Sample records for nitric oxide pathway

  1. 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.

  2. 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

  3. 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.

  4. Inhibition of the adrenomedullin/nitric oxide signaling pathway in early diabetic retinopathy.

    PubMed

    Blom, Jan J; Giove, Thomas J; Favazza, Tara L; Akula, James D; Eldred, William D

    2011-06-01

    The nitric oxide (NO) signaling pathway is integrally involved in visual processing and changes in the NO pathway are measurable in eyes of diabetic patients. The small peptide adrenomedullin (ADM) can activate a signaling pathway to increase the enzyme activity of neuronal nitric oxide synthase (nNOS). ADM levels are elevated in eyes of diabetic patients and therefore, ADM may play a role in the pathology of diabetic retinopathy. The goal of this research was to test the effects of inhibiting the ADM/NO signaling pathway in early diabetic retinopathy. Inhibition of this pathway decreased NO production in high-glucose retinal cultures. Treating diabetic mice with the PKC β inhibitor ruboxistaurin for 5 weeks lowered ADM mRNA levels and ADM-like immunoreactivity and preserved retinal function as assessed by electroretinography. The results of this study indicate that inhibiting the ADM/NO signaling pathway prevents neuronal pathology and functional losses in early diabetic retinopathy.

  5. 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.

  6. 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

  7. 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.

  8. The nitric oxide pathway and possible therapeutic options in pre-eclampsia.

    PubMed

    Johal, Tamanrit; Lees, Christoph C; Everett, Thomas R; Wilkinson, Ian B

    2014-08-01

    Pre-eclampsia is a serious multisystem disorder with diverse clinical manifestations. Although not causal, endothelial dysfunction and reduced nitric oxide bioavailability are likely to play an important role in the maternal and fetal pathophysiology of this condition. Lack of treatment modalities that can target the underlying pathophysiological changes and reverse the endothelial dysfunction frequently leads to iatrogenic preterm delivery of the fetus, causing neonatal morbidity and mortality, and the condition itself is associated with short- and longer term maternal morbidity and mortality. Drugs that target various components of the nitric oxide-soluble guanylyl cyclase pathway can help to increase NO bioavailability. The purpose of this review is to outline the current status of clinical research involving these therapeutic modalities in the context of pre-eclampsia, with the focus being on the following: nitric oxide donors, including organic nitrates and S-nitrosothiols; l-arginine, the endogenous precursor of NO; inhibitors of cyclic guanosine 3',5'-monophosphate breakdown, including sildenafil; and other novel inhibitors of NO donor metabolism. The advantages and limitations of each modality are outlined, and scope for development into established therapeutic options for pre-eclampsia is explored. © 2013 The British Pharmacological Society.

  9. [Nitric oxide pathway and female lower urinary tract. Physiological and pathophysiological role].

    PubMed

    Gamé, X; Rischmann, P; Arnal, J-F; Malavaud, B

    2013-09-01

    The aim was to review the literature on nitric oxide and female lower urinary tract. A literature review through the PubMed library until December, 31 2012 was carried out using the following keywords: lower urinary tract, bladder, urethra, nervous central system, innervation, female, women, nitric oxide, phosphodiesterase, bladder outlet obstruction, urinary incontinence, overactive bladder, urinary tract infection. Two nitric oxide synthase isoforms, the neuronal (nNOS) and the endothelial (eNOS), are constitutively expressed in the lower urinary tract. Nevertheless, nNOS is mainly expressed in the bladder neck and the urethra. In the bladder, NO modulates the afferent neurons activity. In pathological condition, inducible NOS expression induces an increase in detrusor contractility and bladder wall thickness and eNOS facilitates Escherichia coli bladder wall invasion inducing recurrent urinary tract infections. In the urethra, NO play a major role in smooth muscle cells relaxation. The NO pathway plays a major role in the female lower urinary tract physiology and physiopathology. While it acts mainly on bladder outlet, in pathological condition, it is involved in bladder dysfunction occurrence. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  10. The nitric oxide pathway and possible therapeutic options in pre-eclampsia

    PubMed Central

    Johal, Tamanrit; Lees, Christoph C; Everett, Thomas R; Wilkinson, Ian B

    2014-01-01

    Pre-eclampsia is a serious multisystem disorder with diverse clinical manifestations. Although not causal, endothelial dysfunction and reduced nitric oxide bioavailability are likely to play an important role in the maternal and fetal pathophysiology of this condition. Lack of treatment modalities that can target the underlying pathophysiological changes and reverse the endothelial dysfunction frequently leads to iatrogenic preterm delivery of the fetus, causing neonatal morbidity and mortality, and the condition itself is associated with short- and longer term maternal morbidity and mortality. Drugs that target various components of the nitric oxide–soluble guanylyl cyclase pathway can help to increase NO bioavailability. The purpose of this review is to outline the current status of clinical research involving these therapeutic modalities in the context of pre-eclampsia, with the focus being on the following: nitric oxide donors, including organic nitrates and S-nitrosothiols; l-arginine, the endogenous precursor of NO; inhibitors of cyclic guanosine 3′,5′-monophosphate breakdown, including sildenafil; and other novel inhibitors of NO donor metabolism. The advantages and limitations of each modality are outlined, and scope for development into established therapeutic options for pre-eclampsia is explored. PMID:24313856

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. A pathway for protons in nitric oxide reductase from Paracoccus denitrificans.

    PubMed

    Reimann, Joachim; Flock, Ulrika; Lepp, Håkan; Honigmann, Alf; Adelroth, Pia

    2007-05-01

    Nitric oxide reductase (NOR) from P. denitrificans is a membrane-bound protein complex that catalyses the reduction of NO to N(2)O (2NO+2e(-)+2H(+)-->N(2)O+H(2)O) as part of the denitrification process. Even though NO reduction is a highly exergonic reaction, and NOR belongs to the superfamily of O(2)-reducing, proton-pumping heme-copper oxidases (HCuOs), previous measurements have indicated that the reaction catalyzed by NOR is non-electrogenic, i.e. not contributing to the proton electrochemical gradient. Since electrons are provided by donors in the periplasm, this non-electrogenicity implies that the substrate protons are also taken up from the periplasm. Here, using direct measurements in liposome-reconstituted NOR during reduction of both NO and the alternative substrate O(2), we demonstrate that protons are indeed consumed from the 'outside'. First, multiple turnover reduction of O(2) resulted in an increase in pH on the outside of the NOR-vesicles. Second, comparison of electrical potential generation in NOR-liposomes during oxidation of the reduced enzyme by either NO or O(2) shows that the proton transfer signals are very similar for the two substrates proving the usefulness of O(2) as a model substrate for these studies. Last, optical measurements during single-turnover oxidation by O(2) show electron transfer coupled to proton uptake from outside the NOR-liposomes with a tau=15 ms, similar to results obtained for net proton uptake in solubilised NOR [U. Flock, N.J. Watmough, P. Adelroth, Electron/proton coupling in bacterial nitric oxide reductase during reduction of oxygen, Biochemistry 44 (2005) 10711-10719]. NOR must thus contain a proton transfer pathway leading from the periplasmic surface into the active site. Using homology modeling with the structures of HCuOs as templates, we constructed a 3D model of the NorB catalytic subunit from P. denitrificans in order to search for such a pathway. A plausible pathway, consisting of conserved protonatable

  16. Umbilical mesenchymal stromal cells provide intestinal protection through nitric oxide dependent pathways.

    PubMed

    Jensen, Amanda R; Drucker, Natalie A; Ferkowicz, Michael J; Markel, Troy A

    2018-04-01

    Umbilical-derived mesenchymal stromal cells (USCs) have shown promise in the protection of ischemic organs. We hypothesized that USCs would improve mesenteric perfusion, preserve intestinal histological architecture, and limit inflammation by nitric oxide-dependent mechanisms following intestinal ischemia/reperfusion (IR) injury. Adult wild-type C57BL/6J (WT) and endothelial nitric oxide synthase knock out (eNOS KO) mice were used: (1) WT IR + vehicle, (2) WT IR + USC, (3) eNOS KO IR + vehicle, and (4) eNOS KO IR + USC. Mice were anesthetized, and a midline laparotomy was performed. The superior mesenteric artery was clamped with a nonoccluding clamp for 60-min. Following IR, mice were treated with an injection of 250 μL phosphate buffered saline or 2 × 10 6 USCs suspended in 250-μL phosphate buffered saline solution. Mesenteric perfusion images were acquired using laser Doppler imaging. Perfusion was analyzed as a percentage of baseline. At 24 h, mice were euthanized, and intestines were harvested. Intestines were evaluated for injury, and data were analyzed using the Mann-Whitney or Kruskal-Wallis tests. Intestinal mesenteric perfusion was significantly improved in WT mice treated with USC therapy compared with eNOS KOs. Intestinal histological architecture was preserved with USC therapy in WT mice. However, in eNOS KO mice, this benefit was abolished. Finally, the presence of several cytokines and growth factors were significantly improved in WT mice compared with eNOS KO mice treated with USCs. The benefits of USC-mediated therapy following intestinal IR injury likely occur via nitric oxide-dependent pathways. Further studies are required to define the molecular mechanisms by which USCs activate endothelial nitric oxide synthase to bring about their protective effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. 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

