrogenase (GAPDH) to generate a complex with the ubiquitin-E3-ligase Siah1 which translocates to the nucleus. With lower cocaine doses, nuclear GAPDH augments CREB signaling, while at higher doses p53 signaling is enhanced. The drug CGP3466B very potently blocks GAPDH nitrosylation, hindering both signaling cascades and inhibits both behavioral activating and neurotoxic effects of cocaine. This system affords potentially novel approaches to the therapy of cocaine abuse.

Prospect of nitric oxide as a new fumigant for postharvest pest control

USDA-ARS?s Scientific Manuscript database

Nitric oxide (NO) is a newly discovered fumigant for postharvest pest control. In laboratory tests, complete control was achieved against all insect and mite species tested to date with 0.2% to 5% NO fumigations in 2 h to 48 h at 2 to 25°C depending on species and life stages. Nitric oxide reacts ...

Oleic acid-dependent modulation of Nitric oxide associated 1 protein levels regulates nitric oxide-mediated defense signaling in Arabidopsis

USDA-ARS?s Scientific Manuscript database

The conserved cellular metabolites nitric oxide (NO) and oleic acid (18:1) are well-known regulators of disease physiologies in diverse organism. We show that NO production in plants is regulated via 18:1. Reduction in 18:1 levels, via a genetic mutation in the 18:1-synthesizing gene SUPPRESSOR OF S...

Mycobacterium tuberculosis-Infected Hematopoietic Stem and Progenitor Cells Unable to Express Inducible Nitric Oxide Synthase Propagate Tuberculosis in Mice.

PubMed

Reece, Stephen T; Vogelzang, Alexis; Tornack, Julia; Bauer, Wolfgang; Zedler, Ulrike; Schommer-Leitner, Sandra; Stingl, Georg; Melchers, Fritz; Kaufmann, Stefan H E

2018-04-23

Persistence of Mycobacterium tuberculosis within human bone marrow stem cells has been identified as a potential bacterial niche during latent tuberculosis. Using a murine model of tuberculosis, we show here that bone marrow stem and progenitor cells containing M. tuberculosis propagated tuberculosis when transferred to naive mice, given that both transferred cells and recipient mice were unable to express inducible nitric oxide synthase, which mediates killing of intracellular bacteria via nitric oxide. Our findings suggest that bone marrow stem and progenitor cells containing M. tuberculosis propagate hallmarks of disease if nitric oxide-mediated killing of bacteria is defective.

Effects of plasma nitric oxide levels on platelet activation in single donor apheresis and random donor concentrates.

PubMed

Büyükkağnici, Demet Iren; Ilhan, Osman; Kavas, Güzin Ozelçi; Arslan, Onder; Arat, Mutlu; Dalva, Klara; Ayyildiz, Erol

2007-02-01

P-selectin is an useful marker to determine platelet activation and nitric oxide inhibits platelet activation, secretion, adhesion and aggregation. The aim of this study was to investigate the relationship between nitric oxide and P-selectin values in both single donor apheresis and random donor platelet concentrates. According to the results of this study, we found that the best platelet concentrate is freshly prepared single donor apheresis concentrate and it is important to prevent activation at the beginning of the donation. Nitric oxide, which is synthesized from platelets during the storage period, is not sufficient to prevent platelet activation.

Effect of caffeine coadministration and of nitric oxide synthesis inhibition on the antinociceptive action of ketorolac.

PubMed

López-Muñoz, F J; Castañeda-Hernández, G; Flores-Murrieta, F J; Granados-Soto, V

1996-07-25

The effects of caffeine and nitric oxide synthesis inhibition on the antinociceptive action of ketorolac were assessed using the pain-induced functional impairment model in the rat. Nociception was induced by the intra-articular injection of uric acid. Ketorolac, but not caffeine, produced an antinociceptive effect which was reduced by NG nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthesis. Caffeine coadministration potentiated the ketorolac effect. L-NAME induced a dose-dependent reduction of this potentiation. The results suggest the participation of the L-arginine-nitric oxide-cyclic GMP pathway in the caffeine potentiation of ketorolac-induced antinociception.

Rocuronium Bromide Inhibits Inflammation and Pain by Suppressing Nitric Oxide Production and Enhancing Prostaglandin E2 Synthesis in Endothelial Cells.

PubMed

Baek, Sang Bin; Shin, Mal Soon; Han, Jin Hee; Moon, Sang Woong; Chang, Boksoon; Jeon, Jung Won; Yi, Jae Woo; Chung, Jun Young

2016-12-01

Rocuronium bromide is a nondepolarizing neuromuscular blocking drug and has been used as an adjunct for relaxation or paralysis of the skeletal muscles, facilitation of endotracheal intubation, and improving surgical conditions during general anesthesia. However, intravenous injection of rocuronium bromide induces injection pain or withdrawal movement. The exact mechanism of rocuronium bromide-induced injection pain or withdrawal movement is not yet understood. We investigated whether rocuronium bromide treatment is involved in the induction of inflammation and pain in vascular endothelial cells. For this study, calf pulmonary artery endothelial (CPAE) cells were used, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, nitric oxide detection, and prostaglandin E 2 immunoassay were conducted. Rocuronium bromide treatment inhibited endothelial nitric oxide synthase and suppressed nitric oxide production in CPAE cells. Rocuronium bromide activated cyclooxygenase-2, inducible nitric oxide synthase and increased prostaglandin E 2 synthesis in CPAE cells. Rocuronium bromide induced inflammation and pain in CPAE cells. Suppressing nitric oxide production and enhancing prostaglandin E 2 synthesis might be associated with rocuronium bromide-induced injection pain or withdrawal movement.

Nitric oxide inhibits calpain-mediated proteolysis of talin in skeletal muscle cells

NASA Technical Reports Server (NTRS)

Koh, T. J.; Tidball, J. G.

2000-01-01

We tested the hypothesis that nitric oxide can inhibit cytoskeletal breakdown in skeletal muscle cells by inhibiting calpain cleavage of talin. The nitric oxide donor sodium nitroprusside prevented many of the effects of calcium ionophore on C(2)C(12) muscle cells, including preventing talin proteolysis and release into the cytosol and reducing loss of vinculin, cell detachment, and loss of cellular protein. These results indicate that nitric oxide inhibition of calpain protected the cells from ionophore-induced proteolysis. Calpain inhibitor I and a cell-permeable calpastatin peptide also protected the cells from proteolysis, confirming that ionophore-induced proteolysis was primarily calpain mediated. The activity of m-calpain in a casein zymogram was inhibited by sodium nitroprusside, and this inhibition was reversed by dithiothreitol. Previous incubation with the active site-targeted calpain inhibitor I prevented most of the sodium nitroprusside-induced inhibition of m-calpain activity. These data suggest that nitric oxide inhibited m-calpain activity via S-nitrosylation of the active site cysteine. The results of this study indicate that nitric oxide produced endogenously by skeletal muscle and other cell types has the potential to inhibit m-calpain activity and cytoskeletal proteolysis.

[Effects of soy bean isoflavone on inhibition of benign prostatic hyperplasia and the expressions of NO and NOS of rats].

PubMed

Yang, Aiqing; Ren, Guofeng; Tang, Ling; Jiang, Weiwei

2009-03-01

To explore the inhibitive effect of soybean isoflavone on the prostatic hyperplasia on the expressions of nitric oxid and nitric oxide synthase in the prostatic hyperplasia rats. Subcutaneously injected testosterone propionate were to induce prostate hyperplasia in rats. The changes of prostate wet weight, prostatic index, liver index, the changes of some biochemical indexes in rat prostate tissue in the control and the treatment, the low, moderate, high dose groups of soybean isoflavone groups were observed. The prostate wet weight and prostatic index in all dose groups were merely lower than those in the treatment and the moderate groups were lowest in all dose group. There were no significant differences in liver index, urea nitrogen, glutamic-pyruvic transaminase of each group. Acid phosphatase, prostatic acid phosphatase and lactate dehydrogenase in all dose groups were merely lower than those in the treatment group. Nitric oxide and nitric oxide synthase in all dose groups were merely higher than those in the treatment group. Soybean isoflavone could inhibit prostate hyperplasia and increase the expressions of nitric oxide and nitric oxide synthase in rats.

Clomiphene citrate increases nitric oxide, interleukin-10 and reduces matrix metalloproteinase-9 in women with polycystic ovary syndrome.

PubMed

Sylus, Angel Mercy; Nandeesha, Hanumanthappa; Sridhar, Magadi Gopalakrishna; Chitra, Thyagaraju; Sreenivasulu, Karli

2018-06-08

Matrix metalloproteinase-9, Nitric oxide and inflammation plays a role in the pathogenesis of poly cystic ovary syndrome (PCOS). Even though these parameters are altered in PCOS, the effect of clomiphene citrate on them has not been studied till date. The present study was done to assess the effect of clomiphene citrate on matrix metalloproteinase-9, nitric oxide and interleukin-10 levels in women with PCOS. 72 women diagnosed with PCOS were enrolled in the study. Matrix metalloproteinase-9, nitric oxide and interleukin-10 levels were compared at baseline and after three weeks following Clomiphene citrate treatment. Clomiphene citrate increases both nitric oxide (p = 0.03) and interleukin-10 (p < 0.001) levels and reduces matrix metalloproteinase-9 levels (p < 0.001) in women with PCOS. It also improves the ovulation rate (52.8%) and clinical pregnancy rate (19.4%) in PCOS. Also there was a significant reduction in matrix metalloproteinase-9 levels in both the ovulatory (p < 0.001) and conceived groups (p = 0.024) compared to non ovulatory and non conceived group. There was no difference in nitric oxide and interleukin-10 levels in ovulatory and conceived groups compared to non ovulatory and non conceived group. We conclude that clomiphene citrate increases the levels of nitric oxide and interleukin-10 and decreases the matrix metalloproteinase - 9 levels and improves the ovulation rate and clinical pregnancy rate in PCOS. Copyright © 2018 Elsevier B.V. All rights reserved.

(-)-Epicatechin-induced recovery of mitochondria from simulated diabetes: Potential role of endothelial nitric oxide synthase.

PubMed

Ramírez-Sánchez, Israel; Rodríguez, Alonso; Moreno-Ulloa, Aldo; Ceballos, Guillermo; Villarreal, Francisco

2016-05-01

(-)-Epicatechin increases indicators associated with mitochondrial biogenesis in endothelial cells and myocardium. We investigated endothelial nitric oxide synthase involvement on (-)-epicatechin-induced increases in indicators associated with mitochondrial biogenesis in human coronary artery endothelial cells cultured in normal-glucose and high-glucose media, as well as to restore indicators of cardiac mitochondria from the effects of simulated diabetes. Here, we demonstrate the role of endothelial nitric oxide synthase on (-)-epicatechin-induced increases in mitochondrial proteins, transcription factors and sirtuin 1 under normal-glucose conditions. In simulated diabetes endothelial nitric oxide synthase function, mitochondrial function-associated and biogenesis-associated indicators were adversely impacted by high glucose, effects that were reverted by (-)-epicatechin. As an animal model of type 2 diabetes, 2-month old C57BL/6 mice were fed a high-fat diet for 16 weeks. Fasting and fed blood glucose levels were increased and NO plasma levels decreased. High-fat-diet-fed mice myocardium revealed endothelial nitric oxide synthase dysfunction, reduced mitochondrial activity and markers of mitochondrial biogenesis. The administration of 1 mg/kg (-)-epicatechin for 15 days by oral gavage shifted these endpoints towards control mice values. Results suggest that endothelial nitric oxide synthase mediates (-)-epicatechin-induced increases of indicators associated with mitochondrial biogenesis in endothelial cells. (-)-Epicatechin also counteracts the negative effects that high glucose or simulated type 2 diabetes has on endothelial nitric oxide synthase function. © The Author(s) 2016.

[Fractional exhaled nitric oxide in monitoring and therapeutic management of asthma].

PubMed

Melo, Bruno; Costa, Patrício; Afonso, Ariana; Machado, Vânia; Moreira, Carla; Gonçalves, Augusta; Gonçalves, Jean-Pierre

2014-01-01

Asthma is a chronic respiratory disease characterized by hyper-responsiveness and bronchial inflammation. The bronchial inflammation in these patients can be monitored by measuring the fractional exhaled nitric oxide. This study aims to determine fractional exhaled nitric oxide association with peak expiratory flow and with asthma control inferred by the Global Initiative for Asthma. Observational, analytical and cross-sectional study of children with asthma, 6-12 years-old, followed in the Outpatient Respiratory Pathology of Braga Hospital. Sociodemographic and clinical information were collected through a questionnaire. fractional exhaled nitric oxide and peak expiratory flow were determined by portable analyzer Niox Mino® and flow meter, respectively. The sample is constituted by 101 asthmatic children, 63 (62.4%) of males and 38 (37.6%) females. The mean age of participants in the sample is 9.18 (1.99) years. The logistic regression performed with the cutoff value obtained by ROC curve, revealed that fractional exhaled nitric oxide (b(FENO classes) = 0.85; χ(2)Wald (1) = 8.71; OR = 2.33; p = 0.003) has a statistical significant effect on the probability of changing level of asthma control. The odds ratio of going from "controlled" to "partly controlled/uncontrolled" is 2.33 per each level of fractional exhaled nitric oxide. The probability of an asthmatic children change their level of asthma control, from 'controlled' to 'partly controlled/uncontrolled', taking into account a change in their fractional exhaled nitric oxide level, increases 133%.

Expression of nitric oxide synthase-2 in the lungs decreases airway resistance and responsiveness.

PubMed

Hjoberg, Josephine; Shore, Stephanie; Kobzik, Lester; Okinaga, Shoji; Hallock, Arlene; Vallone, Joseph; Subramaniam, Venkat; De Sanctis, George T; Elias, Jack A; Drazen, Jeffrey M; Silverman, Eric S

2004-07-01

Individuals with asthma have increased levels of nitric oxide in their exhaled air. To explore its role, we have developed a regulatable transgenic mouse capable of overexpressing inducible nitric oxide synthase in a lung-specific fashion. The CC10-rtTA-NOS-2 mouse contains two transgenes, a reverse tetracycline transactivator under the control of the Clara cell protein promoter and the mouse nitric oxide synthase-2 (NOS-2) coding region under control of a tetracycline operator. Addition of doxycycline to the drinking water of CC10-rtTA-NOS-2 mice causes an increase in nitric oxide synthase-2 that is largely confined to the airway epithelium. The fraction of expired nitric oxide increases over the first 24 h from approximately 10 parts per billion to a plateau of approximately 20 parts per billion. There were no obvious differences between CC10-rtTA-NOS-2 mice, with or without doxycycline, and wild-type mice in lung histology, bronchoalveolar protein, total cell count, or count differentials. However, airway resistance was lower in CC10-rtTA-NOS-2 mice with doxycycline than in CC10-rtTA-NOS-2 mice without doxycycline or wild-type mice with doxycycline. Moreover, doxycycline-treated CC10-rtTA-NOS-2 mice were hyporesponsive to methacholine compared with other groups. These data suggest that increased nitric oxide in the airways has no proinflammatory effects per se and may have beneficial effects on pulmonary function.

Migraines Are Correlated with Higher Levels of Nitrate-, Nitrite-, and Nitric Oxide-Reducing Oral Microbes in the American Gut Project Cohort

PubMed Central

Gonzalez, Antonio; Hyde, Embriette; Sangwan, Naseer; Gilbert, Jack A.; Viirre, Erik

2016-01-01

ABSTRACT Nitrates, such as cardiac therapeutics and food additives, are common headache triggers, with nitric oxide playing an important role. Facultative anaerobic bacteria in the oral cavity may contribute migraine-triggering levels of nitric oxide through the salivary nitrate-nitrite-nitric oxide pathway. Using high-throughput sequencing technologies, we detected observable and significantly higher abundances of nitrate, nitrite, and nitric oxide reductase genes in migraineurs versus nonmigraineurs in samples collected from the oral cavity and a slight but significant difference in fecal samples. IMPORTANCE Recent work has demonstrated a potentially symbiotic relationship between oral commensal bacteria and humans through the salivary nitrate-nitrite-nitric oxide pathway (C. Duncan et al., Nat Med 1:546–551, 1995, http://dx.doi.org/10.1038/nm0695-546). Oral nitrate-reducing bacteria contribute physiologically relevant levels of nitrite and nitric oxide to the human host that may have positive downstream effects on cardiovascular health (V. Kapil et al., Free Radic Biol Med 55:93–100, 2013, http://dx.doi.org/10.1016/j.freeradbiomed.2012.11.013). In the work presented here, we used 16S rRNA Illumina sequencing to determine whether a connection exists between oral nitrate-reducing bacteria, nitrates for cardiovascular disease, and migraines, which are a common side effect of nitrate medications (U. Thadani and T. Rodgers, Expert Opin Drug Saf 5:667–674, 2006, http://dx.doi.org/10.1517/14740338.5.5.667). PMID:27822557

Role of nitric oxide in long-term potentiation of the rat medial vestibular nuclei.

PubMed

Grassi, S; Pettorossi, V E

2000-01-01

In rat brainstem slices, we investigated the role of nitric oxide in long-term potentiation induced in the ventral portion of the medial vestibular nuclei by high-frequency stimulation of the primary vestibular afferents. The nitric oxide scavenger [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide ] and the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester were administered before and after induction of potentiation. Both drugs completely prevented long-term potentiation, whereas they did not impede the potentiation build-up, or affect the already established potentiation. These results demonstrate that the induction, but not the maintenance of vestibular long-term potentiation, depends on the synthesis and release into the extracellular medium of nitric oxide. In addition, we analysed the effect of the nitric oxide donor sodium nitroprusside on vestibular responses. Sodium nitroprusside induced long-term potentiation, as evidenced through the field potential enhancement and unit peak latency decrease. This potentiation was impeded by D, L-2-amino-5-phosphonopentanoic acid, and was reduced under blockade of synaptosomal platelet-activating factor receptors by ginkgolide B and group I metabotropic glutamate receptors by (R,S)-1-aminoindan-1, 5-dicarboxylic acid. When reduced, potentiation fully developed following the washout of antagonist, demonstrating an involvement of platelet-activating factor and group I metabotropic glutamate receptors in its full development. Potentiation induced by sodium nitroprusside was also associated with a decrease in the paired-pulse facilitation ratio, which persisted under ginkgolide B, indicating that nitric oxide increases glutamate release independently of platelet-activating factor-mediated presynaptic events. We suggest that nitric oxide, released after the activation of N-methyl-D-aspartate receptors, acts as a retrograde messenger leading to an enhancement of glutamate release to a sufficient level for triggering potentiation. Once the synaptic efficacy has changed, it becomes a long-lasting phenomenon only through a subsequent action of platelet-activating factor.

Neuronal Nitric-Oxide Synthase Deficiency Impairs the Long-Term Memory of Olfactory Fear Learning and Increases Odor Generalization

ERIC Educational Resources Information Center

Pavesi, Eloisa; Heldt, Scott A.; Fletcher, Max L.

2013-01-01

Experience-induced changes associated with odor learning are mediated by a number of signaling molecules, including nitric oxide (NO), which is predominantly synthesized by neuronal nitric oxide synthase (nNOS) in the brain. In the current study, we investigated the role of nNOS in the acquisition and retention of conditioned olfactory fear. Mice…

Measurements of nitric oxide after a nuclear burst

NASA Technical Reports Server (NTRS)

Mcghan, M.; Shaw, A.; Megill, L. R.; Sedlacek, W.; Guthals, P. R.; Fowler, M. M.

1981-01-01

Measurements of ozone and nitric oxide in a nuclear cloud 7 days after the explosion are reported. No measurable increase above ambient density of either ozone or nitric oxide was found. Results from a chemistry model of the cloud do not agree with the measurement unless 'nonstandard' assumptions are made with regard to the operating chemical processes. A number of possible explanations of the results are discussed.

Temporal pattern changes in duodenal protein tyrosine nitration events in response to Eimeria acervulina infection in chickens

USDA-ARS?s Scientific Manuscript database

Intracellular generation of nitric oxide (NO) and superoxide anion (SOA) can result in the formation of 3'-nitrotyrosine proteins (NTp). Nitrated proteins usually are associated with significant perturbation in protein function, apoptosis, and cell death. We undertook the present study to establis...

A MODEL OF TURBULENT DIFFUSION FLAMES AND NITRIC OXIDE GENERATION

EPA Science Inventory

The report describes a new view of mixing and chemical reactions in turbulent fuel jets discharging into air. Review of available fundamental data from jet flames leads to the idea that mixing begins with a large scale, inviscid intertwining of entrained air and fuel throughout t...

Brassica juncea nitric oxide synthase like activity is stimulated by PKC activators and calcium suggesting modulation by PKC-like kinase.

PubMed

Talwar, Pooja Saigal; Gupta, Ravi; Maurya, Arun Kumar; Deswal, Renu

2012-11-01

Nitric oxide (NO) is an important signaling molecule having varied physiological and regulatory roles in biological systems. The fact that nitric oxide synthase (NOS) is responsible for NO generation in animals, prompted major search for a similar enzyme in plants. Arginine dependent NOS like activity (BjNOSla) was detected in Brassica juncea seedlings using oxyhemoglobin and citrulline assays. BjNOSla showed 25% activation by NADPH (0.4 mM) and 40% by calcium (0.4 mM) but the activity was flavin mononucleotide (FMN), flavin dinucleotide (FAD) and calmodulin (CaM) independent. Pharmacological approach using mammalian NOS inhibitors, NBT (300 μM) and l-NAME (5 mM), showed significant inhibition (100% and 67% respectively) supporting that the BjNOSla operates via the oxidative pathway. Most of the BjNOSla activity (80%) was confined to shoot while root showed only 20% activity. Localization studies by NADPH-diaphorase and DAF-2DA staining showed the presence of BjNOSla in guard cells. Kinetic analysis showed positive cooperativity with calcium as reflected by a decreased K(m) (∼13%) and almost two fold increase in V(max). PMA (438 nM), a kinase activator, activated BjNOSla ∼1.9 fold while its inactive analog 4αPDD was ineffective. Calcium and PMA activated the enzyme to ∼3 folds. Interestingly, 1,2-DG6 (2.5 μM) and PS (1 μM) with calcium activated the enzyme activity to ∼7 fold. A significant inhibition of BjNOSla by PKC inhibitors-staurosporine (∼90%) and calphostin-C (∼40%), further supports involvement of PKC-like kinase. The activity was also enhanced by abiotic stress conditions (7-46%). All these findings suggest that BjNOSla generates NO via oxidative pathway and is probably regulated by phosphorylation. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Recommendation of ruthenium source for sludge batch flowsheet studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodham, W.

Included herein is a preliminary analysis of previously-generated data from sludge batches 7a, 7b, 8, and 9 sludge simulant and real-waste testing, performed to recommend a form of ruthenium for future sludge batch simulant testing under the nitric-formic flowsheet. Focus is given to reactions present in the Sludge Receipt and Adjustment Tank cycle, given that this cycle historically produces the most changes in chemical composition during Chemical Process Cell processing. Data is presented and analyzed for several runs performed under the nitric-formic flowsheet, with consideration given to effects on the production of hydrogen gas, nitrous oxide gas, consumption of formate,more » conversion of nitrite to nitrate, and the removal and recovery of mercury during processing. Additionally, a brief discussion is given to the effect of ruthenium source selection under the nitric-glycolic flowsheet. An analysis of data generated from scaled demonstration testing, sludge batch 9 qualification testing, and antifoam degradation testing under the nitric-glycolic flowsheet is presented. Experimental parameters of interest under the nitric-glycolic flowsheet include N2O production, glycolate destruction, conversion of glycolate to formate and oxalate, and the conversion of nitrite to nitrate. To date, the number of real-waste experiments that have been performed under the nitric-glycolic flowsheet is insufficient to provide a complete understanding of the effects of ruthenium source selection in simulant experiments with regard to fidelity to real-waste testing. Therefore, a determination of comparability between the two ruthenium sources as employed under the nitric-glycolic flowsheet is made based on available data in order to inform ruthenium source selection for future testing under the nitric-glycolic flowsheet.« less

NFκB in the Mechanism of Ammonia-Induced Astrocyte Swelling in Culture

PubMed Central

Sinke, A.P.; Jayakumar, A.R.; Panickar, K.S.; Moriyama, M.; Reddy, P.V.B.; Norenberg, M.D.

2008-01-01

Astrocyte swelling and brain edema are major neuropathological findings in the acute form of hepatic encephalopathy (fulminant hepatic failure, FHF), and substantial evidence supports the view that elevated brain ammonia level is an important etiological factor in this condition. Although the mechanism by which ammonia brings about astrocyte swelling remains to be determined, oxidative/nitrosative stress and mitogen-activated protein kinases (MAPKs) have been considered as important elements in this process. One factor known to be activated by both oxidative stress and MAPKs is nuclear factor κB (NFκB), a transcription factor that activates many genes, including inducible nitric oxide synthase (iNOS). Since the product of iNOS, nitric oxide (NO), is known to cause astrocyte swelling, we examined the potential involvement of NFκB in ammonia-induced astrocyte swelling. Western blot analysis of cultured astrocytes showed a significant increase in NFκB nuclear translocation (a measure of NFκB activation) from 12 h to 2 days after treatment with NH4Cl (5 mM). Cultures treated with antioxidants, including superoxide dismutase, catalase and vitamin E, as well as the MAPKs inhibitors SB239063 (an inhibitor of p38-MAPK), and SP600125 (an inhibitor of c-Jun N-terminal kinase, JNK) significantly diminished NFκB activation by ammonia, supporting a role of oxidative stress and MAPKs in NFκB activation. The activation of NFκB was associated with increased iNOS protein expression and NO generation, and these changes were blocked by BAY 11-7082, an inhibitor of NFκB. Additionally, ammonia-induced astrocyte swelling was inhibited by the NFκB inhibitors BAY 11-7082 and SN-50, thereby implicating NFκB in the mechanism of astrocyte swelling. Our studies indicate that cultured astrocytes exposed to ammonia display NFκB activation, which is likely a consequence of oxidative stress and activation of MAPKs. NFκB activation appears to contribute to the mechanism of ammonia-induced astrocyte swelling, apparently through its upregulation of iNOS protein expression and the subsequent generation of nitric oxide. PMID:18662246

Efficient photochemical generation of peroxycarboxylic nitric anhydrides with ultraviolet light-emitting diodes

NASA Astrophysics Data System (ADS)

Rider, N. D.; Taha, Y. M.; Odame-Ankrah, C. A.; Huo, J. A.; Tokarek, T. W.; Cairns, E.; Moussa, S. G.; Liggio, J.; Osthoff, H. D.

2015-07-01

Photochemical sources of peroxycarboxylic nitric anhydrides (PANs) are utilized in many atmospheric measurement techniques for calibration or to deliver an internal standard. Conventionally, such sources rely on phosphor-coated low-pressure mercury (Hg) lamps to generate the UV light necessary to photo-dissociate a dialkyl ketone (usually acetone) in the presence of a calibrated amount of nitric oxide (NO) and oxygen (O2). In this manuscript, a photochemical PAN source in which the Hg lamp has been replaced by arrays of ultraviolet light-emitting diodes (UV-LEDs) is described. The output of the UV-LED source was analyzed by gas chromatography (PAN-GC) and thermal dissociation cavity ring-down spectroscopy (TD-CRDS). Using acetone, diethyl ketone (DIEK), diisopropyl ketone (DIPK), or di-n-propyl ketone (DNPK), respectively, the source produces peroxyacetic (PAN), peroxypropionic (PPN), peroxyisobutanoic (PiBN), or peroxy-n-butanoic nitric anhydride (PnBN) from NO in high yield (> 90 %). Box model simulations with a subset of the Master Chemical Mechanism (MCM) were carried out to rationalize product yields and to identify side products. The present work demonstrates that UV-LED arrays are a viable alternative to current Hg lamp setups.

Analysis of the isoprene chemistry observed during the New England Air Quality Study (NEAQS) 2002 intensive experiment

NASA Astrophysics Data System (ADS)

Roberts, James M.; Marchewka, Mathew; Bertman, Steven B.; Goldan, Paul; Kuster, William; de Gouw, Joost; Warneke, Carsten; Williams, Eric; Lerner, Brian; Murphy, Paul; Apel, Eric; Fehsenfeld, Fred C.

2006-12-01

Isoprene and its first and second generation photochemical products, methyl vinyl ketone (MVK), methacrolein (MACR), and peroxymethacrylic nitric anhydride (MPAN), were measured off the coast of New England during the 2002 New England Air Quality Study (NEAQS) on board the NOAA Research Vessel Ronald H. Brown. The results of these measurements were analyzed using a simple sequential reaction model that has been used previously to examine regional oxidant chemistry. The highest isoprene impact was observed in air masses that had passed over an area of high isoprene emission WSW of Boston. The relative concentrations of isoprene and its first generation products show that the photochemistry is consistently "older" than the isoprene photochemistry observed at continental sites. The sequential reaction model was also applied to the aldehyde-PANs (Peroxycarboxylic nitric anhydride) system, and the resulting PPN (peroxypropionic nitric anhydride)/propanal and PAN (peroxyacetic nitric anhydride)/acetaldehyde relationships were consistent with additional sources of PAN in this environment, e.g., isoprene photochemistry. This isoprene source was estimated to result in approximately 1.6 to 4 times more PAN in this environment relative to that produced from anthropogenic VOCs (volatile organic compounds) alone.

Numerical simulations of the seasonal/latitudinal variations of atomic oxygen and nitric oxide in the lower thermosphere and mesosphere

NASA Technical Reports Server (NTRS)

Rees, D.; Fuller-Rowell, T. J.

1989-01-01

A 2-Dimensional zonally-averaged thermospheric model and the global University College London (UCL) thermospheric model have been used to investigate the seasonal, solar activity and geomagnetic variation of atomic oxygen and nitric oxide. The 2-dimensional model includes detailed oxygen and nitrogen chemistry, with appropriate completion of the energy equation, by adding the thermal infrared cooling by O and NO. This solution includes solar and auroral production of odd nitrogen compounds and metastable species. This model has been used for three investigations; firstly, to study the interactions between atmospheric dynamics and minor species transport and density; secondly, to examine the seasonal variations of atomic oxygen and nitric oxide within the upper mesosphere and thermosphere and their response to solar and geomagnetic activity variations; thirdly, to study the factor of 7 to 8 peak nitric oxide density increase as solar F sub 10.7 cm flux increases from 70 to 240 reported from the Solar Mesospheric Explorer. Auroral production of NO is shown to be the dominant source at high latitudes, generating peak NO densities a factor of 10 greater than typical number densities at low latitudes. At low latitudes, the predicted variation of the peak NO density, near 110 km, with the solar F sub 10.7 cm flux is rather smaller than is observed. This is most likely due to an overestimate of the soft X-ray flux at low solar activity, for times of extremely low support number, as occurred in June 1986. As observed on pressure levels, the variation of O density is small. The global circulation during solstice and periods of elevated geomagnetic activity causes depletion of O in regions of upwelling, and enhancements in regions of downwelling.

Experimental investigation of aerodynamics, combustion, and emissions characteristics within the primary zone of a gas turbine combustor

NASA Astrophysics Data System (ADS)

Elkady, Ahmed M.

2006-04-01

The present work investigates pollutant emissions production, mainly nitric oxides and carbon monoxide, within the primary zone of a highly swirling combustion and methods with which to reduce their formation. A baseline study was executed at different equivalence ratios and different inlet air temperatures. The study was then extended to investigate the effects of utilizing transverse air jets on pollutant emission characteristics at different jet locations, jet mass ratio, and overall equivalence ratio as well as to investigate the jets' overall interactions with the recirculation zone. A Fourier Transform Infrared (FTIR) spectrometer was employed to measure emissions concentrations generated during combustion of Jet-A fuel in a swirl-cup assembly. Laser Doppler Velocimetry (LDV) was employed to investigate the mean flow aerodynamics within the combustor. Particle Image Velocimetry (PIV) was utilized to capture the instantaneous aerodynamic behavior of the non-reacting primary zone. Results illustrate that NOx production is a function of both the recirculation zone and the flame length. At low overall equivalence ratios, the recirculation zone is found to be the main producer of NOx. At near stoichiometric conditions, the post recirculation zone appears to be responsible for the majority of NOx produced. Results reveal the possibility of injecting air into the recirculation zone without altering flame stability to improve emission characteristics. Depending on the jet location and strength, nitric oxides as well as carbon monoxide can be reduced simultaneously. Placing the primary air jet just downstream of the fuel rich recirculation zone can lead to a significant reduction in both nitric oxides and carbon monoxide. In the case of fuel lean recirculation zone, reduction of nitric oxides can occur by placing the jets below the location of maximum radius of the recirculation zone.

microRNAs regulate nitric oxide release from endothelial cells by targeting NOS3.

PubMed

Qin, Ji-Zheng; Wang, Shao-Jie; Xia, Chun

2018-06-13

Endothelial nitric oxide synthase (eNOS) encoded by nitric oxide synthase 3 (NOS3), can generate nitric oxide (NO) which serves as an important deterrent to the pathogenesis of thrombosis by modulating the activation, adhesion and aggregate formation of platelets. Three serum miRNAs (miR-195, miR-532 and miR-582) have been suggested as biomarkers for the diagnosis of deep vein thrombosis (DVT), however their potential roles in DVT is not clear. The effect of miRNAs inhibiting the expression of NOS3 was evaluated in vitro. miR-195, miR-532 and miR-582 mimic, inhibitor, and control miRNAs were transfected into endothelial cells. The roles of miR-195, miR-532 and miR-582 regulating the expression of eNOS were evaluated by real-time quantitative PCR, Western Blotting and luciferase reporter assays. NO release was measured by Griess method. We confirmed NOS3 as a direct target of miR-195 and miR-582, which binds to the 3'-UTR of NOS3 mRNA in endothelial cells. A significantly inverse correlation between these two miRNAs and eNOS expression was detected. NO release from endothelial cells was decreased when the expression level of miR-195 and miR-582 was up-regulated. These findings indicated that miR-195 and miR-582 regulated NO release by targeting 3'-UTR of NOS3 post-transcriptionally in endothelial cells. Therefore, miR-195 and miR-582 might play an important role in maintaining endothelial NO bioavailability and could be a novel target for treatment of thrombotic diseases.

Nitric oxide inhibits ATPase activity and induces resistance to topoisomerase II-poisons in human MCF-7 breast tumor cells.

PubMed

Sinha, Birandra K; Kumar, Ashutosh; Mason, Ronald P

2017-07-01

Topoisomerase poisons are important drugs for the management of human malignancies. Nitric oxide ( • NO), a physiological signaling molecule, induces nitrosylation (or nitrosation) of many cellular proteins containing cysteine thiol groups, altering their cellular functions. Topoisomerases contain several thiol groups which are important for their activity and are also targets for nitrosation by nitric oxide. Here, we have evaluated the roles of • NO/ • NO-derived species in the stability and activity of topo II (α and β) both in vitro and in human MCF-7 breast tumor cells. Furthermore, we have examined the effects of • NO on the ATPase activity of topo II. Treatment of purified topo IIα and β with propylamine propylamine nonoate (PPNO), an NO donor, resulted in inhibition of the catalytic activity of topo II. Furthermore, PPNO significantly inhibited topo II-dependent ATP hydrolysis. • NO-induced inhibition of these topo II (α and β) functions resulted in a decrease in cleavable complex formation in MCF-7 cells in the presence of m-AMSA and XK469 and induced significant resistance to both drugs in MCF-7 cells. PPNO treatment resulted in the nitrosation of the topo II protein in MCF-7 cancer cells and inhibited both catalytic-, and ATPase activities of topo II. Furthermore, PPNO significantly affected the DNA damage and cytotoxicity of m-AMSA and XK469 in MCF-7 tumor cells. As tumors express nitric oxide synthase and generate • NO, inhibition of topo II functions by • NO/ • NO-derived species could render tumors resistant to certain topo II-poisons in the clinic.

Arrest of B16 Melanoma Cells in the Mouse Pulmonary Microcirculation Induces Endothelial Nitric Oxide Synthase-Dependent Nitric Oxide Release that Is Cytotoxic to the Tumor Cells

PubMed Central

Qiu, Hongming; Orr, F.William; Jensen, Derrek; Wang, Hui Helen; McIntosh, Alan R.; Hasinoff, Brian B.; Nance, Dwight M.; Pylypas, Susan; Qi, Ke; Song, Chun; Muschel, Ruth J.; Al-Mehdi, Abu-Bakr

2003-01-01

Metastatic cancer cells seed the lung via blood vessels. Because endothelial cells generate nitric oxide (NO) in response to shear stress, we postulated that the arrest of cancer cells in the pulmonary microcirculation causes the release of NO in the lung. After intravenous injection of B16F1 melanoma cells, pulmonary NO increased sevenfold throughout 20 minutes and approached basal levels by 4 hours. NO induction was blocked by NG-nitro-l-arginine methyl ester (L-NAME) and was not observed in endothelial nitric oxide synthase (eNOS)-deficient mice. NO production, visualized ex vivo with the fluorescent NO probe diaminofluorescein diacetate, increased rapidly at the site of tumor cell arrest, and continued to increase throughout 20 minutes. Arrested tumor cells underwent apoptosis with apoptotic counts more than threefold over baseline at 8 and 48 hours. Neither the NO signals nor increased apoptosis were seen in eNOS knockout mice or mice pretreated with L-NAME. At 48 hours, 83% of the arrested cells had cleared from the lungs of wild-type mice but only ∼55% of the cells cleared from eNOS-deficient or L-NAME pretreated mice. eNOS knockout and L-NAME-treated mice had twofold to fivefold more metastases than wild-type mice, measured by the number of surface nodules or by histomorphometry. We conclude that tumor cell arrest in the pulmonary microcirculation induces eNOS-dependent NO release by the endothelium adjacent to the arrested tumor cells and that NO is one factor that causes tumor cell apoptosis, clearance from the lung, and inhibition of metastasis. PMID:12547699

Mycobacterium tuberculosis-Infected Hematopoietic Stem and Progenitor Cells Unable to Express Inducible Nitric Oxide Synthase Propagate Tuberculosis in Mice

PubMed Central

Reece, Stephen T; Vogelzang, Alexis; Tornack, Julia; Bauer, Wolfgang; Zedler, Ulrike; Schommer-Leitner, Sandra; Stingl, Georg; Melchers, Fritz; Kaufmann, Stefan H E

2018-01-01

Abstract Persistence of Mycobacterium tuberculosis within human bone marrow stem cells has been identified as a potential bacterial niche during latent tuberculosis. Using a murine model of tuberculosis, we show here that bone marrow stem and progenitor cells containing M. tuberculosis propagated tuberculosis when transferred to naive mice, given that both transferred cells and recipient mice were unable to express inducible nitric oxide synthase, which mediates killing of intracellular bacteria via nitric oxide. Our findings suggest that bone marrow stem and progenitor cells containing M. tuberculosis propagate hallmarks of disease if nitric oxide-mediated killing of bacteria is defective. PMID:29471332

Enhanced biogenic emissions of nitric oxide and nitrous oxide following surface biomass burning

Treesearch

Iris C. Anderson; Joel S. Levine; Mark A. Poth; Philip J. Riggan

1988-01-01

Recent measurements indicate significantly enhanced biogenic soil emissions of both nitric oxide (NO) and nitrous oxide (N2O) following surface burning. These enhanced fluxes persisted for at least 6 months following the burn. Simultaneous measurements indicate enhanced levels of...

Nitric oxide enhances development of lateral roots in tomato (Solanum lycopersicum L.) under elevated carbon dioxide.

PubMed

Wang, Huan; Xiao, Wendan; Niu, Yaofang; Jin, Chongwei; Chai, Rushan; Tang, Caixian; Zhang, Yongsong

2013-01-01

Elevated carbon dioxide (CO₂) has been shown to enhance the growth and development of plants, especially of roots. Amongst them, lateral roots play an important role in nutrient uptake, and thus alleviate the nutrient limitation to plant growth under elevated CO₂. This paper examined the mechanism underlying CO₂ elevation-induced lateral root formation in tomato. The endogenous nitric oxide (NO) in roots was detected by the specific probe 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM DA). We suggest that CO₂ elevation-induced NO accumulation was important for lateral root formation. Elevated CO₂ significantly increased the activity of nitric oxide synthase in roots, but not nitrate reductase activity. Moreover, the pharmacological evidence showed that nitric oxide synthase rather than nitrate reductase was responsible for CO₂ elevation-induced NO accumulation. Elevated CO₂ enhanced the activity of nitric oxide synthase and promoted production of NO, which was involved in lateral root formation in tomato under elevated CO₂.

Acute electroacupuncture inhibits nitric oxide synthase expression in the spinal cord of neuropathic rats.

PubMed

Cha, Myeoung Hoon; Bai, Sun Joon; Lee, Kyung Hee; Cho, Zang Hee; Kim, Young-Bo; Lee, Hye-Jung; Lee, Bae Hwan

2010-02-01

To examine the effects of electroacupuncture stimulation on behavioral changes and neuronal nitric oxide synthase expression in the rat spinal cord after nerve injury. Under pentobarbital anesthesia, male Sprague-Dawley rats were subjected to neuropathic surgery by tightly ligating and cutting the left tibial and sural nerves. Behavioral responses to mechanical stimulation were tested for 2 weeks post-operatively. At the end of behavioral testing, electroacupuncture stimulation was applied to ST36 (Choksamni) and SP9 (Eumleungcheon) acupoints. Immunocytochemical staining was performed to investigate changes in the expression of neuronal nitric oxide synthase-immunoreactive neurons in the L4-5 spinal cord. Mechanical allodynia was observed by nerve injury. The mechanical allodynia was decreased after electroacupuncture stimulation. Neuronal nitric oxide synthase expression was also decreased in L4-5 spinal cord by electroacupuncture treatment. These results suggest that electroacupuncture relieves mechanical allodynia in the neuropathic rats possibly by the inhibition of neuronal nitric oxide synthase expression in the spinal cord.

Chemical kinetic models for combustion of hydrocarbons and formation of nitric oxide

NASA Technical Reports Server (NTRS)

Jachimowski, C. J.; Wilson, C. H.

1980-01-01

The formation of nitrogen oxides NOx during combustion of methane, propane, and a jet fuel, JP-4, was investigated in a jet stirred combustor. The results of the experiments were interpreted using reaction models in which the nitric oxide (NO) forming reactions were coupled to the appropriate hydrocarbon combustion reaction mechanisms. Comparison between the experimental data and the model predictions reveals that the CH + N2 reaction process has a significant effect on NO formation especially in stoichiometric and fuel rich mixtures. Reaction models were assembled that predicted nitric oxide levels that were in reasonable agreement with the jet stirred combustor data and with data obtained from a high pressure (5.9 atm (0.6 MPa)), prevaporized, premixed, flame tube type combustor. The results also suggested that the behavior of hydrocarbon mixtures, like JP-4, may not be significantly different from that of pure hydrocarbons. Application of the propane combustion and nitric oxide formation model to the analysis of NOx emission data reported for various aircraft gas turbines showed the contribution of the various nitric oxide forming processes to the total NOx formed.

Process for treating alkaline wastes for vitrification

DOEpatents

Hsu, Chia-lin W.

1995-01-01

A process for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO.sub.2 to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO.sub.2, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product.

Process for treating alkaline wastes for vitrification

DOEpatents

Hsu, C.L.W.

1995-07-25

A process is described for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO{sub 2} to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO{sub 2}, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product. 4 figs.

Peroxisome proliferator-activated receptor-α agonists protect cortical neurons from inflammatory mediators and improve peroxisomal function.

PubMed

Gray, Elizabeth; Ginty, Mark; Kemp, Kevin; Scolding, Neil; Wilkins, Alastair

2011-04-01

Inflammation is known to cause significant neuronal damage and axonal injury in many neurological disorders. Among the range of inflammatory mediators, nitric oxide is a potent neurotoxic agent. Recent evidence has suggested that cellular peroxisomes may be important in protecting neurons from inflammatory damage. To assess the influence of peroxisomal activation on nitric oxide-mediated neurotoxicity, we investigated the effects of the peroxisomal proliferator-activated receptor (PPAR)-α agonist fenofibrate on cortical neurons exposed to a nitric oxide donor or co-cultured with activated microglia. Fenofibrate protected neurons and axons against both nitric oxide donor-induced and microglia-derived nitric oxide-induced toxicity. Moreover, cortical neurons treated with this compound showed a significant increase in gene expression of ABCD3 (the gene encoding for peroxisomal membrane protein-70), with a concomitant increase in protein levels of PPAR-α and catalase, which was associated with a functional increase in the activity of this enzyme. Collectively, these observations provide evidence that modulation of PPAR-α activity and peroxisomal function by fenofibrate attenuates nitric oxide-mediated neuronal and axonal damage, suggesting a new therapeutic approach to protect against neurodegenerative changes associated with neuroinflammation. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Caffeinated nitric oxide-releasing lozenge improves cycling time trial performance.