  18. 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

  19. Nitric Oxide-Induced Apoptosis of Human Dental Pulp Cells Is Mediated by the Mitochondria-Dependent Pathway

    PubMed Central

    Park, Min Young; Jeong, Yeon Jin; Kang, Gi Chang; Kim, Mi-Hwa; Kim, Sun Hun; Chung, Hyun-Ju

    2014-01-01

    Nitric oxide (NO) is recognized as a mediator and regulator of inflammatory responses. NO is produced by nitric oxide synthase (NOS), and NOS is abundantly expressed in the human dental pulp cells (HDPCs). NO produced by NOS can be cytotoxic at higher concentrations to HDPCs. However, the mechanism by which this cytotoxic pathway is activated in cells exposed to NO is not known. The purpose of this study was to elucidate the NO-induced cytotoxic mechanism in HDPCs. Sodium nitroprusside (SNP), a NO donor, reduced the viability of HDPCs in a dose- and time-dependent manner. We investigated the in vitro effects of nitric oxide on apoptosis of cultured HDPCs. Cells showed typical apoptotic morphology after exposure to SNP. Besides, the number of Annexin V positive cells was increased among the SNP-treated HDPCs. SNP enhanced the production of reactive oxygen species (ROS), and N-acetylcysteine (NAC) ameliorated the decrement of cell viability induced by SNP. However, a soluble guanylate cyclase inhibitor (ODQ) did not inhibited the decrement of cell viability induced by SNP. SNP increased cytochrome c release from the mitochondria to the cytosol and the ratio of Bax/Bcl-2 expression levels. Moreover, SNP-treated HDPCs elevated activities of caspase-3 and caspase-9. While pretreatment with inhibitors of caspase (z-VAD-fmk, z-DEVD-fmk) reversed the NO-induced apoptosis of HDPCs. From these results, it can be suggested that NO induces apoptosis of HDPCs through the mitochondria-dependent pathway mediated by ROS and Bcl-2 family, but not by the cyclic GMP pathway. PMID:24634593

  20. 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

  1. 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

  2. Fatty acid-binding protein 4 impairs the insulin-dependent nitric oxide pathway in vascular endothelial cells

    PubMed Central

    2012-01-01

    Background Recent studies have shown that fatty acid-binding protein 4 (FABP4) plasma levels are associated with impaired endothelial function in type 2 diabetes (T2D). In this work, we analysed the effect of FABP4 on the insulin-mediated nitric oxide (NO) production by endothelial cells in vitro. Methods In human umbilical vascular endothelial cells (HUVECs), we measured the effects of FABP4 on the insulin-mediated endothelial nitric oxide synthase (eNOS) expression and activation and on NO production. We also explored the impact of exogenous FABP4 on the insulin-signalling pathway (insulin receptor substrate 1 (IRS1) and Akt). Results We found that eNOS expression and activation and NO production are significantly inhibited by exogenous FABP4 in HUVECs. FABP4 induced an alteration of the insulin-mediated eNOS pathway by inhibiting IRS1 and Akt activation. These results suggest that FABP4 induces endothelial dysfunction by inhibiting the activation of the insulin-signalling pathway resulting in decreased eNOS activation and NO production. Conclusion These findings provide a mechanistic linkage between FABP4 and impaired endothelial function in diabetes, which leads to an increased cardiovascular risk. PMID:22709426

  3. A meta-analysis of biomarkers related to oxidative stress and nitric oxide pathway in migraine.

    PubMed

    Neri, Monica; Frustaci, Alessandra; Milic, Mirta; Valdiglesias, Vanessa; Fini, Massimo; Bonassi, Stefano; Barbanti, Piero

    2015-09-01

    Oxidative and nitrosative stress are considered key events in the still unclear pathophysiology of migraine. Studies comparing the level of biomarkers related to nitric oxide (NO) pathway/oxidative stress in the blood/urine of migraineurs vs. unaffected controls were extracted from the PubMed database. Summary estimates of mean ratios (MR) were carried out whenever a minimum of three papers were available. Nineteen studies were included in the meta-analyses, accounting for more than 1000 patients and controls, and compared with existing literature. Most studies measuring superoxide dismutase (SOD) showed lower activity in cases, although the meta-analysis in erythrocytes gave null results. On the contrary, plasma levels of thiobarbituric acid reactive substances (TBARS), an aspecific biomarker of oxidative damage, showed a meta-MR of 2.20 (95% CI: 1.65-2.93). As for NOs, no significant results were found in plasma, serum and urine. However, higher levels were shown during attacks, in patients with aura, and an effect of diet was found. The analysis of glutathione precursor homocysteine and asymmetric dimethylarginine (ADMA), an NO synthase inhibitor, gave inconclusive results. The role of the oxidative pathway in migraine is still uncertain. Interesting evidence emerged for TBARS and SOD, and concerning the possible role of diet in the control of NOx levels. © International Headache Society 2015.

  4. 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.

  5. Nitric Oxide Plays a Key Role in Ovariectomy-Induced Apoptosis in Anterior Pituitary: Interplay between Nitric Oxide Pathway and Estrogen.

    PubMed

    Ronchetti, Sonia A; Machiavelli, Leticia I; Quinteros, Fernanda A; Duvilanski, Beatriz H; Cabilla, Jimena P

    2016-01-01

    Changes in the estrogenic status produce deep changes in pituitary physiology, mainly because estrogens (E2) are one of the main regulators of pituitary cell population. Also, E2 negatively regulate pituitary neuronal nitric oxide synthase (nNOS) activity and expression and may thereby modulate the production of nitric oxide (NO), an important regulator of cell death and survival. Little is known about how ovary ablation affects anterior pituitary cell remodelling and molecular mechanisms that regulate this process have not yet been elucidated. In this work we used freshly dispersed anterior pituitaries as well as cell cultures from ovariectomized female rats in order to study whether E2 deficiency induces apoptosis in the anterior pituitary cells, the role of NO in this process and effects of E2 on the NO pathway. Our results showed that cell activity gradually decreases after ovariectomy (OVX) as a consequence of cell death, which is completely prevented by a pan-caspase inhibitor. Furthermore, there is an increase of fragmented nuclei and DNA cleavage thereby presenting the first direct evidence of the existence of apoptosis in the anterior pituitary gland after OVX. NO production and soluble guanylyl cyclase (sGC) expression in anterior pituitary cells increased concomitantly to the apoptosis. Inhibition of both, NO synthase (NOS) and sGC activities prevented the drop of cell viability after OVX, showing for the first time that increased NO levels and sGC activity observed post-OVX play a key role in the induction of apoptosis. Conversely, E2 and prolactin treatments decreased nNOS expression and activity in pituitary cells from OVX rats in a time- and E2 receptor-dependent manner, thus suggesting interplay between NO and E2 pathways in anterior pituitary.

  6. Nitric Oxide Plays a Key Role in Ovariectomy-Induced Apoptosis in Anterior Pituitary: Interplay between Nitric Oxide Pathway and Estrogen

    PubMed Central

    Quinteros, Fernanda A.; Duvilanski, Beatriz H.; Cabilla, Jimena P.

    2016-01-01

    Changes in the estrogenic status produce deep changes in pituitary physiology, mainly because estrogens (E2) are one of the main regulators of pituitary cell population. Also, E2 negatively regulate pituitary neuronal nitric oxide synthase (nNOS) activity and expression and may thereby modulate the production of nitric oxide (NO), an important regulator of cell death and survival. Little is known about how ovary ablation affects anterior pituitary cell remodelling and molecular mechanisms that regulate this process have not yet been elucidated. In this work we used freshly dispersed anterior pituitaries as well as cell cultures from ovariectomized female rats in order to study whether E2 deficiency induces apoptosis in the anterior pituitary cells, the role of NO in this process and effects of E2 on the NO pathway. Our results showed that cell activity gradually decreases after ovariectomy (OVX) as a consequence of cell death, which is completely prevented by a pan-caspase inhibitor. Furthermore, there is an increase of fragmented nuclei and DNA cleavage thereby presenting the first direct evidence of the existence of apoptosis in the anterior pituitary gland after OVX. NO production and soluble guanylyl cyclase (sGC) expression in anterior pituitary cells increased concomitantly to the apoptosis. Inhibition of both, NO synthase (NOS) and sGC activities prevented the drop of cell viability after OVX, showing for the first time that increased NO levels and sGC activity observed post-OVX play a key role in the induction of apoptosis. Conversely, E2 and prolactin treatments decreased nNOS expression and activity in pituitary cells from OVX rats in a time- and E2 receptor-dependent manner, thus suggesting interplay between NO and E2 pathways in anterior pituitary. PMID:27611913

  7. 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

  8. 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.

  9. 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.

  10. Mature coconut water exhibits antidiabetic and antithrombotic potential via L-arginine-nitric oxide pathway in alloxan induced diabetic rats.

    PubMed

    Preetha, Prabhakaran Prabha; Devi, Vishalakshiamma Girija; Rajamohan, Thankappan

    2015-11-01

    The aims of the present study were to assess whether the antidiabetic activity of mature coconut water (MCW) is mediated through L-arginine-nitric oxide pathway in diabetic rats, and to study the effects of MCW on blood coagulation. Diabetes was induced in male Sprague-Dawley rats by injecting them with alloxan (150 mg/kg body weight). MCW (4 mL/100 g body weight) and L-arginine (7.5 mg/100 g body weight) was given orally for 45 days. L-NAME was given at a dose of 0.5 mg/kg body weight. Concentrations of blood glucose, plasma insulin, glycosylated hemoglobin (HbA1c), L-arginine, urine volume and urinary creatinine levels, activity of nitric oxide synthase (NOS), and arginase as well as the abnormalities in hemostasis and thrombosis were measured in all the experimental groups. Treatment with MCW and L-arginine reduced the concentration of blood glucose and HbA1c in diabetic rats. MCW and L-arginine treatment exhibited significant antithrombotic activity in diabetic rats, which was evident from the reduced levels of WBC, platelets, fibrin, and fibrinogen. MCW and L-arginine treatment prolonged the prothrombin time in diabetic rats and reduced the activity of Factor V. In addition to this, the activity of nitric oxide synthase, liver and plasma arginine content, and urinary nitrite were higher in MCW-treated diabetic rats whereas L-NAME treatment inhibited the beneficial effects induced by MCW and arginine. The results clearly indicate that L-arginine is a major factor responsible for the antidiabetic and antithrombotic potential of coconut water, and is mediated through the L-arginine-nitric oxide pathway.

  11. Extracellular Protein Kinase A Modulates Intracellular Calcium/Calmodulin-Dependent Protein Kinase II, Nitric Oxide Synthase, and the Glutamate-Nitric Oxide-cGMP Pathway in Cerebellum. Differential Effects in Hyperammonemia.

    PubMed

    Cabrera-Pastor, Andrea; Llansola, Marta; Felipo, Vicente

    2016-12-21

    Extracellular protein kinases, including cAMP-dependent protein kinase (PKA), modulate neuronal functions including N-methyl-d-aspartate (NMDA) receptor-dependent long-term potentiation. NMDA receptor activation increases calcium, which binds to calmodulin and activates nitric oxide synthase (NOS), increasing nitric oxide (NO), which activates guanylate cyclase, increasing cGMP, which is released to the extracellular fluid, allowing analysis of this glutamate-NO-cGMP pathway in vivo by microdialysis. The function of this pathway is impaired in hyperammonemic rats. The aims of this work were to assess (1) whether the glutamate-NO-cGMP pathway is modulated in cerebellum in vivo by an extracellular PKA, (2) the role of phosphorylation and activity of calcium/calmodulin-dependent protein kinase II (CaMKII) and NOS in the pathway modulation by extracellular PKA, and (3) whether the effects are different in hyperammonemic and control rats. The pathway was analyzed by in vivo microdialysis. The role of extracellular PKA was analyzed by inhibiting it with a membrane-impermeable inhibitor. The mechanisms involved were analyzed in freshly isolated cerebellar slices from control and hyperammonemic rats. In control rats, inhibiting extracellular PKA reduces the glutamate-NO-cGMP pathway function in vivo. This is due to reduction of CaMKII phosphorylation and activity, which reduces NOS phosphorylation at Ser1417 and NOS activity, resulting in reduced guanylate cyclase activation and cGMP formation. In hyperammonemic rats, under basal conditions, CaMKII phosphorylation and activity are increased, increasing NOS phosphorylation at Ser847, which reduces NOS activity, guanylate cyclase activation, and cGMP. Inhibiting extracellular PKA in hyperammonemic rats normalizes CaMKII phosphorylation and activity, NOS phosphorylation, NOS activity, and cGMP, restoring normal function of the pathway.

  12. 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.

  13. Inorganic Nitrate Promotes the Browning of White Adipose Tissue through the Nitrate-Nitrite-Nitric Oxide Pathway

    PubMed Central

    Roberts, Lee D; Ashmore, Tom; Kotwica, Aleksandra O; Murfitt, Steven A; Fernandez, Bernadette O; Feelisch, Martin; Griffin, Julian L

    2015-01-01

    Inorganic nitrate was once considered an oxidation end-product of nitric oxide metabolism with little biological activity. However, recent studies have demonstrated that dietary nitrate can modulate mitochondrial function in man and is effective in reversing features of the metabolic syndrome in mice. Using a combined histological, metabolomics, and transcriptional and protein analysis approach we mechanistically define that nitrate not only increases the expression of thermogenic genes in brown-adipose tissue but also induces the expression of brown adipocyte-specific genes and proteins in white adipose tissue, substantially increasing oxygen consumption and fatty acid β-oxidation in adipocytes. Nitrate induces these phenotypic changes through a mechanism distinct from known physiological small molecule activators of browning, the recently identified nitrate-nitrite-nitric oxide pathway. The nitrate-induced browning effect was enhanced in hypoxia, a serious co-morbidity affecting white adipose tissue in obese individuals, and corrected impaired brown adipocyte-specific gene expression in white adipose tissue in a murine model of obesity. Since resulting beige/brite cells exhibit anti-obesity and anti-diabetic effects, nitrate may be an effective means of inducing the browning response in adipose tissue to treat the metabolic syndrome. PMID:25249574

  14. 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.

  15. Mangiferin Prevents Guinea Pig Tracheal Contraction via Activation of the Nitric Oxide-Cyclic GMP Pathway

    PubMed Central

    Vieira, Aline B.; Coelho, Luciana P.; Insuela, Daniella B. R.; Carvalho, Vinicius F.; dos Santos, Marcelo H.; Silva, Patricia MR.; Martins, Marco A.

    2013-01-01

    Previous studies have described the antispasmodic effect of mangiferin, a natural glucoside xanthone (2-C-β-Dgluco-pyranosyl-1,3,6,7-tetrahydroxyxanthone) that is present in mango trees and other plants, but its mechanism of action remains unknown. The aim of this study was to examine the potential contribution of the nitric oxide-cyclic GMP pathway to the antispasmodic effect of mangiferin on isolated tracheal rings preparations. The functional effect of mangiferin on allergic and non-allergic contraction of guinea pig tracheal rings was assessed in conventional organ baths. Cultured tracheal rings were exposed to mangiferin or vehicle, and nitric oxide synthase (NOS) 3 and cyclic GMP (cGMP) levels were quantified using western blotting and enzyme immunoassays, respectively. Mangiferin (0.1–10 µM) inhibited tracheal contractions induced by distinct stimuli, such as allergen, histamine, 5-hydroxytryptamine or carbachol, in a concentration-dependent manner. Mangiferin also caused marked relaxation of tracheal rings that were precontracted by carbachol, suggesting that it has both anti-contraction and relaxant properties that are prevented by removing the epithelium. The effect of mangiferin was inhibited by the nitric oxide synthase inhibitor, Nω-nitro-L-arginine methyl ester (L-NAME) (100 µM), and the soluble guanylate cyclase inhibitor, 1H-[1], [2], [4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) (10 µM), but not the adenylate cyclase inhibitor, 9-(tetrahydro-2-furyl)adenine (SQ22536) (100 µM). The antispasmodic effect of mangiferin was also sensitive to K+ channel blockers, such as tetraethylammonium (TEA), glibenclamide and apamin. Furthermore, mangiferin inhibited Ca2+-induced contractions in K+ (60 mM)-depolarised tracheal rings preparations. In addition, mangiferin increased NOS3 protein levels and cGMP intracellular levels in cultured tracheal rings. Finally, mangiferin-induced increase in cGMP levels was abrogated by co-incubation with either ODQ or L

  16. 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.

  17. 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.

  18. 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

  19. Requirement of the inducible nitric oxide synthase pathway for IL-1-induced osteoclastic bone resorption

    PubMed Central

    van't Hof, R. J.; Armour, K. J.; Smith, L. M.; Armour, K. E.; Wei, X. Q.; Liew, F. Y.; Ralston, S. H.