PubMed

Lee, J; Kim, H T; Solares, G J; Kim, K; Ding, Z; Ivy, J L

2015-02-01

Boosting nitric oxide production during exercise by various means has been found to improve exercise performance. We investigated the effects of a nitric oxide releasing lozenge with added caffeine (70 mg) on oxygen consumption during steady-state exercise and cycling time trial performance using a double-blinded randomized, crossover experimental design. 15 moderately trained cyclists (7 females and 8 males) were randomly assigned to ingest the caffeinated nitric oxide lozenge or placebo 5 min before exercise. Oxygen consumption and blood lactate were assessed at rest and at 50%, 65% and 75% maximal oxygen consumption. Exercise performance was assessed by time to complete a simulated 20.15 km cycling time-trial course. No significant treatment effects for oxygen consumption or blood lactate at rest or during steady-state exercise were observed. However, time-trial performance was improved by 2.1% (p<0.01) when participants consumed the nitric oxide lozenge (2,424±69 s) compared to placebo (2,476±78 s) and without a significant difference in rating of perceived exertion. These results suggest that acute supplementation with a caffeinated nitric oxide releasing lozenge may be a practical and effective means of improving aerobic exercise performance. © Georg Thieme Verlag KG Stuttgart · New York.

Connection between the striatal neurokinin-1 receptor and nitric oxide formation during methamphetamine exposure.

PubMed

Wang, Jing; Xu, Wenjing; Ali, Syed F; Angulo, Jesus A

2008-10-01

Methamphetamine (METH) is a widely used "club drug" that produces neural damage in the brain, including the loss of some neurons. METH-induced striatal neuronal loss has been attenuated by pretreatment with the neurokinin-1 receptor antagonist WIN-51,708 in mice. Using a histologic method, we have observed the internalization of the neurokinin-1 receptor into endosomes in the striatal somatostatin/NPY/nitric oxide synthase interneurons. To investigate the role of this interneuron in the striatal cell death induced by METH, we assessed by immunohistochemistry the number of striatal nitric oxide synthase-positive neurons in the presence of METH at 8 and 16 hours after systemic injection of a bolus of METH (30 mg/kg, i.p.). We found the number of striatal nitric oxide synthase-positive neurons unchanged at these time points after METH. In a separate experiment we measured the levels of striatal 3-nitrotyrosine (3-NT) by HPLC (high-pressure liquid chromatography) as an indirect index of nitric oxide synthesis. METH increased the levels of 3-nitrotyrosine in the striatum and this increase was significantly attenuated by pretreatment with a selective neurokinin-1 receptor antagonist. These observations suggest a causal relationship between the neurokinin-1 receptor and the activation of neuronal nitric oxide synthase that warrants further investigation.

The role of nitric oxide in the reversal of hemorrhagic shock by oxotremorine.

PubMed

Gören, M Z; Akici, A; Karaalp, A; Aker, R; Oktay, S

2001-10-05

In the present study, the effect of the nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methylester (L-NAME), on the antishock actions of oxotremorine was investigated in rats subjected to hemorrhagic shock under urethane anesthesia. L-citrulline production in the AV3V region, as an indicator of nitric oxide (NO) synthesis, was assayed by high-performance liquid chromatography (HPLC) with fluorescent detection throughout the experiment. The rats were pretreated with either intravenous (i.v.) physiological saline or L-NAME (2.5 mg/kg) before bleeding. L-NAME potentiated the reversal of hypotension by oxotremorine (25 microg/kg, i.v.). However, oxotremorine either alone or in combination with L-NAME did not produce any significant change in 60-min survival rate at this low dose. Analysis of microdialysis samples collected from the AV3V region showed that L-citrulline concentration increased during bleeding and that this increase was abolished by L-NAME pretreatment. These results may suggest that nitric oxide production contributes to hypotension in rats bled to shock since nitric oxide levels in the AV3V region increased in response to bleeding and nitric oxide synthase (NOS) inhibition abolished this increase and potentiated the oxotremorine-induced reversal of hypotension.

Direct hydride shift mechanism and stereoselectivity of P450nor confirmed by QM/MM calculations.

PubMed

Krámos, Balázs; Menyhárd, Dóra K; Oláh, Julianna

2012-01-19

Nitric oxide reductase (P450(nor)) found in Fusarium oxysporum catalyzes the reduction of nitric oxide to N(2)O in a multistep process. The reducing agent, NADH, is bound in the distal pocket of the enzyme, and direct hydride transfer occurs from NADH to the nitric oxide bound heme enzyme, forming intermediate I. Here we studied the possibility of hydride transfer from NADH to both the nitrogen and oxygen of the heme-bound nitric oxide, using quantum chemical and combined quantum mechanics/molecular mechanics (QM/MM) calculations, on two different protein models, representing both possible stereochemistries, a syn- and an anti-NADH arrangement. All calculations clearly favor hydride transfer to the nitrogen of nitric oxide, and the QM-only barrier and kinetic isotope effects are good agreement with the experimental values of intermediate I formation. We obtained higher barriers in the QM/MM calculations for both pathways, but hydride transfer to the nitrogen of nitric oxide is still clearly favored. The barriers obtained for the syn, Pro-R conformation of NADH are lower and show significantly less variation than the barriers obtained in the case of anti conformation. The effect of basis set and wide range of functionals on the obtained results are also discussed.

Reciprocal regulation of the nitric oxide and cyclooxygenase pathway in pathophysiology: relevance and clinical implications

PubMed Central

Kim, Sangwon F.; Mollace, Vincenzo

2013-01-01

The nitric oxide (NO) and cyclooxygenase (COX) pathways share a number of similarities. Nitric oxide is the mediator generated from the NO synthase (NOS) pathway, and COX converts arachidonic acid to prostaglandins, prostacyclin, and thromboxane A2. Two major forms of NOS and COX have been identified to date. The constitutive isoforms critically regulate several physiological states. The inducible isoforms are overexpressed during inflammation in a variety of cells, producing large amounts of NO and prostaglandins, which may underlie pathological processes. The cross-talk between the COX and NOS pathways was initially reported by Salvemini and colleagues in 1993, when they demonstrated in a series of in vitro and in vivo studies that NO activates the COX enzymes to produce increased amounts of prostaglandins. Those studies led to the concept that COX enzymes represent important endogenous “receptor” targets for amplifying or modulating the multifaceted roles of NO in physiology and pathology. Since then, numerous studies have furthered our mechanistic understanding of these interactions in pathophysiological settings and delineated potential clinical outcomes. In addition, emerging evidence suggests that the canonical nitroxidative species (NO, superoxide, and/or peroxynitrite) modulate biosynthesis of prostaglandins through non-COX-related pathways. This article provides a comprehensive state-of-the art overview in this area. PMID:23389111

S-nitrosocaptopril nanoparticles as nitric oxide-liberating and transnitrosylating anti-infective technology.

PubMed

Mordorski, Breanne; Pelgrift, Robert; Adler, Brandon; Krausz, Aimee; da Costa Neto, Alexandre Batista; Liang, Hongying; Gunther, Leslie; Clendaniel, Alicea; Harper, Stacey; Friedman, Joel M; Nosanchuk, Joshua D; Nacharaju, Parimala; Friedman, Adam J

2015-02-01

Nitric oxide (NO), an essential agent of the innate immune system, exhibits multi-mechanistic antimicrobial activity. Previously, NO-releasing nanoparticles (NO-np) demonstrated increased antimicrobial activity when combined with glutathione (GSH) due to formation of S-nitrosoglutathione (GSNO), a transnitrosylating agent. To capitalize on this finding, we incorporated the thiol-containing ACE-inhibitor, captopril, with NO-np to form SNO-CAP-np, nanoparticles that both release NO and form S-nitrosocaptopril. In the presence of GSH, SNO-CAP-np demonstrated increased transnitrosylation activity compared to NO-np, as exhibited by increased GSNO formation. Escherichia coli and methicillin-resistant Staphylococcus aureus were highly susceptible to SNO-CAP-np in a dose-dependent fashion, with E. coli being most susceptible, and SNO-CAP-np were nontoxic in zebrafish embryos at translatable concentrations. Given SNO-CAP-np's increased transnitrosylation activity and increased E. coli susceptibility compared to NO-np, transnitrosylation rather than free NO is likely responsible for overcoming E. coli's resistance mechanisms and ultimately killing the pathogen. This team of authors incorporated the thiol-containing ACE-inhibitor, captopril, into a nitric oxide releasing nanoparticle system, generating nanoparticles that both release NO and form S-nitrosocaptopril, with pronounced toxic effects on MRSA and E. coli in the presented model system. Copyright © 2015 Elsevier Inc. All rights reserved.

Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling.

PubMed

Diao, Qian-Nan; Song, Yong-Jun; Shi, Dong-Mei; Qi, Hong-Yan

Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H 2 O 2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato's response to chilling stress.

Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling*#

PubMed Central

Diao, Qian-Nan; Song, Yong-Jun; Shi, Dong-Mei; Qi, Hong-Yan

2016-01-01

Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H2O2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato’s response to chilling stress. PMID:27921397

Inducible nitric oxide synthase evoked nitric oxide counteracts capsaicin-induced airway smooth muscle contraction, but exacerbates plasma extravasation.

PubMed

Li, Ping-Chia; Shaw, Chen-Fu; Kuo, Tin-Fan; Chien, Chiang-Ting

2005-04-18

The contribution of nitric oxide (NO) to capsaicin-evoked airway responses was investigated in rats. The measurement of plasma NO level, airway dynamics, airway smooth muscle electromyogram, and plasma extravasation by India ink and Evans blue leakage technique was adapted. Capsaicin-evoked hypotension, bronchoconstriction, trachea plasma extravasation as well as increases in plasma NO level in a dose-dependent manner. L-732138 (NK1 receptor antagonist) or SR-48968 (NK2 receptor antagonist) pretreatment reduced capsaicin-enhanced hypotension, bronchoconstriction, plasma extravasation, and plasma NO level. N(G)-nitro-L-Arginine methyl ester (L-NAME, 10 mg/kg, i.v.), a non-selective NO synthase (NOS) inhibitor, or aminoguanidine (10 mg/kg, i.v.), a selective inducible NOS (iNOS) inhibitor, reduced capsaicin-induced increases in plasma NO level and protected against capsaicin-induced plasma extravasation, whereas L-arginine (150 mg/kg, i.v.), a NO precursor, enhanced capsaicin-evoked plasma NO level and plasma extravasation. L-Arginine pretreatment ameliorated capsaicin-induced bronchoconstriction, whereas L-NAME and aminoguanidine exaggerated capsaicin-induced bronchoconstriction. In summary, NK1 and NK2 receptors and iNOS play a role in NO formation and on capsaicin-induced bronchoconstriction and plasma extravasation. NO generated by iNOS counteracts tachykinin-mediated bronchoconstriction, but exacerbates tachykinin-mediated plasma extravasation.

Feedback inhibition of nitric oxide synthase activity by nitric oxide.

PubMed Central

Assreuy, J.; Cunha, F. Q.; Liew, F. Y.; Moncada, S.

1993-01-01

1. A murine macrophage cell line, J774, expressed nitric oxide (NO) synthase activity in response to interferon-gamma (IFN-gamma, 10 u ml-1) plus lipopolysaccharide (LPS, 10 ng ml-1). The enzyme activity was first detectable 6 h after incubation, peaked at 12 h and became undetectable after 48 h. 2. The decline in the NO synthase activity was not due to inhibition by stable substances secreted by the cells into the culture supernatant. 3. The decline in the NO synthase activity was significantly slowed down in cells cultured in a low L-arginine medium or with added haemoglobin, suggesting that NO may be involved in a feedback inhibitory mechanism. 4. The addition of NO generators, S-nitroso-acetyl-penicillamine (SNAP) or S-nitroso-glutathione (GSNO) markedly inhibited the NO synthase activity in a dose-dependent manner. The effect of NO on the enzyme was not due to the inhibition of de novo protein synthesis. 5. SNAP directly inhibited the inducible NO synthase extracted from activated J774 cells, as well as the constitutive NO synthase extracted from the rat brain. 6. The enzyme activity of J774 cells was not restored after the removal of SNAP by gel filtration, suggesting that NO inhibits NO synthase irreversibly. PMID:7682140

Ethylene and nitric oxide interact to regulate the magnesium deficiency-induced root hair development in Arabidopsis.

PubMed

Liu, Miao; Liu, Xing Xing; He, Xiao Lin; Liu, Li Juan; Wu, Hao; Tang, Cai Xian; Zhang, Yong Song; Jin, Chong Wei

2017-02-01

Nitric oxide (NO) and ethylene respond to biotic and abiotic stresses through either similar or independent processes. This study examines the mechanism underlying the effects of NO and ethylene on promoting root hair development in Arabidopsis under magnesium (Mg) deficiency. The interaction between NO and ethylene in the regulation of Mg deficiency-induced root hair development was investigated using NO- and ethylene-related mutants and pharmacological methods. Mg deficiency triggered a burst of NO and ethylene, accompanied by a stimulated development of root hairs. Interestingly, ethylene facilitated NO generation by activation of both nitrate reductase and nitric oxide synthase-like (NOS-L) in the roots of Mg-deficient plants. In turn, NO enhanced ethylene synthesis through stimulating the activities of 1-aminocyclopropane-1-carboxylate (ACC) oxidase and ACC synthase (ACS). These two processes constituted an NO-ethylene feedback loop. Blocking either of these two processes inhibited the stimulation of root hair development under Mg deficiency. In conclusion, we suggest that Mg deficiency increases the production of NO and ethylene in roots, each influencing the accumulation and role of the other, and thus these two signals interactively regulate Mg deficiency-induced root hair morphogenesis. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Molecular biological effects of selective neuronal nitric oxide synthase inhibition in ovine lung injury

PubMed Central

Westphal, Martin; Enkhbaatar, Perenlei; Wang, Jianpu; Pazdrak, Konrad; Nakano, Yoshimitsu; Hamahata, Atsumori; Jonkam, Collette C.; Lange, Matthias; Connelly, Rhykka L.; Kulp, Gabriela A.; Cox, Robert A.; Hawkins, Hal K.; Schmalstieg, Frank C.; Horvath, Eszter; Szabo, Csaba; Traber, Lillian D.; Whorton, Elbert; Herndon, David N.; Traber, Daniel L.

2010-01-01

Neuronal nitric oxide synthase is critically involved in the pathogenesis of acute lung injury resulting from combined burn and smoke inhalation injury. We hypothesized that 7-nitroindazole, a selective neuronal nitric oxide synthase inhibitor, blocks central molecular mechanisms involved in the pathophysiology of this double-hit insult. Twenty-five adult ewes were surgically prepared and randomly allocated to 1) an uninjured, untreated sham group (n = 7), 2) an injured control group with no treatment (n = 7), 3) an injury group treated with 7-nitroindazole from 1-h postinjury to the remainder of the 24-h study period (n = 7), or 4) a sham-operated group subjected only to 7-nitroindazole to judge the effects in health. The combination injury was associated with twofold increased activity of neuronal nitric oxide synthase and oxidative/nitrosative stress, as indicated by significant increases in plasma nitrate/nitrite concentrations, 3-nitrotyrosine (an indicator of peroxynitrite formation), and malondialdehyde lung tissue content. The presence of systemic inflammation was evidenced by twofold, sixfold, and threefold increases in poly(ADP-ribose) polymerase, IL-8, and myeloperoxidase lung tissue concentrations, respectively (each P < 0.05 vs. sham). These molecular changes were linked to tissue damage, airway obstruction, and pulmonary shunting with deteriorated gas exchange. 7-Nitroindazole blocked, or at least attenuated, all these pathological changes. Our findings suggest 1) that nitric oxide formation derived from increased neuronal nitric oxide synthase activity represents a pivotal reactive agent in the patho-physiology of combined burn and smoke inhalation injury and 2) that selective neuronal nitric oxide synthase inhibition represents a goal-directed approach to attenuate the degree of injury. PMID:19965980

Nitric Oxide Decreases Acute Kidney Injury and Stage 3 Chronic Kidney Disease after Cardiac Surgery.

PubMed

Lei, Chong; Berra, Lorenzo; Rezoagli, Emanuele; Yu, Binglan; Dong, Hailong; Yu, Shiqiang; Hou, Lihong; Chen, Min; Chen, Wensheng; Wang, Hongbing; Zheng, Qijun; Shen, Jie; Jin, Zhenxiao; Chen, Tao; Zhao, Rong; Christie, Emily; Sabbisetti, Venkata S; Nordio, Francesco; Bonventre, Joseph V; Xiong, Lize; Zapol, Warren M

2018-06-22

No medical intervention has been identified that decreases acute kidney injury and improves renal outcome at 1-year after cardiac surgery. To determine whether administration of nitric oxide reduces the incidence of post-operative acute kidney injury and improves long-term kidney outcomes after multiple cardiac valve replacement requiring prolonged cardiopulmonary bypass. 244 Patients undergoing elective, multiple valve replacement surgery mostly due to rheumatic fever were randomized to receive either nitric oxide (treatment) or nitrogen (control). Nitric oxide and nitrogen were administered via the gas exchanger during cardiopulmonary bypass and by inhalation for 24h post-operatively. Primary outcome: Oxidation of ferrous plasma oxyhemoglobin to ferric methemoglobin was associated to a reduced post-operative acute kidney injury from 64% (control group) to 50% (nitric oxide) (RR, 95% CI; 0.78, 0.62-0.97;P=0.014). At 90-days, transition to stage 3 chronic kidney disease was reduced from 33% in the controls to 21% in the treatment group (RR, 95%CI; 0.64, 0.41 - 0.99;P=0.024); and at 1-year, from 31% to 18% (RR, 95% CI; 0.59, 0.36 - 0.96;P=0.017). Nitric oxide treatment reduced the overall major adverse kidney events at 30-days (RR, 95% CI; 0.40, 0.18 - 0.92;P=0.016, 90-days (RR, 95% CI; 0.40, 0.17 - 0.92;P=0.015 and 1-year (RR, 95% CI; 0.47, 0.20-1.10;P=0.041). In patients undergoing multiple valve replacement and prolonged cardiopulmonary bypass, administration of nitric oxide decreased the incidence of acute kidney injury, transition to stage 3 chronic kidney disease and major adverse kidney events at 30-days, 90-days, and 1-year. Clinical trial registered with ClinicalTrials.gov (NCT01802619).

Circadian variation in the effects of nitric oxide synthase inhibitors on body temperature, feeding and activity in rats.

PubMed

Kamerman, Peter; Mitchell, Duncan; Laburn, Helen

2002-02-01

We have investigated whether there is circadian variation in the effects of nitric oxide synthase inhibitors on body temperature, physical activity and feeding. We used nocturnally active Sprague-Dawley rats, housed at approximately 24 degrees C with a 12:12 h light:dark cycle (lights on 07:00 hours) and provided with food and water ad libitum. Nitric oxide synthesis was inhibited by intraperitoneal injection of the unspecific nitric oxide synthase inhibitor N-nitro- L-arginine methyl ester ( L-NAME, 100, 50, 25, 10 mg/kg), or the relatively selective inducible nitric oxide synthase inhibitor aminoguanidine (100, 50 mg/kg), during the day ( approximately 09:00 hours) or night ( approximately 21:00 hours). Body temperature and physical activity were measured using radiotelemetry, while food intake was calculated by weighing each animal's food before as well as 12 and 24 h after each injection. We found that daytime injection of L-NAME and aminoguanidine had no effect on daytime body temperature. However, daytime injection of both drugs did decrease nocturnal food intake ( P<0.05) and activity ( P<0.05). When injected at night, L-NAME reduced night-time body temperature ( P<0.01), activity ( P<0.05) and food intake ( P<0.05) in a dose-dependent manner, but night-time injection of aminoguanidine inhibited only night-time activity ( P<0.05). The effects of nitric oxide synthase inhibition on body temperature, feeding and activity therefore are primarily a consequence of inhibiting constitutively expressed nitric oxide synthase, and are subject to circadian variation.

Effects of resveratrol-related hydroxystilbenes on the nitric oxide production in macrophage cells: structural requirements and mechanism of action.

PubMed

Cho, Dong-Im; Koo, Na-Youn; Chung, Woon Jae; Kim, Tae-Sung; Ryu, Shi Yong; Im, Suhn Young; Kim, Kyeong-Man

2002-09-13

NF-kappaB that plays an important role in iNOS expression is one of the targets of various potential anti-inflammatory agents including resveratrol. Resveratrol contains a structural similarity with estrogen, and there has been speculation about resveratrol as estrogen agonist. In this study, the mechanism and structural requirements of resveratrol and related hydroxystilbenes for the inhibition of LPS-induced nitric oxide production were studied in macrophage cells (RAW 264.7 and J774) by comparing its effect on LPS-induced NF-kappaB translocation and nitric oxide production, and by considering the possibility of involvement of an estrogen receptor. LPS-induced nitric oxide production was inhibited only when cells were treated with resveratrol prior to stimulation with LPS, suggesting that resveratrol does not affect the enzyme itself. A higher concentration of resveratrol than needed for the inhibition of nitric oxide production was required for the inhibition of NF-kappaB mobilization or iNOS expression. Estrogen and diethylstilbesterol, an estrogen agonist, caused only weak inhibition of nitric oxide production, and the effects of resveratrol were not noticeably blocked by ICI-182780, an estrogen antagonist. Structure-activity analysis of resveratrol and nine hydroxystilbenes suggests that the structural balance between oxygen functional groups on the benzene rings is important for their activity. Our results suggest that resveratrol might act on other cellular targets as well as NF-kappaB at the initial stage of gene expression. Unique structural features of hydroxystilbenes are needed for suppression of nitric oxide production and it is unlikely that estrogen receptor is involved in it.

Quantitative RT-PCR Comparison of the Urea and Nitric Oxide Cycle Gene Transcripts in Adult Human Tissues

PubMed Central

Neill, Meaghan Anne; Aschner, Judy; Barr, Frederick; Summar, Marshall L.

2009-01-01

The urea cycle and nitric oxide cycle play significant roles in complex biochemical and physiologic reactions. These cycles have distinct biochemical goals including the clearance of waste nitrogen; the production of the intermediates ornithine, citrulline, and arginine for the urea cycle; and the production of nitric oxide for the nitric oxide pathway. Despite their disparate functions, the two pathways share two enzymes, argininosuccinic acid synthase and argininosuccinic acid lyase, and a transporter, citrin. Studying the gene expression of these enzymes is paramount in understanding these complex biochemical pathways. Here, we examine the expression of genes involved in the urea cycle and the nitric oxide cycle in a panel of eleven different tissue samples obtained from individual adults without known inborn errors of metabolism. In this study, the pattern of co-expressed enzymes provides a global view of the metabolic activity of the urea and nitric oxide cycles in human tissues. Our results show that these transcripts are differentially expressed in different tissues. The pattern of co-expressed enzymes provides a global view of the metabolic activity of the urea and nitric oxide cycles in human tissues. Using the co-expression profiles, we discovered that the combination of expression of enzyme transcripts as detected in our study, might serve to fulfill specific physiologic function(s) in tissue including urea production/nitrogen removal, arginine/citrulline production, nitric oxide production, and ornithine production. Our study reveals the importance of studying not only the expression profile of an enzyme of interest, but also studying the expression profiles of the other enzymes involved in a particular pathway so as to better understand the context of expression. The tissue patterns we observed highlight the variety of important functions they conduct and provide insight into many of the clinical observations from their disruption. PMID:19345634

Mediated electrochemical oxidation of organic wastes using a Co (III) mediator in a nitric acid based system

DOEpatents

Balazs, G. Bryan; Chiba, Zoher; Lewis, Patricia R.; Nelson, Norvell; Steward, G. Anthony

1999-01-01

An electrochemical cell with a Co(III) mediator and nitric acid electrolyte provides efficient destruction of organic and mixed wastes. The organic waste is concentrated in the anolyte reservoir, where the mediator oxidizes the organics and insoluble transuranic compounds and is regenerated at the anode until the organics are converted to CO.sub.2. The nitric acid is an excellent oxidant that facilitates the destruction of the organic components. The anode is not readily attacked by the nitric acid solution, thus the cell can be used for extended continual operation without electrode replacement.

[Studies on the oxidation reaction of octanol-2 with nitric acid by infrared spectroscopy].

PubMed

Zhang, G; Zhao, G; Wang, Y; Zhang, Q; Zhang, S; Lu, F

1998-04-01

In this paper, the reaction process of oxidation of octanol-2 with nitric acid has been studied by IR spectroscopy. It is found that the main components of non-sapoifiable matter are different in different oxidation degrees. The relation between oxidation products and the amount of nitric acid are investigated,the reaction mechanism has also been studied. Experimental results show that the oxidation process of octanol-2 is as follows: first, octanol-2 is oxidated to octanone-2, or to nitrate, nitrite and nitrile copmpounds, then these compounds are reoxidated to caproic acid in the meantime some by-products, such as valeric, enanthic acids are also found in oxidated products.

Phenotypic Consequences of a Genetic Predisposition to Enhanced Nitric Oxide Signaling.

PubMed

Emdin, Connor A; Khera, Amit V; Klarin, Derek; Natarajan, Pradeep; Zekavat, Seyedeh M; Nomura, Akihiro; Haas, Mary; Aragam, Krishna; Ardissino, Diego; Wilson, James G; Schunkert, Heribert; McPherson, Ruth; Watkins, Hugh; Elosua, Roberto; Bown, Matthew J; Samani, Nilesh J; Baber, Usman; Erdmann, Jeanette; Gormley, Padhraig; Palotie, Aarno; Stitziel, Nathan O; Gupta, Namrata; Danesh, John; Saleheen, Danish; Gabriel, Stacey; Kathiresan, Sekar

2018-01-16

Nitric oxide signaling plays a key role in the regulation of vascular tone and platelet activation. Here, we seek to understand the impact of a genetic predisposition to enhanced nitric oxide signaling on risk for cardiovascular diseases, thus informing the potential utility of pharmacological stimulation of the nitric oxide pathway as a therapeutic strategy. We analyzed the association of common and rare genetic variants in 2 genes that mediate nitric oxide signaling (Nitric Oxide Synthase 3 [ NOS3 ] and Guanylate Cyclase 1, Soluble, Alpha 3 [ GUCY1A3 ]) with a range of human phenotypes. We selected 2 common variants (rs3918226 in NOS3 and rs7692387 in GUCY1A3 ) known to associate with increased NOS3 and GUCY1A3 expression and reduced mean arterial pressure, combined them into a genetic score, and standardized this exposure to a 5 mm Hg reduction in mean arterial pressure. Using individual-level data from 335 464 participants in the UK Biobank and summary association results from 7 large-scale genome-wide association studies, we examined the effect of this nitric oxide signaling score on cardiometabolic and other diseases. We also examined whether rare loss-of-function mutations in NOS3 and GUCY1A3 were associated with coronary heart disease using gene sequencing data from the Myocardial Infarction Genetics Consortium (n=27 815). A genetic predisposition to enhanced nitric oxide signaling was associated with reduced risks of coronary heart disease (odds ratio, 0.37; 95% confidence interval [CI], 0.31-0.45; P =5.5*10 -26 ], peripheral arterial disease (odds ratio 0.42; 95% CI, 0.26-0.68; P =0.0005), and stroke (odds ratio, 0.53; 95% CI, 0.37-0.76; P =0.0006). In a mediation analysis, the effect of the genetic score on decreased coronary heart disease risk extended beyond its effect on blood pressure. Conversely, rare variants that inactivate the NOS3 or GUCY1A3 genes were associated with a 23 mm Hg higher systolic blood pressure (95% CI, 12-34; P =5.6*10 -5 ) and a 3-fold higher risk of coronary heart disease (odds ratio, 3.03; 95% CI, 1.29-7.12; P =0.01). A genetic predisposition to enhanced nitric oxide signaling is associated with reduced risks of coronary heart disease, peripheral arterial disease, and stroke. Pharmacological stimulation of nitric oxide signaling may prove useful in the prevention or treatment of cardiovascular disease. © 2017 American Heart Association, Inc.

Changes in the Antioxidant Systems as Part of the Signaling Pathway Responsible for the Programmed Cell Death Activated by Nitric Oxide and Reactive Oxygen Species in Tobacco Bright-Yellow 2 Cells1

PubMed Central

de Pinto, Maria Concetta; Tommasi, Franca; De Gara, Laura

2002-01-01

Nitric oxide (NO) has been postulated to be required, together with reactive oxygen species (ROS), for the activation of the hypersensitive reaction, a defense response induced in the noncompatible plant-pathogen interaction. However, its involvement in activating programmed cell death (PCD) in plant cells has been questioned. In this paper, the involvement of the cellular antioxidant metabolism in the signal transduction triggered by these bioactive molecules has been investigated. NO and ROS levels were singularly or simultaneously increased in tobacco (Nicotiana tabacum cv Bright-Yellow 2) cells by the addition to the culture medium of NO and/or ROS generators. The individual increase in NO or ROS had different effects on the studied parameters than the simultaneous increase in the two reactive species. NO generation did not cause an increase in phenylalanine ammonia-lyase (PAL) activity or induction of cellular death. It only induced minor changes in ascorbate (ASC) and glutathione (GSH) metabolisms. An increase in ROS induced oxidative stress in the cells, causing an oxidation of the ASC and GSH redox pairs; however, it had no effect on PAL activity and did not induce cell death when it was generated at low concentrations. In contrast, the simultaneous increase of NO and ROS activated a process of death with the typical cytological and biochemical features of hypersensitive PCD and a remarkable rise in PAL activity. Under the simultaneous generation of NO and ROS, the cellular antioxidant capabilities were also suppressed. The involvement of ASC and GSH as part of the transduction pathway leading to PCD is discussed. PMID:12376637

Fluorescent probes for real-time measurement of nitric oxide in living cells.

PubMed

Li, Huili; Wan, Ajun

2015-11-07

Nitric oxide (NO) is an important signaling molecule in biology. Both NO excess and insufficiency have been implicated in numerous physiological and pathological conditions. In order to study the diverse biological roles of NO in cells and tissues, many techniques have been developed for assaying NO. Recently, new generations of fluorescent probes have become indispensible tools for the study of NO biology because of their sensitivity, selectivity, spatiotemporal resolution, and experimental feasibility. Rational application of these probes in the study requires the understanding of the molecular mechanism that the probes are involved in. In this review, we will present an arsenal of fluorescent probes used to detect NO in living cells and animal tissues. We will also discuss the molecular mechanisms, actualities and prospects of fluorescent probes in detecting NO in cell biology.

Sodic alkaline stress mitigation by exogenous melatonin in tomato needs nitric oxide as a downstream signal.

PubMed

Liu, Na; Gong, Biao; Jin, Zhiyong; Wang, Xiufeng; Wei, Min; Yang, Fengjuan; Li, Yan; Shi, Qinghua

2015-08-15

The present study was designed to determine the interactive effect of exogenous melatonin and nitric oxide (NO) on sodic alkaline stress mitigation in tomato seedlings. It was observed that exogenous melatonin treatment elevated NO levels in alkaline-stressed tomato roots. However, exogenous NO had little effects on melatonin levels. Importantly, melatonin-induced NO generation was accompanied by increased tolerance to alkaline stress. Chemical scavenging of NO reduced melatonin-induced alkaline stress tolerance and defense genes' expression. However, inhibition of melatonin biosynthesis had a little effect on NO-induced alkaline stress tolerance. These results strongly suggest that NO, acting as a downstream signal, is involved in the melatonin-induced tomato tolerance to alkaline stress. This process creates a new signaling pathway for improving stress tolerance in plant. Copyright © 2015 Elsevier GmbH. All rights reserved.

Nitric oxide protects carbon assimilation process of watermelon from boron-induced oxidative injury.

PubMed

Farag, Mohamed; Najeeb, Ullah; Yang, Jinghua; Hu, Zhongyuan; Fang, Zhang Ming

2017-02-01

Nitric oxide (NO) mediates plant response to a variety of abiotic stresses; however, limited information is available on its effect on boron (B)-stressed watermelon plants. The present study investigates the mechanism through which NO protects watermelon seedlings from B deficiency and toxicity stresses. Five days old watermelon seedlings were exposed to B (0, 0.5 and 10 mg L -1 ) alone or with 75 μmole of NO donor sodium nitroprusside (SNP) for 30 days. Both low and high B concentrations in the media altered nutrient accumulation and impaired various physiological processes of watermelon seedlings, leading to a significant reduction in biomass production. The plants exposed to B deficient or toxic concentrations had 66 and 69% lower shoot dry weight, respectively compared with optimum B levels. B toxicity-induced growth inhibition of watermelon seedlings was associated with high B translocation to shoot tissues, which caused lipid membrane peroxidation (12% increase) and chlorophyll destruction (25% reduction). In contrast, B deficiency accelerated generation of reactive oxygen species (ROS), specifically OH -1 and induced cellular oxidative injury. Exogenously applied SNP promoted leaf chlorophyll, photosynthesis and consequently biomass production in B-stressed watermelon seedlings by reducing B accumulation, lipid membrane peroxidation and ROS generation. It also activated antioxidant enzymes such as SOD, POD and APX, and protected the seedlings from ROS-induced cellular burst. Copyright © 2016. Published by Elsevier Masson SAS.

Cytotoxicity of citral against melanoma cells: The involvement of oxidative stress generation and cell growth protein reduction.

PubMed

Sanches, Larissa Juliani; Marinello, Poliana Camila; Panis, Carolina; Fagundes, Tatiane Renata; Morgado-Díaz, José Andrés; de-Freitas-Junior, Julio Cesar Madureira; Cecchini, Rubens; Cecchini, Alessandra Lourenço; Luiz, Rodrigo Cabral

2017-03-01

Citral is a natural compound that has shown cytotoxic and antiproliferative effects on breast and hematopoietic cancer cells; however, there are few studies on melanoma cells. Oxidative stress is known to be involved in all stages of melanoma development and is able to modulate intracellular pathways related to cellular proliferation and death. In this study, we hypothesize that citral exerts its cytotoxic effect on melanoma cells by the modulation of cellular oxidative status and/or intracellular signaling. To test this hypothesis, we investigated the antiproliferative and cytotoxic effects of citral on B16F10 murine melanoma cells evaluating its effects on cellular oxidative stress, DNA damage, cell death, and important signaling pathways, as these pathways, namely, extracellular signal-regulated kinases 1/2 (ERK1/2), AKT, and phosphatidylinositol-3 kinase, are involved in cell proliferation and differentiation. The p53 and nuclear factor kappa B were also investigated due to their ability to respond to intracellular stress. We observed that citral exerted antiproliferative and cytotoxic effects in B16F10; induced oxidative stress, DNA lesions, and p53 nuclear translocation; and reduced nitric oxide levels and nuclear factor kappa B, ERK1/2, and AKT. To investigate citral specificity, we used non-neoplastic human and murine cells, HaCaT (human skin keratinocytes) and NIH-3T3 cells (murine fibroblasts), and observed that although citral effects were not specific for cancer cells, non-neoplastic cells were more resistant to citral than B16F10. These findings highlight the potential clinical utility of citral in melanoma, with a mechanism of action involving the oxidative stress generation, nitric oxide depletion, and interference in signaling pathways related to cell proliferation.

Detection of Nitric Oxide by Electron Paramagnetic Resonance Spectroscopy

PubMed Central

Hogg, Neil

2010-01-01

Electron paramagnetic resonance (EPR) spectroscopy has been used in a number of ways to study nitric oxide chemistry and biology. As an intrinsically stable and relatively unreactive diatomic free radical, the challenges for detecting this species by EPR are somewhat different than those for transient radical species. This review gives a basic introduction to EPR spectroscopy and discusses its uses to assess and quantify nitric oxide formation in biological systems. PMID:20304044

Role of nitric oxide in progression and regression of atherosclerosis.

PubMed Central

Cooke, J P

1996-01-01

Endothelium-derived nitric oxide is a potent endogenous vasodilator that is derived from the metabolism of L-arginine. This endothelial factor inhibits circulating blood elements from interacting with the vessel wall. Platelet adherence and aggregation as well as monocyte adherence and infiltration are opposed by this paracrine substance. By virtue of these characteristics, endothelium-derived nitric oxide inhibits atherogenesis in animal models and may even induce regression. Images Figure 1. PMID:8686299

Investigation on Quantitative Structure Activity Relationships of a Series of Inducible Nitric Oxide.

PubMed

Sharma, Mukesh C; Sharma, S

2016-12-01

A series of 2-dihydro-4-quinazolin with potent highly selective inhibitors of inducible nitric oxide synthase activities was subjected to quantitative structure activity relationships (QSAR) analysis. Statistically significant equations with high correlation coefficient (r 2  = 0.8219) were developed. The k-nearest neighbor model has showed good cross-validated correlation coefficient and external validation values of 0.7866 and 0.7133, respectively. The selected electrostatic field descriptors the presence of blue ball around R1 and R4 in the quinazolinamine moiety showed electronegative groups favorable for nitric oxide synthase activity. The QSAR models may lead to the structural requirements of inducible nitric oxide compounds and help in the design of new compounds.

[State of mitochondrial respiration and calcium capacity in livers of rats with different resistance to hypoxia after injections of L-arginine].

PubMed

Kurhaliuk, N M

2001-01-01

In experiments on rats with different resistance to hypoxia are investigated processes of mitochondrial respiration, oxidative phosphorylation and calcium capacity in liver under precursor nitric oxide L-arginine (600 mg/kg) and blockator nitric oxide synthase L-NNA (35 mg/kg) injections. We are used next substrates of oxidation: 0.35 mM succinate, 1 mM alpha-ketoglutarate, 1 mM alpha-ketoglutarate and 2 mM malonic acid. Increasing of ADP-stimulation respiration states under exogenous L-arginine injection, decreasing efficacy of respiration processes (respiration control on Chance and ADP/O) under such substrates oxidation, testify to oxide energy support decreasing and reversing nitric oxide inhibit in such conditions. This will be used as mechanism cell regulation succinate dehydrogenase activity. It has shown that L-arginine injection increase calcium mitochondrial capacity low resistance to hypoxia rats using substrates of oxidation succinate and alpha-ketoglutarate to control meanings of high resistance rats. Effects of nitric oxide precursor influence on this processes limit NO-synthase inhibitor L-NNA.

Phosphine polymerization by nitric oxide: experimental characterization and theoretical predictions of mechanism.

PubMed

Zhao, Yi-Lei; Flora, Jason W; Thweatt, William David; Garrison, Stephen L; Gonzalez, Carlos; Houk, K N; Marquez, Manuel

2009-02-02

A yellow solid material [P(x)H(y)] has been obtained in the reaction of phosphine (PH(3)) and nitric oxide (NO) at room temperature and characterized by thermogravimetric analysis mass spectrometry (TGA-MS) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. In this work using complete basis set (CBS-QB3) methods a plausible mechanism has been investigated for phosphine polymerization in the presence of nitric oxide (NO). Theoretical explorations with the ab initio method suggest (a) instead of the monomer the nitric oxide dimer acts as an initial oxidant, (b) the resulting phosphine oxides (H(3)P=O <--> H(3)P(+)O(-)) in the gas phase draw each other via strong dipolar interactions between the P-O groups, and (c) consequently an autocatalyzed polymerization occurs among the phosphine oxides, forming P-P chemical bonds and losing water. The possible structures of polyhydride phosphorus polymer were discussed. In the calculations a series of cluster models was computed to simulate polymerization.

Nitric oxide negatively regulates mammalian adult neurogenesis

NASA Astrophysics Data System (ADS)

Packer, Michael A.; Stasiv, Yuri; Benraiss, Abdellatif; Chmielnicki, Eva; Grinberg, Alexander; Westphal, Heiner; Goldman, Steven A.; Enikolopov, Grigori

2003-08-01

Neural progenitor cells are widespread throughout the adult central nervous system but only give rise to neurons in specific loci. Negative regulators of neurogenesis have therefore been postulated, but none have yet been identified as subserving a significant role in the adult brain. Here we report that nitric oxide (NO) acts as an important negative regulator of cell proliferation in the adult mammalian brain. We used two independent approaches to examine the function of NO in adult neurogenesis. In a pharmacological approach, we suppressed NO production in the rat brain by intraventricular infusion of an NO synthase inhibitor. In a genetic approach, we generated a null mutant neuronal NO synthase knockout mouse line by targeting the exon encoding active center of the enzyme. In both models, the number of new cells generated in neurogenic areas of the adult brain, the olfactory subependyma and the dentate gyrus, was strongly augmented, which indicates that division of neural stem cells in the adult brain is controlled by NO and suggests a strategy for enhancing neurogenesis in the adult central nervous system.

Nitric Oxide Protects against Infection-Induced Neuroinflammation by Preserving the Stability of the Blood-Brain Barrier

PubMed Central

Olivera, Gabriela C.; Ren, Xiaoyuan; Vodnala, Suman K.; Lu, Jun; Coppo, Lucia; Leepiyasakulchai, Chaniya; Holmgren, Arne; Kristensson, Krister; Rottenberg, Martin E.

2016-01-01

Nitric oxide (NO) generated by inducible NO synthase (iNOS) is critical for defense against intracellular pathogens but may mediate inflammatory tissue damage. To elucidate the role of iNOS in neuroinflammation, infections with encephalitogenic Trypanosoma brucei parasites were compared in inos -/- and wild-type mice. Inos -/- mice showed enhanced brain invasion by parasites and T cells, and elevated protein permeability of cerebral vessels, but similar parasitemia levels. Trypanosome infection stimulated T cell- and TNF-mediated iNOS expression in perivascular macrophages. NO nitrosylated and inactivated pro-inflammatory molecules such as NF-κΒp65, and reduced TNF expression and signalling. iNOS-derived NO hampered both TNF- and T cell-mediated parasite brain invasion. In inos -/- mice, TNF stimulated MMP, including MMP9 activity that increased cerebral vessel permeability. Thus, iNOS-generated NO by perivascular macrophages, strategically located at sites of leukocyte brain penetration, can serve as a negative feed-back regulator that prevents unlimited influx of inflammatory cells by restoring the integrity of the blood-brain barrier. PMID:26915097

Insulin regulates its own delivery to skeletal muscle by feed-forward actions on the vasculature

PubMed Central

Wang, Hong; Upchurch, Charles T.; Liu, Zhenqi

2011-01-01

Insulin, at physiological concentrations, regulates the volume of microvasculature perfused within skeletal and cardiac muscle. It can also, by relaxing the larger resistance vessels, increase total muscle blood flow. Both of these effects require endothelial cell nitric oxide generation and smooth muscle cell relaxation, and each could increase delivery of insulin and nutrients to muscle. The capillary microvasculature possesses the greatest endothelial surface area of the body. Yet, whether insulin acts on the capillary endothelial cell is not known. Here, we review insulin's actions at each of three levels of the arterial vasculature as well as recent data suggesting that insulin can regulate a vesicular transport system within the endothelial cell. This latter action, if it occurs at the capillary level, could enhance insulin delivery to muscle interstitium and thereby complement insulin's actions on arteriolar endothelium to increase insulin delivery. We also review work that suggests that this action of insulin on vesicle transport depends on endothelial cell nitric oxide generation and that insulin's ability to regulate this vesicular transport system is impaired by inflammatory cytokines that provoke insulin resistance. PMID:21610226

Neutrophil microparticle production and inflammasome activation by hyperglycemia due to cytoskeletal instability.

PubMed

Thom, Stephen R; Bhopale, Veena M; Yu, Kevin; Huang, Weiliang; Kane, Maureen A; Margolis, David J

2017-11-03

Microparticles are lipid bilayer-enclosed vesicles produced by cells under oxidative stress. MP production is elevated in patients with diabetes, but the underlying cellular mechanisms are poorly understood. We hypothesized that raising glucose above the physiological level of 5.5 mm would stimulate leukocytes to produce MPs and activate the nucleotide-binding domain, leucine-rich repeat pyrin domain-containing 3 (NLRP3) inflammasome. We found that when incubated in buffer with up to 20 mm glucose, human and murine neutrophils, but not monocytes, generate progressively more MPs with high interleukin (IL)-1β content. Enhanced MP production required generation of reactive chemical species by mitochondria, NADPH oxidase, and type 2 nitric-oxide synthase (NOS-2) and resulted in S -nitrosylation of actin. Depleting cells of capon (C-terminal PDZ ligand of neuronal nitric-oxide synthase protein), apoptosis-associated speck-like protein containing C-terminal caspase recruitment domain (ASC), or pro-IL-1β prevented the hyperglycemia-induced enhancement of reactive species production, MP generation, and IL-1β synthesis. Additional components required for these responses included inositol 1,3,5-triphosphate receptors, PKC, and enhancement of filamentous-actin turnover. Numerous proteins become localized to short filamentous actin in response to S -nitrosylation, including vasodilator-stimulated phosphoprotein, focal adhesion kinase, the membrane phospholipid translocation enzymes flippase and floppase, capon, NLRP3, and ASC. We conclude that an interdependent oxidative stress response to hyperglycemia perturbs neutrophil cytoskeletal stability leading to MP production and IL-1β synthesis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

JS-K, a Nitric Oxide Prodrug, Has Enhanced Cytotoxicity in Colon Cancer Cells with Knockdown of Thioredoxin Reductase 1

PubMed Central

Edes, Kornelia; Cassidy, Pamela; Shami, Paul J.; Moos, Philip J.

2010-01-01

Background The selenoenzyme thioredoxin reductase 1 has a complex role relating to cell growth. It is induced as a component of the cellular response to potentially mutagenic oxidants, but also appears to provide growth advantages to transformed cells by inhibiting apoptosis. In addition, selenocysteine-deficient or alkylated forms of thioredoxin reductase 1 have also demonstrated oxidative, pro-apoptotic activity. Therefore, a greater understanding of the role of thioredoxin reductase in redox initiated apoptotic processes is warranted. Methodology The role of thioredoxin reductase 1 in RKO cells was evaluated by attenuating endogenous thioredoxin reductase 1 expression with siRNA and then either inducing a selenium-deficient thioredoxin reductase or treatment with distinct redox challenges including, hydrogen peroxide, an oxidized lipid, 4-hydroxy-2-nonenol, and a nitric oxide donating prodrug. Thioredoxin redox status, cellular viability, and effector caspase activity were measured. Conclusions/Significance In cells with attenuated endogenous thioredoxin reductase 1, a stably integrated selenocysteine-deficient form of the enzyme was induced but did not alter either the thioredoxin redox status or the cellular growth kinetics. The oxidized lipid and the nitric oxide donor demonstrated enhanced cytotoxicity when thioredoxin reductase 1 was knocked-down; however, the effect was more pronounced with the nitric oxide prodrug. These results are consistent with the hypothesis that attenuation of the thioredoxin-system can promote apoptosis in a nitric oxide-dependent manner. PMID:20098717

Signalling pathway involved in nitric oxide synthase type II activation in chondrocytes: synergistic effect of leptin with interleukin-1

PubMed Central

Otero, Miguel; Lago, Rocío; Lago, Francisca; Reino, Juan Jesús Gomez; Gualillo, Oreste

2005-01-01

The objective of the present study was to investigate the effect of leptin, alone or in combination with IL-1, on nitric oxide synthase (NOS) type II activity in vitro in human primary chondrocytes, in the mouse chondrogenic ATDC5 cell line, and in mature and hypertrophic ATDC5 differentiated chondrocytes. For completeness, we also investigated the signalling pathway of the putative synergism between leptin and IL-1. For this purpose, nitric oxide production was evaluated using the Griess colorimetric reaction in culture medium of cells stimulated over 48 hours with leptin (800 nmol/l) and IL-1 (0.025 ng/ml), alone or combined. Specific pharmacological inhibitors of NOS type II (aminoguanidine [1 mmol/l]), janus kinase (JAK)2 (tyrphostin AG490 and Tkip), phosphatidylinositol 3-kinase (PI3K; wortmannin [1, 2.5, 5 and 10 μmol/l] and LY294002 [1, 2.5, 5 and 10 μmol/l]), mitogen-activated protein kinase kinase (MEK)1 (PD098059 [1, 5, 10, 20 and 30 μmol/l]) and p38 kinase (SB203580 [1, 5, 10, 20 and 30 μmol/l]) were added 1 hour before stimulation. Nitric oxide synthase type II mRNA expression in ATDC5 chondrocytes was investigated by real-time PCR and NOS II protein expression was analyzed by western blot. Our results indicate that stimulation of chondrocytes with IL-1 results in dose-dependent nitric oxide production. In contrast, leptin alone was unable to induce nitric oxide production or expression of NOS type II mRNA or its protein. However, co-stimulation with leptin and IL-1 resulted in a net increase in nitric oxide concentration over IL-1 challenge that was eliminated by pretreatment with the NOS II specific inhibitor aminoguanidine. Pretreatment with tyrphostin AG490 and Tkip (a SOCS-1 mimetic peptide that inhibits JAK2) blocked nitric oxide production induced by leptin/IL-1. Finally, wortmannin, LY294002, PD098059 and SB203580 significantly decreased nitric oxide production. These findings were confirmed in mature and hypertrophic ATDC5 chondrocytes, and in human primary chondrocytes. This study indicates that leptin plays a proinflammatory role, in synergy with IL-1, by inducing NOS type II through a signalling pathway that involves JAK2, PI3K, MEK-1 and p38 kinase. PMID:15899045

Influence of elastin-derived peptides, glucose, LDL and oxLDL on nitric oxide synthase expression in human umbilical artery endothelial cells.

PubMed

Garczorz, Wojciech; Francuz, Tomasz; Gmiński, Jan; Likus, Wirginia; Siemianowicz, Krzysztof; Jurczak, Teresa; Strzałka-Mrozik, Barbara

2011-01-01

Endothelial dysfunction plays an important role in the development of atherosclerosis. Elastin-derived peptides (EDP), hyperglycemia, hypercholesterolemia and oxidized LDL have a proven proatherosclerotic potential. Nitric oxide generated by endothelial nitric oxide synthase (eNOS; EC 1.14.13.39) is an important vasorelaxant. Here we studied the influence of those proatherosclerotic factors on eNOS gene and protein expression in artery-derived endothelial cells. Human umbilical artery endothelial cells (HUAEC) were incubated with or without: glucose (270 mg/dl), LDL (200 mg/dl), oxidized LDL (oxLDL 25 mg/dl) or κ-elastin (0.5 and 2.5 µg/ml). Gene expression was assessed by real time RT-PCR, whilst the eNOS protein by ELISA. In cells incubated with 2.5 µg/ml of κ-elastin, a 31 % increase of eNOS mRNA expression was observed, but the protein level remained unchanged. OxLDL, LDL and glucose decreased the eNOS protein level by 74 %, 37 % and 29 %, respectively. OxLDL decreased eNOS mRNA by 42 %. LDL non-significantly decreased eNOS mRNA expression. An elevated glucose level did not affect the eNOS mRNA expression. Hyperglycemia and an elevated level of LDL, particularly oxLDL, decreased the level of eNOS protein in endothelial cells. As κ-elastin did not decrease the expression of eNOS gene in HUAEC, the proatherogenic properties of elastin-derived peptides are unlikely to be due to their influence on eNOS.

Structure and Reactivity of a Thermostable Prokaryotic Nitric-oxide Synthase That Forms a Long-lived Oxy-Heme Complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sudhamsu,J.; Crane, B.

2006-01-01

In an effort to generate more stable reaction intermediates involved in substrate oxidation by nitric-oxide synthases (NOSs), we have cloned, expressed, and characterized a thermostable NOS homolog from the thermophilic bacterium Geobacillus stearothermophilus (gsNOS). As expected, gsNOS forms nitric oxide (NO) from L-arginine via the stable intermediate N-hydroxy L-arginine (NOHA). The addition of oxygen to ferrous gsNOS results in long-lived heme-oxy complexes in the presence (Soret peak 427 nm) and absence (Soret peak 413 nm) of substrates L-arginine and NOHA. The substrate-induced red shift correlates with hydrogen bonding between substrate and heme-bound oxygen resulting in conversion to a ferric heme-superoxymore » species. In single turnover experiments with NOHA, NO forms only in the presence of H4B. The crystal structure of gsNOS at 3.2 A Angstroms of resolution reveals great similarity to other known bacterial NOS structures, with the exception of differences in the distal heme pocket, close to the oxygen binding site. In particular, a Lys-356 (Bacillus subtilis NOS) to Arg-365 (gsNOS) substitution alters the conformation of a conserved Asp carboxylate, resulting in movement of an Ile residue toward the heme. Thus, a more constrained heme pocket may slow ligand dissociation and increase the lifetime of heme-bound oxygen to seconds at 4 degC. Similarly, the ferric-heme NO complex is also stabilized in gsNOS. The slow kinetics of gsNOS offer promise for studying downstream intermediates involved in substrate oxidation.« less

Rapid cycling of reactive nitrogen in the marine boundary layer.

PubMed

Ye, Chunxiang; Zhou, Xianliang; Pu, Dennis; Stutz, Jochen; Festa, James; Spolaor, Max; Tsai, Catalina; Cantrell, Christopher; Mauldin, Roy L; Campos, Teresa; Weinheimer, Andrew; Hornbrook, Rebecca S; Apel, Eric C; Guenther, Alex; Kaser, Lisa; Yuan, Bin; Karl, Thomas; Haggerty, Julie; Hall, Samuel; Ullmann, Kirk; Smith, James N; Ortega, John; Knote, Christoph

2016-04-28

Nitrogen oxides are essential for the formation of secondary atmospheric aerosols and of atmospheric oxidants such as ozone and the hydroxyl radical, which controls the self-cleansing capacity of the atmosphere. Nitric acid, a major oxidation product of nitrogen oxides, has traditionally been considered to be a permanent sink of nitrogen oxides. However, model studies predict higher ratios of nitric acid to nitrogen oxides in the troposphere than are observed. A 'renoxification' process that recycles nitric acid into nitrogen oxides has been proposed to reconcile observations with model studies, but the mechanisms responsible for this process remain uncertain. Here we present data from an aircraft measurement campaign over the North Atlantic Ocean and find evidence for rapid recycling of nitric acid to nitrous acid and nitrogen oxides in the clean marine boundary layer via particulate nitrate photolysis. Laboratory experiments further demonstrate the photolysis of particulate nitrate collected on filters at a rate more than two orders of magnitude greater than that of gaseous nitric acid, with nitrous acid as the main product. Box model calculations based on the Master Chemical Mechanism suggest that particulate nitrate photolysis mainly sustains the observed levels of nitrous acid and nitrogen oxides at midday under typical marine boundary layer conditions. Given that oceans account for more than 70 per cent of Earth's surface, we propose that particulate nitrate photolysis could be a substantial tropospheric nitrogen oxide source. Recycling of nitrogen oxides in remote oceanic regions with minimal direct nitrogen oxide emissions could increase the formation of tropospheric oxidants and secondary atmospheric aerosols on a global scale.

Process for combined control of mercury and nitric oxide.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Livengood, C. D.; Mendelsohn, M. H.

Continuing concern about the effects of mercury in the environment may lead to requirements for the control of mercury emissions from coal-fired power plants. If such controls are mandated, the use of existing flue-gas cleanup systems, such as wet scrubbers currently employed for flue-gas desulfurization, would be desirable, Such scrubbers have been shown to be effective for capturing oxidized forms of mercury, but cannot capture the very insoluble elemental mercury (Hg{sup 0}) that can form a significant fraction of the total emissions. At Argonne National Laboratory, we have proposed and tested a concept for enhancing removal of Hg{sup 0}, as well as nitric oxide, through introduction of an oxidizing agent into the flue gas upstream of a scrubber, which readily absorbs the soluble reaction products. Recently, we developed a new method for introducing the oxidizing agent into the flue-gas stream that dramatically improved reactant utilization. The oxidizing agent employed was NOXSORB{trademark}, which is a commercial product containing chloric acid and sodium chlorate. When a dilute solution of this agent was introduced into a gas stream containing Hg{sup 0} and other typical flue-gas species at 300 F, we found that about 100% of the mercury was removed from the gas phase and recovered in process liquids. At the same time, approximately 80% of the nitric oxide was removed. The effect of sulfur dioxide on this process was also investigated and the results showed that it slightly decreased the amount of Hg{sup 0} oxidized while appearing to increase the removal of nitric oxide from the gas phase. We are currently testing the effects of variations in NOXSORB{trademark} concentration, sulfur dioxide concentration, nitric oxide concentration, and reaction time (residence time). Preliminary economic projections based on the results to date indicate that the chemical cost for nitric oxide oxidation could be less thanmore » $$5,000/ton removed, while for Hg{sup 0} oxidation it would be about $$20,000/lb removed.« less

Estriol-induced fibrinolysis due to the activation of plasminogen to plasmin by nitric oxide synthesis in platelets.

PubMed

Jana, Pradipta; Maiti, Smarajit; Kahn, Nighat N; Sinha, Asru K

2015-04-01

Estriol, an oestrogen, at 0.6 nmol/l was reported to inhibit ADP-induced platelet aggregation through nitric oxide synthesis. As nitric oxide has been reported to cause fibrinolysis due to the activation of plasminogen to plasmin, the role of estriol as a fibrinolytic agent was investigated. Also, the mechanism of estriol-induced nitric oxide synthesis in anucleated platelets was investigated. The estriol-induced lysis of platelet-rich plasma (PRP) clot was determined by photography of the clot lysis and by the assay of fibrin degradation products in the lysate and was obtained by SDS-PAGE. Nitric oxide was determined by methemoglobin method. The platelet membrane protein was isolated from the platelets by using Triton X-100 (0.05% v/v). The binding of estriol to the protein was determined by Scatchard plot by using an ELISA for estriol. Estriol at 0.6 nmol/l was found to lyse the clotted PRP due to fibrinolysis that produced fibrin degradation products in the lysate. The amino acid analysis of the platelet membrane protein, which resembles with nitric oxide synthase (NOS) activity, was activated nearly 10-fold over the control in the presence of estriol and was identified to be a human serum albumin precursor (Mr. 69 kDa) that binds to estriol with Kd1 of 6.0 × 10 mol/l and 39 ± 2 molecules of estriol bound the NOS molecule. The estriol-induced nitric oxide is capable of inducing fibrinolysis of the clotted PRP. The binding of estriol to platelet membrane NOS activated the enzyme in the absence of DNA in the platelet.

A pentapeptide monocyte locomotion inhibitory factor protects brain ischemia injury by targeting the eEF1A1/endothelial nitric oxide synthase pathway.

PubMed

Zhang, Yuefan; Chen, Jun; Li, Fan; Li, Dong; Xiong, Qinhui; Lin, Yang; Zhang, Dazhi; Wang, Xiao-Fan; Yang, Pengyuan; Rui, Yao-Cheng

2012-10-01

Ischemic stroke is a major cause of death worldwide but lacks viable treatment or treatment targets. Monocyte locomotion inhibitory factor (MLIF) is a small heat-stable pentapeptide produced by Entamoeba histolytica in axenic culture, which is supposed to protect the brain from ischemic injury; the mechanism, however, remains unknown. In this study, we further investigated the mechanism underlying the protective role of MLIF in brain ischemia. A middle cerebral artery occlusion model in rats was used for detecting the effect of MLIF in the brain ischemia in vivo. To identify targets of MLIF in brain endothelial cells, we performed immunoprecipitation of biotin-conjugated MLIF and mass spectrometry. MLIF can protect the brain from ischemic injury in vivo, yielding decreased ischemic volume, prolonged survival, and improved neurological outcome. In vitro studies showed that MLIF displayed protective effects through inhibition of expression of pathological inflammatory adhesion molecules and enhancing endothelial nitric oxide synthase expression and nitric oxide release in the cerebrovascular endothelium. The target screening experiments demonstrated binding of MLIF to the ribosomal protein translation elongation factor eEF1A1. MLIF enhanced endothelial nitric oxide synthase expression through stabilization of endothelial nitric oxide synthase mRNA, and eEF1A1 was shown to be necessary for this enhanced expression. Knockdown of eEF1A1 or inhibition of endothelial nitric oxide synthase attenuated MLIF-mediated inhibition of adhesion molecule expression. In this study, we identified a new potential pharmacologically targetable mechanism underlying MLIF's protective effects in brain ischemia through the eEF1A1/endothelial nitric oxide synthase pathway.

Pulmonary Hypertension in Lambs Transfused with Stored Blood is Prevented by Breathing Nitric Oxide

PubMed Central

Baron, David M.; Yu, Binglan; Lei, Chong; Bagchi, Aranya; Beloiartsev, Arkadi; Stowell, Christopher P.; Steinbicker, Andrea U.; Malhotra, Rajeev; Bloch, Kenneth D.; Zapol, Warren M.

2012-01-01

Background During extended storage, erythrocytes undergo functional changes. These changes reduce the viability of erythrocytes leading to release of oxyhemoglobin, a potent scavenger of nitric oxide. We hypothesized that transfusion of ovine packed erythrocytes (PRBC) stored for prolonged periods would induce pulmonary vasoconstriction in lambs, and that reduced vascular nitric oxide concentrations would increase this vasoconstrictor effect. Methods We developed a model of autologous stored blood transfusion in lambs (n=36). Leukoreduced blood was stored for either 2 days (fresh PRBC) or 40 days (stored PRBC). Fresh or stored PRBC were transfused into donors instrumented for awake hemodynamic measurements. Hemodynamic effects of PRBC transfusion were also studied after infusion of NG-nitro-L-arginine methyl-ester (25 mg/kg) or during inhalation of nitric oxide (80 ppm). Results Cell-free hemoglobin levels were higher in the supernatant of stored PRBC than in supernatant of fresh PRBC (Mean±SD, 148±20 versus 41±13 mg/dl, respectively, P<0.001). Pulmonary artery pressure during transfusion of stored PRBC transiently increased from 13±1 to 18±1 mmHg (P<0.001) and was associated with increased plasma hemoglobin concentrations. NG-nitro-L-arginine methyl-ester potentiated the increase in pulmonary arterial pressure induced by transfusing stored PRBC, whereas inhalation of nitric oxide prevented the vasoconstrictor response. Conclusions Our results suggest that patients with reduced vascular nitric oxide levels due to endothelial dysfunction may be more susceptible to adverse effects of transfusing blood stored for prolonged periods. These patients might benefit from transfusion of fresh PRBC, when available, or inhaled nitric oxide supplementation to prevent the pulmonary hypertension associated with transfusion of stored PRBC. PMID:22293717

Modulation of parathion toxicity by glucose feeding: Is nitric oxide involved?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Jing; Gupta, Ramesh C.; Goad, John T.

2007-03-15

Glucose feeding can markedly exacerbate the toxicity of the anticholinesterase insecticide, parathion. We determined the effects of parathion on brain nitric oxide and its possible role in potentiation of toxicity by glucose feeding. Adult rats were given water or 15% glucose in water for 3 days and challenged with vehicle or parathion (18 mg/kg, s.c.) on day 4. Functional signs, plasma glucose and brain cholinesterase, citrulline (an indicator of nitric oxide production) and high-energy phosphates (HEPs) were measured 1-3 days after parathion. Glucose feeding exacerbated cholinergic toxicity. Parathion increased plasma glucose (15-33%) and decreased cortical cholinesterase activity (81-90%), with nomore » significant differences between water and glucose treatment groups. In contrast, parathion increased brain regional citrulline (40-47%) and decreased HEPs (18-40%) in rats drinking water, with significantly greater changes in glucose-fed rats (248-363% increase and 31-61% decrease, respectively). We then studied the effects of inhibiting neuronal nitric oxide synthase (nNOS) by 7-nitroindazole (7NI, 30 mg/kg, i.p. x4) on parathion toxicity and its modulation by glucose feeding. Co-exposure to parathion and 7NI led to a marked increase in cholinergic signs of toxicity and lethality, regardless of glucose intake. Thus, glucose feeding enhanced the accumulation of brain nitric oxide following parathion exposure, but inhibition of nitric oxide synthesis was ineffective at counteracting increased parathion toxicity associated with glucose feeding. Evidence is therefore presented to suggest that nitric oxide may play both toxic and protective roles in cholinergic toxicity, and its precise contribution to modulation by glucose feeding requires further investigation.« less

Iron(II) porphyrins induced conversion of nitrite into nitric oxide: A computational study.

PubMed

Zhang, Ting Ting; Liu, Yong Dong; Zhong, Ru Gang

2015-09-01

Nitrite reduction to nitric oxide by heme proteins was reported as a protective mechanism to hypoxic injury in mammalian physiology. In this study, the pathways of nitrite reduction to nitric oxide mediated by iron(II) porphyrin (P) complexes, which were generally recognized as models for heme proteins, were investigated by using density functional theory (DFT). In view of two type isomers of combination of nitrite and Fe(II)(P), N-nitro- and O-nitrito-Fe(II)-porphyrin complexes, and two binding sites of proton to the different O atoms of nitrite moiety, four main pathways for the conversion of nitrite into nitric oxide mediated by iron(II) porphyrins were proposed. The results indicate that the pathway of N-bound Fe(II)(P)(NO2) isomer into Fe(III)(P)(NO) and water is similar to that of O-bound isomer into nitric oxide and Fe(III)(P)(OH) in both thermodynamical and dynamical aspects. Based on the initial computational studies of five-coordinate nitrite complexes, the conversion of nitrite into NO mediated by Fe(II)(P)(L) complexes with 14 kinds of proximal ligands was also investigated. Generally, the same conclusion that the pathways of N-bound isomers are similar to those of O-bound isomer was obtained for iron(II) porphyrin with ligands. Different effects of ligands on the reduction reactions were also found. It is notable that the negative proximal ligands can improve reactive abilities of N-nitro-iron(II) porphyrins in the conversion of nitrite into nitric oxide compared to neutral ligands. The findings will be helpful to expand our understanding of the mechanism of nitrite reduction to nitric oxide by iron(II) porphyrins. Copyright © 2015 Elsevier Inc. All rights reserved.

Nitric oxide contributes to substance P-induced increases in lung rapidly adapting receptor activity in guinea-pigs.

PubMed Central

Joad, J P; Kott, K S; Bonham, A C

1997-01-01

1. Substance P induces fluid flux via nitric oxide, and fluid flux stimulates lung rapidly adapting receptors (RARs). We therefore proposed that nitric oxide contributes to substance P-evoked increases in RAR activity. Since substance P decreases dynamic compliance (Cdyn), which can stimulate RARs, we also determined whether nitric oxide contributed to substance P-induced effects on pulmonary function. 2. In anaesthetized guinea-pigs, the effects of substance P on RAR activity, Cdyn, pulmonary resistance (RL), and arterial blood pressure were measured before and after i.v. infusion of NG-methyl-L-arginine (L-NMMA; a nitric oxide synthase inhibitor), or L-NMMA followed by L-arginine (a nitric oxide precursor which reverses the effects of L-NMMA). 3. Substance P-evoked increases in RAR activity were blunted by L-NMMA (P = 0.006) but not by L-NMMA-L-arginine (P = 0.42). 4. Substance P-evoked decreases in Cdyn were slightly inhibited by L-NMMA (P = 0.02) and slightly enhanced by L-NMMA-L-arginine (P = 0.004). However, at the time at which L-NMMA maximally reduced substance P-induced RAR stimulation (the first 30 s), it did not change substance P-induced decreases in Cdyn. 5. Substance P-evoked increases in RL were not changed by L-NMMA (P = 0.10) and were enhanced by L-NMMA-L-arginine (P = 0.03). 6. L-NMMA-evoked increases in mean arterial blood pressure were reversed by L-arginine. Substance P-evoked decreases in mean arterial blood pressure were not changed by L-NMMA or by L-NMMA-L-arginine. 7. We conclude that nitric oxide contributes to substance P-evoked increases in RAR activity and that the increases are most probably independent of decreases in Cdyn. PMID:9379417

Mediated electrochemical oxidation of organic wastes using a Co (III) mediator in a nitric acid based system

DOEpatents

Balazs, G.B.; Chiba, Z.; Lewis, P.R.; Nelson, N.; Steward, G.A.

1999-06-15

An electrochemical cell with a Co(III) mediator and nitric acid electrolyte provides efficient destruction of organic and mixed wastes. The organic waste is concentrated in the anolyte reservoir, where the mediator oxidizes the organics and insoluble transuranic compounds and is regenerated at the anode until the organics are converted to CO[sub 2]. The nitric acid is an excellent oxidant that facilitates the destruction of the organic components. The anode is not readily attacked by the nitric acid solution, thus the cell can be used for extended continual operation without electrode replacement. 2 figs.

Monoclonal L-citrulline immunostaining reveals nitric oxide-producing vestibular neurons

NASA Technical Reports Server (NTRS)

Holstein, G. R.; Friedrich, V. L. Jr; Martinelli, G. P.

2001-01-01

Nitric oxide is an unstable free radical that serves as a novel messenger molecule in the central nervous system (CNS). In order to understand the interplay between classic and novel chemical communication systems in vestibular pathways, the staining obtained using a monoclonal antibody directed against L-citrulline was compared with the labeling observed using more traditional markers for the presence of nitric oxide. Brainstem tissue from adult rats was processed for immunocytochemistry employing a monoclonal antibody directed against L-citrulline, a polyclonal antiserum against neuronal nitric oxide synthase, and/or NADPH-diaphorase histochemistry. Our findings demonstrate that L-citrulline can be fixed in situ by vascular perfusion, and can be visualized in fixed CNS tissue sections by immunocytochemistry. Further, the same vestibular regions and cell types are labeled by NADPH-diaphorase histochemistry, by the neuronal nitric oxide synthase antiserum, and by our anti-L-citrulline antibody. Clusters of L-citrulline-immunoreactive neurons are present in subregions of the vestibular nuclei, including the caudal portion of the inferior vestibular nucleus, the magnocellular portion of the medial vestibular nucleus, and the large cells in the ventral tier of the lateral vestibular nucleus. NADPH-diaphorase histochemical staining of these neurons clearly demonstrated their multipolar, fusiform and globular somata and long varicose dendritic processes. These results provide support for the suggestion that nitric oxide serves key roles in both vestibulo-autonomic and vestibulo-spinal pathways.

Evidence for involvement of nitric oxide and GABAB receptors in MK-801- stimulated release of glutamate in rat prefrontal cortex

PubMed Central

Roenker, Nicole L.; Gudelsky, Gary A.; Ahlbrand, Rebecca; Horn, Paul S.; Richtand, Neil M.

2012-01-01

Systemic administration of NMDA receptor antagonists elevates extracellular glutamate within prefrontal cortex. The cognitive and behavioral effects of NMDA receptor blockade have direct relevance to symptoms of schizophrenia, and recent studies demonstrate an important role for nitric oxide and GABAB receptors in mediating the effects of NMDA receptor blockade on these behaviors. We sought to extend those observations by directly measuring the effects of nitric oxide and GABAB receptor mechanisms on MK-801-induced glutamate release in the prefrontal cortex. Systemic MK-801 injection (0.3 mg/kg) to male Sprague-Dawley rats significantly increased extracellular glutamate levels in prefrontal cortex, as determined by microdialysis. This effect was blocked by pretreatment with the nitric oxide synthase inhibitor L-NAME (60 mg/kg). Reverse dialysis of the nitric oxide donor SNAP (0.5 – 5 mM) directly into prefrontal cortex mimicked the effect of systemic MK-801, dose-dependently elevating cortical extracellular glutamate. The effect of MK-801 was also blocked by systemic treatment with the GABAB receptor agonist baclofen (5 mg/kg). In combination, these data suggest increased nitric oxide formation is necessary for NMDA antagonist-induced elevations of extracellular glutamate in the prefrontal cortex. Additionally, the data suggest GABAB receptor activation can modulate the NMDA antagonist-induced increase in cortical glutamate release. PMID:22579658

Pu-erh Tea Reduces Nitric Oxide Levels in Rats by Inhibiting Inducible Nitric Oxide Synthase Expression through Toll-Like Receptor 4

PubMed Central

Xu, Yang; Wang, Guan; Li, Chunjie; Zhang, Min; Zhao, Hang; Sheng, Jun; Shi, Wei

2012-01-01

Pu-erh tea undergoes a unique fermentation process and contains theabrownins, polysaccharides and caffeine; although it is unclear about which component is associated with the down regulation of nitric oxide levels or how this process is mediated. To address this question we examined the effects of pu-erh tea on nitric oxide synthase (NOS) genes. Cohorts of rats were separately given four-week treatments of water as control, pu-erh tea, or the tea components: theabrownins, caffeine or polysaccharides. Five experimental groups were injected with lipopolysaccharides (LPS) to induce nitric oxide (NO) production, while the corresponding five control groups were injected with saline as a negative control. The serum and liver NO concentrations were examined and the NOS expression of both mRNA and protein was measured in liver. The results showed that the rats which were fed pu-erh tea or polysaccharides had lower levels of NO which corresponded with the down-regulation of inducible nitric oxide synthase (iNOS) expression. We further demonstrate that this effect is mediated through reduction of Toll-like receptor 4 (TLR4) signaling. Thus we find that the polysaccharide components in pu-erh tea reduce NO levels in an animal model by inhibiting the iNOS expression via signaling through TLR4. PMID:22837686

Interaction of Hydrogen Sulfide with Nitric Oxide in the Cardiovascular System

PubMed Central

Nagpure, B. V.; Bian, Jin-Song

2016-01-01

Historically acknowledged as toxic gases, hydrogen sulfide (H2S) and nitric oxide (NO) are now recognized as the predominant members of a new family of signaling molecules, “gasotransmitters” in mammals. While H2S is biosynthesized by three constitutively expressed enzymes (CBS, CSE, and 3-MST) from L-cysteine and homocysteine, NO is generated endogenously from L-arginine by the action of various isoforms of NOS. Both gases have been transpired as the key and independent regulators of many physiological functions in mammalian cardiovascular, nervous, gastrointestinal, respiratory, and immune systems. The analogy between these two gasotransmitters is evident not only from their paracrine mode of signaling, but also from the identical and/or shared signaling transduction pathways. With the plethora of research in the pathophysiological role of gasotransmitters in various systems, the existence of interplay between these gases is being widely accepted. Chemical interaction between NO and H2S may generate nitroxyl (HNO), which plays a specific effective role within the cardiovascular system. In this review article, we have attempted to provide current understanding of the individual and interactive roles of H2S and NO signaling in mammalian cardiovascular system, focusing particularly on heart contractility, cardioprotection, vascular tone, angiogenesis, and oxidative stress. PMID:26640616

Nitric Oxide Dependent Degradation of Polyethylene Glycol-Modified Single-Walled Carbon Nanotubes: Implications for Intra-Articular Delivery.

PubMed

Bhattacharya, Kunal; Sacchetti, Cristiano; Costa, Pedro M; Sommertune, Jens; Brandner, Birgit D; Magrini, Andrea; Rosato, Nicola; Bottini, Nunzio; Bottini, Massimo; Fadeel, Bengt

2018-03-01

Polyethylene glycol (PEG)-modified carbon nanotubes have been successfully employed for intra-articular delivery in mice without systemic or local toxicity. However, the fate of the delivery system itself remains to be understood. In this study 2 kDa PEG-modified single-walled carbon nanotubes (PNTs) are synthesized, and trafficking and degradation following intra-articular injection into the knee-joint of healthy mice are studied. Using confocal Raman microspectroscopy, PNTs can be imaged in the knee-joint and are found to either egress from the synovial cavity or undergo biodegradation over a period of 3 weeks. Raman analysis discloses that PNTs are oxidatively degraded mainly in the chondrocyte-rich cartilage and meniscus regions while PNTs can also be detected in the synovial membrane regions, where macrophages can be found. Furthermore, using murine chondrocyte (ATDC-5) and macrophage (RAW264.7) cell lines, biodegradation of PNTs in activated, nitric oxide (NO)-producing chondrocytes, which is blocked upon pharmacological inhibition of inducible nitric oxide synthase (iNOS), can be shown. Biodegradation of PNTs in macrophages is also noted, but after a longer period of incubation. Finally, cell-free degradation of PNTs upon incubation with the peroxynitrite-generating compound, SIN-1 is demonstrated. The present study paves the way for the use of PNTs as delivery systems in the treatment of diseases of the joint. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Detection and removal of impurities in nitric oxide generated from air by pulsed electrical discharge.

PubMed

Yu, Binglan; Blaesi, Aron H; Casey, Noel; Raykhtsaum, Grigory; Zazzeron, Luca; Jones, Rosemary; Morrese, Alexander; Dobrynin, Danil; Malhotra, Rajeev; Bloch, Donald B; Goldstein, Lee E; Zapol, Warren M

2016-11-30

Inhalation of nitric oxide (NO) produces selective pulmonary vasodilation without dilating the systemic circulation. However, the current NO/N 2 cylinder delivery system is cumbersome and expensive. We developed a lightweight, portable, and economical device to generate NO from air by pulsed electrical discharge. The objective of this study was to investigate and optimize the purity and safety of NO generated by this device. By using low temperature streamer discharges in the plasma generator, we produced therapeutic levels of NO with very low levels of nitrogen dioxide (NO 2 ) and ozone. Despite the low temperature, spark generation eroded the surface of the electrodes, contaminating the gas stream with metal particles. During prolonged NO generation there was gradual loss of the iridium high-voltage tip (-90 μg/day) and the platinum-nickel ground electrode (-55 μg/day). Metal particles released from the electrodes were trapped by a high-efficiency particulate air (HEPA) filter. Quadrupole mass spectroscopy measurements of effluent gas during plasma NO generation showed that a single HEPA filter removed all of the metal particles. Mice were exposed to breathing 50 parts per million of electrically generated NO in air for 28 days with only a scavenger and no HEPA filter; the mice did not develop pulmonary inflammation or structural changes and iridium and platinum particles were not detected in the lungs of these mice. In conclusion, an electric plasma generator produced therapeutic levels of NO from air; scavenging and filtration effectively eliminated metallic impurities from the effluent gas. Copyright © 2016 Elsevier Inc. All rights reserved.

Detection and Removal of Impurities in Nitric Oxide Generated from Air by Pulsed Electrical Discharge

PubMed Central

Yu, Binglan; Blaesi, Aron H.; Casey, Noel; Raykhtsaum, Grigory; Zazzeron, Luca; Jones, Rosemary; Morrese, Alexander; Dobrynin, Danil; Malhotra, Rajeev; Bloch, Donald B.; Goldstein, Lee E.; Zapol, Warren M.

2016-01-01

Inhalation of nitric oxide (NO) produces selective pulmonary vasodilation without dilating the systemic circulation. However, the current NO/N2 cylinder delivery system is cumbersome and expensive. We developed a lightweight, portable, and economical device to generate NO from air by pulsed electrical discharge. The objective of this study was to investigate and optimize the purity and safety of NO generated by this device. By using low temperature streamer discharges in the plasma generator, we produced therapeutic levels of NO with very low levels of nitrogen dioxide (NO2) and ozone. Despite the low temperature, spark generation eroded the surface of the electrodes, contaminating the gas stream with metal particles. During prolonged NO generation there was gradual loss of the iridium high-voltage tip (−90 µg/day) and the platinum-nickel ground electrode (−55 µg/day). Metal particles released from the electrodes were trapped by a high-efficiency particulate air (HEPA) filter. Quadrupole mass spectroscopy measurements of effluent gas during plasma NO generation showed that a single HEPA filter removed all of the metal particles. Mice were exposed to breathing 50 parts per million of electrically generated NO in air for 28 days with only a scavenger and no HEPA filter; the mice did not develop pulmonary inflammation or structural changes and iridium and platinum particles were not detected in the lungs of these mice. In conclusion, an electric plasma generator produced therapeutic levels of NO from air; scavenging and filtration effectively eliminated metallic impurities from the effluent gas. PMID:27592386

Nitric oxide: A new possible biomarker in heart failure? Relationship with pulmonary hypertension secondary to left heart failure.

PubMed

Bonafede, Roberto Jorge; Calvo, Juan Pablo; Fausti, Julia María Valeria; Puebla, Sonia; Gambarte, Adolfo Juan; Manucha, Walter

Heart failure (HF) is a growing medical problem and it is of interest to study new biomarkers for better characterisation. In this sense, nitric oxide, reactive oxygen species (ROS), NADPH, and superoxide dismutase (SOD) were evaluated, along with their possible predictive value in patients with HF. An analysis was also performed on the potential differences between patients with and without secondary pulmonary hypertension (SPH), considered to have a worse prognosis. A significant decrease of nitric oxide and SOD was noted in HF, whereas ROS and NADPH were increased. These results agree with the pathophysiological changes characteristic of HF. It was also demonstrated that in patients with HF and SPH that nitric oxide and SOD were decreased when compared to HF without SPH, whereas ROS and NADPH were increased. Therefore, our results suggest that nitric oxide, ROS, NADPH, and SOD, could be considered as possible markers in HF, and could also characterise patients with SPH. Copyright © 2017 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

Satellite observations of the nitric oxide dayglow Implications for the behavior of mesospheric and lower-thermospheric odd nitrogen

NASA Technical Reports Server (NTRS)

Frederick, J. E.; Serafino, G. N.

1985-01-01

The solar backscattered ultraviolet spectral radiometer on the Nimbus 7 satellite routinely measures fluorescence emissions from the nitric oxide (1, 4) gamma band that are imposed on the large Rayleigh-scattered signal in the wavelength range 255-256 nm. The gamma band feature, when isolated from the background radiance, provide information on the seasonal and latitudinal variations in the nitric oxide column abundance over the altitude region from 40 to 45 km upward through the thermosphere. At latitudes from 30 deg to 45 deg in the Northern Hemisphere the measurements show an annual cycle with maximum nitric oxide abundance in summer. The Southern Hemisphere pattern is qualitatively similar to this, although the amplitude of the seasonal variation is substantially smaller. The most prominent feature of the data base is a large maximum in nitric oxide emission that develops poleward of 45 deg latitude in both Hemispheres during late autumn and early winter. These maxima dissipate rapidly as spring approaches and are no longer evident in the data for Northern Hemisphere March and Southern Hemisphere September.

Molecular Steps in the Immune Signaling Pathway Evoked by Plant Elicitor Peptides: Ca2+-Dependent Protein Kinases, Nitric Oxide, and Reactive Oxygen Species Are Downstream from the Early Ca2+ Signal1[OPEN

PubMed Central

Ma, Yi; Zhao, Yichen; Walker, Robin K.; Berkowitz, Gerald A.

2013-01-01

Endogenous plant elicitor peptides (Peps) can act to facilitate immune signaling and pathogen defense responses. Binding of these peptides to the Arabidopsis (Arabidopsis thaliana) plasma membrane-localized Pep receptors (PEPRs) leads to cytosolic Ca2+ elevation, an early event in a signaling cascade that activates immune responses. This immune response includes the amplification of signaling evoked by direct perception of pathogen-associated molecular patterns by plant cells under assault. Work included in this report further characterizes the Pep immune response and identifies new molecular steps in the signal transduction cascade. The PEPR coreceptor BRASSINOSTEROID-INSENSITIVE1 Associated Kinase1 contributes to generation of the Pep-activated Ca2+ signal and leads to increased defense gene expression and resistance to a virulent bacterial pathogen. Ca2+-dependent protein kinases (CPKs) decode the Ca2+ signal, also facilitating defense gene expression and enhanced resistance to the pathogen. Nitric oxide and reduced nicotinamide adenine dinucleotide phosphate oxidase-dependent reactive oxygen species generation (due to the function of Respiratory Burst Oxidase Homolog proteins D and F) are also involved downstream from the Ca2+ signal in the Pep immune defense signal transduction cascade, as is the case with BRASSINOSTEROID-INSENSITIVE1 Associated Kinase1 and CPK5, CPK6, and CPK11. These steps of the pathogen defense response are required for maximal Pep immune activation that limits growth of a virulent bacterial pathogen in the plant. We find a synergism between function of the PEPR and Flagellin Sensing2 receptors in terms of both nitric oxide and reactive oxygen species generation. Presented results are also consistent with the involvement of the secondary messenger cyclic GMP and a cyclic GMP-activated Ca2+-conducting channel in the Pep immune signaling pathway. PMID:24019427

Nitric oxide functions as a signal in plant disease resistance.

PubMed

Delledonne, M; Xia, Y; Dixon, R A; Lamb, C

1998-08-06

Recognition of an avirulent pathogen triggers the rapid production of the reactive oxygen intermediates superoxide (O2-) and hydrogen peroxide (H2O2). This oxidative burst drives crosslinking of the cell wall, induces several plant genes involved in cellular protection and defence, and is necessary for the initiation of host cell death in the hypersensitive disease-resistance response. However, this burst is not enough to support a strong disease-resistance response. Here we show that nitric oxide, which acts as a signal in the immune, nervous and vascular systems, potentiates the induction of hypersensitive cell death in soybean cells by reactive oxygen intermediates and functions independently of such intermediates to induce genes for the synthesis of protective natural products. Moreover, inhibitors of nitric oxide synthesis compromise the hypersensitive disease-resistance response of Arabidopsis leaves to Pseudomonas syringae, promoting disease and bacterial growth. We conclude that nitric oxide plays a key role in disease resistance in plants.

Nitric oxide is a mediator of methamphetamine (METH)-induced neurotoxicity. In vitro evidence from primary cultures of mesencephalic cells.

PubMed

Sheng, P; Cerruti, C; Ali, S; Cadet, J L

1996-10-31

METH is a monoaminergic toxic that destroys dopamine terminals in vivo. Oxidative mechanisms associated with DA metabolism are thought to play an important role in its toxic effects. These ideas were supported by the demonstration that CuZn-superoxide dismutase (CuZnSOD) transgenic mice were protected against the toxic effects of the drug. In the present study, we sought to determine if nitric oxide (NO) production was also involved in METH-induced neurotoxicity using primary cultures obtained from fetal rat mesencephalon. METH caused dose- and time-dependent cell death in vitro. Blockade of nitric oxide (NO) formation with several nitric oxide (NO) synthase blockers attenuated METH-mediated toxicity. Moreover, inhibition of ADP-ribosylation with nicotinamide and benzamide also provided protection against the toxicity of the drug. These results, together with our previous results in transgenic mice, support a role for free radicals in METH-induced toxic effects.

Nitric oxide leads to cytoskeletal reorganization in the retinal pigment epithelium under oxidative stress.

PubMed

Sripathi, Srinivas R; He, Weilue; Um, Ji-Yeon; Moser, Trevor; Dehnbostel, Stevie; Kindt, Kimberly; Goldman, Jeremy; Frost, Megan C; Jahng, Wan Jin

2012-01-01

Light is a risk factor for various eye diseases, including age-related macular degeneration (AMD) and retinitis pigmentosa (RP). We aim to understand how cytoskeletal proteins in the retinal pigment epithetlium (RPE) respond to oxidative stress, including light and how these responses affect apoptotic signaling. Previously, proteomic analysis revealed that the expression levels of vimentin and serine/threonine protein phosphatase 2A (PP2A) are significantly increased when mice are exposed under continuous light for 7 days compared to a condition of 12 hrs light/dark cycling exposure using retina degeneration 1 (rd1) model. When melatonin is administered to animals while they are exposed to continuous light, the levels of vimentin and PP2A return to a normal level. Vimentin is a substrate of PP2A that directly binds to vimentin and dephosphorylates it. The current study shows that upregulation of PP2Ac (catalytic subunit) phosphorylation negatively correlates with vimentin phosphorylation under stress condition. Stabilization of vimentin appears to be achieved by decreased PP2Ac phosphorylation by nitric oxide induction. We tested our hypothesis that site-specific modifications of PP2Ac may drive cytoskeletal reorganization by vimentin dephosphorylation through nitric oxide signaling. We speculate that nitric oxide determines protein nitration under stress conditions. Our results demonstrate that PP2A and vimentin are modulated by nitric oxide as a key element involved in cytoskeletal signaling. The current study suggests that external stress enhances nitric oxide to regulate PP2Ac and vimentin phosphorylation, thereby stabilizing or destabilizing vimentin. Phosphorylation may result in depolymerization of vimentin, leading to nonfilamentous particle formation. We propose that a stabilized vimentin might act as an anti-apoptotic molecule when cells are under oxidative stress.