    2000-01-01

    Nitric oxide has been suggested to be involved in the regulation of bone turnover, especially in pathological conditions characterized by release of bone-resorbing cytokines. The cytokine IL-1 is thought to act as a mediator of periarticular bone loss and tissue damage in inflammatory diseases such as rheumatoid arthritis. IL-1 is a potent stimulator of both osteoclastic bone resorption and expression of inducible nitric oxide synthase (iNOS) in bone cells and other cell types. In this study, we investigated the role that the iNOS pathway plays in mediating the bone-resorbing effects of IL-1 by studying mice with targeted disruption of the iNOS gene. Studies in vitro and in vivo showed that iNOS-deficient mice exhibited profound defects of IL-1-induced osteoclastic bone resorption but responded normally to calciotropic hormones such as 1,25 dihydroxyvitamin D3 and parathyroid hormone. Immunohistochemical studies and electrophoretic mobility shift assays performed on bone marrow cocultures from iNOS-deficient mice showed abnormalities in IL-1-induced nuclear translocation of the p65 component of NFκB and in NFκB-DNA binding, which were reversed by treatment with the NO donor S-nitroso-acetyl penicillamine. These results show that the iNOS pathway is essential for IL-1-induced bone resorption and suggest that the effects of NO may be mediated by modulating IL-1-induced nuclear activation of NFκB in osteoclast precursors. PMID:10869429

  20. Contemporary approaches to modulating the nitric oxide-cGMP pathway in cardiovascular disease

    PubMed Central

    Kraehling, Jan R.; Sessa, William C.

    2017-01-01

    Endothelial cells lining the vessel wall control important aspects of vascular homeostasis. In particular, the production of endothelium-derived nitric oxide and activation of soluble guanylate cyclase promotes endothelial quiescence and governs vasomotor function and proportional remodeling of blood vessels. Here, we discuss novel approaches to improve endothelial nitric oxide generation and preserve its bioavailability. We also discuss therapeutic opportunities aimed at activation of soluble guanylate cyclase for multiple cardiovascular indications. PMID:28360348

  1. 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.

  2. 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

  3. 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.

  4. Contemporary Approaches to Modulating the Nitric Oxide-cGMP Pathway in Cardiovascular Disease.

    PubMed

    Kraehling, Jan R; Sessa, William C

    2017-03-31

    Endothelial cells lining the vessel wall control important aspects of vascular homeostasis. In particular, the production of endothelium-derived nitric oxide and activation of soluble guanylate cyclase promotes endothelial quiescence and governs vasomotor function and proportional remodeling of blood vessels. Here, we discuss novel approaches to improve endothelial nitric oxide generation and preserve its bioavailability. We also discuss therapeutic opportunities aimed at activation of soluble guanylate cyclase for multiple cardiovascular indications. © 2017 American Heart Association, Inc.

  5. 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

  6. Lower urinary tract symptoms/benign prostatic hypertrophy and vascular function: Role of the nitric oxide-phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate pathway.

    PubMed

    Higashi, Yukihito

    2017-06-01

    It is well known that there is an association of lower urinary tract symptoms/benign prostatic hypertrophy with cardiovascular disease, suggesting that lower urinary tract symptoms/benign prostatic hypertrophy is a risk factor for cardiovascular events. Vascular function, including endothelial function and vascular smooth muscle function, is involved in the pathogenesis, maintenance and development of atherosclerosis, leading to cardiovascular events. Vascular dysfunction per se should also contribute to lower urinary tract symptoms/benign prostatic hypertrophy. Both lower urinary tract symptoms/benign prostatic hypertrophy and vascular dysfunction have cardiovascular risk factors, such as hypertension, dyslipidemia, diabetes mellitus, aging, obesity and smoking. Inactivation of the phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate-nitric oxide pathway causes lower urinary tract symptoms/benign prostatic hypertrophy through an enhancement of sympathetic nervous activity, endothelial dysfunction, increase in Rho-associated kinase activity and vasoconstriction, and decrease in blood flow of pelvic viscera. Both endogenous nitric oxide and exogenous nitric oxide act as vasodilators on vascular smooth muscle cells through an increase in the content of cyclic guanosine 3',5'-monophosphate, which is inactivated by phosphodiesterase type 5. In a clinical setting, phosphodiesterase type 5 inhibitors are widely used in patients with lower urinary tract symptoms/benign prostatic hypertrophy. Phosphodiesterase type 5 inhibitors might have beneficial effects on vascular function through not only inhibition of cyclic guanosine 3',5'-monophosphate degradation, but also increases in testosterone levels and nitric oxide bioavailability, increase in the number and improvement of the function of endothelial progenitor cells, and decrease in insulin resistance. In the present review, the relationships between lower urinary tract symptoms/benign prostatic hypertrophy, the

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Arbuscular mycorrhizal fungal inoculation increases phenolic synthesis in clover roots via hydrogen peroxide, salicylic acid and nitric oxide signaling pathways.

    PubMed

    Zhang, Rui-Qin; Zhu, Hong-Hui; Zhao, Hai-Quan; Yao, Qing

    2013-01-01

    Arbuscular mycorrhizal fungi can increase the host resistance to pathogens via promoted phenolic synthesis, however, the signaling pathway responsible for it still remains unclear. In this study, in order to reveal the signaling molecules involved in this process, we inoculated Trifolium repense L. with an arbuscular mycorrhizal fungus (AMF), Glomus mosseae, and monitored the contents of phenolics and signaling molecules (hydrogen peroxide (H(2)O(2)), salicylic acid (SA), and nitric oxide (NO)) in roots, measured the activities of l-phenylalanine ammonia-lyase (PAL) and nitric oxide synthase (NOS), and the expression of pal and chs genes. Results demonstrated that AMF colonization promoted the phenolic synthesis, in parallel with the increase in related enzyme activity and gene expression. Meanwhile, the accumulation of all three signaling molecules was also up-regulated by AMF. This study suggested that AMF increased the phenolic synthesis in roots probably via signaling pathways of H(2)O(2), SA and NO in a signaling cascade. Copyright © 2012 Elsevier GmbH. All rights reserved.

  12. Use of zinc chloride as alternative stimulant for in vitro study of nitric oxide production pathway in avian splenocyte culture.

    PubMed

    Pan, D; Bera, A K; Das, S; Bandyopadhyay, S; Rana, T; Bandyopadhyay, S; Das, S K; Bhattacharya, D

    2010-06-01

    Nitric Oxide (NO) plays an important role for regulation of cellular and vascular response of inflammation and initiates killing mechanism in the host-defense reactions. NO production is regulated through inducible nitric oxide synthase (iNOS) pathway in response to infections and injurious agents besides pro-inflammatory cytokines secreted by the host. Evaluation of NO pathway is one of the major targets which can evaluate various immunomodulators for their therapeutic interaction on innate immune system. Lipopolysaccharide (LPS) and concavalin A (ConA) are used as standard mitogen for peripheral blood mononuclear cells and splenocyte of mammalian and avian cell culture. During the present investigation ZnCl(2) has been explored as standard mitogen and result was comparable with standard mitogen. The result has been evaluated on the basis of relative mRNA expression of iNOS and interferon gamma and nitrite assay. Observation indicated significantly higher expression of both biomolecules in comparison to control, LPS, ConA treated group. This study indicated that, ZnCl(2) can also be used as standard stimulant for molecular mining of innate immunity.

  13. 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.

  14. Role of nitric oxide pathway in the conditioned rewarding effects of MDMA in mice.

    PubMed

    García-Pardo, M P; Rodríguez-Arias, M; Miñarro, J; Aguilar, M A

    2017-07-14

    It is estimated that 2.1 million young adults used MDMA/Ecstasy in the last year in Europe. Vulnerable subjects can develop dependence after MDMA abuse but currently there does not exist an effective treatment for this disorder. The nitric oxide (NO) pathway seems to have an important role on the rewarding effects of different drugs and has been proposed as a new pharmacological treatment for psychostimulant addiction. In the present study, we intend to evaluate whether the blockade of the NO synthesis (NOS) interferes with the rewarding effects of MDMA in the conditioned preference place (CPP) paradigm in young adult male mice. Our results indicated that mice treated with 7-nitroindazole (a NOS inhibitor) did not show CPP after conditioning with MDMA (1.25mg/kg). These results demonstrated the role of the NO pathway in the rewarding effects of MDMA and suggested that the manipulation of this pathway could be a new therapeutic option for MDMA abuse. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. L-Arginine supplementation improves antioxidant defenses through L-arginine/nitric oxide pathways in exercised rats.