Nitric oxide leads to cytoskeletal reorganization in the retinal pigment epithelium under oxidative stress

PubMed Central

Um, Ji-Yeon; Moser, Trevor; Dehnbostel, Stevie; Kindt, Kimberly; Goldman, Jeremy; Frost, Megan C.; Jahng, Wan Jin

2016-01-01

Light is a risk factor for various eye diseases, including age-related macular degeneration (AMD) and retinitis pigmentosa (RP). We aim to understand how cytoskeletal proteins in the retinal pigment epithetlium (RPE) respond to oxidative stress, including light and how these responses affect apoptotic signaling. Previously, proteomic analysis revealed that the expression levels of vimentin and serine/threonine protein phosphatase 2A (PP2A) are significantly increased when mice are exposed under continuous light for 7 days compared to a condition of 12 hrs light/dark cycling exposure using retina degeneration 1 (rd1) model. When melatonin is administered to animals while they are exposed to continuous light, the levels of vimentin and PP2A return to a normal level. Vimentin is a substrate of PP2A that directly binds to vimentin and dephosphorylates it. The current study shows that upregulation of PP2Ac (catalytic subunit) phosphorylation negatively correlates with vimentin phosphorylation under stress condition. Stabilization of vimentin appears to be achieved by decreased PP2Ac phosphorylation by nitric oxide induction. We tested our hypothesis that site-specific modifications of PP2Ac may drive cytoskeletal reorganization by vimentin dephosphorylation through nitric oxide signaling. We speculate that nitric oxide determines protein nitration under stress conditions. Our results demonstrate that PP2A and vimentin are modulated by nitric oxide as a key element involved in cytoskeletal signaling. The current study suggests that external stress enhances nitric oxide to regulate PP2Ac and vimentin phosphorylation, thereby stabilizing or destabilizing vimentin. Phosphorylation may result in depolymerization of vimentin, leading to nonfilamentous particle formation. We propose that a stabilized vimentin might act as an anti-apoptotic molecule when cells are under oxidative stress. PMID:27974994

Glycoinositolphospholipids from Trypanosomatids Subvert Nitric Oxide Production in Rhodnius prolixus Salivary Glands

PubMed Central

Gazos-Lopes, Felipe; Mesquita, Rafael Dias; Silva-Cardoso, Lívia; Senna, Raquel; Silveira, Alan Barbosa; Jablonka, Willy; Cudischevitch, Cecília Oliveira; Carneiro, Alan Brito; Machado, Ednildo Alcantara; Lima, Luize G.; Monteiro, Robson Queiroz; Nussenzveig, Roberto Henrique; Folly, Evelize; Romeiro, Alexandre; Vanbeselaere, Jorick; Mendonça-Previato, Lucia; Previato, José Osvaldo; Valenzuela, Jesus G.; Ribeiro, José Marcos Chaves; Atella, Georgia Correa; Silva-Neto, Mário Alberto Cardoso

2012-01-01

Background Rhodnius prolixus is a blood-sucking bug vector of Trypanosoma cruzi and T. rangeli. T. cruzi is transmitted by vector feces deposited close to the wound produced by insect mouthparts, whereas T. rangeli invades salivary glands and is inoculated into the host skin. Bug saliva contains a set of nitric oxide-binding proteins, called nitrophorins, which deliver NO to host vessels and ensure vasodilation and blood feeding. NO is generated by nitric oxide synthases (NOS) present in the epithelium of bug salivary glands. Thus, T. rangeli is in close contact with NO while in the salivary glands. Methodology/Principal Findings Here we show by immunohistochemical, biochemical and molecular techniques that inositolphosphate-containing glycolipids from trypanosomatids downregulate NO synthesis in the salivary glands of R. prolixus. Injecting insects with T. rangeli-derived glycoinositolphospholipids (Tr GIPL) or T. cruzi-derived glycoinositolphospholipids (Tc GIPL) specifically decreased NO production. Salivary gland treatment with Tc GIPL blocks NO production without greatly affecting NOS mRNA levels. NOS protein is virtually absent from either Tr GIPL- or Tc GIPL-treated salivary glands. Evaluation of NO synthesis by using a fluorescent NO probe showed that T. rangeli-infected or Tc GIPL-treated glands do not show extensive labeling. The same effect is readily obtained by treatment of salivary glands with the classical protein tyrosine phosphatase (PTP) inhibitor, sodium orthovanadate (SO). This suggests that parasite GIPLs induce the inhibition of a salivary gland PTP. GIPLs specifically suppressed NO production and did not affect other anti-hemostatic properties of saliva, such as the anti-clotting and anti-platelet activities. Conclusions/Significance Taken together, these data suggest that trypanosomatids have overcome NO generation using their surface GIPLs. Therefore, these molecules ensure parasite survival and may ultimately enhance parasite transmission. PMID:23077586

Active nitric oxide produced in the red cell under hypoxic conditions by deoxyhemoglobin-mediated nitrite reduction.

PubMed

Nagababu, Enika; Ramasamy, Somasundaram; Abernethy, Darrell R; Rifkind, Joseph M

2003-11-21

Recent studies have generated a great deal of interest in a possible role for red blood cells in the transport of nitric oxide (NO) to the microcirculation and the vascular effect of this nitric oxide in facilitating the flow of blood through the microcirculation. Many questions have, however, been raised regarding such a mechanism. We have instead identified a completely new mechanism to explain the role of red cells in the delivery of NO to the microcirculation. This new mechanism results in the production of NO in the microcirculation where it is needed. Nitrite produced when NO reacts with oxygen in arterial blood is reutilized in the arterioles when the partial pressure of oxygen decreases and the deoxygenated hemoglobin formed reduces the nitrite regenerating NO. Nitrite reduction by hemoglobin results in a major fraction of the NO generated retained in the intermediate state where NO is bound to Hb(III) and in equilibrium with the nitrosonium cation bound to Hb(II). This pool of NO, unlike Hb(II)NO, is weakly bound and can be released from the heme. The instability of Hb(III)NO in oxygen and its displacement when flushed with argon requires that reliable determinations of red blood cell NO must be performed on freshly lysed samples without permitting the sample to be oxygenated. In fresh blood samples Hb(III)NO accounts for 75% of the red cell NO with appreciably higher values in venous blood than arterial blood. These findings confirm that nitrite reduction at reduced oxygen pressures is a major source for red cell NO. The formation and potential release from the red cell of this NO could have a major impact in regulating the flow of blood through the microcirculation.

The Krebs cycle and mitochondrial mass are early victims of endothelial dysfunction: proteomic approach.

PubMed

Addabbo, Francesco; Ratliff, Brian; Park, Hyeong-Cheon; Kuo, Mei-Chuan; Ungvari, Zoltan; Csiszar, Anna; Ciszar, Anna; Krasnikov, Boris; Krasnikof, Boris; Sodhi, Komal; Zhang, Fung; Nasjletti, Alberto; Goligorsky, Michael S

2009-01-01

Endothelial cell dysfunction is associated with bioavailable nitric oxide deficiency and an excessive generation of reactive oxygen species. We modeled this condition by chronically inhibiting nitric oxide generation with subpressor doses of N(G)-monomethyl-L-arginine (L-NMMA) in C57B6 and Tie-2/green fluorescent protein mouse strains. L-NMMA-treated mice exhibited a slight reduction in vasorelaxation ability, as well as detectable abnormalities in soluble adhesion molecules (soluble intercellular adhesion molecule-1 and vascular cellular adhesion molecule-1, and matrix metalloproteinase 9), which represent surrogate indicators of endothelial dysfunction. Proteomic analysis of the isolated microvasculature using 2-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy revealed abnormal expression of a cluster of mitochondrial enzymes, which was confirmed using immunodetection. Aconitase-2 and enoyl-CoA-hydratase-1 expression levels were decreased in L-NMMA-treated animals; this phenotype was absent in nitric oxide synthase-1 and -3 knockout mice. Depletion of aconitase-2 and enoyl-CoA-hydratase-1 resulted in the inhibition of the Krebs cycle and enhanced pyruvate shunting toward the glycolytic pathway. To assess mitochondrial mass in vivo, co-localization of green fluorescent protein and MitoTracker fluorescence was detected by intravital microscopy. Quantitative analysis of fluorescence intensity showed that L-NMMA-treated animals exhibited lower fluorescence of MitoTracker in microvascular endothelia as a result of reduced mitochondrial mass. These findings provide conclusive and unbiased evidence that mitochondriopathy represents an early manifestation of endothelial dysfunction, shifting cell metabolism toward "metabolic hypoxia" through the selective depletion of both aconitase-2 and enoyl-CoA-hydratase-1. These findings may contribute to an early preclinical diagnosis of endothelial dysfunction.

Next-generation sequencing analysis of gene regulation in the rat model of retinopathy of prematurity.

PubMed

Griffith, Rachel M; Li, Hu; Zhang, Nan; Favazza, Tara L; Fulton, Anne B; Hansen, Ronald M; Akula, James D

2013-08-01

The purpose of this study was to identify the genes, biochemical signaling pathways, and biological themes involved in the pathogenesis of retinopathy of prematurity (ROP). Next-generation sequencing (NGS) was performed on the RNA transcriptome of rats with the Penn et al. (Pediatr Res 36:724-731, 1994) oxygen-induced retinopathy model of ROP at the height of vascular abnormality, postnatal day (P) 19, and normalized to age-matched, room-air-reared littermate controls. Eight custom-developed pathways with potential relevance to known ROP sequelae were evaluated for significant regulation in ROP: The three major Wnt signaling pathways, canonical, planar cell polarity (PCP), and Wnt/Ca(2+); two signaling pathways mediated by the Rho GTPases RhoA and Cdc42, which are, respectively, thought to intersect with canonical and non-canonical Wnt signaling; nitric oxide signaling pathways mediated by two nitric oxide synthase (NOS) enzymes, neuronal (nNOS) and endothelial (eNOS); and the retinoic acid (RA) signaling pathway. Regulation of other biological pathways and themes was detected by gene ontology using the Kyoto Encyclopedia of Genes and Genomes and the NIH's Database for Annotation, Visualization, and Integrated Discovery's GO terms databases. Canonical Wnt signaling was found to be regulated, but the non-canonical PCP and Wnt/Ca(2+) pathways were not. Nitric oxide signaling, as measured by the activation of nNOS and eNOS, was also regulated, as was RA signaling. Biological themes related to protein translation (ribosomes), neural signaling, inflammation and immunity, cell cycle, and cell death were (among others) highly regulated in ROP rats. These several genes and pathways identified by NGS might provide novel targets for intervention in ROP.

Investigation of molecular mechanisms and regulatory pathways of pro-angiogenic nanorods

NASA Astrophysics Data System (ADS)

Nethi, Susheel Kumar; Veeriah, Vimal; Barui, Ayan Kumar; Rajendran, Saranya; Mattapally, Saidulu; Misra, Sanjay; Chatterjee, Suvro; Patra, Chitta Ranjan

2015-05-01

Angiogenesis, a process involving the growth of new blood vessels from the pre-existing vasculature, plays a crucial role in various pathophysiological conditions. We have previously demonstrated that europium hydroxide [EuIII(OH)3] nanorods (EHNs) exhibit pro-angiogenic properties through the generation of reactive oxygen species (ROS) and mitogen activated protein kinase (MAPK) activation. Considering the enormous implication of angiogenesis in cardiovascular diseases (CVDs) and cancer, it is essential to understand in-depth molecular mechanisms and signaling pathways in order to develop the most efficient and effective alternative treatment strategy for CVDs. However, the exact underlying mechanism and cascade signaling pathways behind the pro-angiogenic properties exhibited by EHNs still remain unclear. Herein, we report for the first time that the hydrogen peroxide (H2O2), a redox signaling molecule, generated by these EHNs activates the endothelial nitric oxide synthase (eNOS) that promotes the nitric oxide (NO) production in a PI3K (phosphoinositide 3-kinase)/Akt dependent manner, eventually triggering angiogenesis. We intensely believe that the investigation and understanding of the in-depth molecular mechanism and signaling pathways of EHNs induced angiogenesis will help us in developing an effective alternative treatment strategy for cardiovascular related and ischemic diseases where angiogenesis plays an important role.Angiogenesis, a process involving the growth of new blood vessels from the pre-existing vasculature, plays a crucial role in various pathophysiological conditions. We have previously demonstrated that europium hydroxide [EuIII(OH)3] nanorods (EHNs) exhibit pro-angiogenic properties through the generation of reactive oxygen species (ROS) and mitogen activated protein kinase (MAPK) activation. Considering the enormous implication of angiogenesis in cardiovascular diseases (CVDs) and cancer, it is essential to understand in-depth molecular mechanisms and signaling pathways in order to develop the most efficient and effective alternative treatment strategy for CVDs. However, the exact underlying mechanism and cascade signaling pathways behind the pro-angiogenic properties exhibited by EHNs still remain unclear. Herein, we report for the first time that the hydrogen peroxide (H2O2), a redox signaling molecule, generated by these EHNs activates the endothelial nitric oxide synthase (eNOS) that promotes the nitric oxide (NO) production in a PI3K (phosphoinositide 3-kinase)/Akt dependent manner, eventually triggering angiogenesis. We intensely believe that the investigation and understanding of the in-depth molecular mechanism and signaling pathways of EHNs induced angiogenesis will help us in developing an effective alternative treatment strategy for cardiovascular related and ischemic diseases where angiogenesis plays an important role. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr01327e

Nitric Oxide Generating Polymeric Coatings for Subcutaneous Glucose Sensors

DTIC Science & Technology

2007-10-01

primary polymer which was then aminated (2) for attachment of (Boc)3-cyclen-N-acetic acid (1). After the conjugation via EDC coupling chemistry, the Boc...SePEI and alginic acid layers). The sensor exhibits good response to NO, with sensitivity of 30-60 nA/µM and a detection limit of 5 nM. To create the...Oxide Release,” J. Biomed. Mater. Res., 75A (4), 755- 766 (2005). 10 2. S. Hwang, W. Cha, M. E. Meyerhoff, " Polymethacrylates with Covalently

Hydroxycarboxylic acids and salts

DOEpatents

Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

2015-02-24

Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

Betaine Treatment Attenuates Chronic Ethanol-Induced Hepatic Steatosis and Alterations to the Mitochondrial Respiratory Chain Proteome

PubMed Central

Kharbanda, Kusum K.; Todero, Sandra L.; King, Adrienne L.; Osna, Natalia A.; McVicker, Benita L.; Tuma, Dean J.; Wisecarver, James L.; Bailey, Shannon M.

2012-01-01

Introduction. Mitochondrial damage and disruption in oxidative phosphorylation contributes to the pathogenesis of alcoholic liver injury. Herein, we tested the hypothesis that the hepatoprotective actions of betaine against alcoholic liver injury occur at the level of the mitochondrial proteome. Methods. Male Wister rats were pair-fed control or ethanol-containing liquid diets supplemented with or without betaine (10 mg/mL) for 4-5 wks. Liver was examined for triglyceride accumulation, levels of methionine cycle metabolites, and alterations in mitochondrial proteins. Results. Chronic ethanol ingestion resulted in triglyceride accumulation which was attenuated in the ethanol plus betaine group. Blue native gel electrophoresis (BN-PAGE) revealed significant decreases in the content of the intact oxidative phosphorylation complexes in mitochondria from ethanol-fed animals. The alcohol-dependent loss in many of the low molecular weight oxidative phosphorylation proteins was prevented by betaine supplementation. This protection by betaine was associated with normalization of SAM : S-adenosylhomocysteine (SAH) ratios and the attenuation of the ethanol-induced increase in inducible nitric oxide synthase and nitric oxide generation in the liver. Discussion/Conclusion. In summary, betaine attenuates alcoholic steatosis and alterations to the oxidative phosphorylation system. Therefore, preservation of mitochondrial function may be another key molecular mechanism responsible for betaine hepatoprotection. PMID:22187660

Dose Dependent Effects of Reactive Oxygen and Nitrogen Species on the Function of Neuronal Nitric Oxide Synthase

PubMed Central

Sun, Jian; Druhan, Lawrence J.; Zweier, Jay L.

2014-01-01

Reactive nitrogen species (RNS) and oxygen species (ROS) have been reported to modulate the function of nitric oxide synthase (NOS); however, the precise dosedependent effects of specific RNS and ROS on NOS function are unknown. Questions remain unanswered regarding whether pathophysiological levels of RNS and ROS alter NOS function, and if this alteration is reversible. We measured the effects of peroxynitrite (ONOO-), superoxide (O2.-), hydroxyl radical (.OH), and H2O2 on nNOS activity. The results showed that NO production was inhibited in a dose-dependent manner by all four oxidants, but only O2.- and ONOO- were inhibitory at pathophysiological concentrations (≤ 50 μM). Subsequent addition of tetrahydrobiopterin (BH4) fully restored activity after O2.- exposure, while BH4 partially rescued the activity decrease induced by the other three oxidants. Furthermore, treatment with either ONOO- or O2.- stimulated nNOS uncoupling with decreased NO and enhanced O2.- generation. Thus, nNOS is reversibly uncoupled by O2.- (≤ 50 μM), but irreversibly uncoupled and inactivated by ONOO-. Additionally, we observed that the mechanism by which oxidative stress alters nNOS activity involves not only BH4 oxidation, but also nNOS monomerization as well as possible degradation of the heme. PMID:18201545

Nitric oxide and superoxide dismutase modulate endothelial progenitor cell function in type 2 diabetes mellitus.

PubMed

Hamed, Saher; Brenner, Benjamin; Aharon, Anat; Daoud, Deeb; Roguin, Ariel

2009-10-30

The function of endothelial progenitor cells (EPCs), which are key cells in vascular repair, is impaired in diabetes mellitus. Nitric oxide (NO) and reactive oxygen species can regulate EPC functions. EPCs tolerate oxidative stress by upregulating superoxide dismutase (SOD), the enzyme that neutralizes superoxide anion (O2-). Therefore, we investigated the roles of NO and SOD in glucose-stressed EPCs. The functions of circulating EPCs from patients with type 2 diabetes were compared to those from healthy individuals. Healthy EPCs were glucose-stressed, and then treated with insulin and/or SOD. We assessed O2- generation, NO production, SOD activity, and their ability to form colonies. EPCs from diabetic patients generated more O2-, had higher NAD(P)H oxidase and SOD activity, but lower NO bioavailability, and expressed higher mRNA and protein levels of p22-phox, and manganese SOD and copper/zinc SOD than those from the healthy individuals. Plasma glucose and HbA1c levels in the diabetic patients were correlated negatively with the NO production from their EPCs. SOD treatment of glucose-stressed EPCs attenuated O2- generation, restored NO production, and partially restored their ability to form colonies. Insulin treatment of glucose-stressed EPCs increased NO production, but did not change O2- generation and their ability to form colonies. However, their ability to produce NO and to form colonies was fully restored after combined SOD and insulin treatment. Our data provide evidence that SOD may play an essential role in EPCs, and emphasize the important role of antioxidant therapy in type 2 diabetic patients.

Antimicrobial Activity of Nitric Oxide-Releasing Ti-6Al-4V Metal Oxide

PubMed Central

Reger, Nina A.; Meng, Wilson S.; Gawalt, Ellen S.

2017-01-01

Titanium and titanium alloy materials are commonly used in joint replacements, due to the high strength of the materials. Pathogenic microorganisms can easily adhere to the surface of the metal implant, leading to an increased potential for implant failure. The surface of a titanium-aluminum-vanadium (Ti-6Al-4V) metal oxide implant material was functionalized to deliver an small antibacterial molecule, nitric oxide. S-nitroso-penicillamine, a S-nitrosothiol nitric oxide donor, was covalently immobilized on the metal oxide surface using self-assembled monolayers. Infrared spectroscopy was used to confirm the attachment of the S-nitrosothiol donor to the Ti-Al-4V surface. Attachment of S-nitroso-penicillamine resulted in a nitric oxide (NO) release of 89.6 ± 4.8 nmol/cm2 under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli and Staphylococcus epidermidis growth by 41.5 ± 1.2% and 25.3 ± 0.6%, respectively. Combining the S-nitrosothiol releasing Ti-6Al-4V with tetracycline, a commonly-prescribed antibiotic, increased the effectiveness of the antibiotic by 35.4 ± 1.3%, which allows for lower doses of antibiotics to be used. A synergistic effect of ampicillin with S-nitroso-penicillamine-modified Ti-6Al-4V against S. epidermidis was not observed. The functionalized Ti-6Al-4V surface was not cytotoxic to mouse fibroblasts. PMID:28635681

METHOD OF ISOTOPE CONCENTRATION

DOEpatents

Taylor, T.I.; Spindel, W.

1960-02-01

A method of concentrating N/sup 15/ in a liquid is described. Gaseous nitric oxide and at least one liquid selected from the group consisting of the aqueous oxyacids and oxides of nitrogen, wherein the atomic ratio of oxygen to nitrogen is greater than unity, are brought into intimate contact to cause an enrichment of the liquid and a depletion of the gas in N/sup 15/. The liquid is, thereafter, reacted with sulfur dioxide to produce a gas contuining nitric oxide. The gas contuining nitric oxide is then continuously passed in countercurrent contact with the liquid to cause further enrichment of the liquid.

21 CFR 862.3080 - Breath nitric oxide test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... fractional nitric oxide concentration in expired breath aids in evaluating an asthma patient's response to anti-inflammatory therapy, as an adjunct to established clinical and laboratory assessments of asthma...

S-Nitroglutathione, a product of the reaction between peroxynitrite and glutathione that generates nitric oxide.

PubMed

Balazy, M; Kaminski, P M; Mao, K; Tan, J; Wolin, M S

1998-11-27

Peroxynitrite (ONOO-) has been shown in studies on vascular relaxation and guanylate cyclase activation to react with glutathione (GSH), generating an intermediate product that promotes a time-dependent production of nitric oxide (NO). In this study, reactions of ONOO- with GSH produced a new substance, which was characterized by liquid chromatography, ultraviolet spectroscopy, and electrospray tandem mass spectrometry. The mass spectrometric data provided evidence that the product of this reaction was S-nitroglutathione (GSNO2) and that S-nitrosoglutathione (GSNO) was not a detectable product of this reaction. Further evidence was obtained by comparison of the spectral and chromatographic properties with synthetic standards prepared by reaction of GSH with nitrosonium or nitronium borofluorates. Both the synthetic and ONOO-/GSH-derived GSNO2 generated a protonated ion, GSNO2H+, at m/z 353, which was unusually resistant to decomposition under collision activation, and no fragmentation was observed at collision energy of 25 eV. In contrast, an ion at m/z 337 (GSNOH+), generated from the synthetic GSNO, readily fragmented with the abundant loss of NO at 9 eV. Reactions of ONOO- with GSH resulted in the generation of NO, which was detected by the head space/NO-chemiluminescence analyzer method. The generation of NO was inhibited by the presence of glucose and/or CO2 in the buffers employed. Synthetic GSNO2 spontaneously generated NO in a manner that was not significantly altered by glucose or CO2. Thus, ONOO- reacts with GSH to form GSNO2, and GSNO2 decomposes in a manner that generates NO.

Corn silk induces nitric oxide synthase in murine macrophages.

PubMed

Kim, Kyung A; Choi, Sang Kyu; Choi, Hye Seon

2004-12-31

Corn silk has been purified as an anticoagulant previously and the active component is a polysaccharide with a molecular mass of 135 kDa. It activates murine macrophages to induce nitric oxide synthase (NOS) and generate substantial amounts of NO in time and dose-dependent manners. It was detectable first at 15 h after stimulation by corn silk, peaked at 24 h, and undetectable by 48 h. Induction of NOS is inhibited by pyrolidine dithiocarbamate (PDTC) and genistein, an inhibitor of nuclear factor kappa B (NF-kappaB) and tyrosine kinase, respectively, indicating that iNOS stimulated by corn silk is associated with tyrosine kinase and NF-kappaB signaling pathways. IkappaB-alpha degradation was detectible at 10 min, and the level was restored at 120 min after treatment of corn silk. Corn silk induced nuclear translocation of NF-kappaB by phosphorylation and degradation of IkappaB-alpha.

Identification and functional analysis of endogenous nitric oxide in a filamentous fungus.

PubMed

Pengkit, Anchalee; Jeon, Seong Sil; Son, Soo Ji; Shin, Jae Ho; Baik, Ku Yeon; Choi, Eun Ha; Park, Gyungsoon

2016-07-18

In spite of its prevalence in animals and plants, endogenous nitric oxide (NO) has been rarely reported in fungi. We present here our observations on production of intracellular NO and its possible roles during development of Neurospora crassa, a model filamentous fungus. Intracellular NO was detected in hypha 8-16 hours after incubation in Vogel's minimal liquid media and conidiophores during conidiation using a fluorescent indicator (DAF-FM diacetate). Treatment with cPTIO, an NO scavenger, significantly reduced fluorescence levels and hindered hyphal growth in liquid media and conidiation, whereas exogenous NO enhanced hyphal extension on VM agar media and conidia formation. NO scavenging also dramatically diminished transcription of con-10 and con-13, genes preferentially expressed during conidiation. Our results suggest that intracellular NO is generated in young hypha growing in submerged culture and during conidia development and regulate mycelial development and conidia formation.

Nitric oxide prevents a pathogen permissive granulocytic inflammation during tuberculosis

PubMed Central

Mishra, Bibhuti B.; Lovewell, Rustin R.; Olive, Andrew J; Zhang, Guoliang; Wang, Wenfei; Eugenin, Eliseo; Smith, Clare M; Yao, Jia Phuah; Long, Jarukit E; Dubuke, Michelle L; Palace, Samantha G.; Goguen, Jon D.; Baker, Richard E.; Nambi, Subhalaxmi; Mishra, Rabinarayan; Booty, Matthew G; Baer, Christina E.; Shaffer, Scott A; Dartois, Veronique; McCormick, Beth; Chen, Xinchun; Sassetti, Christopher M.

2017-01-01

Nitric oxide (NO) contributes to protection from tuberculosis (TB). It is generally assumed that this protection is due to direct inhibition of Mycobacterium tuberculosis (Mtb) growth, which prevents subsequent pathological inflammation. In contrast, we report NO primarily protects mice by repressing an interleukin-1 and 12/15-lipoxygenase dependent neutrophil recruitment cascade that promotes bacterial replication. Using Mtb mutants as indicators of the pathogen's environment, we inferred that granulocytic inflammation generates a nutrient-replete niche that supports Mtb growth. Parallel clinical studies indicate that a similar inflammatory pathway promotes TB in patients. The human 12/15 lipoxygenase ortholog, ALOX12, is expressed in cavitary TB lesions, the abundance of its products correlate with the number of airway neutrophils and bacterial burden, and a genetic polymorphism that increases ALOX12 expression is associated with TB risk. These data suggest that Mtb exploits neutrophilic inflammation to preferentially replicate at sites of tissue damage that promote contagion. PMID:28504669

Zeb1-Hdac2-eNOS circuitry identifies early cardiovascular precursors in naive mouse embryonic stem cells.

PubMed

Cencioni, Chiara; Spallotta, Francesco; Savoia, Matteo; Kuenne, Carsten; Guenther, Stefan; Re, Agnese; Wingert, Susanne; Rehage, Maike; Sürün, Duran; Siragusa, Mauro; Smith, Jacob G; Schnütgen, Frank; von Melchner, Harald; Rieger, Michael A; Martelli, Fabio; Riccio, Antonella; Fleming, Ingrid; Braun, Thomas; Zeiher, Andreas M; Farsetti, Antonella; Gaetano, Carlo

2018-03-29

Nitric oxide (NO) synthesis is a late event during differentiation of mouse embryonic stem cells (mESC) and occurs after release from serum and leukemia inhibitory factor (LIF). Here we show that after release from pluripotency, a subpopulation of mESC, kept in the naive state by 2i/LIF, expresses endothelial nitric oxide synthase (eNOS) and endogenously synthesizes NO. This eNOS/NO-positive subpopulation (ESNO+) expresses mesendodermal markers and is more efficient in the generation of cardiovascular precursors than eNOS/NO-negative cells. Mechanistically, production of endogenous NO triggers rapid Hdac2 S-nitrosylation, which reduces association of Hdac2 with the transcriptional repression factor Zeb1, allowing mesendodermal gene expression. In conclusion, our results suggest that the interaction between Zeb1, Hdac2, and eNOS is required for early mesendodermal differentiation of naive mESC.

Identification and functional analysis of endogenous nitric oxide in a filamentous fungus

PubMed Central

Pengkit, Anchalee; Jeon, Seong Sil; Son, Soo Ji; Shin, Jae Ho; Baik, Ku Yeon; Choi, Eun Ha; Park, Gyungsoon

2016-01-01

In spite of its prevalence in animals and plants, endogenous nitric oxide (NO) has been rarely reported in fungi. We present here our observations on production of intracellular NO and its possible roles during development of Neurospora crassa, a model filamentous fungus. Intracellular NO was detected in hypha 8–16 hours after incubation in Vogel’s minimal liquid media and conidiophores during conidiation using a fluorescent indicator (DAF-FM diacetate). Treatment with cPTIO, an NO scavenger, significantly reduced fluorescence levels and hindered hyphal growth in liquid media and conidiation, whereas exogenous NO enhanced hyphal extension on VM agar media and conidia formation. NO scavenging also dramatically diminished transcription of con-10 and con-13, genes preferentially expressed during conidiation. Our results suggest that intracellular NO is generated in young hypha growing in submerged culture and during conidia development and regulate mycelial development and conidia formation. PMID:27425220

Reactions of a Chromium(III)-Superoxo Complex and Nitric Oxide That Lead to the Formation of Chromium(IV)-Oxo and Chromium(III)-Nitrito Complexes

PubMed Central

Yokoyama, Atsutoshi; Cho, Kyung-Bin

2013-01-01

The reaction of an end-on Cr(III)-superoxo complex bearing a 14-membered tetraazamacrocyclic TMC ligand, [CrIII(14-TMC)(O2)(Cl)]+, with nitric oxide (NO) resulted in the generation of a stable Cr(IV)-oxo species, [CrIV(14-TMC)(O)(Cl)]+, via the formation of a Cr(III)-peroxynitrite intermediate and homolytic O-O bond cleavage of the peroxynitrite ligand. Evidence for the latter comes from EPR spectroscopy, computational chemistry, and the observation of phenol nitration chemistry. The Cr(IV)-oxo complex does not react with nitrogen dioxide (NO2), but reacts with NO to afford a Cr(III)-nitrito complex, [CrIII(14-TMC)(NO2)(Cl)]+. The Cr(IV)-oxo and Cr(III)-nitrito complexes were also characterized spectroscopically and/or structurally. PMID:24066924

Bioimaging techniques for subcellular localization of plant hemoglobins and measurement of hemoglobin-dependent nitric oxide scavenging in planta.

PubMed

Hebelstrup, Kim H; Østergaard-Jensen, Erik; Hill, Robert D

2008-01-01

Plant hemoglobins are ubiquitous in all plant families. They are expressed at low levels in specific tissues. Several studies have established that plant hemoglobins are scavengers of nitric oxide (NO) and that varying the endogenous level of hemoglobin in plant cells negatively modulates bioactivity of NO generated under hypoxic conditions or during cellular signaling. Earlier methods for determination of hemoglobin-dependent scavenging in planta were based on measuring activity in whole plants or organs. Plant hemoglobins do not contain specific organelle localization signals; however, earlier reports on plant hemoglobin have demonstrated either cytosolic or nuclear localization, depending on the method or cell type investigated. We have developed two bioimaging techniques: one for visualization of hemoglobin-catalyzed scavenging of NO in specific cells and another for visualization of subcellular localization of green fluorescent protein-tagged plant hemoglobins in transformed Arabidopsis thaliana plants.

[The effect of electromagnetic waves of very high frequency of molecular spectra of radiation and absorption of nitric oxide on the functional activity of platelets].

PubMed

Kirichuk, V F; Maĭborodin, A V; Volin, M V; Krenitskiĭ, A P; Tupikin, V D

2001-01-01

A study was made of the effect of electromagnetic EMI MMD-fluctuation on the frequencies of molecular spectra of radiation, and nitric oxide absorption under in vitro conditions on the functional activity of platelets in patients with unstable angina pectoris, with the help of a specially created generator. At amplitude-modulated and continuous modes of EMI MMD-irradiation of platelet-rich plasma for 5, 15 and 30 min the platelet functional activity decreases, which was shown up in reduction of their activation and fall of aggregative ability. The degree, to which platelet functional activity was inhibited, depended on the mode of irradiation and on duration of EMI MMD effect. The most obvious changes in platelet activation and in their readiness to aggregative response were observed at a continuous mode of irradiation within a 15 min interval.

Nitric Oxide Donor-Based Cancer Therapy: Advances and Prospects.

PubMed

Huang, Zhangjian; Fu, Junjie; Zhang, Yihua

2017-09-28

The increasing understanding of the role of nitric oxide (NO) in cancer biology has generated significant progress in the use of NO donor-based therapy to fight cancer. These advances strongly suggest the potential adoption of NO donor-based therapy in clinical practice, and this has been supported by several clinical studies in the past decade. In this review, we first highlight several types of important NO donors, including recently developed NO donors bearing a dinitroazetidine skeleton, represented by RRx-001, with potential utility in cancer therapy. Special emphasis is then given to the combination of NO donor(s) with other therapies to achieve synergy and to the hybridization of NO donor(s) with an anticancer drug/agent/fragment to enhance the activity or specificity or to reduce toxicity. In addition, we briefly describe inducible NO synthase gene therapy and nanotechnology, which have recently entered the field of NO donor therapy.

A case study of nitrogen saturation in western U.S. forests

Treesearch

Mark E. Fenn; Mark A. Poth

2001-01-01

Virtually complete nitrification of the available ammonium in soil and nitrification activity in the forest floor are important factors predisposing forests in the San Bernardino Mountains of southern California to nitrogen (N) saturation. As a result, inorganic N in the soil solution is dominated by nitrate. High nitrification rates also generate elevated nitric oxide...

Assessment of nitric oxide production in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome with the use of a stable isotope tracer infusion technique

USDA-ARS?s Scientific Manuscript database

Mitochondrial disorders result from dysfunctional mitochondria that are unable to generate sufficient energy to meet the needs of various organs. Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the most frequent maternally inherited mitochondrial...

Dual Role of Endothelial Nitric Oxide Synthase in Oxidized LDL-Induced, p66Shc-Mediated Oxidative Stress in Cultured Human Endothelial Cells

PubMed Central

Shi, Yi; Lüscher, Thomas F.; Camici, Giovanni G.

2014-01-01

Background The aging gene p66Shc, is an important mediator of oxidative stress-induced vascular dysfunction and disease. In cultured human aortic endothelial cells (HAEC), p66Shc deletion increases endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) bioavailability via protein kinase B. However, the putative role of the NO pathway on p66Shc activation remains unclear. This study was designed to elucidate the regulatory role of the eNOS/NO pathway on p66Shc activation. Methods and Results Incubation of HAEC with oxidized low density lipoprotein (oxLDL) led to phosphorylation of p66Shc at Ser-36, resulting in an enhanced production of superoxide anion (O2 -). In the absence of oxLDL, inhibition of eNOS by small interfering RNA or L-NAME, induced p66Shc phosphorylation, suggesting that basal NO production inhibits O2 - production. oxLDL-induced, p66Shc-mediated O2- was prevented by eNOS inhibition, suggesting that when cells are stimulated with oxLDL eNOS is a source of reactive oxygen species. Endogenous or exogenous NO donors, prevented p66Shc activation and reduced O2- production. Treatment with tetrahydrobiopterin, an eNOS cofactor, restored eNOS uncoupling, prevented p66Shc activation, and reduced O2- generation. However, late treatment with tetrahydropterin did not yield the same result suggesting that eNOS uncoupling is the primary source of reactive oxygen species. Conclusions The present study reports that in primary cultured HAEC treated with oxLDL, p66Shc-mediated oxidative stress is derived from eNOS uncoupling. This finding contributes novel information on the mechanisms of p66Shc activation and its dual interaction with eNOS underscoring the importance eNOS uncoupling as a putative antioxidant therapeutical target in endothelial dysfunction as observed in cardiovascular disease. PMID:25247687

Dual role of endothelial nitric oxide synthase in oxidized LDL-induced, p66Shc-mediated oxidative stress in cultured human endothelial cells.

PubMed

Shi, Yi; Lüscher, Thomas F; Camici, Giovanni G

2014-01-01

The aging gene p66Shc, is an important mediator of oxidative stress-induced vascular dysfunction and disease. In cultured human aortic endothelial cells (HAEC), p66Shc deletion increases endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) bioavailability via protein kinase B. However, the putative role of the NO pathway on p66Shc activation remains unclear. This study was designed to elucidate the regulatory role of the eNOS/NO pathway on p66Shc activation. Incubation of HAEC with oxidized low density lipoprotein (oxLDL) led to phosphorylation of p66Shc at Ser-36, resulting in an enhanced production of superoxide anion (O2-). In the absence of oxLDL, inhibition of eNOS by small interfering RNA or L-NAME, induced p66Shc phosphorylation, suggesting that basal NO production inhibits O2- production. oxLDL-induced, p66Shc-mediated O2- was prevented by eNOS inhibition, suggesting that when cells are stimulated with oxLDL eNOS is a source of reactive oxygen species. Endogenous or exogenous NO donors, prevented p66Shc activation and reduced O2- production. Treatment with tetrahydrobiopterin, an eNOS cofactor, restored eNOS uncoupling, prevented p66Shc activation, and reduced O2- generation. However, late treatment with tetrahydropterin did not yield the same result suggesting that eNOS uncoupling is the primary source of reactive oxygen species. The present study reports that in primary cultured HAEC treated with oxLDL, p66Shc-mediated oxidative stress is derived from eNOS uncoupling. This finding contributes novel information on the mechanisms of p66Shc activation and its dual interaction with eNOS underscoring the importance eNOS uncoupling as a putative antioxidant therapeutical target in endothelial dysfunction as observed in cardiovascular disease.

Application of Cavity Enhanced Absorption Spectroscopy to the Detection of Nitric Oxide, Carbonyl Sulphide, and Ethane—Breath Biomarkers of Serious Diseases

PubMed Central

Wojtas, Jacek

2015-01-01

The paper presents one of the laser absorption spectroscopy techniques as an effective tool for sensitive analysis of trace gas species in human breath. Characterization of nitric oxide, carbonyl sulphide and ethane, and the selection of their absorption lines are described. Experiments with some biomarkers showed that detection of pathogenic changes at the molecular level is possible using this technique. Thanks to cavity enhanced spectroscopy application, detection limits at the ppb-level and short measurements time (<3 s) were achieved. Absorption lines of reference samples of the selected volatile biomarkers were probed using a distributed feedback quantum cascade laser and a tunable laser system consisting of an optical parametric oscillator and difference frequency generator. Setup using the first source provided a detection limit of 30 ppb for nitric oxide and 250 ppb for carbonyl sulphide. During experiments employing a second laser, detection limits of 0.9 ppb and 0.3 ppb were obtained for carbonyl sulphide and ethane, respectively. The conducted experiments show that this type of diagnosis would significantly increase chances for effective therapy of some diseases. Additionally, it offers non-invasive and real time measurements, high sensitivity and selectivity as well as minimizing discomfort for patients. For that reason, such sensors can be used in screening for early detection of serious diseases. PMID:26091398

Nitric oxide-dependent vasorelaxation induced by extractive solutions and fractions of Maytenus ilicifolia Mart ex Reissek (Celastraceae) leaves.

PubMed

Rattmann, Yanna D; Cipriani, Thales R; Sassaki, Guilherme L; Iacomini, Marcello; Rieck, Lia; Marques, Maria C A; da Silva-Santos, José E

2006-04-06

This study reveals that an ethanolic supernatant obtained from an aqueous extractive solution prepared from residues of methanolic extracts of ground leaves of Maytenus ilicifolia is able to cause a concentration- and endothelium-dependent relaxation in pre-contract rat aorta rings, with EC(50) of 199.7 (190-210) microg/ml. The non-selective nitric oxide synthase inhibitors l-NAME and l-NMMA abolished this effect, while superoxide dismutase and MnTBAP (a non-enzymatic superoxide dismutase mimetic) enhanced it. Further, relaxation induced by this ethanolic supernatant have been strongly inhibited by the guanylate cyclase inhibitors methylene blue and ODQ, as well as by the potassium channel blockers 4-aminopyridine and tetraethylammonium, but was unchanged by the cyclooxygenase inhibitor indomethacin and the membrane receptor antagonists atropine, HOE-140 and pirilamine. Partition of the ethanolic supernatant between H(2)O and EtOAc generated a fraction several times more potent, able to fully relax endothelium-intact aorta rings with an EC(50) of 4.3 (3.9-4.8) microg/ml. (13)C NMR spectrum of this fraction showed signals typical of catechin. This study reveals that the leaves of M. ilicifolia possess one or more potent substances able to relax endothelium-intact rat aorta rings, an event that appears to involve nitric oxide production, guanylate cyclase activation and potassium channel opening.

Application of Cavity Enhanced Absorption Spectroscopy to the Detection of Nitric Oxide, Carbonyl Sulphide, and Ethane--Breath Biomarkers of Serious Diseases.

PubMed

Wojtas, Jacek

2015-06-17

The paper presents one of the laser absorption spectroscopy techniques as an effective tool for sensitive analysis of trace gas species in human breath. Characterization of nitric oxide, carbonyl sulphide and ethane, and the selection of their absorption lines are described. Experiments with some biomarkers showed that detection of pathogenic changes at the molecular level is possible using this technique. Thanks to cavity enhanced spectroscopy application, detection limits at the ppb-level and short measurements time (<3 s) were achieved. Absorption lines of reference samples of the selected volatile biomarkers were probed using a distributed feedback quantum cascade laser and a tunable laser system consisting of an optical parametric oscillator and difference frequency generator. Setup using the first source provided a detection limit of 30 ppb for nitric oxide and 250 ppb for carbonyl sulphide. During experiments employing a second laser, detection limits of 0.9 ppb and 0.3 ppb were obtained for carbonyl sulphide and ethane, respectively. The conducted experiments show that this type of diagnosis would significantly increase chances for effective therapy of some diseases. Additionally, it offers non-invasive and real time measurements, high sensitivity and selectivity as well as minimizing discomfort for patients. For that reason, such sensors can be used in screening for early detection of serious diseases.

Variation of nitric oxide concentration before the Kobe earthquake, Japan

NASA Astrophysics Data System (ADS)

Matsuda, Tokiyoshi; Ikeya, Motoji

The variation and spatial distribution of the atmospheric concentration of nitric oxide (NO) near the epicenter of the Kobe earthquake at local time 5:46, 17 January 1995 have been studied using data at monitoring stations of the local environmental protection agencies. The concentration of NO 8 days before the earthquake was 199 ppb, about ten times larger than the average peak level of 19 ppb, accompanying the retrospectively reported precursory earthquake lightning, increase of radon concentration in well water and of the counts of electromagnetic (EM) signals. The reported thunderstorm over the Japan Sea about 150 km away was too far for the thunder-generated NO to reach the epicenter area. The concentration of NO was also found to have increased before other major earthquakes (Magnitude>5.0) in Japan. Atmospheric discharges by electric charges or EM waves before earthquakes may have generated NO. However, the generation of NO by human activities of fuel combustion soon after holidays is enormously high every year, which makes it difficult to clearly link the increase with the earthquakes. The increase soon after the earthquake due to traffic jams is clear. The concentration of NO should be monitored at a several sites away from human activities as background data of natural variation and to study its generation at a seismic area before a large earthquake.

Nitric Oxide Induces Ca2+-independent Activity of the Ca2+/Calmodulin-dependent Protein Kinase II (CaMKII)*

PubMed Central

Coultrap, Steven J.; Bayer, K. Ulrich

2014-01-01

Both signaling by nitric oxide (NO) and by the Ca2+/calmodulin (CaM)-dependent protein kinase II α isoform (CaMKIIα) are implicated in two opposing forms of synaptic plasticity underlying learning and memory, as well as in excitotoxic/ischemic neuronal cell death. For CaMKIIα, these functions specifically involve also Ca2+-independent autonomous activity, traditionally generated by Thr-286 autophosphorylation. Here, we demonstrate that NO-induced S-nitrosylation of CaMKIIα also directly generated autonomous activity, and that CaMKII inhibition protected from NO-induced neuronal cell death. NO induced S-nitrosylation at Cys-280/289, and mutation of either site abolished autonomy, indicating that simultaneous nitrosylation at both sites was required. Additionally, autonomy was generated only when Ca2+/CaM was present during NO exposure. Thus, generation of this form of CaMKIIα autonomy requires simultaneous signaling by NO and Ca2+. Nitrosylation also significantly reduced subsequent CaMKIIα autophosphorylation specifically at Thr-286, but not at Thr-305. A previously described reduction of CaMKII activity by S-nitrosylation at Cys-6 was also observed here, but only after prolonged (>5 min) exposure to NO donors. These results demonstrate a novel regulation of CaMKII by another second messenger system and indicate its involvement in excitotoxic neuronal cell death. PMID:24855644

Influence of chirality on catalytic generation of nitric oxide and platelet behavior on selenocystine immobilized TiO2 films.

PubMed

Fan, Yonghong; Pan, Xiaxin; Wang, Ke; Wu, Sisi; Han, Honghong; Yang, Ping; Luo, Rifang; Wang, Hong; Huang, Nan; Tan, Wei; Weng, Yajun

2016-09-01

As nitric oxide (NO) plays vital roles in the cardiovascular system, incorporating this molecule into cardiovascular stents is considered as an effective method. In the present study, selenocystine with different chirality (i.e., l- and d-selenocystine) was used as the catalytic molecule immobilized on TiO2 films for decomposing endogenous NO donor. The influences of surface chirality on NO release and platelet behavior were evaluated. Results show that although the amount of immobilized l-selenocystine on the surface was nearly the same as that of immobilized d-selenocystine, in vitro catalytic NO release tests showed that l-selenocystine immobilized surfaces were more capable of catalyzing the decomposition of S-nitrosoglutathione and thus generating more NO. Accordingly, l-selenocystine immobilized surfaces demonstrated significantly increased inhibiting effects on the platelet adhesion and activation, when compared to d-selenocystine immobilized ones. Measurement of the cGMP concentration of platelets further confirmed that surface chirality played an important role in regulating NO generation and platelet behaviors. Additionally, using bovine serum albumin and fibrinogen as model proteins, the protein adsorption determined with quartz crystal microbalance showed that the l-selenocystine immobilized surface enhanced protein adsorption. In conclusion, surface chirality significantly influences protein adsorption and NO release, which may have significant implications in the design of NO-generating cardiovascular stents. Copyright © 2016 Elsevier B.V. All rights reserved.

Nitric oxide induces hypoxia ischemic injury in the neonatal brain via the disruption of neuronal iron metabolism.

PubMed

Lu, Qing; Harris, Valerie A; Rafikov, Ruslan; Sun, Xutong; Kumar, Sanjiv; Black, Stephen M

2015-12-01

We have recently shown that increased hydrogen peroxide (H2O2) generation is involved in hypoxia-ischemia (HI)-mediated neonatal brain injury. H2O2 can react with free iron to form the hydroxyl radical, through Fenton Chemistry. Thus, the objective of this study was to determine if there was a role for the hydroxyl radical in neonatal HI brain injury and to elucidate the underlying mechanisms. Our data demonstrate that HI increases the deposition of free iron and hydroxyl radical formation, in both P7 hippocampal slice cultures exposed to oxygen-glucose deprivation (OGD), and the neonatal rat exposed to HI. Both these processes were found to be nitric oxide (NO) dependent. Further analysis demonstrated that the NO-dependent increase in iron deposition was mediated through increased transferrin receptor expression and a decrease in ferritin expression. This was correlated with a reduction in aconitase activity. Both NO inhibition and iron scavenging, using deferoxamine administration, reduced hydroxyl radical levels and neuronal cell death. In conclusion, our results suggest that increased NO generation leads to neuronal cell death during neonatal HI, at least in part, by altering iron homeostasis and hydroxyl radical generation. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Tissue injury and repair following cutaneous exposure of mice to sulfur mustard

PubMed Central

Joseph, Laurie B.; Composto, Gabriella; Heck, Diane E.

2016-01-01

In mouse skin, sulfur mustard is a potent vesicant, damaging both the epidermis and the dermis. The extent of wounding is dependent on the dose of sulfur mustard and the duration of exposure. Initial responses include erythema, pruritus, edema, and xerosis; this is followed by an accumulation of inflammatory leukocytes in the tissue, activation of mast cells, and the release of mediators, including proinflammatory cytokines and bioactive lipids. These proinflammatory mediators contribute to damaging the epidermis, hair follicles, and sebaceous glands and to disruption of the epidermal basement membrane. This can lead to separation of the epidermis from the dermis, resulting in a blister, which ruptures, leading to the formation of an eschar. The eschar stimulates the formation of a neoepidermis and wound repair and may result in persistent epidermal hyperplasia. Epidermal damage and repair is associated with upregulation of enzymes generating proinflammatory and progrowth/pro–wound healing mediators, including cyclooxygenase-2 (COX-2), which generates prostanoids, inducible nitric oxide synthase (iNOS), which generates nitric oxide, fibroblast growth factor receptor 2 (FGFR2), and galectin-3. Characterization of the mediators regulating structural changes in the skin during sulfur mustard–induced tissue damage and wound healing will aid in the development of therapeutic modalities to mitigate toxicity and stimulate tissue repair processes. PMID:27371823

Tissue injury and repair following cutaneous exposure of mice to sulfur mustard.

PubMed

Joseph, Laurie B; Composto, Gabriella M; Heck, Diane E

2016-08-01

In mouse skin, sulfur mustard (SM) is a potent vesicant, damaging both the epidermis and the dermis. The extent of wounding is dependent on the dose of SM and the duration of exposure. Initial responses include erythema, pruritus, edema, and xerosis; this is followed by an accumulation of inflammatory leukocytes in the tissue, activation of mast cells, and the release of mediators, including proinflammatory cytokines and bioactive lipids. These proinflammatory mediators contribute to damaging the epidermis, hair follicles, and sebaceous glands and to disruption of the epidermal basement membrane. This can lead to separation of the epidermis from the dermis, resulting in a blister, which ruptures, leading to the formation of an eschar. The eschar stimulates the formation of a neoepidermis and wound repair and may result in persistent epidermal hyperplasia. Epidermal damage and repair is associated with upregulation of enzymes generating proinflammatory and pro-growth/pro-wound healing mediators, including cyclooxygenase-2, which generates prostanoids, inducible nitric oxide synthase, which generates nitric oxide, fibroblast growth factor receptor 2, and galectin-3. Characterization of the mediators regulating structural changes in the skin during SM-induced tissue damage and wound healing will aid in the development of therapeutic modalities to mitigate toxicity and stimulate tissue repair processes. © 2016 New York Academy of Sciences.

The occurrence and control of nitric oxide generation by the plant mitochondrial electron transport chain.

PubMed

Alber, Nicole A; Sivanesan, Hampavi; Vanlerberghe, Greg C

2017-07-01

The plant mitochondrial electron transport chain (ETC) is bifurcated such that electrons from ubiquinol are passed to oxygen via the usual cytochrome path or through alternative oxidase (AOX). We previously showed that knockdown of AOX in transgenic tobacco increased leaf concentrations of nitric oxide (NO), implying that an activity capable of generating NO had been effected. Here, we identify the potential source of this NO. Treatment of leaves with antimycin A (AA, Q i -site inhibitor of Complex III) increased NO amount more than treatment with myxothiazol (Myxo, Q o -site inhibitor) despite both being equally effective at inhibiting respiration. Comparison of nitrate-grown wild-type with AOX knockdown and overexpression plants showed a negative correlation between AOX amount and NO amount following AA. Further, Myxo fully negated the ability of AA to increase NO amount. With ammonium-grown plants, neither AA nor Myxo strongly increased NO amount in any plant line. When these leaves were supplied with nitrite alongside the AA or Myxo, then the inhibitor effects across lines mirrored that of nitrate-grown plants. Hence the ETC, likely the Q-cycle of Complex III generates NO from nitrite, and AOX reduces this activity by acting as a non-energy-conserving electron sink upstream of Complex III. © 2016 John Wiley & Sons Ltd.

Inducible nitric oxide synthase expression is reduced in cystic fibrosis murine and human airway epithelial cells.

PubMed Central

Kelley, T J; Drumm, M L

1998-01-01

It has been reported that exhaled nitric oxide levels are reduced in cystic fibrosis (CF) patients. We have examined the inducible isoform of nitric oxide synthase (iNOS) in the airways by immunostaining and found that iNOS is constitutively expressed in the airway epithelia of non-CF mouse and human tissues but essentially absent in the epithelium of CF airways. We explored potential consequences of lost iNOS expression and found that iNOS inhibition significantly increases mouse nasal trans-epithelial potential difference, and hindered the ability of excised mouse lungs to prevent growth of Pseudomonas aeruginosa. The absence of continuous nitric oxide production in epithelial cells of CF airways may play a role in two CF-associated characteristics: hyperabsorption of sodium and susceptibility to bacterial infections. PMID:9739054

Possible involvement of nitric oxide in pilocarpine induced seminal emission in rats.

PubMed

Tomé, A R; da Silva, J C; Souza, A A; Mattos, J P; Vale, M R; Rao, V S

1999-12-01

Intraperitoneal injection of pilocarpine (0.75-3.0 mg/kg) caused a dose-related seminal emission in adult male rats. The seminal emission response to 3 mg/kg of pilocarpine was greatly reduced in atropinized (5 and 10 mg/kg, SC) animals, suggesting a cholinomimetic effect. Nw-nitro-L-arginine methyl ester (5, 10, and 20 mg/kg, SC), a nitric oxide synthesis inhibitor, also inhibited the pilocarpine-induced seminal emission, which was reversed by L-arginine (600 mg/kg, SC) or by coinjection of sodium nitroprusside (0.5 mg/kg, SC). Urine analysis for levels of nitric oxide metabolites, nitrate/nitrite (NO3-/NO2-), showed marked alterations in accordance with the drug treatments. The results suggest that nitric oxide mediates the inhibitory neurotransmission responsible for seminal emission in pilocarpine stimulated rats.

Role of nitric oxide in in vitro contractile activity of the third compartment of the stomach in llamas.

PubMed

Van Hoogmoed, L; Rakestraw, P C; Snyder, J R; Harmon, F A

1998-09-01

To determine the role of nitric oxide and an apamin-sensitive nonadrenergic-noncholinergic inhibitory transmitter in in vitro contractile activity of the third compartment in llamas. Isolated strips of third compartment of the stomach from 5 llamas. Strips were mounted in tissue baths containing oxygenated Kreb's buffer solution and connected to a polygraph chart recorder to measure contractile activity. Atropine, guanethidine, and indomethacin were added to tissue baths to inhibit muscarinic receptors, adrenoreceptors, and prostaglandin synthesis. Responses to electrical field stimulation following addition of the nitric oxide antagonist Nwo-nitro-L-arginine methyl ester (L-NAME) and apamin were evaluated. Electrical field stimulation (EFS) resulted in a reduction in the amplitude and frequency of contractile activity, followed by rebound contraction when EFS was stopped. Addition of L-NAME resulted in a significant reduction in inhibition of contractile activity. Addition of apamin also resulted in a significant reduction in inhibitory contractile activity at most stimulation frequencies. The combination of L-NAME and apamin resulted in a significant reduction in inhibition at all frequencies. Nitric oxide and a transmitter acting via an apamin-sensitive mechanism appear to be involved in inhibition of contractile activity of the third compartment in llamas. Results suggest that nitric oxide plays an important role in mediating contractile activity of the third compartment in llamas. Use of nitric oxide synthase inhibitors may have a role in the therapeutic management of llamas with lesions of the third compartment.

Improvement of Tissue Survival of Skin Flaps by 5α-Reductase Inhibitors: Possible Involvement of Nitric Oxide and Inducible Nitric Oxide Synthase

PubMed Central

Karimi, Ali Asghar; Ajami, Marjan; Asadi, Yasin; Aboutaleb, Nahid; Gorjipour, Fazel; Malekloo, Roya; Pazoki-Toroudi, Hamidreza

2015-01-01

Background: Skin flap grafting is a popular approach for reconstruction of critical skin and underlying soft tissue injuries. In a previous study, we demonstrated the beneficial effects of two 5α-reductase inhibitors, azelaic acid and finasteride, on tissue survival in a rat model of skin flap grafting. In the current study, we investigated the involvement of nitric oxide and inducible nitric oxide synthase (iNOS) in graft survival mediated by these agents. Methods: A number of 42 male rats were randomly allocated into six groups: 1, normal saline topical application; 2, azelaic acid (100 mg/flap); 3, finasteride (1 mg/flap); 4, injection of L-NG-nitroarginine methyl ester (L-NAME) (i.p., 20 mg/kg); 5, L-NAME (20 mg/kg, i.p.) + azelaic acid (100 mg/flap, topical); 6, L-NAME (20 mg/kg, i.p.) + finasteride (1 mg/flap, topical). Tissue survival, level of nitric oxide, and iNOS expression in groups were measured. Results: Our data revealed that azelaic acid and finasteride significantly increased the expression of iNOS protein and nitric oxide (NO) levels in graft tissue (P < 0.05). These increases in iNOS expression and NO level were associated with higher survival of the graft tissue. Conclusion: It appears that alterations of the NO metabolism are implicated in the azelaic acid- and finasteride-mediated survival of the skin flaps. PMID:25864816

The Nitric Acid Oxidation of Selected Alcohols and Ketones.

ERIC Educational Resources Information Center

Field, Kurt W.; And Others

1985-01-01

Shows that nitric acid can be used as a rapid, versatile, and economical oxidant for selected organic substances. The experiments (with background information, procedures, and results provided) require one three-hour laboratory period but could serve as open-ended projects since substrates not described could be oxidized. (JN)

Arsenic moiety in gallium arsenide is responsible for neuronal apoptosis and behavioral alterations in rats.

PubMed

Flora, Swaran J S; Bhatt, Kapil; Mehta, Ashish

2009-10-15

Gallium arsenide (GaAs), an intermetallic semiconductor finds widespread applications in high frequency microwave and millimeter wave, and ultra fast supercomputers. Extensive use of GaAs has led to increased exposure to humans working in semiconductor industry. GaAs has the ability to dissociate into its constitutive moieties at physiological pH and might be responsible for the oxidative stress. The present study was aimed at evaluating, the principle moiety (Ga or As) in GaAs to cause neurological dysfunction based on its ability to cause apoptosis, in vivo and in vitro and if this neuronal dysfunction translated to neurobehavioral changes in chronically exposed rats. Result indicated that arsenic moiety in GaAs was mainly responsible for causing oxidative stress via increased reactive oxygen species (ROS) and nitric oxide (NO) generation, both in vitro and in vivo. Increased ROS further caused apoptosis via mitochondrial driven pathway. Effects of oxidative stress were also confirmed based on alterations in antioxidant enzymes, GPx, GST and SOD in rat brain. We noted that ROS induced oxidative stress caused changes in the brain neurotransmitter levels, Acetylcholinesterase and nitric oxide synthase, leading to loss of memory and learning in rats. The study demonstrates for the first time that the slow release of arsenic moiety from GaAs is mainly responsible for oxidative stress induced apoptosis in neuronal cells causing behavioral changes.

Bio-Physicochemical Interactions of Engineered Nanomaterials in in Vitro Cell Culture Model

DTIC Science & Technology

2014-10-11

are the important factors to study their toxicity . To investigate the potential role of oxidative stress as a mechanism of toxicity , reactive oxygen...of oxidative stress as a mechanism of toxicity , reactive oxygen species (ROS), nitric oxide (NO) lactate dehydrogenase (LDH) level and reduction in...potential role of oxidative stress as a mechanism of toxicity , reactive oxygen species (ROS), nitric oxide (NO), lactate dehydrogenase (LDH) level

Endothelium-derived relaxing factor (nitric oxide) has protective actions in the stomach

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacNaughton, W.K.; Wallace, J.L.; Cirino, G.

1989-01-01

The role that nitric oxide, an endothelium-derived relaxing factor, may play in the regulation of gastric mucosal defense was investigated by assessing the potential protective actions of this factor against the damage caused by ethanol in an ex vivo chamber preparation of the rat stomach. Topical application of glyceryl trinitrate and sodium nitroprusside, which have been shown to release nitric oxide, markedly reduced the area of 70% ethanol-induced hemorrhagic damage. Topical application of a 0.01% solution of authentic nitric oxide also significantly reduced the severity of mucosal damage. Pretreatment with indomethacin precluded the involvement of endogenous prostaglandins in the protectivemore » effects of these agents. The protective effects of NO were transient, since a delay of 5 minutes between NO administration and ethanal administration resulted in a complete loss of the protective activity. The protection against ethanol afforded by 10 ug/ml nitroprusside could be completely reversed by intravenous infusion of either 1% methylene blue or 1 mM hemoglobin, both of which inhibit vasodilation induced by nitric oxide. Intravenous infusion of 1% methylene blue significantly increased the susceptibility of the mucosa to damage induced by topical 20% ethanol.« less

The effect of piracetam on brain damage and serum nitric oxide levels in dogs submitted to hemorrhagic shock.

PubMed

Ozkan, Seda; Ikizceli, Ibrahim; Sözüer, Erdoğan Mütevelli; Avşaroğullari, Levent; Oztürk, Figen; Muhtaroğlu, Sebahattin; Akdur, Okhan; Küçük, Can; Durukan, Polat

2008-10-01

To demonstrate the effect of piracetam on changes in brain tissue and serum nitric oxide levels in dogs submitted to hemorrhagic shock. The subjects were randomized into four subgroups each consisting of 10 dogs. Hemorrhagic shock was induced in Group I for 1 hour and no treatment was given to this group. Blood and saline solutions were administered to Group II following 1 hour hemorrhagic shock. Blood and piracetam were given to Group III following 1 hour shock. No shock was induced and no treatment was applied to Group IV. Blood samples were obtained at the onset of the experiment and at 60, 120 and 180 minutes for nitric oxide analysis. For histopathological examination, brain tissue samples were obtained at the end of the experiment. The observed improvement in blood pressure and pulse rates in Group III was more than in Group II. Nitric oxide levels were increased in Group I; however, no correlation between piracetam and nitric oxide levels was determined. It was seen that recovery in brain damage in Group III was greater than in the control group. Piracetam, added to the treatment, may ecrease ischemic damage in hemorrhagic shock.

Sport physiology, dopamine and nitric oxide - Some speculations and hypothesis generation.

PubMed

Landers, J G; Esch, Tobias

2015-12-01

Elite Spanish professional soccer players surprisingly showed a preponderance of an allele coding for nitric oxide synthase (NOS) that resulted in lower nitric oxide (NO) compared with Spanish endurance and power athletes and sedentary men. The present paper attempts a speculative explanation. Soccer is an "externally-paced" (EP) sport and team work dependent, requiring "executive function skills". We accept that time interval estimation skill is, in part, also an executive skill. Dopamine (DA) is prominent among the neurotransmitters with a role in such skills. Polymorphisms affecting dopamine (especially DRD2/ANKK1-Taq1a which leads to lower density of dopamine D2 receptors in the striatum, leading to increased striatal dopamine synthesis) and COMT val 158 met (which prolongs the action of dopamine in the cortex) feature both in the time interval estimation and the executive skills literatures. Our paper may be a pioneering attempt to stimulate empirical efforts to show how genotypes among soccer players may be connected via neurotransmitters to certain cognitive abilities that predict sporting success, perhaps also in some other externally-paced team sports. Graphing DA levels against time interval estimation accuracy and also against certain executive skills reveals an inverted-U relationship. A pathway from DA, via endogenous morphine and mu3 receptors on endothelia, to the generation of NO in tiny quantities has been demonstrated. Exercise up-regulates DA and this pathway. With somewhat excessive exercise, negative feedback from NO down-regulates DA, hypothetically keeping it near the peak of the inverted-U. Other research, not yet done on higher animals or humans, shows NO "fine-tuning" movement. We speculate that Caucasian men, playing soccer recreationally, would exemplify the above pattern and their nitric oxide synthase (NOS) would reflect the norm of their community, whereas professional players of soccer and perhaps other EP sports, with DA boosted by very frequent and intense practice and extra stress from public scrutiny, would potentially have their negative feedback system overwhelmed, were it not that many of them carry the C allele of the NOS3-786T/C polymorphism. Then, even very high DA would not result in so much NO as to shut the system down. We add some evolutionary speculations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nitric Oxide and Peroxynitrite in Health and Disease

PubMed Central

PACHER, PÁL; BECKMAN, JOSEPH S.; LIAUDET, LUCAS

2008-01-01

The discovery that mammalian cells have the ability to synthesize the free radical nitric oxide (NO) has stimulated an extraordinary impetus for scientific research in all the fields of biology and medicine. Since its early description as an endothelial-derived relaxing factor, NO has emerged as a fundamental signaling device regulating virtually every critical cellular function, as well as a potent mediator of cellular damage in a wide range of conditions. Recent evidence indicates that most of the cytotoxicity attributed to NO is rather due to peroxynitrite, produced from the diffusion-controlled reaction between NO and another free radical, the superoxide anion. Peroxynitrite interacts with lipids, DNA, and proteins via direct oxidative reactions or via indirect, radical-mediated mechanisms. These reactions trigger cellular responses ranging from subtle modulations of cell signaling to overwhelming oxidative injury, committing cells to necrosis or apoptosis. In vivo, peroxynitrite generation represents a crucial pathogenic mechanism in conditions such as stroke, myocardial infarction, chronic heart failure, diabetes, circulatory shock, chronic inflammatory diseases, cancer, and neurodegenerative disorders. Hence, novel pharmacological strategies aimed at removing peroxynitrite might represent powerful therapeutic tools in the future. Evidence supporting these novel roles of NO and peroxynitrite is presented in detail in this review. PMID:17237348

Patterned Electrode-Based Amperometric Gas Sensor for Direct Nitric Oxide Detection within Microfluidic Devices

PubMed Central

Cha, Wansik; Tung, Yi-Chung; Meyerhoff, Mark E.; Takayama, Shuichi

2010-01-01

This manuscript describes a thin amperometric nitric oxide (NO) sensor that can be microchannel embedded to enable direct real-time detection of NO produced by cells cultured within the microdevice. A key for achieving the thin (~ 1 mm) planar sensor configuration required for sensor-channel integration is the use of gold/indium-tin oxide patterned electrode directly on a porous polymer membrane (pAu/ITO) as the base working electrode. Electrochemically deposited Au-hexacyanoferrate layer on pAu/ITO is used to catalyze NO oxidation to nitrite at lower applied potentials (0.65 ~ 0.75 V vs. Ag/AgCl) and stabilize current output. Furthermore, use of a gas-permeable membrane to separate internal sensor compartments from the sample phase imparts excellent NO selectivity over common interferents (e.g., nitrite, ascorbate, ammonia, etc.) present in culture media and biological fluids. The optimized sensor design reversibly detects NO down to ~1 nM level in stirred buffer and <10 nM in flowing buffer when integrated within a polymeric microfluidic device. We demonstrate utility of the channel-embedded sensor by monitoring NO generation from macrophages cultured within non-gas permeable microchannels, as they are stimulated with endotoxin. PMID:20329749

Oxidative stress and NO generation in the rat pancreatitis induced by pancreatic duct ligation.

PubMed

Buchwalow, Igor; Schnekenburger, Jürgen; Atiakshin, Dmitri; Samoilova, Vera; Wolf, Eduard; Boecker, Werner; Tiemann, Katharina

2017-04-01

The interaction between nitric oxide (NO) and superoxides is critical in the development of an acute pancreatitis. Previously, we reported that the expression of superoxides and of the NO-generating enzyme (NO synthase, NOS) was up-regulated in the human pancreatitis, especially within the exocrine compartment indicating an exceptional susceptibility of the exocrine parenchyma to oxidative stress. The aim of the present study was to compare the regulation of NO signalling pathways in the human pancreatitis and in an animal model of an acute pancreatitis induced by pancreatic duct ligation (PDL) in rats. In the PDL-induced rat pancreatitis, we revealed a similar pattern of oxidative stress and NOS up-regulation in acinar and in ductal compartments, like in the human pancreatitis. This demonstrates that the PDL-induced rat pancreatitis is a proper model for further studies of acute pancreatitis development in humans. Copyright © 2017 Elsevier GmbH. All rights reserved.

Different Impact of Essential Hypertension on Structural and Functional Age-Related Vascular Changes.

PubMed

Bruno, Rosa Maria; Duranti, Emiliano; Ippolito, Chiara; Segnani, Cristina; Bernardini, Nunzia; Di Candio, Giulio; Chiarugi, Massimo; Taddei, Stefano; Virdis, Agostino

2017-01-01

We evaluated whether vascular remodeling is present in physiological aging and whether hypertension accelerates the aging process for vascular function and structure. Small arteries from 42 essential hypertensive patients (HT) and 41 normotensive individuals (NT) were dissected after subcutaneous biopsy. Endothelium-dependent vasodilation (pressurized myograph) was assessed by acetylcholine, repeated under the nitric oxide synthase inhibitor N-nitro-l-arginine methylester or the antioxidant tempol. Structure was evaluated by media-lumen ratio (M/L). Intravascular oxidative generation and collagen deposition were assessed. Inhibition by N-nitro-l-arginine methylester on ACh was inversely related to age in both groups (P<0.0001) and blunted in HT versus NT for each age range. In NT, tempol enhanced endothelial function in the oldest subgroup; in HT, the potentiating effect started earlier. HT showed an increased M/L (P<0.001) versus control. In both groups, M/L was directly related to age (P<0.0001). M/L was greater in HT, starting from 31 to 45 years range. A significant age-hypertension interaction occurred (P=0.0009). In NT, intravascular superoxide emerged in the oldest subgroup, whereas it appeared earlier among HT. Among NT, aged group displayed an increment of collagen fibers versus young group. In HT, collagen deposition was already evident in youngest, with a further enhancement in the aged group. In small arteries, ageing shows a eutrophic vascular remodeling and a reduced nitric oxide availability. Oxidative stress and fibrosis emerge in advanced age. In HT, nitric oxide availability is early reduced, but the progression rate with age is similar. Structural alterations include wide collagen deposition and intravascular reactive oxygen species, and the progression rate with age is steeper. © 2016 American Heart Association, Inc.

Microparticle formation by platelets exposed to high gas pressures - An oxidative stress response.

PubMed

Bhullar, Jasjeet; Bhopale, Veena M; Yang, Ming; Sethuraman, Kinjal; Thom, Stephen R

2016-12-01

This investigation explored the mechanism for microparticles (MPs) production by human and murine platelets exposed to high pressures of inert gases. Results demonstrate that MPs production occurs via an oxidative stress response in a dose-dependent manner and follows the potency series N 2 >Ar>He. Gases with higher van der Waals volumes or polarizability such as SF 6 and N 2 O, or hydrostatic pressure, do not cause MPs production. Singlet O 2 is generated by N 2 , Ar and He, which is linked to NADPH oxidase (NOX) activity. Progression of oxidative stress involves activation of nitric oxide synthase (NOS) leading to S-nitrosylation of cytosolic actin. Exposure to gases enhances actin filament turnover and associations between short actin filaments, NOS, vasodilator-stimulated phosphoprotein (VASP), focal adhesion kinase (FAK) and Rac1. Inhibition of NOS or NOX by chemical inhibitors or using platelets from mice lacking NOS2 or the gp91phox component of NOX diminish generation of reactive species, enhanced actin polymerization and MP generation by high pressure gases. We conclude that by initiating a sequence of progressive oxidative stress responses high pressure gases cause platelets to generate MPs. Copyright © 2016 Elsevier Inc. All rights reserved.

Targeting Nitric Oxide with Natural Derived Compounds as a Therapeutic Strategy in Vascular Diseases

PubMed Central

Forte, Maurizio; Damato, Antonio; Ambrosio, Mariateresa; Puca, Annibale A.; Sciarretta, Sebastiano; Frati, Giacomo; Vecchione, Carmine

2016-01-01

Within the family of endogenous gasotransmitters, nitric oxide (NO) is the smallest gaseous intercellular messenger involved in the modulation of several processes, such as blood flow and platelet aggregation control, essential to maintain vascular homeostasis. NO is produced by nitric oxide synthases (NOS) and its effects are mediated by cGMP-dependent or cGMP-independent mechanisms. Growing evidence suggests a crosstalk between the NO signaling and the occurrence of oxidative stress in the onset and progression of vascular diseases, such as hypertension, heart failure, ischemia, and stroke. For these reasons, NO is considered as an emerging molecular target for developing therapeutic strategies for cardio- and cerebrovascular pathologies. Several natural derived compounds, such as polyphenols, are now proposed as modulators of NO-mediated pathways. The aim of this review is to highlight the experimental evidence on the involvement of nitric oxide in vascular homeostasis focusing on the therapeutic potential of targeting NO with some natural compounds in patients with vascular diseases. PMID:27651855

Nitric oxide-induced interstrand cross-links in DNA.

PubMed

Caulfield, Jennifer L; Wishnok, John S; Tannenbaum, Steven R

2003-05-01

The DNA damaging effects of nitrous acid have been extensively studied, and the formation of interstrand cross-links have been observed. The potential for this cross-linking to occur through a common nitrosating intermediate derived from nitric oxide is investigated here. Using a HPLC laser-induced fluorescence (LIF) system, the amount of interstrand cross-link formed on nitric oxide treatment of the 5'-fluorescein-labeled oligomer ATATCGATCGATAT was determined. This self-complimentary sequence contains two 5'-CG sequences, which is the preferred site for nitrous acid-induced cross-linking. Nitric oxide was delivered to an 0.5 mM oligomer solution at 15 nmol/mL/min to give a final nitrite concentration of 652 microM. The resulting concentration of the deamination product, xanthine, in this sample was found to be 211 +/- 39 nM, using GC/MS, and the amount of interstrand cross-link was determined to be 13 +/- 2.5 nM. Therefore, upon nitric oxide treatment, the cross-link is found at approximately 6% of the amount of the deamination product. Using this system, detection of the cross-link is also possible for significantly lower doses of nitric oxide, as demonstrated by treatment of the same oligomer with NO at a rate of 18 nmol/mL/min resulting in a final nitrite concentration of 126 microM. The concentration of interstrand cross-link was determined to be 3.6 +/- 0.1 nM in this sample. Therefore, using the same dose rate, when the total nitric oxide concentration delivered drops by a factor of approximately 5, the concentration of cross-link drops by a factor of about 4-indicating a qausi-linear response. It may now be possible to predict the number of cross-links in a small genome based on the number of CpG sequences and the yield of xanthine derived from nitrosative deamination.

Nano-sized and micro-sized polystyrene particles affect phagocyte function

PubMed Central

Prietl, B.; Meindl, C.; Roblegg, E.; Pieber, T. R.; Lanzer, G.; Fröhlich, E.

2015-01-01

Adverse effect of nanoparticles may include impairment of phagocyte function. To identify the effect of nanoparticle size on uptake, cytotoxicity, chemotaxis, cytokine secretion, phagocytosis, oxidative burst, nitric oxide production and myeloperoxidase release, leukocytes isolated from human peripheral blood, monocytes and macrophages were studied. Carboxyl polystyrene (CPS) particles in sizes between 20 and 1,000 nm served as model particles. Twenty nanometers CPS particles were taken up passively, while larger CPS particles entered cells actively and passively. Twenty nanometers CPS were cytotoxic to all phagocytes, ≥500 nm CPS particles only to macrophages. Twenty nanometers CPS particles stimulated IL-8 secretion in human monocytes and induced oxidative burst in monocytes. Five hundred nanometers and 1,000 nm CPS particles stimulated IL-6 and IL-8 secretion in monocytes and macrophages, chemotaxis towards a chemotactic stimulus of monocytes and phagocytosis of bacteria by macrophages and provoked an oxidative burst of granulocytes. At very high concentrations, CPS particles of 20 and 500 nm stimulated myeloperoxidase release of granulocytes and nitric oxide generation in macrophages. Cytotoxic effect could contribute to some of the observed effects. In the absence of cytotoxicity, 500 and 1,000 nm CPS particles appear to influence phagocyte function to a greater extent than particles in other sizes. PMID:24292270

Role of Dietary Antioxidants in the Preservation of Vascular Function and the Modulation of Health and Disease

PubMed Central

Varadharaj, Saradhadevi; Kelly, Owen J.; Khayat, Rami N.; Kumar, Purnima S.; Ahmed, Naseer; Zweier, Jay L.

2017-01-01

In vascular diseases, including hypertension and atherosclerosis, vascular endothelial dysfunction (VED) occurs secondary to altered function of endothelial nitric oxide synthase (eNOS). A novel redox regulated pathway was identified through which eNOS is uncoupled due to S-glutathionylation of critical cysteine residues, resulting in superoxide free radical formation instead of the vasodilator molecule, nitric oxide. In addition, the redox sensitive cofactor tetrahydrobiopterin, BH4, is also essential for eNOS coupling. Antioxidants, either individually or combined, can modulate eNOS uncoupling by scavenging free radicals or impairing specific radical generating pathways, thus preventing oxidative stress and ameliorating VED. Epidemiological evidence and dietary guidelines suggest that diets high in antioxidants, or antioxidant supplementation, could preserve vascular health and prevent cardiovascular diseases (CVDs). Therefore, the purpose of this review is to highlight the possible role of dietary antioxidants in regulating eNOS function and uncoupling which is critical for maintenance of vascular health with normal blood flow/circulation and prevention of VED. We hypothesize that a conditioned dietary approach with suitable antioxidants may limit systemic oxidation, maintain a beneficial ratio of reduced to oxidized glutathione, and other redox markers, and minimize eNOS uncoupling serving to prevent CVD and possibly other chronic diseases. PMID:29164133

Nano-sized and micro-sized polystyrene particles affect phagocyte function.

PubMed

Prietl, B; Meindl, C; Roblegg, E; Pieber, T R; Lanzer, G; Fröhlich, E

2014-02-01

Adverse effect of nanoparticles may include impairment of phagocyte function. To identify the effect of nanoparticle size on uptake, cytotoxicity, chemotaxis, cytokine secretion, phagocytosis, oxidative burst, nitric oxide production and myeloperoxidase release, leukocytes isolated from human peripheral blood, monocytes and macrophages were studied. Carboxyl polystyrene (CPS) particles in sizes between 20 and 1,000 nm served as model particles. Twenty nanometers CPS particles were taken up passively, while larger CPS particles entered cells actively and passively. Twenty nanometers CPS were cytotoxic to all phagocytes, ≥500 nm CPS particles only to macrophages. Twenty nanometers CPS particles stimulated IL-8 secretion in human monocytes and induced oxidative burst in monocytes. Five hundred nanometers and 1,000 nm CPS particles stimulated IL-6 and IL-8 secretion in monocytes and macrophages, chemotaxis towards a chemotactic stimulus of monocytes and phagocytosis of bacteria by macrophages and provoked an oxidative burst of granulocytes. At very high concentrations, CPS particles of 20 and 500 nm stimulated myeloperoxidase release of granulocytes and nitric oxide generation in macrophages. Cytotoxic effect could contribute to some of the observed effects. In the absence of cytotoxicity, 500 and 1,000 nm CPS particles appear to influence phagocyte function to a greater extent than particles in other sizes.

l-Arginine is a Radioprotector for Hematopoietic Progenitor Cells

PubMed Central

Pearce, Linda L.; Zheng, Xichen; Martinez-Bosch, Sandra; Kerr, Patrick P.; Khlangwiset, Pornsri; Epperly, Michael W.; Fink, Mitchell P.; Greenberger, Joel S.; Peterson, Jim

2012-01-01

l-Arginine is shown to protect hematopoietic progenitor (32D cl 3) cells from death due to exposure to γ radiation (137Cs). Some of the other intermediates in the urea cycle, namely ornithine and citrulline, plus urea itself, were not found to have any significant impact on cell survival after irradiation. Intriguingly, supplementation of irradiated cells with l-arginine results in decreased production of peroxynitrite, suggesting that suppression of superoxide generation by nitric oxide synthase in one or more microenvironments is an important factor in the observed radioprotection. The absence of any radioprotective effect of l-arginine in cells at 3% oxygen also confirms the involvement of one or more oxygen-derived species. Knockdown experiments with nitric oxide synthase (NOS) siRNAs in cells and NOS knockout animals confirm that the observed radioprotection is associated with nNOS (NOS-1). l-Arginine also ameliorates the transient inhibition of the electron-transport chain complex I that occurs within 30 min of completing the dose (10 Gy) and that appears to be a functional marker for postirradiation mitochondrial oxidant production. PMID:22175298

Role of reactive nitrogen species generated via inducible nitric oxide synthase in vesicant-induced lung injury, inflammation and altered lung functioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sunil, Vasanthi R., E-mail: sunilvr@eohsi.rutgers.edu; Shen, Jianliang; Patel-Vayas, Kinal

2012-05-15

Pulmonary toxicity induced by sulfur mustard and related vesicants is associated with oxidative stress. In the present studies we analyzed the role of reactive nitrogen species (RNS) generated via inducible nitric oxide synthase (iNOS) in lung injury and inflammation induced by vesicants using 2-chloroethyl ethyl sulfide (CEES) as a model. C57Bl/6 (WT) and iNOS −/− mice were sacrificed 3 days or 14 days following intratracheal administration of CEES (6 mg/kg) or control. CEES intoxication resulted in transient (3 days) increases in bronchoalveolar lavage (BAL) cell and protein content in WT, but not iNOS −/− mice. This correlated with expression ofmore » Ym1, a marker of oxidative stress in alveolar macrophages and epithelial cells. In contrast, in iNOS −/− mice, Ym1 was only observed 14 days post-exposure in enlarged alveolar macrophages, suggesting that they are alternatively activated. This is supported by findings that lung tumor necrosis factor and lipocalin Lcn2 expression, mediators involved in tissue repair were also upregulated at this time in iNOS −/− mice. Conversely, CEES-induced increases in the proinflammatory genes, monocyte chemotactic protein-1 and cyclooxygenase-2, were abrogated in iNOS −/− mice. In WT mice, CEES treatment also resulted in increases in total lung resistance and decreases in compliance in response to methacholine, effects blunted by loss of iNOS. These data demonstrate that RNS, generated via iNOS play a role in the pathogenic responses to CEES, augmenting oxidative stress and inflammation and suppressing tissue repair. Elucidating inflammatory mechanisms mediating vesicant-induced lung injury is key to the development of therapeutics to treat mustard poisoning. -- Highlights: ► Lung injury, inflammation and oxidative stress are induced by the model vesicant CEES ► RNS generated via iNOS are important in the CEES-induced pulmonary toxicity ► iNOS −/− mice are protected from CEES-induced lung toxicity and altered lung functioning.« less

Nebivolol: impact on cardiac and endothelial function and clinical utility.

PubMed

Toblli, Jorge Eduardo; DiGennaro, Federico; Giani, Jorge Fernando; Dominici, Fernando Pablo

2012-01-01

Endothelial dysfunction is a systemic pathological state of the endothelium characterized by a reduction in the bioavailability of vasodilators, essentially nitric oxide, leading to impaired endothelium-dependent vasodilation, as well as disarrangement in vascular wall metabolism and function. One of the key factors in endothelial dysfunction is overproduction of reactive oxygen species which participate in the development of hypertension, atherosclerosis, diabetes, cardiac hypertrophy, heart failure, ischemia-reperfusion injury, and stroke. Because impaired endothelial activity is believed to have a major causal role in the pathophysiology of vascular disease, hypertension, and heart failure, therapeutic agents which modify this condition are of clinical interest. Nebivolol is a third-generation β-blocker with high selectivity for β1-adrenergic receptors and causes vasodilation by interaction with the endothelial L-arginine/ nitric oxide pathway. This dual mechanism of action underscores several hemodynamic qualities of nebivolol, which include reductions in heart rate and blood pressure and improvements in systolic and diastolic function. Although nebivolol reduces blood pressure to a degree similar to that of conventional β-blockers and other types of antihypertensive drugs, it may have advantages in populations with difficult-to-treat hypertension, such as patients with heart failure along with other comorbidities, like diabetes and obesity, and elderly patients in whom nitric oxide-mediated endothelial dysfunction may be more pronounced. Furthermore, recent data indicate that nebivolol appears to be a cost-effective treatment for elderly patients with heart failure compared with standard care. Thus, nebivolol is an effective and well tolerated agent with benefits above those of traditional β-blockers due to its influence on nitric oxide release, which give it singular hemodynamic effects, cardioprotective activity, and a good tolerability profile. This paper reviews the pharmacology structure and properties of nebivolol, focusing on endothelial dysfunction, clinical utility, comparative efficacy, side effects, and quality of life in general with respect to the other antihypertensive agents.

BIOCHEMISTRY OF MOBILE ZINC AND NITRIC OXIDE REVEALED BY FLUORESCENT SENSORS

PubMed Central

Pluth, Michael D.; Tomat, Elisa; Lippard, Stephen J.

2010-01-01

Biologically mobile zinc and nitric oxide (NO) are two prominent examples of inorganic compounds involved in numerous signaling pathways in living systems. In the past decade, a synergy of regulation, signaling, and translocation of these two species has emerged in several areas of human physiology, providing additional incentive for developing adequate detection systems for Zn(II) ions and NO in biological specimens. Fluorescent probes for both of these bioinorganic analytes provide excellent tools for their detection, with high spatial and temporal resolution. We review the most widely used fluorescent sensors for biological zinc and nitric oxide, together with promising new developments and unmet needs of contemporary Zn(II) and NO biological imaging. The interplay between zinc and nitric oxide in the nervous, cardiovascular, and immune systems is highlighted to illustrate the contributions of selective fluorescent probes to the study of these two important bioinorganic analytes. PMID:21675918

Nitric Oxide in the Crustacean Brain: Regulation of Neurogenesis and Morphogenesis in the Developing Olfactory Pathway

PubMed Central

Benton, J.L.; Sandeman, D.C.; Beltz, B.S.

2009-01-01

Nitric oxide (NO) plays major roles during development and in adult organisms. We examined the temporal and spatial patterns of nitric oxide synthase (NOS) appearance in the embryonic lobster brain to localize sources of NO activity; potential NO targets were identified by defining the distribution of NO-induced cGMP. Staining patterns are compared with NOS and cyclic 3,5 guanosine monophosphate (cGMP) distribution in adult lobster brains. Manipulation of NO levels influences olfactory glomerular formation and stabilization, as well as levels of neurogenesis among the olfactory projection neurons. In the first 2 days following ablation of the lateral antennular flagella in juvenile lobsters, a wave of increased NOS immunoreactivity and a reduction in neurogenesis occur. These studies implicate nitric oxide as a developmental architect and also support a role for this molecule in the neural response to injury in the olfactory pathway. PMID:17948307

Understanding the Latitude Structure of Nitric Oxide in the Mesosphere and Lower Thermosphere

NASA Technical Reports Server (NTRS)

Fuller-Rowell, T.J.

1997-01-01

The goal of the proposed work was to understand the latitude structure of nitric oxide in the mesosphere and lower thermosphere. The problem was portrayed by a clear difference between predictions of the nitric oxide distribution from chemical/dynamical models and data from observations made by the Solar Mesosphere Explorer (SMEE) in the early to mid eighties. The data exhibits a flat latitude structure of NO, the models tend to produce at equatorial maximum. The first task was to use the UARS-HALOE data to confirm the SME observations. The purpose of this first phase was to verify the UARS-NO structure is consistent with the SME data. The next task was to determine the cause of the discrepancy between modeled and observed nitric oxide latitude structure. The result from the final phase indicated that the latitude structure in the Photo-Electron (PE) production rate was the most important.

Progesterone modulates the LPS-induced nitric oxide production by a progesterone-receptor independent mechanism.

PubMed

Wolfson, Manuel Luis; Schander, Julieta Aylen; Bariani, María Victoria; Correa, Fernando; Franchi, Ana María

2015-12-15

Genital tract infections caused by Gram-negative bacteria induce miscarriage and are one of the most common complications of human pregnancy. LPS administration to 7-day pregnant mice induces embryo resorption after 24h, with nitric oxide playing a fundamental role in this process. We have previously shown that progesterone exerts protective effects on the embryo by modulating the inflammatory reaction triggered by LPS. Here we sought to investigate whether the in vivo administration of progesterone modulated the LPS-induced nitric oxide production from peripheral blood mononuclear cells from pregnant and non-pregnant mice. We found that progesterone downregulated LPS-induced nitric oxide production by a progesterone receptor-independent mechanism. Moreover, our results suggest a possible participation of glucocorticoid receptors in at least some of the anti-inflammatory effects of progesterone. Copyright © 2015 Elsevier B.V. All rights reserved.

Placebo neural systems: nitric oxide, morphine and the dopamine brain reward and motivation circuitries.

PubMed

Fricchione, Gregory; Stefano, George B

2005-05-01

Evidence suggests that the placebo response is related to the tonic effects of constitutive nitric oxide in neural, vascular and immune tissues. Constitutive nitric oxide levels play a role in the modulation of dopamine outflow in the nigrostriatal movement and the mesolimbic and mesocortical reward and motivation circuitries. Endogenous morphine, which stimulates constitutive nitric oxide, may be an important signal molecule working at mu receptors on gamma aminobutyric acid B interneurons to disinhibit nigral and tegmental dopamine output. We surmise that placebo induced belief will activate the prefrontal cortex with downstream stimulatory effects on these dopamine systems as well as on periaqueductal grey opioid output neurons. Placebo responses in Parkinson's disease, depression and pain disorder may result. In addition, mesolimbic/mesocortical control of the stress response systems may provide a way for the placebo response to benefit other medical conditions.

Mycobacterial glycolipids di-O-acylated trehalose and tri-O-acylated trehalose downregulate inducible nitric oxide synthase and nitric oxide production in macrophages.

PubMed

Espinosa-Cueto, Patricia; Escalera-Zamudio, Marina; Magallanes-Puebla, Alejandro; López-Marín, Luz María; Segura-Salinas, Erika; Mancilla, Raúl

2015-06-23

Tuberculosis (TB) remains a serious human health problem that affects millions of people in the world. Understanding the biology of Mycobacterium tuberculosis (Mtb) is essential for tackling this devastating disease. Mtb possesses a very complex cell envelope containing a variety of lipid components that participate in the establishment of the infection. We have previously demonstrated that di-O-acylated trehalose (DAT), a non-covalently linked cell wall glycolipid, inhibits the proliferation of T lymphocytes and the production of cytokines. In this work we show that DAT and the closely related tri-O-acylated trehalose (TAT) inhibits nitric oxide (NO) production and the inducible nitric oxide synthase (iNOS) expression in macrophages (MØ). These findings show that DAT and TAT are cell-wall located virulence factors that downregulate an important effector of the immune response against mycobacteria.