    PubMed

    Shan, Lingling; Wang, Bin; Gao, Guizhen; Cao, Wengen; Zhang, Yunkun

    2013-10-15

    l-Arginine (l-Arg) supplementation has been shown to enhance physical exercise capacity and delay onset of fatigue. This work investigated the potential beneficial mechanism(s) of l-Arg supplementation by examining its effect on the cellular oxidative and nitrosative stress pathways in the exercised rats. Forty-eight rats were randomly divided into six groups: sedentary control; sedentary control with l-Arg treatment; endurance training (daily swimming training for 8 wk) control; endurance training with l-Arg treatment; an exhaustive exercise (one time swimming to fatigue) control; and an exhaustive exercise with l-Arg treatment. l-Arg (500 mg/kg body wt) or saline was given to rats by intragastric administration 1 h before the endurance training and the exhaustive swimming test. Expression levels and activities of the l-Arg/nitric oxide (NO) pathway components and parameters of the oxidative stress and antioxidant defense capacity were investigated in l-Arg-treated and control rats. The result show that the l-Arg supplementation completely reversed the exercise-induced activation of NO synthase and superoxide dismutase, increased l-Arg transport capacity, and increased NO and anti-superoxide anion levels. These data demonstrate that l-Arg supplementation effectively reduces the exercise-induced imbalance between oxidative stress and antioxidant defense capacity, and this modulation is likely mediated through the l-Arg/NO pathways. The findings of this study improved our understanding of how l-Arg supplementation prevents elevations of reactive oxygen species and favorably enhances the antioxidant defense capacity during physical exercise.

  16. 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

  17. 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.

  18. 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

  19. 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

  20. Commiphora molmol Modulates Glutamate-Nitric Oxide-cGMP and Nrf2/ARE/HO-1 Pathways and Attenuates Oxidative Stress and Hematological Alterations in Hyperammonemic Rats

    PubMed Central

    Alqahtani, Sultan; Othman, Sarah I.; Germoush, Mousa O.; Hussein, Omnia E.; Al-Basher, Gadh; Khim, Jong Seong; Al-Qaraawi, Maha A.; Al-Harbi, Hanan M.; Fadel, Abdulmannan; Allam, Ahmed A.

    2017-01-01

    Hyperammonemia is a serious complication of liver disease and may lead to encephalopathy and death. This study investigated the effects of Commiphora molmol resin on oxidative stress, inflammation, and hematological alterations in ammonium chloride- (NH4Cl-) induced hyperammonemic rats, with an emphasis on the glutamate-NO-cGMP and Nrf2/ARE/HO-1 signaling pathways. Rats received NH4Cl and C. molmol for 8 weeks. NH4Cl-induced rats showed significant increase in blood ammonia, liver function markers, and tumor necrosis factor-alpha (TNF-α). Concurrent supplementation of C. molmol significantly decreased circulating ammonia, liver function markers, and TNF-α in hyperammonemic rats. C. molmol suppressed lipid peroxidation and nitric oxide and enhanced the antioxidant defenses in the liver, kidney, and cerebrum of hyperammonemic rats. C. molmol significantly upregulated Nrf2 and HO-1 and decreased glutamine and nitric oxide synthase, soluble guanylate cyclase, and Na+/K+-ATPase expression in the cerebrum of NH4Cl-induced hyperammonemic rats. Hyperammonemia was also associated with hematological and coagulation system alterations. These alterations were reversed by C. molmol. Our findings demonstrated that C. molmol attenuates ammonia-induced liver injury, oxidative stress, inflammation, and hematological alterations. This study points to the modulatory effect of C. molmol on glutamate-NO-cGMP and Nrf2/ARE/HO-1 pathways in hyperammonemia. Therefore, C. molmol might be a promising protective agent against hyperammonemia. PMID:28744340

  1. Inhibition of the L-arginine-nitric oxide pathway mediates the antidepressant effects of ketamine in rats in the forced swimming test.

    PubMed

    Zhang, Guang-Fen; Wang, Nan; Shi, Jin-Yun; Xu, Shi-Xia; Li, Xiao-Min; Ji, Mu-Huo; Zuo, Zhi-Yi; Zhou, Zhi-Qiang; Yang, Jian-Jun

    2013-09-01

    Converging evidence shows that the acute administration of a sub-anaesthetic dose ketamine produces fast-acting and robust antidepressant properties in patients suffering from major depressive disorder. However, the underlying mechanisms have not been fully elucidated. The present study aimed to investigate the role of the L-arginine-nitric oxide pathway in the antidepressant effects of ketamine in rats performing the forced swimming test (FST). Ketamine (10 mg/kg) significantly decreased immobility times in the FST and the activities of total nitric oxide synthases (T-NOS), inducible NOS (iNOS), and endothelial NOS (eNOS) in the rat hippocampus. Interestingly, the plasma activities of T-NOS, iNOS, and eNOS increased after administration of ketamine. Furthermore, the activities of neuronal NOS (nNOS) did not change significantly in either the hippocampus or plasma after ketamine administration. The antidepressant effects of ketamine were prevented by pre-treatment with l-arginine (750 mg/kg). Pre-treatment with the NOS inhibitor L-NG-nitroarginine methyl ester at a sub-antidepressant dose of 50 mg/kg and ketamine at a sub-antidepressant dose of 3 mg/kg reduced immobility time in the FST compared to treatment with either drug alone. None of the drugs affected crossing and rearing scores in the open field test. These results suggest that the L-arginine-nitric oxide pathway is involved in the antidepressant effects of ketamine observed in rats in the FST and this involvement is characterised by the inhibition of brain T-NOS, iNOS, and eNOS activities. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. 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.

  3. 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...

  4. 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...

  5. Cancer cell metabolism and the modulating effects of nitric oxide.

    PubMed

    Chang, Ching-Fang; Diers, Anne R; Hogg, Neil

    2015-02-01

    Altered metabolic phenotype has been recognized as a hallmark of tumor cells for many years, but this aspect of the cancer phenotype has come into greater focus in recent years. NOS2 (inducible nitric oxide synthase of iNOS) has been implicated as a component in many aggressive tumor phenotypes, including melanoma, glioblastoma, and breast cancer. Nitric oxide has been well established as a modulator of cellular bioenergetics pathways, in many ways similar to the alteration of cellular metabolism observed in aggressive tumors. In this review we attempt to bring these concepts together with the general hypothesis that one function of NOS2 and NO in cancer is to modulate metabolic processes to facilitate increased tumor aggression. There are many mechanisms by which NO can modulate tumor metabolism, including direct inhibition of respiration, alterations in mitochondrial mass, oxidative inhibition of bioenergetic enzymes, and the stimulation of secondary signaling pathways. Here we review metabolic alterations in the context of cancer cells and discuss the role of NO as a potential mediator of these changes. Copyright © 2015. Published by Elsevier Inc.

  6. Cancer Cell Metabolism and the Modulating Effects of Nitric Oxide

    PubMed Central

    Chang, Ching-Fang; Diers, Anne R.; Hogg, Neil

    2016-01-01

    Altered metabolic phenotype has been recognized as a hallmark of tumor cells for many years, but this aspect of the cancer phenotype has come into greater focus in recent years. NOS2 (inducible nitric oxide synthase of iNOS) has been implicated as a component in many aggressive tumor phenotypes, including melanoma, glioblastoma and breast cancer. Nitric oxide has been well established as a modulator of cellular bioenergetics pathways, in many ways similar to the alteration of cellular metabolism observed in aggressive tumors. In this review we attempt to bring these concepts together with the general hypothesis that one function of NOS2 and NO in cancer is to modulate metabolic processes to facilitate increased tumor aggression. There are many mechanisms by which NO can modulate tumor metabolism, including direct inhibition of respiration, alterations in mitochondrial mass, oxidative inhibition of bioenergetic enzymes, and the stimulation of secondary signaling pathways. Here we review metabolic alterations in the context of cancer cells and discuss the role of NO as a potential mediator of these changes. PMID:25464273

  7. 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

  8. Oxidized LDL at low concentration promotes in-vitro angiogenesis and activates nitric oxide synthase through PI3K/Akt/eNOS pathway in human coronary artery endothelial cells

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

    Yu, Shan; Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong; Wong, Siu Ling