The Polar Night Nitric Oxide Experiment

NASA Image and Video Library

2017-12-08

The Polar Night Nitric Oxide or PolarNOx experiment from Virginia Tech is launched aboard a NASA Black Brant IX sounding rocket at 8:45 a.m. EST, Jan. 27, from the Poker Flat Research Range in Alaska. PolarNOx is measuring nitric oxide in the polar night sky. Nitric oxide in the polar night sky is created by auroras. Under appropriate conditions it can be transported to the stratosphere where it may destroy ozone resulting in possible changes in stratospheric temperature and wind and may even impact the circulation at Earth’s surface. Credit: NASA/Wallops/Jamie Adkins NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Influence of heme-thiolate in shaping the catalytic properties of a bacterial nitric-oxide synthase.

PubMed

Hannibal, Luciana; Somasundaram, Ramasamy; Tejero, Jesús; Wilson, Adjele; Stuehr, Dennis J

2011-11-11

Nitric-oxide synthases (NOS) are heme-thiolate enzymes that generate nitric oxide (NO) from L-arginine. Mammalian and bacterial NOSs contain a conserved tryptophan (Trp) that hydrogen bonds with the heme-thiolate ligand. We mutated Trp(66) to His and Phe (W66H, W66F) in B. subtilis NOS to investigate how heme-thiolate electronic properties control enzyme catalysis. The mutations had opposite effects on heme midpoint potential (-302, -361, and -427 mV for W66H, wild-type (WT), and W66F, respectively). These changes were associated with rank order (W66H < WT < W66F) changes in the rates of oxygen activation and product formation in Arg hydroxylation and N-hydroxyarginine (NOHA) oxidation single turnover reactions, and in the O(2) reactivity of the ferrous heme-NO product complex. However, enzyme ferrous heme-O(2) autoxidation showed an opposite rank order. Tetrahydrofolate supported NO synthesis by WT and the mutant NOS. All three proteins showed similar extents of product formation (L-Arg → NOHA or NOHA → citrulline) in single turnover studies, but the W66F mutant showed a 2.5 times lower activity when the reactions were supported by flavoproteins and NADPH. We conclude that Trp(66) controls several catalytic parameters by tuning the electron density of the heme-thiolate bond. A greater electron density (as in W66F) improves oxygen activation and reactivity toward substrate, but decreases heme-dioxy stability and lowers the driving force for heme reduction. In the WT enzyme the Trp(66) residue balances these opposing effects for optimal catalysis.

Method for combined removal of mercury and nitrogen oxides from off-gas streams

DOEpatents

Mendelsohn, Marshall H [Downers Grove, IL; Livengood, C David [Lockport, IL

2006-10-10

A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

Mechanisms of perinatal cerebral injury in fetus and newborn.

PubMed

Delivoria-Papadopoulos, M; Mishra, O P

2000-01-01

Cerebral hypoxia in the fetus and newborn results in neonatal morbidity and mortality as well as long-term sequelae such as mental retardation, seizure disorders, and cerebral palsy. In the developing brain, determinants of susceptibility to hypoxia should include the lipid composition of the brain cell membrane, the rate of lipid peroxidation, the presence of antioxidant defenses, and the development and modulation of excitatory amino acid neurotransmitter receptors such as the N-methyl-D-aspartate (NMDA) receptor, the intracellular Ca2+, and the intranuclear Ca(2+)-dependent mechanisms. In addition to the developmental status of these cellular components, the response of these potential mechanisms to hypoxia determines the fate of the hypoxic brain cell in the developing brain. Using electron spin resonance spectroscopy of alpha-phenyl-N-tert-butyl-nitrone spin adducts, studies from our laboratory demonstrated that tissue hypoxia results in increased free radical generation in the cortex of fetal guinea pigs and newborn piglets. Pretreatment with MgSO4 significantly decreased the hypoxia-induced increase in free radical generation in the term fetal brain. We also showed that brain tissue hypoxia modifies the NMDA receptor ion-channel recognition and modulatory sites. Furthermore, a higher increase in NMDA receptor agonist-dependent Ca2+ in synaptosomes was demonstrated. The increase in intracellular Ca2+ may activate several enzymatic pathways such as phospholipase A2 and metabolism of archidonic acid by cyclooxygenase and lipoxygenase, conversion of xanthine dehydrogenase to xanthine oxidase by proteases, and activation of nitric oxide synthase. Using inhibitors of each of these enzymes such as cyclooxygenase (indomethacin), lipoxygenase (nordihydroguaiaretic acid), xanthine oxidase (allopurinol), and nitric oxide synthase (N-nitro-L-arginine), studies have shown that these enzyme reactions result in oxygen free radical generation, membrane peroxidation, and cell membrane dysfunction in the hypoxic brain. Specifically, generation of nitric oxide free radicals during hypoxia may lead to nitration and nitrosylation of specific membrane proteins and receptors, resulting in dysfunction of receptors and enzymes. We conclude that hypoxia-induced modification of the NMDA receptor leading to increased intracellular Ca2+ results in free radical generation and cell injury. We suggest that during hypoxia the increased intracellular Ca2+ may lead to increased intranuclear Ca2+ concentration and alter nuclear events including transcription of specific apoptotic genes and activation of endonucleases, resulting in programmed cell death.

Salmonella enterica biofilm-mediated dispersal by nitric oxide donors in association with cellulose nanocrystal hydrogels.

PubMed

Marvasi, Massimiliano; Durie, Ian A; McLamore, Eric S; Vanegas, Diana C; Chaturvedi, Prachee

2015-01-01

Protected by extracellular polymers, microbes within biofilms are significantly more resistant to disinfectants. Current research has been instrumental in identifying nitric oxide donors and hydrogels as potential disinfectant additives. Nitric oxide (NO) donors are considered a very promising molecule as biofilm dispersal agents and hydrogels have recently attracted a lot of interest due to their biocompatible properties and ability to form stable thin films. When the NO donor MAHMA NONOate was dissolved in phosphate saline buffer, it was able to reduce the biomass of well-established biofilms up to 15% for at least 24 h of contact time. Encapsulation of MAHMA NONOate and molsidomine within a hydrogel composed of cellulose nanocrystals (CNC) has shown a synergistic effect in dispersing well-established biofilms: after 2 h of exposure, moderate but significant dispersion was measured. After 6 h of exposure, the number of cells transitioning from the biofilm to the planktonic state was up to 0.6 log higher when compared with non-treated biofilms. To further explore the transport processes of NO donors within hydrogels, we measured the nitric oxide flux from gels, at 25°C for a composite of 0.1 µM MAHMA NONOate-CNC. Nitric oxide diffuses up to 500 µm from the hydrogel surface, with flux decreasing according to Fick's law. 60% of NO was released from the hydrogel composite during the first 23 min. These data suggest that the combined treatments with nitric oxide donor and hydrogels may allow for new sustainable cleaning strategies.

Metagenomic analysis of nitrate-reducing bacteria in the oral cavity: implications for nitric oxide homeostasis.

PubMed

Hyde, Embriette R; Andrade, Fernando; Vaksman, Zalman; Parthasarathy, Kavitha; Jiang, Hong; Parthasarathy, Deepa K; Torregrossa, Ashley C; Tribble, Gena; Kaplan, Heidi B; Petrosino, Joseph F; Bryan, Nathan S

2014-01-01

The microbiota of the human lower intestinal tract helps maintain healthy host physiology, for example through nutrient acquisition and bile acid recycling, but specific positive contributions of the oral microbiota to host health are not well established. Nitric oxide (NO) homeostasis is crucial to mammalian physiology. The recently described entero-salivary nitrate-nitrite-nitric oxide pathway has been shown to provide bioactive NO from dietary nitrate sources. Interestingly, this pathway is dependent upon oral nitrate-reducing bacteria, since humans lack this enzyme activity. This pathway appears to represent a newly recognized symbiosis between oral nitrate-reducing bacteria and their human hosts in which the bacteria provide nitrite and nitric oxide from nitrate reduction. Here we measure the nitrate-reducing capacity of tongue-scraping samples from six healthy human volunteers, and analyze metagenomes of the bacterial communities to identify bacteria contributing to nitrate reduction. We identified 14 candidate species, seven of which were not previously believed to contribute to nitrate reduction. We cultivated isolates of four candidate species in single- and mixed-species biofilms, revealing that they have substantial nitrate- and nitrite-reduction capabilities. Colonization by specific oral bacteria may thus contribute to host NO homeostasis by providing nitrite and nitric oxide. Conversely, the lack of specific nitrate-reducing communities may disrupt the nitrate-nitrite-nitric oxide pathway and lead to a state of NO insufficiency. These findings may also provide mechanistic evidence for the oral systemic link. Our results provide a possible new therapeutic target and paradigm for NO restoration in humans by specific oral bacteria.

Metagenomic Analysis of Nitrate-Reducing Bacteria in the Oral Cavity: Implications for Nitric Oxide Homeostasis

PubMed Central

Hyde, Embriette R.; Andrade, Fernando; Vaksman, Zalman; Parthasarathy, Kavitha; Jiang, Hong; Parthasarathy, Deepa K.; Torregrossa, Ashley C.; Tribble, Gena; Kaplan, Heidi B.; Petrosino, Joseph F.; Bryan, Nathan S.

2014-01-01

The microbiota of the human lower intestinal tract helps maintain healthy host physiology, for example through nutrient acquisition and bile acid recycling, but specific positive contributions of the oral microbiota to host health are not well established. Nitric oxide (NO) homeostasis is crucial to mammalian physiology. The recently described entero-salivary nitrate-nitrite-nitric oxide pathway has been shown to provide bioactive NO from dietary nitrate sources. Interestingly, this pathway is dependent upon oral nitrate-reducing bacteria, since humans lack this enzyme activity. This pathway appears to represent a newly recognized symbiosis between oral nitrate-reducing bacteria and their human hosts in which the bacteria provide nitrite and nitric oxide from nitrate reduction. Here we measure the nitrate-reducing capacity of tongue-scraping samples from six healthy human volunteers, and analyze metagenomes of the bacterial communities to identify bacteria contributing to nitrate reduction. We identified 14 candidate species, seven of which were not previously believed to contribute to nitrate reduction. We cultivated isolates of four candidate species in single- and mixed-species biofilms, revealing that they have substantial nitrate- and nitrite-reduction capabilities. Colonization by specific oral bacteria may thus contribute to host NO homeostasis by providing nitrite and nitric oxide. Conversely, the lack of specific nitrate-reducing communities may disrupt the nitrate-nitrite-nitric oxide pathway and lead to a state of NO insufficiency. These findings may also provide mechanistic evidence for the oral systemic link. Our results provide a possible new therapeutic target and paradigm for NO restoration in humans by specific oral bacteria. PMID:24670812

Effect of Eimeria acervulina infection on cell-specific xanthine oxidase (XO) and inducible NO synthase (iNOS) activities and duodenal protein tyrosine nitration (NTp) in chickens

USDA-ARS?s Scientific Manuscript database

Intracellular generation of nitric oxide (NO) and superoxide anion (O¯2) during pro-inflammatory stress can result in the formation of 3'-nitrotyrosine proteins (NTp) that correlate with alteration in protein function and metabolic impairment. Our objective was to determine the cell-specific relati...

Midlatitude sporadic-E episodes viewed by L-band split-spectrum InSAR

NASA Astrophysics Data System (ADS)

Furuya, Masato; Suzuki, Takato; Maeda, Jun; Heki, Kosuke

2017-12-01

Sporadic-E (Es) is a layer of ionization that irregularly appears within the E region of the ionosphere and is known to generate an unusual propagation of very high frequency waves over long distances. The detailed spatial structure of Es remains unclear due to the limited spatial resolution in the conventional ionosonde observations. We detect midlatitude Es by interferometric synthetic aperture radar (InSAR), which can clarify the spatial structure of Es with unprecedented resolution. Moreover, we use the range split-spectrum method (SSM) to separate dispersive and nondispersive components in the InSAR image. While InSAR SSM largely succeeds in decomposing into dispersive and nondispersive signals, our results indicate that small-scale dispersive signals due to the total electron content anomalies are accompanied by nondispersive signals with similar spatial scale at the same locations. We also examine the effects of higher-order terms in the refractive index for dispersive media. Both of these detected Es episodes indicate that smaller-scale dispersive effects originate from higher-order effects. We interpret that the smaller-scale nondispersive signals could indicate the emergence of nitric oxide (NO) generated by the reactions of metals, Mg and Fe, with nitric oxide ion (NO+) during the Es.

Odorant-Dependent Generation of Nitric Oxide in Mammalian Olfactory Sensory Neurons

PubMed Central

Brunert, Daniela; Kurtenbach, Stefan; Isik, Sonnur; Benecke, Heike; Gisselmann, Günter; Schuhmann, Wolfgang; Hatt, Hanns; Wetzel, Christian H.

2009-01-01

The gaseous signalling molecule nitric oxide (NO) is involved in various physiological processes including regulation of blood pressure, immunocytotoxicity and neurotransmission. In the mammalian olfactory bulb (OB), NO plays a role in the formation of olfactory memory evoked by pheromones as well as conventional odorants. While NO generated by the neuronal isoform of NO synthase (nNOS) regulates neurogenesis in the olfactory epithelium, NO has not been implicated in olfactory signal transduction. We now show the expression and function of the endothelial isoform of NO synthase (eNOS) in mature olfactory sensory neurons (OSNs) of adult mice. Using NO-sensitive micro electrodes, we show that stimulation liberates NO from isolated wild-type OSNs, but not from OSNs of eNOS deficient mice. Integrated electrophysiological recordings (electro-olfactograms or EOGs) from the olfactory epithelium of these mice show that NO plays a significant role in modulating adaptation. Evidence for the presence of eNOS in mature mammalian OSNs and its involvement in odorant adaptation implicates NO as an important new element involved in olfactory signal transduction. As a diffusible messenger, NO could also have additional functions related to cross adaptation, regeneration, and maintenance of MOE homeostasis. PMID:19430528

Anti-Inflammatory Effects of Adrenomedullin on Acute Lung Injury Induced by Carrageenan in Mice

PubMed Central

Elena, Talero; Rosanna, Di Paola; Emanuela, Mazzon; Esposito, Emanuela; Virginia, Motilva; Salvatore, Cuzzocrea

2012-01-01

Adrenomedullin (AM) is a 52 amino acid peptide that has shown predominant anti-inflammatory activities. In the present study, we evaluated the possible therapeutic effect of this peptide in an experimental model of acute inflammation, the carrageenan- (CAR-) induced pleurisy. Pleurisy was induced by injection of CAR into the pleural cavity of mice. AM (200 ng/kg) was administered by intraperitoneal route 1 h after CAR, and the animals were sacrificed 4 h after that. AM treatment attenuated the recruitment of leucocytes in the lung tissue and the generation and/or the expression of the proinflammatory cytokines as well as the expression of the intercellular cell adhesion molecules. Moreover, AM inhibited the induction of inducible nitric oxide synthase (iNOS), thereby abating the generation of nitric oxide (NO) and prevented the oxidative and nitroxidative lung tissue injury, as shown by the reduction of nitrotyrosine, malondialdehyde (MDA), and poly (ADP-ribose) polymerase (PARP) levels. Finally, we demonstrated that these anti-inflammatory effects of AM were associated with the inhibition of nuclear factor-κB (NF-κB) activation. All these parameters were markedly increased by intrapleural CAR in the absence of any treatment. We report that treatment with AM significantly reduces the development of acute lung injury by downregulating a broad spectrum of inflammatory factors. PMID:22685374

Regulation of nitrate reductase by nitric oxide in Chinese cabbage pakchoi (Brassica chinensis L.).

PubMed

Du, Shaoting; Zhang, Yongsong; Lin, Xianyong; Wang, Yue; Tang, Caixian

2008-02-01

Nitrate reductase (NR), a committed enzyme in nitrate assimilation, involves generation of nitric oxide (NO) in plants. Here we show that the NR activity was significantly enhanced by the addition of NO donors sodium nitroprusside (SNP) and NONOate (diethylamine NONOate sodium) to the culturing solution, whereas it was decreased by NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (cPTIO). Interestingly, both NO gas and SNP directly enhanced but cPTIO inhibited the NR activities of crude enzyme extracts and purified NR enzyme. The cPTIO terminated the interaction between NR-generated NO and the NR itself. Furthermore, the NR protein content was not affected by the SNP treatment. The investigation of the partial reactions catalysed by purified NR using various electron donors and acceptors indicated that the haem and molybdenum centres in NR were the two sites activated by NO. The results suggest that the activation of NR activity by NO is regulated at the post-translational level, probably via a direct interaction mechanism. Accordingly, the concentration of nitrate both in leaves and roots was decreased after 2 weeks of cultivation with SNP. The present study identifies a new mechanism of NR regulation and nitrate assimilation, which provides important new insights into the complex regulation of N-metabolism in plants.

Silk provides a new avenue for third generation biosensors: Sensitive, selective and stable electrochemical detection of nitric oxide.

PubMed

Musameh, Mustafa M; Dunn, Christopher J; Uddin, Md Hemayet; Sutherland, Tara D; Rapson, Trevor D

2018-04-30

Using heme entrapped in recombinant silk films, we have produced 3rd generation biosensors, which allow direct electron transfer from the heme center to an electrode avoiding the need for electron mediators. Here, we demonstrate the use of these heme-silk films for the detection of nitric oxide (NO) at nanomolar levels in the presence and absence of oxygen. The sensor was prepared by drop-casting a silk solution on a glassy carbon electrode modified with multiwalled carbon nanotubes (MWCNT) followed by infusion with heme. The sensor was characterized by cyclic voltammetry and showed well defined and reversible Fe + / Fe 3+ redox couple activity, with NO detection by oxidation at potentials above +0.45V or reduction at potentials below - 0.7V. Evaluation of the effect of pH on the sensor response to NO reduction indicated a maximum response at pH 3. The sensor showed good linearity in the concentration range from 19 to 190nM (R 2 = 0.99) with a detection limit of 2nM. The sensor had excellent selectivity towards NO with no or negligible interference from oxygen, nitrite, nitrate, dopamine and ascorbic acid and retained 86% of response after 2 months of operation and storage at room temperature. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Nitric oxide

Integrated Risk Information System (IRIS)

Nitric oxide ; CASRN 10102 - 43 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

75 FR 43535 - NIH Consensus Development Conference on Inhaled Nitric Oxide Therapy for Premature Infants

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-26

... problems with long-term lung health, brain development, and brain function. Nitric oxide is a chemical... and brain development and function. Since its approval, researchers have examined expanding the use of...

Real-time cytometric assay of nitric oxide and superoxide interaction in peripheral blood monocytes: A no-wash, no-lyse kinetic method.

PubMed

Balaguer, Susana; Diaz, Laura; Gomes, Angela; Herrera, Guadalupe; O'Connor, José-Enrique; Urios, Amparo; Felipo, Vicente; Montoliu, Carmina

2017-05-01

Nitric oxide (NO) and its related reactive nitrogen species (RNS) and reactive oxygen species (ROS) are crucial in monocyte responses against pathogens and also in inflammatory conditions. Central to both processes is the generation of the strong oxidant peroxynitrite (ONOO) by a fast reaction between NO and superoxide anion. ONOO is a biochemical junction for ROS- and RNS cytotoxicity and causes protein nitrosylation. Circulating by-products of protein nitrosylation are early biomarkers of inflammation-based conditions, including minimal hepatic encephalopathy in cirrhotic patients (Montoliu et al., Am J Gastroenterol 2011; 106:1629-1637). In this context, we have designed a novel no-wash, no-lyse real-time flow cytometry assay to detect and follow-up the NO- and superoxide-driven generation of ONOO in peripheral blood monocytes. Whole blood samples were stained with CD45 and CD14 antibodies plus one of a series of fluorescent probes sensitive to RNS, ROS, or glutathione, namely 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate, dihydrorhodamine 123, MitoSOX Red, dihydroethidium, and 5-chloromethylfluorescein diacetate. Samples were exposed sequentially to a NO donor and three different superoxide donors, and analyzed in real time by kinetic flow cytometry. Relevant kinetic descriptors, such as the rate of fluorescence change, were calculated from the kinetic plot. The generation of ONOO, which consumes both NO and superoxide, led to a decrease in the intensity of the cellular fluorescence of the probes sensitive to these molecules. This is a fast and simple assay that may be used to monitor the intracellular generation of ONOO in physiological, pathological, and pharmacological contexts. © 2015 International Clinical Cytometry Society. © 2015 International Clinical Cytometry Society.

Nitric oxide and superoxide dismutase modulate endothelial progenitor cell function in type 2 diabetes mellitus

PubMed Central

Hamed, Saher; Brenner, Benjamin; Aharon, Anat; Daoud, Deeb; Roguin, Ariel

2009-01-01

Background The function of endothelial progenitor cells (EPCs), which are key cells in vascular repair, is impaired in diabetes mellitus. Nitric oxide (NO) and reactive oxygen species can regulate EPC functions. EPCs tolerate oxidative stress by upregulating superoxide dismutase (SOD), the enzyme that neutralizes superoxide anion (O2-). Therefore, we investigated the roles of NO and SOD in glucose-stressed EPCs. Methods The functions of circulating EPCs from patients with type 2 diabetes were compared to those from healthy individuals. Healthy EPCs were glucose-stressed, and then treated with insulin and/or SOD. We assessed O2- generation, NO production, SOD activity, and their ability to form colonies. Results EPCs from diabetic patients generated more O2-, had higher NAD(P)H oxidase and SOD activity, but lower NO bioavailability, and expressed higher mRNA and protein levels of p22-phox, and manganese SOD and copper/zinc SOD than those from the healthy individuals. Plasma glucose and HbA1c levels in the diabetic patients were correlated negatively with the NO production from their EPCs. SOD treatment of glucose-stressed EPCs attenuated O2- generation, restored NO production, and partially restored their ability to form colonies. Insulin treatment of glucose-stressed EPCs increased NO production, but did not change O2- generation and their ability to form colonies. However, their ability to produce NO and to form colonies was fully restored after combined SOD and insulin treatment. Conclusion Our data provide evidence that SOD may play an essential role in EPCs, and emphasize the important role of antioxidant therapy in type 2 diabetic patients. PMID:19878539

Synthesis and recycling of tetrahydrobiopterin in endothelial function and vascular disease.

PubMed

Crabtree, Mark J; Channon, Keith M

2011-08-01

Nitric oxide, generated by the nitric oxide synthase (NOS) enzymes, plays pivotal roles in cardiovascular homeostasis and in the pathogenesis of cardiovascular disease. The NOS cofactor, tetrahydrobiopterin (BH4), is an important regulator of NOS function, since BH4 is required to maintain enzymatic coupling of L-arginine oxidation, to produce NO. Loss or oxidation of BH4 to 7,8-dihydrobiopterin (BH2) is associated with NOS uncoupling, resulting in the production of superoxide rather than NO. In addition to key roles in folate metabolism, dihydrofolate reductase (DHFR) can 'recycle' BH2, and thus regenerate BH4. It is therefore likely that net BH4 cellular bioavailability reflects the balance between de novo BH4 synthesis, loss of BH4 by oxidation to BH2, and the regeneration of BH4 by DHFR. Recent studies have implicated BH4 recycling in the direct regulation of eNOS uncoupling, showing that inhibition of BH4 recycling using DHFR-specific siRNA and methotrexate treatment leads to eNOS uncoupling in endothelial cells and the hph-1 mouse model of BH4 deficiency, even in the absence of oxidative stress. These studies indicate that not only BH4 level, but the recycling pathways regulating BH4 bioavailability represent potential therapeutic targets and will be discussed in this review. Copyright © 2011 Elsevier Inc. All rights reserved.

Type II flavohemoglobin of Mycobacterium smegmatis oxidizes d-lactate and mediate electron transfer.

PubMed

Thakur, Naveen; Kumar, Ashwani; Dikshit, Kanak L

2018-06-01

Two distantly related flavohemoglobins (FHbs), MsFHbI and MsFHbII, having crucial differences in their heme and reductase domains, co-exist in Mycobacterium smegmatis. Function of MsFHbI is associated with nitric-oxide detoxification but physiological relevance of MsFHbII remains unknown. This study unravels some unique spectral and functional characteristics of MsFHbII. Unlike conventional type I FHbs, MsFHbII lacks nitric-oxide dioxygenase and NADH oxidase activities but utilizes d-lactate as an electron donor to mediate electron transfer. MsFHbII carries a d-lactate dehydrogenase type FAD binding motif in its reductase domain and oxidizes d-lactate in a FAD dependent manner to reduce the heme iron, suggesting that the globin is acting as an electron acceptor. Importantly, expression of MsFHbII in Escherichia coli imparted protection under oxidative stress, suggesting its important role in stress management of its host. Since M. smegmatis lacks the gene encoding for d-lactate dehydrogenase and d-lactate is produced during aerobic metabolism and also as a by-product of lipid peroxidation, the ability of MsFHbII to metabolize d-lactate may provide it a unique ability to balance the oxidative stress generated due to accumulation of d-lactate in the cell and at the same time sequester electrons and pass it to the respiratory apparatus. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of intermittent fasting on age-related changes on Na,K-ATPase activity and oxidative status induced by lipopolysaccharide in rat hippocampus.

PubMed

Vasconcelos, Andrea Rodrigues; Kinoshita, Paula Fernanda; Yshii, Lidia Mitiko; Marques Orellana, Ana Maria; Böhmer, Ana Elisa; de Sá Lima, Larissa; Alves, Rosana; Andreotti, Diana Zukas; Marcourakis, Tania; Scavone, Cristoforo; Kawamoto, Elisa Mitiko

2015-05-01

Chronic neuroinflammation is a common characteristic of neurodegenerative diseases, and lipopolysaccharide (LPS) signaling is linked to glutamate-nitric oxide-Na,K-ATPase isoforms pathway in central nervous system (CNS) and also causes neuroinflammation. Intermittent fasting (IF) induces adaptive responses in the brain that can suppress inflammation, but the age-related effect of IF on LPS modulatory influence on nitric oxide-Na,K-ATPase isoforms is unknown. This work compared the effects of LPS on the activity of α1,α2,3 Na,K-ATPase, nitric oxide synthase gene expression and/or activity, cyclic guanosine monophosphate, 3-nitrotyrosine-containing proteins, and levels of thiobarbituric acid-reactive substances in CNS of young and older rats submitted to the IF protocol for 30 days. LPS induced an age-related effect in neuronal nitric oxide synthase activity, cyclic guanosine monophosphate, and levels of thiobarbituric acid-reactive substances in rat hippocampus that was linked to changes in α2,3-Na,K-ATPase activity, 3-nitrotyrosine proteins, and inducible nitric oxide synthase gene expression. IF induced adaptative cellular stress-response signaling pathways reverting LPS effects in rat hippocampus of young and older rats. The results suggest that IF in both ages would reduce the risk for deficits on brain function and neurodegenerative disorders linked to inflammatory response in the CNS. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of a portable mini-generator to safely produce nitric oxide for the treatment of infants with pulmonary hypertension.

PubMed

Yu, Binglan; Ferrari, Michele; Schleifer, Grigorij; Blaesi, Aron H; Wepler, Martin; Zapol, Warren M; Bloch, Donald B

2018-05-01

To test the safety of a novel miniaturized device that produces nitric oxide (NO) from air by pulsed electrical discharge, and to demonstrate that the generated NO can be used to vasodilate the pulmonary vasculature in rabbits with chemically-induced pulmonary hypertension. A miniature NO (mini-NO) generator was tested for its ability to produce therapeutic levels (20-80 parts per million (ppm)) of NO, while removing potentially toxic gases and metal particles. We studied healthy 6-month-old New Zealand rabbits weighing 3.4 ± 0.4 kg (mean ± SD, n = 8). Pulmonary hypertension was induced by chemically increasing right ventricular systolic pressure to 28-30 mmHg. The mini-NO generator was placed near the endotracheal tube. Production of NO was triggered by a pediatric airway flowmeter during the first 0.5 s of inspiration. In rabbits with acute pulmonary hypertension, the mini-NO generator produced sufficient NO to induce pulmonary vasodilation. Potentially toxic nitrogen dioxide (NO 2 ) and ozone (O 3 ) were removed by the Ca(OH) 2 scavenger. Metallic particles, released from the electrodes by the electric plasma, were removed by a 0.22 μm filter. While producing 40 ppm NO, the mini-NO generator was cooled by a flow of air (70 ml/min) and the external temperature of the housing did not exceed 31 °C. The mini-NO generator safely produced therapeutic levels of NO from air. The mini-NO generator is an effective and economical approach to producing NO for treating neonatal pulmonary hypertension and will increase the accessibility and therapeutic uses of life-saving NO therapy worldwide. Copyright © 2018 Elsevier Inc. All rights reserved.

Gene variations of nitric oxide synthase regulate the effects of a saturated fat rich meal on endothelial function

USDA-ARS?s Scientific Manuscript database

Objective: Endothelial nitric oxide synthase gene variations have been linked to a higher risk for cardiovascular diseases by unknown mechanisms. Our aim was to determine if two SNPs located in NOS3 (E298D and i19342) interfere with microvascular endothelial function (MEF) and/or oxidative stress du...

Real time and in vivo monitoring of nitric oxide by electrochemical sensors--from dream to reality.

PubMed

Zhang, Xueji

2004-09-01

Nitric oxide is a key intercellular messenger in the human and animal bodies. The identification of nitric oxide (NO) as the endothelium-derived relaxing factor (EDRF) has driven an enormous effort to further elucidate the chemistry, biology and therapeutic actions of this important molecule. It has found that nitric oxide is involved in many disease states such as such as chronic heart failure, stroke, impotent (erectile dysfunction). The bioactivity of nitric oxide intrinsically linked to its diffusion from its site production to the sites of action. Accurate reliable in real time detection of NO in various biological systems is therefore crucial to understanding its biological role. However, the instability of NO in aqueous solution and its high reactivity with other molecules can cause difficulties for its measurement depending on the detection method employed. Although a variety of methods have been described to measure NO in aqueous environments, it is now generally accepted that electrochemical (amperometric) detection using NO-specific electrodes is the most reliable and sensitive technique available for real-time in situ detection of NO. In 1992 the first commercial NO electrode-based amperometric detection system was developed by WPI. The system has been used successfully for a number of years in a wide range of research applications, both in vitro and in vivo. Recently, many new electrochemical nitric sensors have been invented and commercialized. Here we describe some of the background principles in NO sensors design, methodology and their applications.

Decomposition of nitric oxide in a hot nitrogen stream to synthesize air for hypersonic wind tunnel combustion testing

NASA Technical Reports Server (NTRS)

Zumdieck, J. F.; Zlatarich, S. A.

1974-01-01

A clean source of high enthalpy air was obtained from the exothermic decomposition of nitric oxide in the presence of strongly heated nitrogen. A nitric oxide jet was introduced into a confined coaxial nitrogen stream. Measurements were made of the extent of mixing and reaction. Experimental results are compared with one- and two-dimensional chemical kinetics computations. Both analyses predict much lower reactivity than was observed experimentally. Inlet nitrogen temperatures above 2400 K were sufficient to produce experimentally a completely reacted gas stream of synthetic air.

In vitro inducible nitric oxide synthesis inhibitory active constituents from Fraxinus rhynchophylla.

PubMed

Kim, N Y; Pae, H O; Ko, Y S; Yoo, J C; Choi, B M; Jun, C D; Chung, H T; Inagaki, M; Higuchi, R; Kim, Y C

1999-10-01

Bioassay-guided fractionation of an H2O extract of the barks of Fraxinus rhynchophylla has furnished two inducible nitric oxide synthase (iNOS) inhibitory compounds, ferulaldehyde (1) and scopoletin (3) together with a coumarin, fraxidin (2). Compounds 1 and 3 showed inhibition of nitric oxide (NO) synthesis in a dose-dependent manner by murine macrophage-like RAW 264.7 cells stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS). The inhibition of NO synthesis of 1 was reflected in the decreased amount of iNOS protein, as determined by Western blotting.

Thiopental inhibits nitric oxide production in rat aorta.

PubMed

Castillo, C; Asbun, J; Escalante, B; Villalón, C M; López, P; Castillo, E F

1999-12-01

We studied whether thiopental affects endothelial nitric oxide dependent vasodilator responses and nitrite production (an indicator of nitric oxide production) elicited by acetylcholine, histamine, and A23187 in rat aorta (artery in which nitric oxide is the main endothelial relaxant factor). In addition, we evaluated the barbiturate effect on nitric oxide synthase (NOS) activity in both rat aorta and kidney homogenates. Thiopental (10-100 microg/mL) reversibly inhibited the endothelium-dependent relaxation elicited by acetylcholine, histamine, and A23187. On the contrary, this anesthetic did not modify the endothelium-independent but cGMP-dependent relaxation elicited by sodium nitroprusside (1 nM - 1 microM) and nitroglycerin (1 nM - 1 microM), thus excluding an effect of thiopental on guanylate cyclase of vascular smooth muscle. Thiopental (100 microg/mL) inhibited both basal (87.8+/-14.3%) and acetylcholine- or A23187-stimulated (78.6+/-3.9 and 39.7+/-5.6%, respectively) production of nitrites in aortic rings. In addition the barbiturate inhibited (100 microg/mL) the NOS (45+/-4 and 42.8+/-9%) in aortic and kidney homogenates, respectively (measured as 14C-labeled citrulline production). In conclusion, thiopental inhibition of endothelium-dependent relaxation and nitrite production in aortic rings strongly suggests an inhibitory effect on NOS. Thiopental inhibition of the NOS provides further support to this contention.

The Effect of Vitamin D3 Alone and Mixed With IFN-γ on Tachyzoites of Toxoplasma gondii (RH Strain) Proliferation and Nitric Oxide (NO) Production in Infected Macrophages of BALB/C Mice.

PubMed

Ghaffarifar, F; Abdolah Pour, M; Sharifi, Z; Dalimi Asl, A; Al-Kawaz, E

2010-09-01

Toxoplasma gondii is an obligatory interacelullar parasite that infects nucleated cells in its intermediate hosts. The aim of the present study was to determine the effect of vitamin D3 on the multiplication of T. gondii in peritoneal macrophage of Balb/c mice and nitric oxide production by macrophages. According to usage of vitamin D3 (one dose or seven doses) and INFγ in vitro and in vivo, this study was divided into four experiments. In all experiments, the macrophages were collected from peritoneum and cultured in RPMI-1640. Then the supernatants were collected after 24 h and their nitric oxide was measure. After 96 h, the macrophages were collected and stained and the number of tachyzoites was measured. The first experiment (the mice were infected with tachyzoites and after 2 h, got one dose vitamin D3 intraperitonealy) showed the best results. The mean of tachyzoites per macrophages was 2.37, and mean±SD of nitric oxide was 187.8±9. High-level production of nitric oxide may be related to the only one injection of vitamin D3. The injection in long time might suppress the immune system.

A variant of the endothelial nitric oxide synthase gene (NOS3) associated with AMS susceptibility is less common in the Quechua, a high altitude Native population.

PubMed

Wang, Pei; Ha, Alice Y N; Kidd, Kenneth K; Koehle, Michael S; Rupert, Jim L

2010-01-01

Endothelial nitric oxide synthase (eNOS) is a vascular enzyme that produces nitric oxide, a transient signaling molecule that by vasodilatation regulates blood flow and pressure. Nitric oxide is believed to play roles in both short-term acclimatization and long-term evolutionary adaptation to environmental hypoxia. Several laboratories, including ours, have shown that variants in NOS3 (the gene encoding eNOS) are overrepresented in individuals with altitude-related illnesses such as high altitude pulmonary edema (HAPE) and acute mountain sickness (AMS), suggesting that NOS3 genotypes contribute to altitude tolerance. To further test our hypothesis that the G allele at the G894T polymorphism in NOS3 (dbSNP number: rs1799983; protein polymorphism Glu298Asp) is beneficial in hypoxic environments, we compared frequencies of this allele in an altitude-adapted Amerindian population, Quechua of the Andean altiplano, with those in a lowland Amerindian population, Maya of the Yucatan Peninsula. While common in both populations, the G allele was significantly more frequent in the highlanders. Taken together, our data suggest that this variant in NOS3, which has been previously associated with higher levels of nitric oxide, contributes to both acclimatization and adaptation to altitude.

Isosorbide 5 mononitrate administration increases nitric oxide blood levels and reduces proteinuria in IgA glomerulonephritis patients with abnormal urinary endothelin/cyclic GMP ratio.

PubMed

Roccatello, D; Mengozzi, G; Ferro, M; Cesano, G; Polloni, R; Mosso, R; Bonetti, G; Inconis, T; Paradisi, L; Sena, L M

1995-09-01

An endothelin urinary hyperexcretion, which is not counterbalanced by an adequate increase in cGMP biosynthesis, was previously detected in some patients with IgA Nephropathy (IgAN). Since this imbalance might potentiate local ET1-mediated hemodynamics effects, 9 IgAN patients with an increased (> or = 0.1) urinary ET1/cGMP ratio (group 1) and 5 IgAN patients with comparable renal function and reduced ET1/cGMP ratio (group 2) were given standard doses of isosorbide 5 mononitrate (as a nitric oxide source). Blood nitric oxide (NO) levels, as detected by electron paramagnetic resonance, significantly increased after isosorbide administration (p < 0.01) and decreased after drug discontinuation in both groups. Nitric oxide levels were significantly related with those of the effective renal plasma flow (p < 0.02), but not with the glomerular filtration rate. Proteinuria levels significantly decreased after drug administration (p < 0.009) in group 1 and returned to baseline levels thereafter, except two cases showing persisting low levels. Values of filtration fraction in the same group decreased after iso5M administration (p < 0.02 compared to basal levels). These results may possibly be related to the counterbalancing effects of nitric oxide on endothelin-mediated mesangial contraction.

Oral treatment with herbal formula B401 alleviates penile toxicity in aging mice with manganism.

PubMed

Hsu, Chih-Hsiang; Lin, Ching-Lung; Wang, Sheue-Er; Sheu, Shuenn-Jyi; Chien, Chiang-Ting; Wu, Chung-Hsin

2015-01-01

The present study aims to elucidate the roles of nitric oxide synthase activity, oxidative stress, inflammation, and apoptosis in penile toxicity of aging mice associated with excess manganese (Mn) treatment and to investigate the effect of oral treatment with the herbal formula B401 in this respect. ICR strain mice were divided into two groups: the vehicle (sham group) and the B401 (50 mg/kg) group. The mice were orally treated for 5 days; then a high single dose of MnCl2 (100 mg/kg) was given by intraperitoneal injection to the mice. One day after MnCl2 treatment, corpora cavernosal tissues of both Mn-treated mice and their controls were simultaneously sampled to examine their immunohistochemical staining and Western blot analysis. Nitric oxide (NO) production, levels of neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS), expression levels of factors governing angiogenesis (vascular endothelial growth factor), oxidative stress (catalase, superoxide dismutase 2,4-hydroxynonenal), inflammation (tumor necrosis factor alpha), apoptosis (B-cell lymphoma 2 [Bcl-2], Bcl-2-associated X protein [Bax], cleaved poly(adenosine diphosphate-ribose) polymerase [c-PARP], cytochrome C, caspase-12, and caspase-3) were evaluated in penile corpus cavernosum of the mice. We found that penile toxicity in the mice was enhanced under excess Mn treatment through reduction of NOS activity and increase in oxidative stress, inflammation, and apoptosis in the penile cavernous tissue. Furthermore, the penile toxicity in mice with manganism was alleviated by oral B401 treatment through enhancement of both nitric oxide synthesis and angiogenesis, with simultaneous reduction of oxidative stress, inflammation, and apoptosis in penile corpus cavernosum. We suggest that the herbal formula B401 may serve as a potential dietotherapeutic supplement for penile toxicity or dysfunction in aging males.

Nitric oxide mediates insect cellular immunity via phospholipase A2 activation

USDA-ARS?s Scientific Manuscript database

After infection or invasion is recognized, biochemical mediators act in signaling insect immune functions. These include biogenic amines, insect cytokines, eicosanoids and nitric oxide (NO). Treating insects or isolated hemocyte populations with different mediators often leads to similar results. Se...

Arginine, citrulline and nitric oxide metabolism in sepsis

USDA-ARS?s Scientific Manuscript database

Arginine has vasodilatory effects, via its conversion by nitric oxide (NO) synthase into NO, and immunomodulatory actions that play important roles in sepsis. Protein breakdown affects arginine availability, and the release of asymmetric dimethylarginine, an inhibitor of NO synthase, may therefore a...

BIOGENIC NITRIC OXIDE EMISSIONS FROM CROPLAND SOILS

EPA Science Inventory

Emissions of nitric oxide (NO) were determined during late spring and summer 1995 and the spring of 1996 from four agricultural soils on which four different crops were grown. These agricultural soils were located at four different sites throughout North Carolina. Emission rates ...

Effects of growth and aging on the reference values of pulmonary nitric oxide dynamics in healthy subjects.

PubMed

Högman, M; Thornadtsson, A; Liv, P; Hua-Huy, T; Dinh-Xuan, A T; Tufvesson, E; Dressel, H; Janson, C; Koskela, K; Oksa, P; Sauni, R; Uitti, J; Moilanen, E; Lehtimäki, L

2017-09-13

The lung just like all other organs is affected by age. The lung matures by the age of 20 and age-related changes start around middle age, at 40-50 years. Exhaled nitric oxide (F E NO) has been shown to be age, height and gender dependent. We hypothesize that the nitric oxide (NO) parameters alveolar NO (C A NO), airway flux (J aw NO), airway diffusing capacity (D aw NO) and airway wall content (C aw NO) will also demonstrate this dependence. Data from healthy subjects were gathered by the current authors from their earlier publications in which healthy individuals were included as control subjects. Healthy subjects (n = 433) ranged in age from 7 to 78 years. Age-stratified reference values of the NO parameters were significantly different. Gender differences were only observed in the 20-49 age group. The results from the multiple regression models in subjects older than 20 years revealed that age, height and gender interaction together explained 6% of variation in F E NO at 50 ml s -1 (F E NO 50 ), 4% in J aw NO, 16% in C aw NO, 8% in D aw NO and 12% in C A NO. In conclusion, in this study we have generated reference values for NO parameters from an extended NO analysis of healthy subjects. This is important in order to be able to use these parameters in clinical practice.

Transport stress induces heart damage in newly hatched chicks via blocking the cytoprotective heat shock response and augmenting nitric oxide production.

PubMed

Sun, F; Zuo, Y-Z; Ge, J; Xia, J; Li, X-N; Lin, J; Zhang, C; Xu, H-L; Li, J-L

2018-04-20

Transport stress affects the animal's metabolism and psychological state. As a pro-survival pathway, the heat shock response (HSR) protects healthy cells from stressors. However, it is unclear whether the HSR plays a role in transport stress-induced heart damage. To evaluate the effects of transport stress on heart damage and HSR protection, newly hatched chicks were treated with transport stress for 2 h, 4 h and 8 h. Transport stress caused decreases in body weight and increases in serum creatine kinase (CK) activity, nitric oxide (NO) content in heart tissue, cardiac nitric oxide syntheses (NOS) activity and NOS isoforms transcription. The mRNA expression of heat shock factors (HSFs, including HSF1-3) and heat shock proteins (HSPs, including HSP25, HSP40, HSP47, HSP60, HSP70, HSP90 and HSP110) in the heart of 2 h transport-treated chicks was upregulated. After 8 h of transport stress in chicks, the transcription levels of the same HSPs and HSF2 were reduced in the heart. It was also found that the changes in the HSP60, HSP70 and HSP90 protein levels had similar tendencies. These results suggested that transport stress augmented NO generation through enhancing the activity of NOS and the transcription of NOS isoforms. Therefore, this study provides new evidence that transport stress induces heart damage in the newly hatched chicks by blocking the cytoprotective HSR and augmenting NO production.

Folic Acid Promotes Recycling of Tetrahydrobiopterin and Protects Against Hypoxia-Induced Pulmonary Hypertension by Recoupling Endothelial Nitric Oxide Synthase.

PubMed

Chalupsky, Karel; Kračun, Damir; Kanchev, Ivan; Bertram, Katharina; Görlach, Agnes

2015-11-10

Nitric oxide (NO) derived from endothelial NO synthase (eNOS) has been implicated in the adaptive response to hypoxia. An imbalance between 5,6,7,8-tetrahydrobiopterin (BH4) and 7,8-dihydrobiopterin (BH2) can result in eNOS uncoupling and the generation of superoxide instead of NO. Dihydrofolate reductase (DHFR) can recycle BH2 to BH4, leading to eNOS recoupling. However, the role of DHFR and eNOS recoupling in the response to hypoxia is not well understood. We hypothesized that increasing the capacity to recycle BH4 from BH2 would improve NO bioavailability as well as pulmonary vascular remodeling (PVR) and right ventricular hypertrophy (RVH) as indicators of pulmonary hypertension (PH) under hypoxic conditions. In human pulmonary artery endothelial cells and murine pulmonary arteries exposed to hypoxia, eNOS was uncoupled as indicated by reduced superoxide production in the presence of the nitric oxide synthase inhibitor, L-(G)-nitro-L-arginine methyl ester (L-NAME). Concomitantly, NO levels, BH4 availability, and expression of DHFR were diminished under hypoxia. Application of folic acid (FA) restored DHFR levels, NO bioavailability, and BH4 levels under hypoxia. Importantly, FA prevented the development of hypoxia-induced PVR, right ventricular pressure increase, and RVH. FA-induced upregulation of DHFR recouples eNOS under hypoxia by improving BH4 recycling, thus preventing hypoxia-induced PH. FA might serve as a novel therapeutic option combating PH.

Nitric oxide inhibits topoisomerase II activity and induces resistance to topoisomerase II-poisons in human tumor cells.

PubMed

Kumar, Ashutosh; Ehrenshaft, Marilyn; Tokar, Erik J; Mason, Ronald P; Sinha, Birandra K

2016-07-01

Etoposide and doxorubicin, topoisomerase II poisons, are important drugs for the treatment of tumors in the clinic. Topoisomerases contain several free sulfhydryl groups which are important for their activity and are also potential targets for nitric oxide (NO)-induced nitrosation. NO, a physiological signaling molecule nitrosates many cellular proteins, causing altered protein and cellular functions. Here, we have evaluated the roles of NO/NO-derived species in the activity/stability of topo II both in vitro and in human tumor cells, and in the cytotoxicity of topo II-poisons, etoposide and doxorubicin. Treatment of purified topo IIα with propylamine propylamine nonoate (PPNO), an NO donor, resulted in inhibition of both the catalytic and relaxation activity in vitro, and decreased etoposide-dependent cleavable complex formation in both human HT-29 colon and MCF-7 breast cancer cells. PPNO treatment also induced significant nitrosation of topo IIα protein in these human tumor cells. These events, taken together, caused a significant resistance to etoposide in both cell lines. However, PPNO had no effect on doxorubicin-induced cleavable complex formation, or doxorubicin cytotoxicity in these cell lines. Inhibition of topo II function by NO/NO-derived species induces significant resistance to etoposide, without affecting doxorubicin cytotoxicity in human tumor cells. As tumors express inducible nitric oxide synthase and generate significant amounts of NO, modulation of topo II functions by NO/NO-derived species could render tumors resistant to certain topo II-poisons in the clinic. Published by Elsevier B.V.

Cross-talk interactions of exogenous nitric oxide and sucrose modulates phenylpropanoid metabolism in yellow lupine embryo axes infected with Fusarium oxysporum.

PubMed

Morkunas, Iwona; Formela, Magda; Floryszak-Wieczorek, Jolanta; Marczak, Łukasz; Narożna, Dorota; Nowak, Witold; Bednarski, Waldemar

2013-10-01

The aim of the study was to examine cross-talk of exogenous nitric oxide (NO) and sucrose in the mechanisms of synthesis and accumulation of isoflavonoids in embryo axes of Lupinus luteus L. cv. Juno. It was verified whether the interaction of these molecules can modulate the defense response of axes to infection and development of the pathogenic fungus Fusarium oxysporum f. sp. lupini. Sucrose alone strongly stimulated a high level of genistein glucoside in axes pretreated with exogenous nitric oxide (SNP or GSNO) and non-pretreated axes. As a result of amplification of the signal coming from sucrose and GSNO, high isoflavonoids accumulation was observed (+Sn+GSNO). It needs to be stressed that infection in tissues pretreated with SNP/GSNO and cultured on the medium with sucrose (+Si+SNP/+Si+GSNO) very strongly enhances the accumulation of free isoflavone aglycones. In +Si+SNP axes phenylalanine ammonia-lyase activity was high up to 72h. As early as at 12h in +Si+SNP axes an increase was recorded in gene expression level of the specific isoflavonoid synthesis pathway. At 24h in +Si+SNP axes a very high total antioxidant capacity dependent on the pool of fast antioxidants was noted. Post-infection generation of semiquinone radicals was lower in axes with a high level of sucrose than with a deficit. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

A screening method for cardiovascular active compounds in marine algae.

PubMed

Agatonovic-Kustrin, S; Kustrin, E; Angove, M J; Morton, D W

2018-05-18

The interaction of bioactive compounds from ethanolic extracts of selected marine algae samples, separated on chromatographic plates, with nitric/nitrous acid was investigated. The nature of bioactive compounds in the marine algae extracts was characterised using UV absorption spectra before and after reaction with diluted nitric acid, and from the characteristic colour reaction after derivatization with anisaldehyde. It was found that diterpenes from Dictyota dichotoma, an edible brown algae, and sterols from green algae Caulerpa brachypus, bind nitric oxide and may act as a nitric oxide carrier. Although the carotenoid fucoxanthin, found in all brown marine algae also binds nitric oxide, the bonds between nitrogen and the fucoxanthin molecule are much stronger. Further studies are required to evaluate the effects of diterpenes from Dictyota dichotoma and sterols from green algae Caulerpa brachypus to see if they have beneficial cardiovascular effects. The method reported here should prove useful in screening large numbers of algae species for compounds with cardiovascular activity. Copyright © 2018 Elsevier B.V. All rights reserved.

Cylinder-averaged histories of nitrogen oxide in a DI diesel with simulated turbocharging

NASA Astrophysics Data System (ADS)

Donahue, Ronald J.; Borman, Gary L.; Bower, Glenn R.

1994-10-01

An experimental study was conducted using the dumping technique (total cylinder sampling) to produce cylinder mass-averaged nitric oxide histories. Data were taken using a four stroke diesel research engine employing a quiescent chamber, high pressure direct injection fuel system, and simulated turbocharging. Two fuels were used to determine fuel cetane number effects. Two loads were run, one at an equivalence ratio of 0.5 and the other at a ratio of 0.3. The engine speed was held constant at 1500 rpm. Under the turbocharged and retarded timing conditions of this study, nitric oxide was produced up to the point of about 85% mass burned. Two different models were used to simulate the engine mn conditions: the phenomenological Hiroyasu spray-combustion model, and the three dimensional, U.W.-ERO modified KIVA-2 computational fluid dynamic code. Both of the models predicted the correct nitric oxide trend. Although the modified KIVA-2 combustion model using Zeldovich kinetics correctly predicted the shapes of the nitric oxide histories, it did not predict the exhaust concentrations without arbitrary adjustment based on experimental values.

Does pharmaconutrition with L-arginine and/or alpha-tocopherol improve the gut barrier in bile duct ligated rats?

PubMed

Tuncyurek, P; Sari, M; Firat, O; Mutaf, I; Gulter, C; Tunger, A; Yuce, G; Yilmaz, M; Makay, O; Dayangac, M; Ersin, S

2006-01-01

Nitric oxide supplementation and antioxidant therapy modulate gut barrier function, but the relationships between enhanced nitric oxide production, antioxidant administration, and biliary obstruction remain unclear. We evaluated the role of nitric oxide and alpha-tocopherol supplementation in bile duct ligated rats. Fifty male Wistar albino rats underwent sham operation (group I; control animals) or bile duct ligation (groups II, III, IV, and V). The ligation groups received the following regimens: standard pellet diet (group II), pellet diet plus intramuscularly administered alpha-tocopherol (group III), and L-arginine-enriched pellet diet without (group IV) or with (group V) alpha-tocopherol. Nitric oxide, malondialdehyde, and alpha-tocopherol concentrations were assessed at the end of 3 weeks. Liver and intestinal samples were scored histologically. Mesenteric lymph node and liver cultures were assessed for bacterial translocation. The liver malondialdehyde concentration was highest in group III. The nitric oxide content in the liver was higher in groups III and V, as were the blood alpha-tocopherol levels. Bacterial translocation was evident following bile duct ligation, but did not differ among the treatment groups. Intestinal histology revealed that group III had the lowest villus height, that group V had the least villus count, and that group II had the highest mucous cell count. The fibrosis scores were higher in groups IV and V. An obvious effect of alpha-tocopherol (with or without L-arginine) on the gut barrier could not be demonstrated. Moreover, the L-arginine-enriched diet promoted fibrosis in the liver. Thus, while biliary duct obstruction triggers bacterial translocation, nitric oxide and/or alpha-tocopherol supplementation did not seem to improve the gut barrier in our model. Copyright 2006 S. Karger AG, Basel.

[Participation of nitric oxide and arachidonic acid metabolites via cytochrome - P450 in the regulation of arterial blood pressure].

PubMed

Sánchez-Mendoza, M Alicia; Martínez-Ayala, Sonia O; Hernández-Hernández, José A; Zúñiga-Sosa, Leonor; Pastelín-Hernández, Gustavo; Escalante-Acosta, Bruno A

2003-01-01

Nitric oxide and cytochrome P450 arachidonic acid metabolites participate in blood pressure regulation. The synthesis of these autacoids leads to arterial hypertension. However, it is not known whether there is an interaction between them. Therefore, we studied the modulatory effect of nitric oxide and cytochrome P450-arachidonic acid metabolites, their interaction on blood pressure, and the renal content of cytochrome P450. Male Wistar rats were divided: 1) control, 2) L-NAME (100 mg/kg/d p.o.), 3) L-NAME + SnCl2 (10 mg/kg/d i.p.), and 4) L-NAME + dexamethasone (1 mg/kg/d s.c.). We measured blood pressure and collected urine and blood for nitric oxide measurement. NO2 was quantified by HPLC. Blood pressure was: control, 97 +/- 7 mmHg; L-NAME, 151 +/- 4.6 mmHg; L-NAME + SnCl2, 133 +/- 3 mmHg, and L-NAME + dexamethasone 152 +/- 4.5 mmHg. Urine nitrite concentration was: 1) 1.832 +/- 0.32, 2) 1.031 +/- 0.23, 3) 1.616 +/- 0.33, and 4) 1.244 +/- 0.33 mumol/mL, while the concentration in blood was: 1) 0.293 +/- 0.06, 2) 0.150 +/- 0.05, 3) 0.373 +/- 0.13, and 4) 0.373 +/- 0.07 mumol/mL. L-NAME + SnCl2 decreased cytochrome P450 renal content, and L-NAME + dexamethasone showed a similar response. In conclusion, both, nitric oxide and CYP-arachidonic acid metabolites play a role in the regulation of blood pressure. Nitric oxide also partially regulates renal cytochrome P450 content.

Nitric oxide synthase expression in foetal placentas of cows with retained fetal membranes.

PubMed

Shixin, Fu; Li, Zhang; Chunhai, Luo; Chuang, Xu; Cheng, Xia; Zhe, Wang; Xiaobing, Li

2011-10-01

The objectives of this study were to investigate relationship of retained fetal membranes (RFM) to expression of NOS and NOS mRNA and to analyze pathohistological changes and the distribution of nitric oxide synthase (NOS) in foetal placentas of cows with RFM. Twenty cows were assigned to two groups, a control group (no retained fetal membranes, NRFM, n = 10) and a diseased group (RFM, n = 10). The endpoint method was used to detect the nitric oxide (NO) content and nitric oxide synthase (NOS) activity in foetal placental tissue fluid and the fluorescent quantitation PCR was used to measure the expression of NOS mRNA. Immunohistochemistry and hematoxylin-eosin staining were used to observe pathohistological changes. Tissue from RFM cows showed fibronecrosis of the chorionic villi, and a decreased number of trophoblastic cells. The majority of trophoblastic cells displayed vacuolar degeneration. Interstitium vessels were distended and congested. Expression of induced nitric oxide synthase (iNOS) protein and iNOS mRNA was significantly higher (P < 0.05) in the cytoplasm of placental villus trophoblastic cells in the RFM group. But expression of endothelial nitric oxide synthase (eNOS) protein and eNOS mRNA was significantly lower (P<0.05) in the RFM group. The NO content and NOS activity of cows with RFM were significantly higher (P < 0.05). A high expression of iNOS protein and iNOS mRNA in the cow foetal placenta could produce high content of NO, which might inhibit uterine contraction. So over expression of iNOS protein and iNOS mRNA might be an important agent of retained fetal membranes in cows, and it may be a potential diagnosis biomarker. Copyright © 2010 Elsevier Ltd. All rights reserved.

Use-dependent loss of active sympathetic neurogenic vasodilation after nitric oxide synthase inhibition in conscious rats. Evidence for the presence of preformed stores of nitric oxide-containing factors

NASA Technical Reports Server (NTRS)

Davisson, R. L.; Shaffer, R. A.; Johnson, A. K.; Lewis, S. J.

1996-01-01

In this study, we examined whether air-jet stress-induced active sympathetic hindlimb vasodilation in conscious rats involves the release of preformed stores of nitric oxide-containing factors. We determined the effects of repeated episodes of air-jet stress (six episodes given 5 minutes apart) on mean arterial pressure and vascular resistances in the mesenteric bed and intact and sympathetically denervated hindlimb beds of conscious rats treated with saline or the nitric oxide synthesis inhibitor N omega-nitro-L-arginine methyl ester (L-NAME, 25 mumol/kg IV). In saline-treated rats, air-jet stress produced alerting behavior, minor changes in blood pressure, pronounced mesenteric vaso-constriction, and immediate and marked vasodilation in the sympathetically intact hindlimb but a minor vasodilation in the sympathetically denervated hindlimb. Each air-jet stress produced virtually identical responses. In L-NAME-treated rats, the first air-jet stress produced vasodilator responses in the sympathetically intact and sympathetically denervated hindlimbs that were similar to those in the saline-treated rats. However, each subsequent air-jet stress produced progressively smaller vasodilator responses in the sympathetically intact but not the sympathetically denervated hindlimb. There was no loss of air-jet stress-induced alerting behavior or mesenteric vasoconstriction, suggesting that L-NAME did not interfere with the central processing of the air-jet or the resultant changes in autonomic nerve activity. The progressive diminution of air-jet stress-induced vasodilation in the intact hindlimb of L-NAME-treated rats may be due to the use-dependent depletion of preformed stores of nitric oxide-containing factors that cannot be replenished in the absence of nitric oxide synthesis.

Domain-Specific Partitioning of Uterine Artery Endothelial Connexin43 and Caveolin-1.

PubMed

Ampey, Bryan C; Morschauser, Timothy J; Ramadoss, Jayanth; Magness, Ronald R

2016-10-01

Uterine vascular adaptations facilitate rises in uterine blood flow during pregnancy, which are associated with gap junction connexin (Cx) proteins and endothelial nitric oxide synthase. In uterine artery endothelial cells (UAECs), ATP activates endothelial nitric oxide synthase in a pregnancy (P)-specific manner that is dependent on Cx43 function. Caveolar subcellular domain partitioning plays key roles in ATP-induced endothelial nitric oxide synthase activation and nitric oxide production. Little is known regarding the partitioning of Cx proteins to caveolar domains or their dynamics with ATP treatment. We observed that Cx43-mediated gap junction function with ATP stimulation is associated with Cx43 repartitioning between the noncaveolar and caveolar domains. Compared with UAECs from nonpregnant (NP) ewes, levels of ATP, PGI2, cAMP, NOx, and cGMP were 2-fold higher (P<0.05) in pregnant UAECs. In pregnant UAECs, ATP increased Lucifer yellow dye transfer, a response abrogated by Gap27, but not Gap 26, indicating involvement of Cx43, but not Cx37. Confocal microscopy revealed domain partitioning of Cx43 and caveolin-1. In pregnant UAECs, LC/MS/MS analysis revealed only Cx43 in the caveolar domain. In contrast, Cx37 was located only in the noncaveolar pool. Western analysis revealed that ATP increased Cx43 distribution (1.7-fold; P=0.013) to the caveolar domain, but had no effect on Cx37. These data demonstrate rapid ATP-stimulated repartitioning of Cx43 to the caveolae, where endothelial nitric oxide synthase resides and plays an important role in nitric oxide-mediated increasing uterine blood flow during pregnancy. © 2016 American Heart Association, Inc.

Changes in Adenosine Triphosphate and Nitric Oxide in the Urothelium of Patients with Benign Prostatic Hyperplasia and Detrusor Underactivity.

PubMed

Cho, Kang Jun; Koh, Jun Sung; Choi, Jinbong; Kim, Joon Chul

2017-12-01

We investigated changes in the levels of adenosine triphosphate and nitric oxide in the urothelium of men with detrusor underactivity and benign prostatic hyperplasia. We prospectively enrolled in study 30 men who planned to undergo surgical treatment for benign prostatic hyperplasia. The 15 patients with a bladder contractility index less than 100 were assigned to the detrusor underactivity group while the 15 with a bladder contractility index more than 100 were assigned to the no detrusor underactivity group. Bladder mucosal specimens were collected at surgical prostate resection, and adenosine triphosphate and endothelial nitric oxide synthase were analyzed in these specimens. The levels of adenosine triphosphate and endothelial nitric oxide synthase were compared between the 2 groups. The correlation of urodynamic parameters with adenosine triphosphate and endothelial nitric oxide synthase was assessed in all patients. Mean ± SEM endothelial nitric oxide synthase did not significantly differ between the detrusor underactivity and no underactivity groups (3.393 ± 0.969 vs 1.941 ± 0.377 IU/ml, p = 0.247). However, the mean level of adenosine triphosphate in the detrusor underactivity group was significantly lower than in the no detrusor underactivity group (1.289 ± 0.320 vs 9.262 ± 3.285 pmol, p = 0.011). In addition, in all patients adenosine triphosphate positively correlated with the bladder contractility index (r = 0.478, p = 0.018) and with detrusor pressure on maximal flow (r = 0.411, p = 0.046). Adenosine triphosphate was significantly decreased in the urothelium in men with detrusor underactivity and benign prostatic hyperplasia, reflecting the change in detrusor function. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Nitric Oxide and ERK mediates regulation of cellular processes by Ecdysterone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Omanakuttan, Athira; Bose, Chinchu; Pandurangan, Nanjan

The complex process of wound healing is a major problem associated with diabetes, venous or arterial disease, old age and infection. A wide range of pharmacological effects including anabolic, anti-diabetic and hepato-protective activities have been attributed to Ecdysterone. In earlier studies, Ecdysterone has been shown to modulate eNOS and iNOS expression in diabetic animals and activate osteogenic differentiation through the Extracellular-signal-Regulated Kinase (ERK) pathway in periodontal ligament stem cells. However, in the wound healing process, Ecdysterone has only been shown to enhance granulation tissue formation in rabbits. There have been no studies to date, which elucidate the molecular mechanism underlyingmore » the complex cellular process involved in wound healing. The present study, demonstrates a novel interaction between the phytosteroid Ecdysterone and Nitric Oxide Synthase (NOS), in an Epidermal Growth Factor Receptor (EGFR)-dependent manner, thereby promoting cell proliferation, cell spreading and cell migration. These observations were further supported by the 4-amino-5-methylamino- 2′ ,7′ -difluorofluorescein diacetate (DAF FM) fluorescence assay which indicated that Ecdysterone activates NOS resulting in increased Nitric Oxide (NO) production. Additionally, studies with inhibitors of both the EGFR and ERK, demonstrated that Ecdysterone activates NOS through modulation of EGFR and ERK. These results clearly demonstrate, for the first time, that Ecdysterone enhances Nitric Oxide production and modulates complex cellular processes by activating ERK1/2 through the EGF pathway. - Highlights: • Ecdysterone significantly enhances cell migration in a dose dependent manner. • Ecdysterone augments cell spreading during the initial phase of cell migration through actin cytoskeletal rearrangement. • Ecdysterone enhances cell proliferation in a nitric oxide dependent manner. • Ecdysterone enhances nitric oxide production via activation of EGFR and phosphorylation of ERK.« less

Gestational Obstructive Sleep Apnea: Biomarker Screening Models and Lack of Postpartum Resolution.

PubMed

Street, Linda M; Aschenbrenner, Carol A; Houle, Timothy T; Pinyan, Clark W; Eisenach, James C

2018-04-15

To measure prevalence and severity of third trimester obstructive sleep apnea and evaluate postpartum resolution. To assess a novel biomarker for screening for obstructive sleep apnea in pregnancy. This prospective observational study was performed at Wake Forest School of Medicine obstetrics clinics between April 2014 and December 2015. Fractional exhaled nitric oxide measurements and sleep studies were obtained and compared at 32 0/7 to 35 6/7 weeks gestation and postpartum. Exhaled nitric oxide and risk factors for the development of gestational sleep apnea were evaluated for predictive ability independently and in screening models. Of 76 women enrolled, 73 performed valid sleep studies in pregnancy and 65 had an additional valid study 6 to 15 weeks postpartum. Twenty-four women (37%) had gestational sleep apnea compared with 23 (35%) with postpartum sleep apnea ( P > .99). Eight of 11 women (73%) retested 6 to 8 months postpartum had persistent sleep apnea. Exhaled nitric oxide had moderate discrimination screening for sleep apnea in pregnancy (area under the receiver operating characteristic curve = 0.64). A model utilizing exhaled nitric oxide, pregnancy-specific screening, and Mallampati score improved ability to identify women at risk for gestational sleep apnea (sensitivity = 46%, specificity = 91% and likelihood ratio = 5.11, area under receiver operating characteristic curve = 0.75). Obstructive sleep apnea is common in the early postpartum period and often persisted at least 6 months. Exhaled nitric oxide as a sole biomarker to screen for sleep apnea in pregnancy has only modest discrimination. Combined with additional parameters sensitivity and specificity improved. Registry: ClinicalTrials.gov, Identifier: NCT02100943, Title: Exhaled Nitric Oxide as a Biomarker of Gestational Obstructive Sleep Apnea and Persistence Postpartum, URL: https://clinicaltrials.gov/ct2/show/NCT02100943. © 2018 American Academy of Sleep Medicine.

Possible involvement of nitric oxide (NO) signaling pathway in the antidepressant-like effect of MK-801(dizocilpine), a NMDA receptor antagonist in mouse forced swim test.

PubMed

Dhir, Ashish; Kulkarni, S K

2008-03-01

L-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) is an important signaling pathway involved in depression. With this information, the present study aimed to study the involvement of this signaling pathway in the antidepressant-like action of MK-801 (dizocilpine; N-methyl-d-aspartate receptor antagonist) in the mouse forced-swim test. Total immobility period was recorded in mouse forced swim test for 6 min. MK-801 (5-25 microg/kg., ip) produced a U-shaped curve in reducing the immobility period. The antidepressant-like effect of MK-801 (10 microg/kg, ip) was prevented by pretreatment with L-arginine (750 mg/kg, ip) [substrate for nitric oxide synthase (NOS)]. Pretreatment of mice with 7-nitroindazole (7-NI) (25 mg/kg, ip) [a specific neuronal nitric oxide synthase inhibitor] produced potentiation of the action of subeffective dose of MK-801 (5 microg/kg, ip). In addition, treatment of mice with methylene blue (10 mg/kg, ip) [direct inhibitor of both nitric oxide synthase and soluble guanylate cyclase] potentiated the effect of MK-801 (5 microg/kg, ip) in the forced-swim test. Further, the reduction in the immobility period elicited by MK-801 (10 microg/kg, ip) was also inhibited by pretreatment with sildenafil (5 mg/kg, ip) [phosphodiesterase 5 inhibitor]. The various modulators used in the study and their combination did not produce any changes in locomotor activity per se and in combination with MK-801. MK-801 however, at higher doses (25 microg/kg, ip) produced hyperlocomotion. The results demonstrated the involvement of nitric oxide signaling pathway in the antidepressant-like effect of MK-801 in mouse forced-swim test.

The peripheral administration of a nitric oxide donor potentiates the local antinociceptive effects of a DOR agonist during chronic inflammatory pain in mice.

PubMed

Hervera, Arnau; Leánez, Sergi; Negrete, Roger; Pol, Olga

2009-10-01

Several works reveal that nitric oxide could enhance the peripheral antinociception induced by opioids during acute inflammation. Nonetheless, the role of nitric oxide in the local antinociceptive effects of delta-opioid receptor (DOR) agonists during chronic peripheral inflammation is not known. The aim of this study is to evaluate whether nitric oxide would enhance the local antinociceptive effects of a DOR agonist during chronic inflammatory pain in mice. Chronic inflammatory pain was induced by the subplantar administration of complete Freund's adjuvant (CFA; 30 microl) and thermal hyperalgesia assessed by plantar test. In C57BL/6J mice, we evaluated the local antinociceptive effects of a DOR agonist, [D-Pen2,5]-enkephalin (DPDPE) and a nitric oxide donor, DETA NONOate DETA/NO 2,2'-(hydroxynitrosohydrazino) Bis-Ethanamine (NOC-18) alone or combined (DPDPE plus NOC-18) at 1, 4, 7, and 10 days after CFA injection. The reversibility of the peripheral antinociceptive effects of DPDPE, alone or combined with NOC-18, was assessed with the local administration of selective (naltrindole) and non-selective (naloxone methiodide) DOR antagonists. The local administration of DPDPE or NOC-18 alone dose-dependently inhibited the thermal hyperalgesia induced by peripheral inflammation. Moreover, the co-administration of NOC-18 with DPDPE significantly increased the antinociceptive effects produced by DPDPE from 1 to 10 days of CFA-induced inflammatory pain (P < 0.05). These effects were completely blocked by naltrindole and naloxone methiodide. Our results demonstrate that nitric oxide might enhance the local antinociceptive effects of a DOR agonist during chronic inflammatory pain by interaction with peripheral DOR, representing a useful strategy for an efficient antinociceptive treatment of peripheral inflammatory pain.

The effect of a selective neuronal nitric oxide synthase inhibitor 3-bromo 7-nitroindazole on spatial learning and memory in rats.

PubMed

Gocmez, Semil Selcen; Yazir, Yusufhan; Sahin, Deniz; Karadenizli, Sabriye; Utkan, Tijen

2015-04-01

Since the discovery of nitric oxide (NO) as a neuronal messenger, its way to modulate learning and memory functions is subject of intense research. NO is an intercellular messenger in the central nervous system and is formed on demand through the conversion of L-arginine to L-citrulline via the enzyme nitric oxide synthase (NOS). Neuronal form of nitric oxide synthase may play an important role in a wide range of physiological and pathological conditions. Therefore the aim of this study was to investigate the effects of chronic 3-bromo 7-nitroindazole (3-Br 7-NI), specific neuronal nitric oxide synthase (nNOS) inhibitor, administration on spatial learning and memory performance in rats using the Morris water maze (MWM) paradigm. Male rats received either 3-Br 7-NI (20mg/kg/day) or saline via intraperitoneal injection for 5days. Daily administration of the specific neuronal nitric oxide synthase (nNOS) inhibitor, 3-Br 7-NI impaired the acquisition of the MWM task. 3-Br 7-NI also impaired the probe trial. The MWM training was associated with a significant increase in the brain-derived neurotrophic factor (BDNF) mRNA expression in the hippocampus. BDNF mRNA expression in the hippocampus did not change after 3-Br 7-NI treatment. L-arginine significantly reversed behavioural parameters, and the effect of 3-Br 7-NI was found to be NO-dependent. There were no differences in locomotor activity and blood pressure in 3-Br 7-NI treated rats. Our results may suggest that nNOS plays a key role in spatial memory formation in rats. Copyright © 2015 Elsevier Inc. All rights reserved.

Human nitric oxide biomarker as potential NO donor in conjunction with superparamagnetic iron oxide @ gold core shell nanoparticles for cancer therapeutics.

PubMed

Singh, Nimisha; Patel, Khushbu; Sahoo, Suban K; Kumar, Rajender

2018-03-01

Nitric oxide releasing superparamagnetic (Fe 3 O 4 -Au@NTHP) nanoparticles were synthesized by conjugation of human biomarker of nitric oxide, N-nitrosothioproline with iron oxide-gold (Fe 3 O 4 -Au) core shell nanoparticles. The structure and morphology of the prepared nanoparticles were confirmed by ATR-FTIR, HR-TEM, EDAX, XPS, DLS and VSM measurements. N-nitrosothioproline is a natural molecule and nontoxic to humans. Thus, the core shell nanoparticles prepared were highly biocompatible. The prepared Fe 3 O 4 -Au@NTHP nanoparticles also provided an excellent release of nitric oxide in dark and upon light irradiation for cancer treatment. The amount of NO release was controllable with the wavelength of light and time of irradiation. The developed nanoparticles provided efficient cellular uptake and good cytotoxicity in picomolar range when tested on HeLa cancerous cells. These nanoparticles on account of their controllable NO release can also be used to release small amount of NO for killing cancerous cells without any toxic effect. Furthermore, the magnetic and photochemical properties of these nanoparticles provides dual platform for magneto therapy and phototherapy for cancer treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Metabolic activation of sodium nitroprusside to nitric oxide in vascular smooth muscle.

PubMed

Kowaluk, E A; Seth, P; Fung, H L

1992-09-01

Sodium nitroprusside (SNP) is thought to exert its vasodilating activity, at least in part, by vascular activation to nitric oxide (NO), but the activation mechanism has not been delineated. This study has examined the potential for vascular metabolism of SNP to NO in bovine coronary arterial smooth muscle subcellular fractions using a sensitive and specific redox-chemiluminescence assay for NO. SNP was readily metabolized to NO in subcellular fractions, and the dominant site of metabolism appeared to be located in the membrane fractions. NO-generating activity was significantly enhanced by, but did not absolutely require, the addition of a NADPH-regenerating system, NADPH per se, NADH or cysteine. A correlation analysis of NO-generating activity (in the presence of a NADPH-regenerating system) with marker enzyme activities indicated that the SNP-directed NO-generating activity was primarily membrane-associated. Radiation inactivation target-size analysis revealed that the microsomal SNP-directed NO-generating activity was relatively insensitive to inactivation by radiation exposure, suggesting that the functioning catalytic unit might be quite small. A molecular weight of 5 to 11 kDa was estimated. NO-generating activity could be solubilized from the crude microsomes with 3-[(3-cholamidopropyl)- dimethylammonio]-1-propane sulfonate, and the solubilized extract was subjected to gel filtration chromatography. NO-generating activity was eluted in two peaks: one peak corresponding to an approximate molecular weight of 4 kDa, thus confirming the existence of a small molecular weight NO-generating activity, and a second activity peak corresponding to a molecular weight of 112 to 169 kDa, the functional significance of which is unclear at present.(ABSTRACT TRUNCATED AT 250 WORDS)

A novel nitric oxide-based anticancer therapeutics by macrophage-targeted poly(l-arginine)-based nanoparticles.

PubMed

Kudo, Shinpei; Nagasaki, Yukio

2015-11-10

In the immune system, macrophages in tumor tissue generate nitric oxide (NO), producing versatile effects including apoptosis of tumor cells, because inducible NO synthase (iNOS) in the cytoplasm of a macrophage produces NO using l-arginine as a substrate. Here, we propose novel NO-triggered immune therapeutics based on our newly designed nanoparticle system. We designed a poly(ethylene glycol)-block-poly(l-arginine) (i.e., PEG-b-P(l-Arg)) block copolymer and prepared polyion complex micelles (PEG-b-P(l-Arg)/m) composed of PEG-b-P(l-Arg) and chondroitin sulfate for systemic anticancer immunotherapy. iNOS treatment of PEG-b-P(l-Arg) did not generate NO, but NO molecules were detected after trypsin pretreatment, indicating that hydrolysis of P(l-Arg) to monomeric arginine was taking place in vitro. RAW264.7 macrophages abundantly generated NO from the PEG-b-P(l-Arg)/m in comparison with control micelles; this finding is indicative of robustness of the proposed method. It is interesting to note that systemic administration of PEG-b-P(l-Arg)/m had no noticeable adverse effects and suppressed the tumor growth rate in C26 tumor-bearing mice in a dose-dependent manner. Our newly designed nanoparticle-assisted arginine delivery system seems to hold promise as an NO-mediated anticancer immunotherapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Hydrogen Peroxide Signaling in Plant Development and Abiotic Responses: Crosstalk with Nitric Oxide and Calcium

PubMed Central

Niu, Lijuan; Liao, Weibiao

2016-01-01

Hydrogen peroxide (H2O2), as a reactive oxygen species, is widely generated in many biological systems. It has been considered as an important signaling molecule that mediates various physiological and biochemical processes in plants. Normal metabolism in plant cells results in H2O2 generation, from a variety of sources. Also, it is now clear that nitric oxide (NO) and calcium (Ca2+) function as signaling molecules in plants. Both H2O2 and NO are involved in plant development and abiotic responses. A wide range of evidences suggest that NO could be generated under similar stress conditions and with similar kinetics as H2O2. The interplay between H2O2 and NO has important functional implications to modulate transduction processes in plants. Moreover, close interaction also exists between H2O2 and Ca2+ in response to development and abiotic stresses in plants. Cellular responses to H2O2 and Ca2+ signaling systems are complex. There is quite a bit of interaction between H2O2 and Ca2+ signaling in responses to several stimuli. This review aims to introduce these evidences in our understanding of the crosstalk among H2O2, NO, and Ca2+ signaling which regulates plant growth and development, and other cellular and physiological responses to abiotic stresses. PMID:26973673

Indoor Spatial Monitoring of Combustion Generated Pollutants (TSP, CO, and BaP) by Indian Cookstoves

DTIC Science & Technology

1988-07-01

various building materials and consumer products, and combustion appliances. People and pets normally emit C02 , moisture, odors, and microbes. Tobacco ...fuels Group II. Sources both indoor and outdoor: Nitric oxide, nitrogen dioxide Fuel-burning, tobacco smoke Polycyclic hydrocarbons Fuel-burning, tobacco ...smoke Carbon monoxide Fuel-burning, tobacco smoke Carbon dioxide Metabolic activity, combustion Suspended particulate matter Resuspension

Nitric oxide releasing plasma polymer coating with bacteriostatic properties and no cytotoxic side effects.

PubMed

Michl, Thomas D; Coad, Bryan R; Doran, Michael; Osiecki, Michael; Kafshgari, Morteza Hasanzadeh; Voelcker, Nicolas H; Hüsler, Amanda; Vasilev, Krasimir; Griesser, Hans J

2015-04-25

We report a stable plasma polymer coating, using isopentyl nitrite as a volatile precursor, which releases nitric oxide at bacteriostatic concentrations when contacted with water, inhibiting bacterial growth without cytotoxic side effects to human mesenchymal stem/stromal cells.

Nitric oxide gamma and delta band emission at twilight

NASA Technical Reports Server (NTRS)

Feldman, P. D.; Takacs, P. Z.

1974-01-01

Nitric oxide twilight emission above 140 km in the gamma- and delta-bands was observed with a rocket-borne spectrophotometer. The relative intensity of the two band systems indicates that the emission is produced predominantly by the chemiluminescent preassociation of oxygen and nitrogen atoms.

EXAMINING THE TEMPORAL VARIABILITY OF AMMONIA AND NITRIC OXIDE EMISSIONS FROM AGRICULTURAL PROCESSES

EPA Science Inventory

This paper examines the temporal variability of airborne emissions of ammonia from livestock operations and fertilizer application and nitric oxide from soils. In the United States, the livestock operations and fertilizer categories comprise the majority of the ammonia emissions...

Apigenin attenuates diabetes-associated cognitive decline in rats via suppressing oxidative stress and nitric oxide synthase pathway

PubMed Central

Mao, Xiao-Yuan; Yu, Jing; Liu, Zhao-Qian; Zhou, Hong-Hao

2015-01-01

Our present investigation aimed to determine the neuroprotection of apigenin (API) against diabetes-associated cognitive decline (DACD) a diabetic rat model and exploring its potential mechanism. Diabetic rat model was induced by intraperitoneal injection of streptozotocin. All experiment animals treated with vehicle or API by doses of 10, 20 and 40 mg/kg for seven weeks. Firstly, the body weight and blood glucose levels were detected. We used Morris water maze test to evaluate learning and memory function. The oxidative indicators (malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH)), cNOS, iNOS, caspase-3 and caspase-9 were measured in cerebral cortex and hippocampus using corresponding commercial kits. API can increase body weight, reduce the blood glucose levels, and improve the cognitive function in rats induced by diabetes. API decrease the MDA content, and increase SOD activity and GSH level of diabetic animals in the cerebral cortex and hippocampus of diabetic rats. Meanwhile, constitutive nitric oxide synthase (cNOS), inducible nitric oxide synthase (iNOS), caspase-3/9 were markedly exhibited in the cerebral cortex and hippocampus of diabetic rats. In summary, our current work discloses that API attenuates DACD in rats via suppressing oxidative stress, nitric oxide and apoptotic cascades synthase pathway. PMID:26629041

The role of nitric oxide pathway in arginine transport and growth of IPEC-1 cells.

PubMed

Xiao, Hao; Zeng, Liming; Shao, Fangyuan; Huang, Bo; Wu, Miaomiao; Tan, Bie; Yin, Yulong

2017-05-02

L-Arginine itself and its metabolite-nitric oxide play great roles in intestinal physiology. However, the molecular mechanism underlying nitric oxide pathway regulating L-Arginine transport and cell growth is not yet fully understood. We report that inhibition of nitric oxide synthase (NOS) significantly induced cell apoptosis (p < 0.05), and promoted the rate of Arginine uptake and the expressions of protein for CAT-2 and y+LAT-1 (p < 0.05), while reduced protein expression of CAT-1. And NOS inhibition markedly decreased the activation of mammalian target of rapamycin (mTOR) and PI3K-Akt pathways by Arginine in the IPEC-1 cells (p < 0.05). Taken together, these data suggest that inhibition of NO pathway by L-NAME induces a negative feedback increasing of Arginine uptake and CAT-2 and y+LAT-1 protein expression, but promotes cell apoptosis which involved inhibiting the activation of mTOR and PI3K-Akt pathways.

Reference models for thermospheric NO

NASA Technical Reports Server (NTRS)

Barth, C. A.

1989-01-01

Nitric oxide has been measured with an ultraviolet spectrometer on the polar-orbiting satellite Solar Mesosphere Explorer (SME) for the period January 1982 to August 1986. The nitric oxide database contains densities at all latitudes sorted into 5 degree bins and at altitudes between 100 and 140 km sorted into 3.3 km-bins. The largest densities occur at latitudes in the auroral zones where the density varies as a function of geomagnetic activity. Variations of a factor of 10 occur between times of intense activity and quiet times. At low latitudes, the nitric oxide density at 110 km varies from a mean value of 3 times 10(exp 7) molecules per cubic cm in January 1982 to a mean value of 4 times 10(exp 6) molecules per cubic cm during solar minimum conditions in 1986. In addition, the low-latitude nitric oxide density varies plus or minus 50 percent with a period of 27 days during times of high solar activity.

Ferulic acid and its water-soluble derivatives inhibit nitric oxide production and inducible nitric oxide synthase expression in rat primary astrocytes.

PubMed

Kikugawa, Masaki; Ida, Tomoaki; Ihara, Hideshi; Sakamoto, Tatsuji

2017-08-01

We recently reported that two water-soluble derivatives of ferulic acid (1-feruloyl glycerol, 1-feruloyl diglycerol) previously developed by our group exhibited protective effects against amyloid-β-induced neurodegeneration in vitro and in vivo. In the current study, we aimed to further understand this process by examining the derivatives' ability to suppress abnormal activation of astrocytes, the key event of neurodegeneration. We investigated the effects of ferulic acid (FA) derivatives on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in rat primary astrocytes. The results showed that these compounds inhibited NO production and iNOS expression in a concentration-dependent manner and that the mechanism underlying these effects was the suppression of the nuclear factor-κB pathway. This evidence suggests that FA and its derivatives may be effective neuroprotective agents and could be useful in the treatment of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease.

The nitric oxide prodrug JS-K and its structural analogues as cancer therapeutic agents.

PubMed

Maciag, Anna E; Saavedra, Joseph E; Chakrapani, Harinath

2009-09-01

Nitric oxide (NO) prodrugs of the diazeniumdiolate class are routinely used as reliable sources of nitric oxide in chemical and biological laboratory settings. O(2)-(2,4-dinitrophenyl) diazeniumdiolates, which are derivatized forms of ionic diazeniumdiolates, have been found to show potent anti-proliferative activity in a variety of cancer cells, presumably through the effects of NO. One important member of this class of diazeniumdiolates, O(2)-(2,4-dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K), has shown promise as a novel cancer therapeutic agent in a number of animal models. This review describes the developments in chemical and biochemical characterization and structure-activity relationship of JS-K and its analogues. In addition, some molecular mechanistic insights into the observed anti-proliferative activity of JS-K are discussed. Finally, a structural motif is presented for O(2)-(aryl) diazeniumdiolate nitric oxide prodrugs that show potency comparable with that of JS-K.

Endomembrane H-Ras Controls Vascular Endothelial Growth Factor-induced Nitric-oxide Synthase-mediated Endothelial Cell Migration*

PubMed Central

Haeussler, Dagmar J.; Pimentel, David R.; Hou, Xiuyun; Burgoyne, Joseph R.; Cohen, Richard A.; Bachschmid, Markus M.

2013-01-01

We demonstrate for the first time that endomembrane-delimited H-Ras mediates VEGF-induced activation of endothelial nitric-oxide synthase (eNOS) and migratory response of human endothelial cells. Using thiol labeling strategies and immunofluorescent cell staining, we found that only 31% of total H-Ras is S-palmitoylated, tethering the small GTPase to the plasma membrane but leaving the function of the large majority of endomembrane-localized H-Ras unexplained. Knockdown of H-Ras blocked VEGF-induced PI3K-dependent Akt (Ser-473) and eNOS (Ser-1177) phosphorylation and nitric oxide-dependent cell migration, demonstrating the essential role of H-Ras. Activation of endogenous H-Ras led to recruitment and phosphorylation of eNOS at endomembranes. The loss of migratory response in cells lacking endogenous H-Ras was fully restored by modest overexpression of an endomembrane-delimited H-Ras palmitoylation mutant. These studies define a newly recognized role for endomembrane-localized H-Ras in mediating nitric oxide-dependent proangiogenic signaling. PMID:23548900

Cortical actin nanodynamics determines nitric oxide release in vascular endothelium.

PubMed

Fels, Johannes; Jeggle, Pia; Kusche-Vihrog, Kristina; Oberleithner, Hans

2012-01-01

The release of the main vasodilator nitric oxide (NO) by the endothelial NO synthase (eNOS) is a hallmark of endothelial function. We aim at elucidating the underlying mechanism how eNOS activity depends on cortical stiffness (К(cortex)) of living endothelial cells. It is hypothesized that cortical actin dynamics determines К(cortex) and directly influences eNOS activity. By combined atomic force microscopy and fluorescence imaging we generated mechanical and optical sections of single living cells. This approach allows the discrimination between К(cortex) and bulk cell stiffness (К(bulk)) and, additionally, the simultaneous analysis of submembranous actin web dynamics. We show that К(cortex) softens when cortical F-actin depolymerizes and that this shift from a gel-like stiff cortex to a soft G-actin rich layer, triggers the stiffness-sensitive eNOS activity. The results implicate that stiffness changes in the ∼100 nm phase of the submembranous actin web, without affecting К(bulk), regulate NO release and thus determines endothelial function.

Nitric Oxide Production by the Human Intestinal Microbiota by Dissimilatory Nitrate Reduction to Ammonium

PubMed Central

Vermeiren, Joan; Van de Wiele, Tom; Verstraete, Willy; Boeckx, Pascal; Boon, Nico

2009-01-01

The free radical nitric oxide (NO) is an important signaling molecule in the gastrointestinal tract. Besides eukaryotic cells, gut microorganisms are also capable of producing NO. However, the exact mechanism of NO production by the gut microorganisms is unknown. Microbial NO production was examined under in vitro conditions simulating the gastrointestinal ecosystem using L-arginine or nitrate as substrates. L-arginine did not influence the microbial NO production. However, NO concentrations in the order of 90 ng NO-N per L feed medium were produced by the fecal microbiota from nitrate. 15N tracer experiments showed that nitrate was mainly reduced to ammonium by the dissimilatory nitrate reduction to ammonium (DNRA) pathway. To our knowledge, this is the first study showing that gastrointestinal microbiota can generate substantial amounts of NO by DNRA and not by the generally accepted denitrification or L-arginine pathway. Further work is needed to elucidate the exact role between NO produced by the gastrointestinal microbiota and host cells. PMID:19888436

A nitric oxide concentration clamp.

PubMed

Zhelyaskov, V R; Godwin, D W

1999-10-01

We report a new method of generating nitric oxide (NO) that possesses several advantages for experimental use. This method consists of a photolysis chamber where NO is released by illuminating photolabile NO donors with light from a xenon lamp, in conjunction with feedback control. Control of the photolysis light was achieved by selectively gating light projected through a shutter before the light was launched into a light guide that conveyed the light to the photolysis chamber. By gating the light in proportion to a sensor that reported nearly instantaneous concentration from the photolysis chamber, a criterion NO concentration could be achieved, which could be easily adjusted to higher or lower criterion levels. To denote the similarity of this process with the electrophysiological process of voltage clamp, we term this process a concentration "clamp." This development enhances the use of the fiber-optic-based system for NO delivery and should enable the execution of experiments where the in situ concentration of NO is particularly critical, such as in biological preparations. Copyright 1999 Academic Press.