    Research highlights: {yields} Low-concentration oxidized LDL enhances angiogenesis through nitric oxide (NO). {yields} Oxidized LDL increases intracellular NO levels via eNOS phosphorylation. {yields} Akt/PI3K signaling mediates oxidized LDL-induced eNOS phosphorylation. -- Abstract: It has long been considered that oxidized low-density lipoprotein (oxLDL) causes endothelial dysfunction and is remarkably related to the development of atherosclerosis. However, the effect of oxLDL at very low concentration (<10 {mu}g/ml) on the endothelial cells remains speculative. Nitric oxide (NO) has a crucial role in the endothelial cell function. In this study, we investigated the effect of oxLDL at low concentration on NO production and proliferation,more » migration, tube formation of the human coronary artery endothelial cells (HCAEC). Results showed that oxLDL at 5 {mu}g/ml enhanced HCAEC proliferation, migration and tube formation. These phenomena were accompanied by an increased intracellular NO production. L-NAME (a NOS inhibitor), LY294002 and wortmannin (PI3K inhibitors) could abolish oxLDL-induced angiogenic effects and prevent NO production in the HCAEC. The phosphorylation of Akt, PI3K and eNOS were up-regulated by oxLDL, which was attenuated by LY294002. Our results suggested that oxLDL at low concentration could promote in-vitro angiogenesis and activate nitric oxide synthesis through PI3K/Akt/eNOS pathway in HCAEC.« less

  9. Nitric oxide protects murine embryonic liver cells (BNL CL.2) from cytotoxicity induced by glucose deprivation.

    PubMed

    Pae, H O; Kim, H G; Paik, Y S; Paik, S G; Kim, Y M; Oh, G S; Chung, H T

    2000-03-01

    We investigated the protective effects of nitric oxide on cell death of murine embryonic liver cells (BNL CL.2) after glucose deprivation. Endogenous nitric oxide production by BNL CL.2 cells was induced by 6 hr pretreatment with interferon-gamma and lipopolysaccharide. We used sodium nitroprusside and S-nitroso-L-glutathione as exogenous nitric oxide-generating compounds. All agents were used at doses that did not show direct cytotoxicity as measured by crystal violet staining assay. In the BNL CL.2 cells, the viability dropped very steeply after 24 hr incubation with glucose-free media. Endogenous nitric oxide produced by treatment of the cells with interferon-gamma and lipopolysaccharide protected the cells from glucose deprivation-induced cytotoxicity, but did not protect them in the presence of the nitric oxide synthesis inhibitor, N(G)-monomethyl-L-arginine. Exogenous nitric oxide protected the cells from glucose deprivation-induced cytotoxicity in a concentration-dependent manner. Cytoprotection by nitric oxide donors was abolished by the use of nitric oxide scavenger, 2-phenyl-4,4,5,5,-tetramethylimidazole, but not by the soluble guanosine cyclase inhibitor, 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one. In addition, cytoprotective effects comparable to endogenous or exogenous nitric oxide were not observed when the cells were incubated with dibutyl guanosine 3',5'-cyclic monophosphate. Based upon these results, we suggest that nitric oxide may enhance the cell survival of BNL CL.2 cells after glucose deprivation via a guanosine 3',5'-cyclic monophosphate-independent pathway.

  10. Oxidation of nitroxyl anion to nitric oxide by copper ions

    PubMed Central

    Nelli, Silvia; Hillen, Mark; Buyukafsar, Kansu; Martin, William

    2000-01-01

    This study made use of a nitric oxide-sensitive electrode to examine possible means of generating nitric oxide from nitroxyl anion (NO−) released upon the decomposition of Angeli's salt. Our results show that copper ions (from CuSO4) catalyze the rapid and efficient oxidation of nitroxyl to nitric oxide. Indeed, the concentrations of copper required to do so (0.1–100 μM) are roughly 100-times lower than those required to generate equivalent amounts of nitric oxide from S-nitroso-N-acetyl-D,L-penicillamine (SNAP). Experiments with ascorbate (1 mM), which reduces Cu2+ ions to Cu+, and with the Cu2+ chelators, EDTA and cuprizone, and the Cu+ chelator, neocuproine, each at 1 mM, suggest that the oxidation is catalyzed by copper ions in both valency states. Some compounds containing other transition metals, i.e. methaemoglobin, ferricytochrome c and Mn(III)TMPyP, were much less efficient than CuSO4 in catalyzing the formation of nitric oxide from nitroxyl, while FeSO4, FeCl3, MnCl2, and ZnSO4 were inactive. Of the copper containing enzymes examined, Cu-Zn superoxide dismutase and ceruloplasmin were weak generators of nitric oxide from nitroxyl, even at concentrations (2500 and 30 u ml−1, respectively) vastly greater than are present endogenously. Two others, ascorbate oxidase (10 u ml−1) and tyrosinase (250 u ml−1) were inactive. Our findings suggest that a copper-containing enzyme may be responsible for the rapid oxidation of nitroxyl to nitric oxide by cells, but the identity of such an enzyme remains elusive. PMID:10991931

  11. 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

  12. Integrating nitric oxide into salicylic acid and jasmonic acid/ ethylene plant defense pathways.

    PubMed

    Mur, Luis A J; Prats, Elena; Pierre, Sandra; Hall, Michael A; Hebelstrup, Kim H

    2013-01-01

    Plant defense against pests and pathogens is known to be conferred by either salicylic acid (SA) or jasmonic acid (JA)/ethylene (ET) pathways, depending on infection or herbivore-grazing strategy. It is well attested that SA and JA/ET pathways are mutually antagonistic allowing defense responses to be tailored to particular biotic stresses. Nitric oxide (NO) has emerged as a major signal influencing resistance mediated by both signaling pathways but no attempt has been made to integrate NO into established SA/JA/ET interactions. NO has been shown to act as an inducer or suppressor of signaling along each pathway. NO will initiate SA biosynthesis and nitrosylate key cysteines on TGA-class transcription factors to aid in the initiation of SA-dependent gene expression. Against this, S-nitrosylation of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1) will promote the NPR1 oligomerization within the cytoplasm to reduce TGA activation. In JA biosynthesis, NO will initiate the expression of JA biosynthetic enzymes, presumably to over-come any antagonistic effects of SA on JA-mediated transcription. NO will also initiate the expression of ET biosynthetic genes but a suppressive role is also observed in the S-nitrosylation and inhibition of S-adenosylmethionine transferases which provides methyl groups for ET production. Based on these data a model for NO action is proposed but we have also highlighted the need to understand when and how inductive and suppressive steps are used.

  13. Integrating nitric oxide into salicylic acid and jasmonic acid/ ethylene plant defense pathways

    PubMed Central

    Mur, Luis A. J.; Prats, Elena; Pierre, Sandra; Hall, Michael A.; Hebelstrup, Kim H.

    2013-01-01

    Plant defense against pests and pathogens is known to be conferred by either salicylic acid (SA) or jasmonic acid (JA)/ethylene (ET) pathways, depending on infection or herbivore-grazing strategy. It is well attested that SA and JA/ET pathways are mutually antagonistic allowing defense responses to be tailored to particular biotic stresses. Nitric oxide (NO) has emerged as a major signal influencing resistance mediated by both signaling pathways but no attempt has been made to integrate NO into established SA/JA/ET interactions. NO has been shown to act as an inducer or suppressor of signaling along each pathway. NO will initiate SA biosynthesis and nitrosylate key cysteines on TGA-class transcription factors to aid in the initiation of SA-dependent gene expression. Against this, S-nitrosylation of NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 (NPR1) will promote the NPR1 oligomerization within the cytoplasm to reduce TGA activation. In JA biosynthesis, NO will initiate the expression of JA biosynthetic enzymes, presumably to over-come any antagonistic effects of SA on JA-mediated transcription. NO will also initiate the expression of ET biosynthetic genes but a suppressive role is also observed in the S-nitrosylation and inhibition of S-adenosylmethionine transferases which provides methyl groups for ET production. Based on these data a model for NO action is proposed but we have also highlighted the need to understand when and how inductive and suppressive steps are used. PMID:23818890

  14. 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.

  15. 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.

  16. Nitric oxide and nitrous oxide turnover in natural and engineered microbial communities: biological pathways, chemical reactions, and novel technologies

    PubMed Central

    Schreiber, Frank; Wunderlin, Pascal; Udert, Kai M.; Wells, George F.