Guanylyl cyclase-dependent chemotaxis of endothelial cells in response to nitric oxide gradients.

PubMed

Isenberg, Jeff S; Ridnour, Lisa A; Thomas, Douglas D; Wink, David A; Roberts, David D; Espey, Michael Graham

2006-03-15

Nitric oxide (NO) is an important regulator of angiogenesis and neovascularization. The nature of endothelial cell motility responses to NO was examined using a Boyden chamber method. NO generated via decomposition of either DEA/NO or DETA/NO produced increases in human umbilical vein endothelial cell (HUVEC) chemotaxis, which were completely abrogated by ODQ, a soluble guanylyl cyclase inhibitor. Measurements of NO either directly by chemiluminescence or its chemistry with diaminofluorescein revealed that chemotaxis was driven by subtle NO gradients between the lower and the upper wells in this system. In addition to diffusion and volatilization from the upper chambers, the data showed that HUVEC consumption of NO contributed to these sustained gradients. Comparison of DEA/NO- and DETA/NO-mediated responses suggested that the persistence of spatial NO gradients is as significant as the absolute magnitude of NO exposure per unit time. The findings suggest that subnanomolar NO gradients are sufficient to mobilize endothelial cell migration into hypoxic tissue during neovascularization events, such as in wound healing and cancer.

Glycoconjugates as Mediators of Nitric Oxide Production upon Exposure to Bacterial Spores by Macrophages

NASA Astrophysics Data System (ADS)

Lahiani, Mohamed; Soderberg, Lee; Tarasenko, Olga

2011-06-01

Phagocytes generate nitric oxide (NO) in large quantities to combat bacteria. The spore-producing Gram-positive organisms of Bacillus cereus family are causative agents from mild to a life threatening infection in humans and domestic animals. Our group have shown that glycoconjugates (GCs) activate macrophages and enhance killing of Bacillus spores. In this investigation, we will explore the effect of different GCs structures on NO production. The objective of this study is to study effects of GCs 2, 4, 6, 8, 10 on NO release upon exposure to B. cereus and Bacillus anthracis spores by macrophages. Our results demonstrated that GCs activated macrophages and increased NO production using studied GCs ligands compared to macrophage only (p<0.001). GC2 and GC8 were able to further increase NO production in macrophages compared to the B. anthracis spores treated macrophages (p<0.001). Our finding suggests that GCs could be used as potential mediators of NO production in macrophages to fight B. anthracis and other pathogens.

Formation of nitrosothiols from gaseous nitric oxide at pH 7.4.

PubMed

Palmerini, Carlo Alberto; Saccardi, Carla; Arienti, Giuseppe; Palombari, Roberto

2002-01-01

Nitric oxide (NO) is generated in biological systems and plays important roles as a regulatory molecule. Its ability to bind to haem iron is well known. Moreover, it may lose an electron, forming the nitrosonium ion, involved in the synthesis of S-nitrosothiols (SNOs). It has been suggested that S-nitrosohaemoglobin (-SNO Hb) and low molecular weight SNOs may act as reservoirs of NO. SNOs are formed in vitro, at strongly acidic pH values; however, the mechanism of their formation at neutral pH values is still debated. In this paper we report the anaerobic formation of SNOs (both high- and low-molecular weight) from low concentrations of NO at pH 7.4, provided Hb is also present. We propose a reaction mechanism entailing the participation of Fehaem in the formation of NO(+) and the transfer of NO(+) either to Cysbeta(93) of Hb or to glutathione; we show that this reaction also occurs in human RBCs. Copyright 2002 Wiley Periodicals, Inc.

Chronic cigarette smoking alters erythrocyte membrane lipid composition and properties in male human volunteers.

PubMed

Padmavathi, Pannuru; Reddy, Vaddi Damodara; Kavitha, Godugu; Paramahamsa, Maturu; Varadacharyulu, Nallanchakravarthula

2010-11-01

Cigarette smoking is a major lifestyle factor influencing the health of human beings. The present study investigates smoking induced alterations on the erythrocyte membrane lipid composition, fluidity and the role of nitric oxide. Thirty experimental and control subjects (age 35+/-8) were selected for the study. Experimental subjects smoke 12+/-2 cigarettes per day for 7-10 years. In smokers elevated nitrite/nitrate levels in plasma and red cell lysates were observed. Smokers showed increased hemolysis, erythrocyte membrane lipid peroxidation, protein carbonyls, C/P ratio (cholesterol and phospholipid ratio), anisotropic (gamma) value with decreased Na(+)/K(+)-ATPase activity and sulfhydryl groups. Alterations in smokers erythrocyte membrane individual phospholipids were also evident from the study. Red cell lysate nitric oxide positively correlated with C/P ratio (r=0.565) and fluorescent anisotropic (gamma) value (r=0.386) in smokers. Smoking induced generation of reactive oxygen/nitrogen species might have altered erythrocyte membrane physico-chemical properties. Copyright 2010 Elsevier Inc. All rights reserved.

Nitric oxide production by the human intestinal microbiota by dissimilatory nitrate reduction to ammonium.

PubMed

Vermeiren, Joan; Van de Wiele, Tom; Verstraete, Willy; Boeckx, Pascal; Boon, Nico

2009-01-01

The free radical nitric oxide (NO) is an important signaling molecule in the gastrointestinal tract. Besides eukaryotic cells, gut microorganisms are also capable of producing NO. However, the exact mechanism of NO production by the gut microorganisms is unknown. Microbial NO production was examined under in vitro conditions simulating the gastrointestinal ecosystem using L-arginine or nitrate as substrates. L-arginine did not influence the microbial NO production. However, NO concentrations in the order of 90 ng NO-N per L feed medium were produced by the fecal microbiota from nitrate. (15)N tracer experiments showed that nitrate was mainly reduced to ammonium by the dissimilatory nitrate reduction to ammonium (DNRA) pathway. To our knowledge, this is the first study showing that gastrointestinal microbiota can generate substantial amounts of NO by DNRA and not by the generally accepted denitrification or L-arginine pathway. Further work is needed to elucidate the exact role between NO produced by the gastrointestinal microbiota and host cells.

Advanced catalytic combustors for low pollutant emissions, phase 1

NASA Technical Reports Server (NTRS)

Dodds, W. J.

1979-01-01

The feasibility of employing the known attractive and distinguishing features of catalytic combustion technology to reduce nitric oxide emissions from gas turbine engines during subsonic, stratospheric cruise operation was investigated. Six conceptual combustor designs employing catalytic combustion were defined and evaluated for their potential to meet specific emissions and performance goals. Based on these evaluations, two parallel-staged, fixed-geometry designs were identified as the most promising concepts. Additional design studies were conducted to produce detailed preliminary designs of these two combustors. Results indicate that cruise nitric oxide emissions can be reduced by an order of magnitude relative to current technology levels by the use of catalytic combustion. Also, these combustors have the potential for operating over the EPA landing-takeoff cycle and at cruise with a low pressure drop, high combustion efficiency and with a very low overall level of emission pollutants. The use of catalytic combustion, however, requires advanced technology generation in order to obtain the time-temperature catalytic reactor performance and durability required for practical aircraft engine combustors.

Nitric oxide bioavailability in the microcirculation: insights from mathematical models.

PubMed

Tsoukias, Nikolaos M

2008-11-01

Over the last 30 years nitric oxide (NO) has emerged as a key signaling molecule involved in a number of physiological functions, including in the regulation of microcirculatory tone. Despite significant scientific contributions, fundamental questions about NO's role in the microcirculation remain unanswered. Mathematical modeling can assist in investigations of microcirculatory NO physiology and address experimental limitations in quantifying vascular NO concentrations. The number of mathematical models investigating the fate of NO in the vasculature has increased over the last few years, and new models are continuously emerging, incorporating an increasing level of complexity and detail. Models investigate mechanisms that affect NO availability in health and disease. They examine the significance of NO release from nonendothelial sources, the effect of transient release, and the complex interaction of NO with other substances, such as heme-containing proteins and reactive oxygen species. Models are utilized to test and generate hypotheses for the mechanisms that regulate NO-dependent signaling in the microcirculation.

Intake of red wine increases the number and functional capacity of circulating endothelial progenitor cells by enhancing nitric oxide bioavailability.

PubMed

Huang, Po-Hsun; Chen, Yung-Hsiang; Tsai, Hsiao-Ya; Chen, Jia-Shiong; Wu, Tao-Cheng; Lin, Feng-Yen; Sata, Masataka; Chen, Jaw-Wen; Lin, Shing-Jong

2010-04-01

Red wine (RW) consumption has been associated with a reduction of cardiovascular events, but limited data are available on potential mediating mechanisms. This study tested the hypothesis that intake of RW may promote the circulating endothelial progenitor cell (EPC) level and function through enhancement of nitric oxide bioavailability. Eighty healthy, young subjects were randomized and assigned to consume water (100 mL), RW (100 mL), beer (250 mL), or vodka (30 mL) daily for 3 weeks. Flow cytometry was used to quantify circulating EPC numbers, and in vitro assays were used to evaluate EPC functions. After RW ingestion, endothelial function determined by flow-mediated vasodilation was significantly enhanced; however, it remained unchanged after water, beer, or vodka intake. There were significantly increased numbers of circulating EPC (defined as KDR(+)CD133(+), CD34(+)CD133(+), CD34(+)KDR(+)) and EPC colony-forming units only in the RW group (all P<0.05). Only RW ingestion significantly enhanced plasma levels of nitric oxide and decreased asymmetrical dimethylarginine (both P<0.01). Incubation of EPC with RW (but not beer or ethanol) and resveratrol in vitro attenuated tumor necrosis factor-alpha-induced EPC senescence and improved tumor necrosis factor-alpha-suppressed EPC functions and tube formation. Incubation with nitric oxide donor sodium nitroprusside significantly ameliorated the inhibition of tumor necrosis factor-alpha on EPC proliferation, but incubation with endothelial nitric oxide synthase inhibitor l-NAME and PI3K inhibitor markedly attenuated the effect of RW on EPC proliferation. The intake of RW significantly enhanced circulating EPC levels and improved EPC functions by modifying nitric oxide bioavailability. These findings may help explain the beneficial effects of RW on the cardiovascular system. This study demonstrated that a moderate intake of RW can enhance circulating levels of EPC in healthy subjects by increasing nitric oxide availability. Direct incubation of EPC with RW and resveratrol can modify the functions of EPC, including attenuation of senescence and promotion of EPC adhesion, migration, and tube formation. These data suggest that RW ingestion may alter the biology of EPC, and these alterations may contribute to its unique cardiovascular-protective effect.

Flavonoid-rich apples and nitrate-rich spinach augment nitric oxide status and improve endothelial function in healthy men and women: a randomized controlled trial.

PubMed

Bondonno, Catherine P; Yang, Xingbin; Croft, Kevin D; Considine, Michael J; Ward, Natalie C; Rich, Lisa; Puddey, Ian B; Swinny, Ewald; Mubarak, Aidilla; Hodgson, Jonathan M

2012-01-01

Flavonoids and nitrates in fruits and vegetables may protect against cardiovascular disease. Dietary flavonoids and nitrates can augment nitric oxide status via distinct pathways, which may improve endothelial function and lower blood pressure. Recent studies suggest that the combination of flavonoids and nitrates can enhance nitric oxide production in the stomach. Their combined effect in the circulation is unclear. Here, our objective was to investigate the independent and additive effects of flavonoid-rich apples and nitrate-rich spinach on nitric oxide status, endothelial function, and blood pressure. A randomized, controlled, crossover trial with healthy men and women (n=30) was conducted. The acute effects of four energy-matched treatments (control, apple, spinach, and apple+spinach), administered in random order, were compared. Measurements included plasma nitric oxide status, assessed by measuring S-nitrosothiols+other nitrosylated species (RXNO) and nitrite, blood pressure, and endothelial function, measured as flow-mediated dilatation of the brachial artery. Results are means and 95% CI. Relative to control, all treatments resulted in higher RXNO (control, 33 nmol/L, 26, 42; apple, 51 nmol/L, 40, 65; spinach, 86 nmol/L, 68, 110; apple+spinach, 69 nmol/L, 54, 88; P<0.01) and higher nitrite (control, 35 nmol/L, 27, 46; apple, 69 nmol/L, 53, 90; spinach, 99 nmol/L, 76, 129; apple+spinach, 80 nmol/L, 61, 104; P<0.01). Compared to control, all treatments resulted in higher flow-mediated dilatation (P<0.05) and lower pulse pressure (P<0.05), and apple and spinach resulted in lower systolic blood pressure (P<0.05). No significant effect was observed on diastolic blood pressure. The combination of apple and spinach did not result in additive effects on nitric oxide status, endothelial function, or blood pressure. In conclusion, flavonoid-rich apples and nitrate-rich spinach can independently augment nitric oxide status, enhance endothelial function, and lower blood pressure acutely, outcomes that may benefit cardiovascular health. Copyright © 2011 Elsevier Inc. All rights reserved.

Role of nitric oxide and KATP channel in the protective effect mediated by nicorandil in bile duct ligation-induced liver fibrosis in rats.

PubMed

Mohamed, Yasmin S; Ahmed, Lamiaa A; Salem, Hesham A; Agha, Azza M

2018-05-01

Liver fibrosis is one of the most serious conditions affecting patients worldwide. In the present study, the role of nitric oxide and KATP channel was investigated for the first time in the possible protection mediated by nicorandil in bile duct ligation-induced liver fibrosis in rats. Nicorandil (3 mg/kg/day) was given orally 24 h after bile duct ligation for 14 days till the end of the experiment. Nicorandil group showed marked improvement in liver function tests, hepatic oxidative stress and inflammatory markers as well as inducible and endothelial nitric oxide synthase protein expressions. Furthermore, nicorandil administration led to significant decrement of phosphorylated protein kinase C, fibrosis and hepatic stellate cells activation as indicated by decreased alpha smooth muscle actin expression. Oral co-administration of glibenclamide (5 mg/kg/day) (a KATP channel blocker) with nicorandil mostly showed similar improvement though not reaching to that of nicorandil group. However, co-adminstration of L-NAME (15 mg/kg/day) (an inhibitor of nitric oxide synthase) completely abolished the protective effects of nicorandil and produced more or less similar results to that of untreated bile duct ligated group. In conclusion, nicorandil is an effective therapy against the development of bile duct ligation-induced liver fibrosis in rats where nitric oxide plays a more prominent role in the protective effect of nicorandil than KATP channel opening. Copyright © 2018 Elsevier Inc. All rights reserved.

Functional Nitric Oxide Nutrition to Combat Cardiovascular Disease.

PubMed

Bryan, Nathan S

2018-03-17

To reveal the mechanisms of nitric oxide (NO) production in humans and how lifestyle, drug therapy, and hygienic practices can decrease NO production. Furthermore, to show how functional nitric oxide nutrition can overcome these limitations to restore endogenous NO production and combat cardiovascular disease. Research over the past decade has revealed that inorganic nitrate and nitrite found naturally in green leafy vegetables and other vegetables such as beets can provide the human body with a source of bioactive nitric oxide. NO is one of the most important molecules produced within the cardiovascular system that maintains normal blood pressure and prevents inflammation, immune dysfunction, and oxidative stress, hallmarks of cardiovascular disease. This pathway is dependent upon the amount of inorganic nitrate and nitrite in the foods we eat, the presence of oral nitrate-reducing bacteria, and sufficient stomach acid production. The concept of food being medicine and medicine being food has lost its place in the practice and implementation of modern medicine over the past century. Certain dietary patterns and specific foods are known to confer very significant protective effects for many human diseases, including cardiovascular disease, the number one killer of men and women in the developed world. However, identification of single or multiple bioactive molecules that are responsible for these effects has escaped scientists and nutritionists for many years. This review will highlight the biochemical, physiological, and epidemiological basis for functional nitric oxide nutrition that can be safely and effectively utilized in patients.

Investigating the sensitivity of nitric oxide infrared emissions to electron impact

NASA Astrophysics Data System (ADS)

Campbell, L.; Brunger, M. J.; Allan, M.

2008-05-01

Integral cross sections for low energy electron excitation of the 0→1, 0→2 and 0→3 vibrational modes in nitric oxide have quite recently become available [Trevisan et al. PRA 71, 052714 (2005)]. In this study we adapt our recent work [Campbell and Brunger GRL, in press (2007)], to look at the effect of these new cross sections on the production of nitric oxide infrared radiation. Predictions from our model are compared with measurements from Espy et al. [Planet. Space Sci. 36, 543 (1988)], with the inclusion of the new cross sections improving the agreement of the shape of the spectrum with the measurements.

Delivery of nitric oxide to the interior of mammalian cell by carbon nanotube: MD simulation.

PubMed

Raczyński, Przemysław; Górny, Krzysztof; Dawid, Aleksander; Gburski, Zygmunt

2014-07-15

Computer simulations have been performed to study the nanoindentation of phospholipid bilayer by the single-walled armchair carbon nanotube, filled with the nitric oxide molecules. The process has been simulated by means of molecular dynamics (MD) technique at physiological temperature T = 310 K with a constant pulling velocity of the nanotube. The force acting on the nanotube during membrane penetration has been calculated. We show that the indentation by carbon nanotube does not permanently destroy the membrane structure (self-sealing of the membrane occurs). The mobility of nitric oxide molecules during the membrane nanoindentation is discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

The production of nitric oxide in the troposphere as a result of solid-rocket-motor afterburning

NASA Technical Reports Server (NTRS)

Stewart, R. B.; Gomberg, R. I.

1976-01-01

As part of an ongoing assessment of the environmental effects of solid-rocket-motor operations in the troposphere, estimates were made of the nitric oxide produced in the troposphere by the space shuttle and Titan 3-C boosters. Calculations were made with the low-altitude plume computer program and included the effects of coupled finite-rate chemistry and turbulent mixing. A recent measurement of nitric oxide taken in the effluent cloud of a Titan 3-C booster is compared with calculations made with this computer code. The various chemical reactions of the exhaust gases are listed in tabular form.

S-nitrosation on zinc finger motif of PARP-1 as a mechanism of DNA repair inhibition by arsenite

PubMed Central

Zhou, Xixi; Cooper, Karen L.; Huestis, Juliana; Xu, Huan; Burchiel, Scott W.; Hudson, Laurie G.; Liu, Ke Jian

2016-01-01

Arsenic, a widely distributed carcinogen, is known to significantly amplify the impact of other carcinogens through inhibition of DNA repair. Our recent work suggests that reactive oxygen/nitrogen species (ROS/RNS) induced by arsenite (AsIII) play an important role in the inhibition of the DNA repair protein Poly(ADP-ribose) polymerase 1 (PARP-1). AsIII-induced ROS lead to oxidation of cysteine residues within the PARP-1 zinc finger DNA binding domain. However, the mechanism underlying RNS-mediated PARP inhibition by arsenic remains unknown. In this work, we demonstrate that AsIII treatment of normal human keratinocyte (HEKn) cells induced S-nitrosation on cysteine residues of PARP-1 protein, in a similar manner to a nitric oxide donor. S-nitrosation of PARP-1 could be reduced by 1400W (inducible nitric oxide synthase inhibitor) or c-PTIO (a nitric oxide scavenger). Furthermore, AsIII treatment of HEKn cells leads to zinc loss and inhibition of PARP-1 enzymatic activity. AsIII and 1400W/c-PTIO co-treatment demonstrate that these effects occur in an iNOS- and NO-dependent manner. Importantly, we confirmed S-nitrosation on the zinc finger DNA binding domain of PARP-1 protein. Taken together, AsIII induces S-nitrosation on PARP-1 zinc finger DNA binding domain by generating NO through iNOS activation, leading to zinc loss and inhibition of PARP-1 activity, thereby increasing retention of damaged DNA. These findings identify S-nitrosation as an important component of the molecular mechanism underlying AsIII inhibition of DNA repair, which may benefit the development of preventive and intervention strategies against AsIII co-carcinogenesis. PMID:27741521

S-nitrosation on zinc finger motif of PARP-1 as a mechanism of DNA repair inhibition by arsenite.

PubMed

Zhou, Xixi; Cooper, Karen L; Huestis, Juliana; Xu, Huan; Burchiel, Scott W; Hudson, Laurie G; Liu, Ke Jian

2016-12-06

Arsenic, a widely distributed carcinogen, is known to significantly amplify the impact of other carcinogens through inhibition of DNA repair. Our recent work suggests that reactive oxygen/nitrogen species (ROS/RNS) induced by arsenite (AsIII) play an important role in the inhibition of the DNA repair protein Poly(ADP-ribose) polymerase 1 (PARP-1). AsIII-induced ROS lead to oxidation of cysteine residues within the PARP-1 zinc finger DNA binding domain. However, the mechanism underlying RNS-mediated PARP inhibition by arsenic remains unknown. In this work, we demonstrate that AsIII treatment of normal human keratinocyte (HEKn) cells induced S-nitrosation on cysteine residues of PARP-1 protein, in a similar manner to a nitric oxide donor. S-nitrosation of PARP-1 could be reduced by 1400W (inducible nitric oxide synthase inhibitor) or c-PTIO (a nitric oxide scavenger). Furthermore, AsIII treatment of HEKn cells leads to zinc loss and inhibition of PARP-1 enzymatic activity. AsIII and 1400W/c-PTIO co-treatment demonstrate that these effects occur in an iNOS- and NO-dependent manner. Importantly, we confirmed S-nitrosation on the zinc finger DNA binding domain of PARP-1 protein. Taken together, AsIII induces S-nitrosation on PARP-1 zinc finger DNA binding domain by generating NO through iNOS activation, leading to zinc loss and inhibition of PARP-1 activity, thereby increasing retention of damaged DNA. These findings identify S-nitrosation as an important component of the molecular mechanism underlying AsIII inhibition of DNA repair, which may benefit the development of preventive and intervention strategies against AsIII co-carcinogenesis.

In silico molecular docking studies of new potential 4-phthalazinyl-hydrazones on selected Trypanosoma cruzi and Leishmania enzyme targets.

PubMed

Romero, Angel H; López, Simón E

2017-09-01

Recently, a series of 4-phthalazinyl-hydrazones under its E-configuration have exhibited excellent in vitro antichagasic and antileishmanial profiles. Preliminary assays on both parasites suggested that the most active derivatives act through oxidative and nitrosative stress mechanisms; however, their exact mode of actions as anti-trypanosomal and anti-leishmanial agents have not been completely elucidated. This motivated to perform a molecular docking study on essential trypanosomatid enzymes such as superoxide dismutase (SOD), trypanothione reductase (TryR), cysteine-protease (CP) and pteridine reductase 1 (PTR1). In addition, to understand the experimental results of nitric oxide production obtained for infected macrophages with Leishmania parasite, a molecular docking was evaluated on nitric oxide synthase (iNOS) enzyme of Rattus norvegicus. Both diastereomers (E and Z) of the 4-phthalazinyl-hydrazones were docked on the mentioned targets. In general, molecular docking on T. cruzi enzymes revealed that the E-diastereomers exhibited lower binding energies than Z-diastereomers on the Fe-SOD and CP enzymes, while Z-diastereomers showed lower docking energies than E-isomers on TryR enzyme. For the Leishmania docking studies, the Z-isomers exhibited the best binding affinities on the PTR1 and iNOS enzymes, while the TryR enzyme showed a minor dependence with the stereoselectivity of the tested phthalazines. However, either the structural information of the ligand-enzyme complexes or the experimental data suggest that the significant antitrypanosomatid activity of the most active derivatives is not associated to the inhibition of the SOD, CP and PTR1 enzymes, while the TryR inhibition and nitric oxide generation in host cells emerge as interesting antitrypanosomatid therapeutic targets. Copyright © 2017 Elsevier Inc. All rights reserved.

Simulation of nitrous oxide and nitric oxide emissions from tropical primary forests in the Costa Rican Atlantic Zone

Treesearch

Shuguanga Liu; William A. Reiners; Michael Keller; Davis S. Schimel

2000-01-01

Nitrous oxide (N2O) and nitric oxide (NO) are important atmospheric trace gases participating in the regulation of global climate and environment. Predictive models on the emissions of N2O and NO emissions from soil into the atmosphere are required. We modified the CENTURY model (Soil Sci. Soc. Am. J., 51 (1987) 1173) to simulate the emissions of N2O and NO from...

Anti-biofilm action of nitric oxide-releasing alkyl-modified poly(amidoamine) dendrimers against Streptococcus mutans.

PubMed

Backlund, Christopher J; Worley, Brittany V; Schoenfisch, Mark H

2016-01-01

The effect of nitric oxide (NO)-releasing dendrimer hydrophobicity on Streptococcus mutans killing and biofilm disruption was examined at pH 7.4 and 6.4, the latter relevant to dental caries. Generation 1 (G1) poly(amidoamine) (PAMAM) dendrimers were modified with alkyl epoxides to generate propyl-, butyl-, hexyl-, octyl-, and dodecyl-functionalized dendrimers. The resulting secondary amines were reacted with NO to form N-diazeniumdiolate NO donor-modified dendrimer scaffolds (total NO ∼1μmol/mg). The bactericidal action of the NO-releasing dendrimers against both planktonic and biofilm-based S. mutans proved greatest with increasing alkyl chain length and at lower pH. Improved bactericidal efficacy at pH 6.4 was attributed to increased scaffold surface charge that enhanced dendrimer-bacteria association and ensuing membrane damage. For shorter alkyl chain (i.e., propyl and butyl) dendrimer modifications, increased antibacterial action at pH 6.4 was due to faster NO-release kinetics from proton-labile N-diazeniumdiolate NO donors. Octyl- and dodecyl-modified PAMAM dendrimers proved most effective for eradicating S. mutans biofilms with NO release mitigating dendrimer scaffold cytotoxicity. We report the antibacterial and anti-biofilm efficacy of dual-action nitric oxide (NO)-releasing dendrimers against S. mutans, an etiological agent in dental caries. This work was undertaken to enhance the anti-biofilm action of these scaffolds by employing various alkyl chain modifications. Furthermore, we evaluated the ability of NO to eradicate cariogenic biofilms. We found that at the lower pH associated with dental caries (pH ∼6.4), NO has a more pronounced antibacterial effect for alkyl modifications less capable of biofilm penetration and membrane disruption. Of greatest significance, we introduce dendrimers as a new macromolecular antibacterial agent against the cariogenic bacteria S. mutans. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Gastric damage and granulocyte infiltration induced by indomethacin in tumour necrosis factor receptor 1 (TNF-R1) or inducible nitric oxide synthase (iNOS) deficient mice

PubMed Central

Souza, M H L P; Lemos, H. Paula; Oliveira, R B; Cunha, F Q

2004-01-01

Background: Tumour necrosis factor α (TNF-α) is involved in non-steroidal anti-inflammatory drug induced gastropathy. Nitric oxide (NO) is a mediator of gastrointestinal mucosal defence but, paradoxically, it also contributes to mucosal damage. Aims: We optimised the C57BL/6 mouse model of indomethacin induced gastropathy to evaluate the role of TNF-α and inducible nitric oxide synthase (iNOS) generated NO in gastric damage and granulocyte infiltration using tumour necrosis factor receptor 1 (TNF-R1−/−) or iNOS (iNOS−/−) deficient mice. Methods: Different doses of indomethacin (2.5, 5, 10, 20 mg/kg) were administered and animals were assessed 6, 12, or 24 hours later. Gastric damage was measured by the sum of all erosions in the gastric mucosa, and gastric granulocyte infiltration was determined by myeloperoxidase (MPO) activity. Other groups of wild-type mice received thalidomide, dexamethasone, fucoidin, l-NAME, or 1400W, and then indomethacin was administered. Additionally, indomethacin was administered to TNF-R1−/− or iNOS−/−. Gastric damage and MPO activity were evaluated 12 hours later. Results: Indomethacin induced dose and time dependent gastric damage and increase in MPO activity in wild-type mice, with the greatest effect at a dose of 10 mg/kg and after 12 hours. Treatment with thalidomide, dexamethasone, or fucoidin reduced gastric damage and MPO activity induced by indomethacin. After indomethacin administration, TNF-R1−/− had less gastric damage and MPO activity than controls. Genetic (knockout mice) or pharmacological (1400W and l-NAME) inhibition of iNOS activity reduced indomethacin induced gastric damage, despite no reduction in MPO activity. Conclusion: TNF-α, acting via TNF-R1, is involved in indomethacin induced gastric damage and granulocyte infiltration. Furthermore, iNOS generated NO is involved in gastric damage induced by indomethacin. PMID:15138204

Interaction between neuronal nitric oxide synthase signaling and temperature influences sarcoplasmic reticulum calcium leak: role of nitroso-redox balance.

PubMed

Dulce, Raul A; Mayo, Vera; Rangel, Erika B; Balkan, Wayne; Hare, Joshua M

2015-01-02

Although nitric oxide (NO) signaling modulates cardiac function and excitation-contraction coupling, opposing results because of inconsistent experimental conditions, particularly with respect to temperature, confound the ability to elucidate NO signaling pathways. Here, we show that temperature significantly modulates NO effects. To test the hypothesis that temperature profoundly affects nitroso-redox equilibrium, thereby affecting sarcoplasmic reticulum (SR) calcium (Ca(2+)) leak. We measured SR Ca(2+) leak in cardiomyocytes from wild-type (WT), NO/redox imbalance (neuronal nitric oxide synthase-deficient mice-1 [NOS1(-/-)]), and hyper S-nitrosoglutathione reductase-deficient (GSNOR(-/-)) mice. In WT cardiomyocytes, SR Ca(2+) leak increased because temperature decreased from 37°C to 23°C, whereas in NOS1(-/-) cells, the leak suddenly increased when the temperature surpassed 30°C. GSNOR(-/-) cardiomyocytes exhibited low leak throughout the temperature range. Exogenously added NO had a biphasic effect on NOS1(-/-) cardiomyocytes; reducing leak at 37°C but increasing it at subphysiological temperatures. Oxypurinol and Tempol diminished the leak in NOS1(-/-) cardiomyocytes. Cooling from 37°C to 23°C increased reactive oxygen species generation in WT but decreased it in NOS1(-/-) cardiomyocytes. Oxypurinol further reduced reactive oxygen species generation. At 23°C in WT cells, leak was decreased by tetrahydrobiopterin, an essential NOS cofactor. Cooling significantly increased SR Ca(2+) content in NOS1(-/-) cells but had no effect in WT or GSNOR(-/-). Ca(2+) leak and temperature are normally inversely proportional, whereas NOS1 deficiency reverses this effect, increasing leak and elevating reactive oxygen species production because temperature increases. Reduced denitrosylation (GSNOR deficiency) eliminates the temperature dependence of leak. Thus, temperature regulates the balance between NO and reactive oxygen species which in turn has a major effect on SR Ca(2+). © 2014 American Heart Association, Inc.

Artemisinin conferred ERK mediated neuroprotection to PC12 cells and cortical neurons exposed to sodium nitroprusside-induced oxidative insult.

PubMed

Zheng, Wenhua; Chong, Cheong-Meng; Wang, Haitao; Zhou, Xuanhe; Zhang, Lang; Wang, Rikang; Meng, Qian; Lazarovici, Philip; Fang, Jiankang

2016-08-01

The production of nitric oxide (NO) is one of the primary mediators of ischemic damage, glutamate neurotoxicity and neurodegeneration and therefore inhibition of NO-induced neurotoxicity may be considered a therapeutic target for reducing neuronal cell death (neuroprotection). In this study, artemisinin, a well-known anti-malaria drug was found to suppress sodium nitroprusside (SNP, a nitric oxide donor)-induced cell death in the PC12 cells and brain primary cortical neuronal cultures. Pretreatment of PC12 cells with artemisinin significantly suppressed SNP-induced cell death by decreasing the extent of oxidation, preventing the decline of mitochondrial membrane potential, restoring abnormal changes in nuclear morphology and reducing lactate dehydrogenase release and inhibiting caspase 3/7 activities. Western blotting analysis revealed that artemisinin was able to activate extracellular regulated protein kinases (ERK) pathway. Furthermore, the ERK inhibitor PD98059 blocked the neuroprotective effect of artemisinin whereas the PI3K inhibitor LY294002 had no effect. Cumulatively these findings support the notion that artemisinin confers neuroprotection from SNP-induce neuronal cell death insult, a phenomenon coincidentally related to activation of ERK phosphorylation. This SNP-induced oxidative insult in PC12 cell culture model may be useful to investigate molecular mechanisms of NO-induced neurotoxicity and drug-induced neuroprotection, and to generate novel therapeutic concepts for ischemic disease treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

[Geomagnetic field variations in the human prenatal period and cancer in adults].

PubMed

Iamshanov, V A

2007-01-01

Our earlier evidence pointed to a relationship between geomagnetic field (GMF) variations in pre- and early postnatal periods and appearance in the future of oncopathology in these patients. It appears to contribute to risk for such malignancies in adults as breast, lung, liver, bladder, kidney, prostate, hypophysis cancer, ovarian carcinoma, skin melanoma, Hodgkin's disease, lymphoma, and probably stomach cancer. No link was detected between esophageal, thyroid, colorectal cancer or cervical carcinoma, on the one hand, and GMF variations in prenatal period, on the other. It is suggested that low intensity of GMF is associated with increased death of macrophages and other granulocytes as well as nitric oxide formation both in fetal and maternal organism. The latter factor induces genes responsible for detoxication. In adults, under normal or disturbed GMF conditions, detoxication processes take care of excessive blood-nitric oxide. Both in fetus and mother, due to high GMF intensity, granulocyte decay is inhibited thus causing nitric oxide levels to fall. As a consequence, detoxication fails. That accounts for excessive blood-nitric oxide formation at adult stage when GMF intensity is low or normal. Nitric oxide causes certain nitrosamines to form, which are tissue-specific carcinogens. Therefore, the lower level of GMF oscillations was in pre- and early postnatal periods than in more late terms tumors appeared (for example, the negative correlation for breast cancer took place).

Antidepressant-like effect of folic acid: Involvement of NMDA receptors and L-arginine-nitric oxide-cyclic guanosine monophosphate pathway.

PubMed

Brocardo, Patrícia de Souza; Budni, Josiane; Lobato, Kelly Ribas; Kaster, Manuella Pinto; Rodrigues, Ana Lúcia S

2008-11-19

Antidepressant-like activity of folic acid in forced swimming test and in the tail suspension test was demonstrated previously by our group. In this study we investigated the involvement of N-methyl-d-aspartate (NMDA) receptors and l-arginine-nitric oxide (NO)-cyclic guanosine monophosphate pathway in its antidepressant-like effect in the forced swimming test in mice. The antidepressant-like effect of folic acid (10 nmol/site, i.c.v.) was prevented by the pretreatment of mice with NMDA (0.1 pmol/site, i.c.v.), l-arginine (750 mg/kg, i.p., substrate for nitric oxide synthase), S-nitroso-N-acetyl-penicillamine (SNAP, 25 microg/site, i.c.v, a NO donor) or sildenafil (5 mg/kg, i.p., phosphodiesterase 5 inhibitor). The administration of 7-nitroindazole (25 and 50 mg/kg, i.p., a specific neuronal nitric oxide synthase (nNOS) inhibitor) or methylene blue (20 mg/kg, i.p., direct inhibitor of both nitric oxide synthase and soluble guanylate cyclase) in combination with a sub-effective dose of folic acid (1 nmol/site, i.c.v.) reduced the immobility time in the FST as compared with either drug alone. Together the results suggest that the antidepressant-like effect of folic acid in the forced swimming test is dependent on an inhibition of either NMDA receptors or NO and cGMP synthesis.

The effect of nitric oxide releasing cream on healing pressure ulcers

PubMed Central

Saidkhani, Vahid; Asadizaker, Marziyeh; Khodayar, Mohammad Javad; Latifi, Sayed Mahmoud

2016-01-01

Background: Pressure ulcer is one of the main concerns of nurses in medical centers around the world, which, if untreated, causes irreparable problems for patients. In recent years, nitric oxide (NO) has been proposed as an effective method for wound healing. This study was conducted to determine the effect of nitric oxide on pressure ulcer healing. Materials and Methods: In this clinical trial, 58 patients with pressure ulcer at hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences were homogenized and later divided randomly into two groups of treatment (nitric oxide cream; n = 29) and control (placebo cream; n = 29). In this research, the data collection tool was the Pressure Ulcer Scale for Healing (PUSH). At the outset of the study (before using the cream), the patients' ulcers were examined weekly in terms of size, amount of exudates, and tissue type using the PUSH tool for 3 weeks. By integrating these three factors, wound healing was determined. Data were analyzed using SPSS. Results: Although no significant difference was found in terms of the mean of score size, the amount of exudates, and the tissue type between the two groups, the mean of total score (healing) between the two groups was statistically significant (P = 0.04). Conclusions: Nitric oxide cream seems to accelerate wound healing. Therefore, considering its easy availability and cost-effectiveness, it can be used for treating pressure ulcers in the future. PMID:27186212

Ginsenoside Rg3 increases nitric oxide production via increases in phosphorylation and expression of endothelial nitric oxide synthase: Essential roles of estrogen receptor-dependent PI3-kinase and AMP-activated protein kinase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hien, Tran Thi; Kim, Nak Doo; Pokharel, Yuba Raj

2010-08-01

We previously showed that ginsenosides increase nitric oxide (NO) production in vascular endothelium and that ginsenoside Rg3 (Rg3) is the most active one among ginseng saponins. However, the mechanism for Rg3-mediated nitric oxide production is still uncertain. In this study, we determined whether Rg3 affects phosphorylation and expression of endothelial nitric oxide synthase (eNOS) in ECV 304 human endothelial cells. Rg3 increased both the phosphorylation and the expression of eNOS in a concentration-dependent manner and a maximal effect was found at 10 {mu}g/ml of Rg3. The enzyme activities of phosphatidylinositol 3-kinase (PI3-kinase), c-Jun N-terminal kinase (JNK), and p38 kinase weremore » enhanced as were estrogen receptor (ER)- and glucocorticoid receptor (GR)-dependent reporter gene transcriptions in Rg3-treated endothelial cells. Rg3-induced eNOS phosphorylation required the ER-mediated PI3-kinase/Akt pathway. Moreover, Rg3 activates AMP-activated protein kinase (AMPK) through up-regulation of CaM kinase II and Rg3-stimulated eNOS phosphorylation was reversed by AMPK inhibition. The present results provide a mechanism for Rg3-stimulated endothelial NO production.« less

Substantial Effect of Melanin Influencing Factors on In vitro Melanogenesis in Muzzle Melanocytes of Differently Colored Hanwoo.

PubMed

Amna, Touseef; Park, Kyoung Mi; Cho, In-Kyung; Choi, Tae Jeong; Lee, Seung Soo; Seo, Kang-Seok; Hwang, Inho

2012-07-01

The present study was designed to investigate the effect of α-melanocyte-stimulating hormone (α-MSH), nitric oxide (NO) and L-cysteine on melanin production and expression of related genes MC1R, Tyr, Tyrp-1 and Tyrp-2 in muzzle melanocytes of differently colored three native Hanwoo cattle. Muzzle samples were taken from black, brindle and brown Hanwoo and purified melanocytes were cultured with α-MSH, nitric oxide and L-cysteine at 100 nM, 50 µM and 0.07 mg/ml of media respectively. The amounts of total melanin, eumelanin and mRNA expression at Tyr, Tyrp-1, Tyrp-2 and MC1R levels were quantified. α-MSH and nitric oxide significantly increased (p<0.05) the amount of total melanin in black and brindle whereas eumelanin production in brown Hanwoo muzzle melanocytes. On the contrary, L-cysteine greatly (p<0.05) depressed the eumelanin production in black color but increased in brown. Simultaneously, up regulation of Tyr by nitric oxide and α-MSH and down regulation of Tyr, Tyrp-2 and MC1R genes by L-cysteine were observed in muzzle melanocytes of all three phenotypes. The results of this study revealed nitric oxide and α-MSH contribute hyper-pigmentation by enhancing eumelanogenesis whereas L-cysteine contributes to pheomelanin production in different colored Hanwoo muzzle melanocytes.

Substantial Effect of Melanin Influencing Factors on In vitro Melanogenesis in Muzzle Melanocytes of Differently Colored Hanwoo

PubMed Central

Amna, Touseef; Park, Kyoung Mi; Cho, In-Kyung; Choi, Tae Jeong; Lee, Seung Soo; Seo, Kang-Seok; Hwang, Inho

2012-01-01

The present study was designed to investigate the effect of α-melanocyte-stimulating hormone (α-MSH), nitric oxide (NO) and L-cysteine on melanin production and expression of related genes MC1R, Tyr, Tyrp-1 and Tyrp-2 in muzzle melanocytes of differently colored three native Hanwoo cattle. Muzzle samples were taken from black, brindle and brown Hanwoo and purified melanocytes were cultured with α-MSH, nitric oxide and L-cysteine at 100 nM, 50 µM and 0.07 mg/ml of media respectively. The amounts of total melanin, eumelanin and mRNA expression at Tyr, Tyrp-1, Tyrp-2 and MC1R levels were quantified. α-MSH and nitric oxide significantly increased (p<0.05) the amount of total melanin in black and brindle whereas eumelanin production in brown Hanwoo muzzle melanocytes. On the contrary, L-cysteine greatly (p<0.05) depressed the eumelanin production in black color but increased in brown. Simultaneously, up regulation of Tyr by nitric oxide and α-MSH and down regulation of Tyr, Tyrp-2 and MC1R genes by L-cysteine were observed in muzzle melanocytes of all three phenotypes. The results of this study revealed nitric oxide and α-MSH contribute hyper-pigmentation by enhancing eumelanogenesis whereas L-cysteine contributes to pheomelanin production in different colored Hanwoo muzzle melanocytes. PMID:25049660

Caveolin versus calmodulin. Counterbalancing allosteric modulators of endothelial nitric oxide synthase.

PubMed

Michel, J B; Feron, O; Sase, K; Prabhakar, P; Michel, T

1997-10-10

Nitric oxide is synthesized in diverse mammalian tissues by a family of calmodulin-dependent nitric oxide synthases. The endothelial isoform of nitric oxide synthase (eNOS) is targeted to the specialized signal-transducing membrane domains termed plasmalemmal caveolae. Caveolin, the principal structural protein in caveolae, interacts with eNOS and leads to enzyme inhibition in a reversible process modulated by Ca2+-calmodulin (Michel, J. B., Feron, O., Sacks, D., and Michel, T. (1997) J. Biol. Chem. 272, 15583-15586). Caveolin also interacts with other structurally distinct signaling proteins via a specific region identified within the caveolin sequence (amino acids 82-101) that appears to subserve the role of a "scaffolding domain." We now report that the co-immunoprecipitation of eNOS with caveolin is completely and specifically blocked by an oligopeptide corresponding to the caveolin scaffolding domain. Peptides corresponding to this domain markedly inhibit nitric oxide synthase activity in endothelial membranes and interact directly with the enzyme to inhibit activity of purified recombinant eNOS expressed in Escherichia coli. The inhibition of purified eNOS by the caveolin scaffolding domain peptide is competitive and completely reversed by Ca2+-calmodulin. These studies establish that caveolin, via its scaffolding domain, directly forms an inhibitory complex with eNOS and suggest that caveolin inhibits eNOS by abrogating the enzyme's activation by calmodulin.

Nitric oxide-induced calcium release: activation of type 1 ryanodine receptor by endogenous nitric oxide.

PubMed

Kakizawa, Sho; Yamazawa, Toshiko; Iino, Masamitsu

2013-01-01

Ryanodine receptors (RyRs), located in the sarcoplasmic/endoplasmic reticulum (SR/ER) membrane, are required for intracellular Ca2+ release that is involved in a wide range of cellular functions. In addition to Ca2+-induced Ca2+ release in cardiac cells and voltage-induced Ca2+ release in skeletal muscle cells, we recently identified another mode of intracellular Ca2+ mobilization mediated by RyR, i.e., nitric oxide-induced Ca2+ release (NICR), in cerebellar Purkinje cells. NICR is evoked by neuronal activity, is dependent on S-nitrosylation of type 1 RyR (RyR1) and is involved in the induction of long-term potentiation (LTP) of cerebellar synapses. In this addendum, we examined whether peroxynitrite, which is produced by the reaction of nitric oxide with superoxide, may also have an effect on the Ca2+ release via RyR1 and the cerebellar LTP. We found that scavengers of peroxynitrite have no significant effect either on the Ca2+ release via RyR1 or on the cerebellar LTP. We also found that an application of a high concentration of peroxynitrite does not reproduce neuronal activity-dependent Ca2+ release in Purkinje cells. These results support that NICR is induced by endogenous nitric oxide produced by neuronal activity through S-nitrosylation of RyR1.