    2012-01-01

    Nitrous oxide (N2O) is an environmentally important atmospheric trace gas because it is an effective greenhouse gas and it leads to ozone depletion through photo-chemical nitric oxide (NO) production in the stratosphere. Mitigating its steady increase in atmospheric concentration requires an understanding of the mechanisms that lead to its formation in natural and engineered microbial communities. N2O is formed biologically from the oxidation of hydroxylamine (NH2OH) or the reduction of nitrite (NO−2) to NO and further to N2O. Our review of the biological pathways for N2O production shows that apparently all organisms and pathways known to be involved in the catabolic branch of microbial N-cycle have the potential to catalyze the reduction of NO−2 to NO and the further reduction of NO to N2O, while N2O formation from NH2OH is only performed by ammonia oxidizing bacteria (AOB). In addition to biological pathways, we review important chemical reactions that can lead to NO and N2O formation due to the reactivity of NO−2, NH2OH, and nitroxyl (HNO). Moreover, biological N2O formation is highly dynamic in response to N-imbalance imposed on a system. Thus, understanding NO formation and capturing the dynamics of NO and N2O build-up are key to understand mechanisms of N2O release. Here, we discuss novel technologies that allow experiments on NO and N2O formation at high temporal resolution, namely NO and N2O microelectrodes and the dynamic analysis of the isotopic signature of N2O with quantum cascade laser absorption spectroscopy (QCLAS). In addition, we introduce other techniques that use the isotopic composition of N2O to distinguish production pathways and findings that were made with emerging molecular techniques in complex environments. Finally, we discuss how a combination of the presented tools might help to address important open questions on pathways and controls of nitrogen flow through complex microbial communities that eventually lead to N2O build

  17. Carbamylated low-density lipoprotein attenuates glucose uptake via a nitric oxide-mediated pathway in rat L6 skeletal muscle cells.

    PubMed

    Choi, Hye-Jung; Lee, Kyoung Jae; Hwang, Eun Ah; Mun, Kyo-Cheol; Ha, Eunyoung

    2015-07-01

    Carbamylation is a cyanate-mediated posttranslational modification. We previously reported that carbamylated low-density lipoprotein (cLDL) increases reactive oxygen species and apoptosis via a lectin-like oxidized LDL receptor mediated pathway in human umbilical vein endothelial cells. A recent study reported an association between cLDL and type 2 diabetes mellitus (T2DM). In the current study, the effects of cLDL on glucose transport were explored in skeletal muscle cells. The effect of cLDL on glucose uptake, glucose transporter 4 (GLUT4) translocation, and signaling pathway were examined in cultured rat L6 muscle cells using 2-deoxyglucose uptake, immunofluorescence staining and western blot analysis. The quantity of nitric oxide (NO) was evaluated by the Griess reaction. The effect of native LDL (nLDL) from patients with chronic renal failure (CRF-nLDL) on glucose uptake was also determined. It was observed that cLDL significantly attenuated glucose uptake and GLUT4 translocation to the membrane, which was mediated via the increase in inducible nitric oxide synthase (iNOS)-induced NO production. Tyrosine nitration of the insulin receptor substrate-1 (IRS‑1) was increased. It was demonstrated that CRF-nLDL markedly reduced glucose uptake compared with nLDL from healthy subjects. Collectively, these findings indicate that cLDL, alone, attenuates glucose uptake via NO-mediated tyrosine nitration of IRS‑1 in L6 rat muscle cells and suggests the possibility that cLDL is involved in the pathogenesis of T2DM.

  18. Two Dimensional Polymer That Generates Nitric Oxide.

    DOEpatents

    McDonald, William F.; Koren, Amy B.

    2005-10-04

    A polymeric composition that generates nitric oxide and a process for rendering the surface of a substrate nonthrombogenic by applying a coating of the polymeric composition to the substrate are disclosed. The composition comprises: (1) a crosslinked chemical combination of (i) a polymer having amino group-containing side chains along a backbone forming the polymer, and (ii) a crosslinking agent containing functional groups capable of reacting with the amino groups; and (2) a plurality of nitric oxide generating functional groups associated with the crosslinked chemical combination. Once exposed to a physiological environment, the coating generates nitric oxide thereby inhibiting platelet aggregation. In one embodiment, the nitric oxide generating functional groups are provided by a nitrated compound (e.g., nitrocellulose) imbedded in the polymeric composition. In another embodiment, the nitric oxide generating functional groups comprise N2O2- groups covalently bonded to amino groups on the polymer.

  19. Arginine pathways and the inflammatory response: interregulation of nitric oxide and polyamines: review article.

    PubMed

    Satriano, J

    2004-07-01

    An early response to an acute inflammatory insult, such as wound healing or experimental glomerulonephritis, is the conversion of arginine to the cytostatic molecule nitric oxide (NO). This 'anti-bacterial' phase is followed by the conversion of arginine to ornithine, which is the precursor for the pro-proliferative polyamines as well as proline for the production of extracellular matrix. This latter, pro-growth phase constitutes a 'repair' phase response. The temporal switch of arginine as a substrate for the cytostatic iNOS/NO axis to the pro-growth arginase/ ornithine/polyamine and proline axis is subject to regulation by inflammatory cytokines as well as interregulation by the arginine metabolites themselves. Arginine is also the precursor for another biogenic amine, agmatine. Here we describe the capacity of these three arginine pathways to interregulate, and propose a model whereby agmatine has the potential to serve in the coordination of the early and repair phase pathways of arginine in the inflammatory response by acting as a gating mechanism at the transition from the iNOS/NO axis to the arginase/ODC/polyamine axis. Due to the pathophysiologic and therapeutic potential, we will further examine the antiproliferative effects of agmatine on the polyamine pathway.

  20. Involvement of l-arginine-nitric oxide pathway in anxiolytic-like effects of zinc chloride in rats.

    PubMed

    Navabi, Seyedeh Parisa; Eshagh Harooni, Hooman; Moazedi, Ahmad Ali; Khajepour, Lotfolah; Fathinia, Kosar

    2016-10-01

    Zinc is crucial for normal development of the brain, and Zinc deficiency has been shown to associate with neurological disorders (e.g. anxiety) through interactions with several neurotransmitter systems such as nitric oxide (NO). In this regard, our study aimed to evaluate the possible involvement of l-arginine NO pathway on anxiolytic effects of zinc in adult male rats. Zinc chloride at doses of 2.5 and 10mg/kg (intraperitoneal or ip) or saline (1ml/kg, ip) were injected 30min before the anxiety test. Zinc administrated rats (10mg/kg) were pre-treated with intra-CA1 microinjection of l-arginine in sub-effective dose of 1μg/rat (dorsal hippocampus, vehicle: saline1μl/rat). In addition, zinc chloride and NG-nitro-l-arginine methyl ester (l-NAME) were intraperitoneally co-administrated in sub-effective doses of 2.5mg/kg and 80mg/kg, respectively. The percentage of open arm time (OAT%), percentage of open arm entry (OAE%), as measures of anxiety, and total number of arm entries, as measures of locomotor activity, were recorded. Treatment with zinc (10mg/kg) markedly produced an increase in OAT% and OAE% in the Elevated plus maze test (EPM). A decrease of OAT% and OAE% was shown in groups which received zinc (10mg/kg) and l-arginine (1μg/rat) concomitantly as compared to the control group. Moreover, an increase of OAE% was revealed in the group exposed to Zinc (2.5mg/kg) and l-NAME (80mg/kg) co-administration. Although, Two-way ANOVA showed no significant differences of anxiety indices in rats received drug+zinc chloride in compare to the zinc pretreated with saline group. Anxiolytic- like effect of zinc reversed by nitric oxide precursor l-arginine. Additionally, the synergistic effects of l-NAME and ZnCl 2 were shown in the EPM. Thus our findings suggest that at least in part the anxiolytic effects of zinc can be mediated through the nitric oxide system. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  1. Nitric oxide detoxification by Fusarium verticillioides involves flavohemoglobins and the denitrification pathway

    USDA-ARS?s Scientific Manuscript database

    Nitric oxide (NO) is a highly mobile and potent signaling molecule, yet as a free radical it can also cause nitrosative stress to cells. To alleviate negative effects from excessive accumulation of endogenous NO or from potential exogenous sources, flavohemoglobin proteins can convert NO into nonto...

  2. 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

  3. Collecting Duct Nitric Oxide Synthase 1ß Activation Maintains Sodium Homeostasis During High Sodium Intake Through Suppression of Aldosterone and Renal Angiotensin II Pathways.

    PubMed

    Hyndman, Kelly A; Mironova, Elena V; Giani, Jorge F; Dugas, Courtney; Collins, Jessika; McDonough, Alicia A; Stockand, James D; Pollock, Jennifer S

    2017-10-24

    During high sodium intake, the renin-angiotensin-aldosterone system is downregulated and nitric oxide signaling is upregulated in order to remain in sodium balance. Recently, we showed that collecting duct nitric oxide synthase 1β is critical for fluid-electrolyte balance and subsequently blood pressure regulation during high sodium feeding. The current study tested the hypothesis that high sodium activation of the collecting duct nitric oxide synthase 1β pathway is critical for maintaining sodium homeostasis and for the downregulation of the renin-angiotensin-aldosterone system-epithelial sodium channel axis. Male control and collecting duct nitric oxide synthase 1β knockout (CDNOS1KO) mice were placed on low, normal, and high sodium diets for 1 week. In response to the high sodium diet, plasma sodium was significantly increased in control mice and to a significantly greater level in CDNOS1KO mice. CDNOS1KO mice did not suppress plasma aldosterone in response to the high sodium diet, which may be partially explained by increased adrenal AT1R expression. Plasma renin concentration was appropriately suppressed in both genotypes. Furthermore, CDNOS1KO mice had significantly higher intrarenal angiotensin II with high sodium diet, although intrarenal angiotensinogen levels and angiotensin-converting enzyme activity were similar between knockout mice and controls. In agreement with inappropriate renin-angiotensin-aldosterone system activation in the CDNOS1KO mice on a high sodium diet, epithelial sodium channel activity and sodium transporter abundance were significantly higher compared with controls. These data demonstrate that high sodium activation of collecting duct nitric oxide synthase 1β signaling induces suppression of systemic and intrarenal renin-angiotensin-aldosterone system, thereby modulating epithelial sodium channel and other sodium transporter abundance and activity to maintain sodium homeostasis. © 2017 The Authors. Published on behalf of the

  4. 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

  5. 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.

  6. 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.

  7. Nitric oxide induces the alternative oxidase pathway in Arabidopsis seedlings deprived of inorganic phosphate.

    PubMed

    Royo, Beatriz; Moran, Jose F; Ratcliffe, R George; Gupta, Kapuganti J

    2015-10-01

    Phosphate starvation compromises electron flow through the cytochrome pathway of the mitochondrial electron transport chain, and plants commonly respond to phosphate deprivation by increasing flow through the alternative oxidase (AOX). To test whether this response is linked to the increase in nitric oxide (NO) production that also increases under phosphate starvation, Arabidopsis thaliana seedlings were grown for 15 d on media containing either 0 or 1mM inorganic phosphate. The effects of the phosphate supply on growth, the production of NO, respiration, the AOX level and the production of superoxide were compared for wild-type (WT) seedlings and the nitrate reductase double mutant nia. Phosphate deprivation increased NO production in WT roots, and the AOX level and the capacity of the alternative pathway to consume electrons in WT seedlings; whereas the same treatment failed to stimulate NO production and AOX expression in the nia mutant, and the plants had an altered growth phenotype. The NO donor S-nitrosoglutathione rescued the growth phenotype of the nia mutants under phosphate deprivation to some extent, and it also increased the respiratory capacity of AOX. It is concluded that NO is required for the induction of the AOX pathway when seedlings are grown under phosphate-limiting conditions. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  8. 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

  9. 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.

  10. Up-regulation of the RhoA/Rho-kinase signaling pathway in corpus cavernosum from endothelial nitric-oxide synthase (NOS), but not neuronal NOS, null mice.

    PubMed

    Priviero, Fernanda B M; Jin, Li-Ming; Ying, Zhekang; Teixeira, Cleber E; Webb, R Clinton

    2010-04-01

    We tested the hypothesis that the basal release of nitric oxide (NO) from endothelial cells modulates contractile activity in the corpus cavernosum (CC) via inhibition of the RhoA/Rho-kinase signaling pathway. Cavernosal strips from wild-type (WT), endothelial nitric-oxide synthase knockout [eNOS(-/-)], and neuronal nitric-oxide synthase knockout [nNOS(-/-)] mice were mounted in myographs, and isometric force was recorded. mRNA and protein expression of key molecules in the RhoA/Rho-kinase pathway were analyzed by real-time polymerase chain reaction and Western blot, respectively. The cGMP levels were determined. The Rho-kinase inhibitors (R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide (Y-27632) and (S)-(+)-2-methyl-1-[(4-methyl-5-isoquinolinyl)sulfonyl] homopiperazine (H-1152) reduced cavernosal contractions evoked by phenylephrine or electrical field stimulation (EFS) in a concentration-dependent manner, although this inhibition was less effective in tissues from eNOS(-/-) mice. Y-27632 enhanced relaxations induced by sodium nitroprusside, EFS, and NO (administered as acidified NaNO2) without affecting the cGMP content of the cavernosal strips. This enhancement was less prominent in CC from eNOS(-/-). The protein expression of RhoA, Rho-guanine dissociation inhibitor, and Rho-kinase beta did not differ among the strains. However, in eNOS(-/-) CC, the protein expression of Rho-kinase alpha and both mRNA and protein expression of p115-Rho-associated guanine exchange factor (RhoGEF), PDZ-RhoGEF, and leukemia-associated RhoGEF were up-regulated. Phosphorylation of MYPT1 at Thr696 was higher in tissues from eNOS(-/-) mice. A high concentration of Y-27632 significantly enhanced NO release in CC stimulated by EFS. These results suggest a basal release of NO from endothelial cells, which inhibits contractions mediated by the RhoA/Rho-kinase pathway and modulates the expression of proteins related to this pathway in mouse CC. It indicates that

  11. 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

  12. Hyperoside protects cortical neurons from oxygen-glucose deprivation-reperfusion induced injury via nitric oxide signal pathway.

    PubMed

    Liu, Rui-Li; Xiong, Qiu-Ju; Shu, Qing; Wu, Wen-Ning; Cheng, Jin; Fu, Hui; Wang, Fang; Chen, Jian-Guo; Hu, Zhuang-Li

    2012-08-21

    Hyperoside is a flavonoid compound and widely used in clinic to relieve pain and improve cardiovascular functions. However, the effects of hyperoside on ischemic neurons and the molecular mechanisms remain unclear. Here, we used an in vitro ischemic model of oxygen-glucose deprivation followed by reperfusion (OGD-R) to investigate the protective effects of hyperoside on ischemic neuron injury and further explore the possible related mechanisms. Our results demonstrated that hyperoside protected cultured cortical neurons from OGD-R injury, it also relieved glutamate-induced neuronal injury and NMDA-induced [Ca(2+)](i) elevation. As for the mechanisms, hyperoside firstly attenuated the phosphorylation of CaMKII caused by OGD-R lesions. Meanwhile, hyperoside lessened iNOS expression induced by OGD-R via inhibition of NF-κB activation. Furthermore, ameliorating of ERK, JNK and Bcl-2 family-related apoptotic signaling pathways were also involved in the neuroprotection of hyperoside. Taken together, these studies revealed that hyperoside had protective effects on neuronal ischemia-reperfusion impairment, which was related to the regulation of nitric oxide signaling pathway. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Formononetin upregulates nitric oxide synthase in arterial endothelium through estrogen receptors and MAPK pathways.

    PubMed

    Sun, Tao; Cao, Lei; Ping, Na-Na; Wu, Yue; Liu, Dong-Zheng; Cao, Yong-Xiao

    2016-03-01

    Formononetin, a phytoestrogen, can improve arterial endothelial cell function by upregulating endothelial nitric oxide synthase (eNOS). The estrogen receptor plays an important role in the regulation of eNOS. This study investigated the hypothesis that formononetin upregulates eNOS through estrogen receptors and MAPK pathways. The rat superior mesenteric arteries were cultured with formononetin or formononetin plus inhibitors for 24 h. The isometric tension of the arteries was measured using a myograph system. The mRNA and protein expression levels of eNOS were determined by real-time PCR and immunohistochemistry, respectively. Acetylcholine (ACh) relaxed the mesenteric arteries precontracted with 5-hydroxytryptamine. This relaxation could be enhanced by formononetin. The removal of endothelium or incubation with l-NAME (a NOS inhibitor) completely abolished the formononetin-enhanced relaxation induced by ACh, suggesting that the formononetin-enhanced vasodilatation is dependent on endothelium and NO pathway. The estrogen receptor inhibitor ICI 182780 attenuated the formononetin-enhanced vasodilatation induced by ACh, suggesting that the formononetin-enhanced arterial relaxation is mediated by the estrogen receptor. Formononetin increased the mRNA and protein expression levels of eNOS. ICI 182780, U0126 (an ERK1/2 inhibitor) and SP600125 (a JNK inhibitor) prevented the increases in arterial relaxation and eNOS levels. Formononetin upregulates eNOS expression in mesenteric arteries via estrogen receptors, ERK1/2 and JNK pathways. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

  14. 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

  15. Calcium mobilization in HeLa cells induced by nitric oxide.

    PubMed

    Huang, Yimei; Zheng, Liqin; Yang, Hongqin; Chen, Jiangxu; Wang, Yuhua; Li, Hui; Xie, Shusen

    2014-01-01

    Nitric oxide (NO) has been proposed to be involved in tumor growth and metastasis. However, the mechanism by which nitric oxide modulates cancer cell growth and metastasis on cellular and molecular level is still not fully understood. This work utilized confocal microscopy and fluorescence microplate reader to investigate the effects of exogenous NO on the mobilization of calcium, which is one of the regulators of cell migration, in HeLa cells. The results show that NO elevates calcium in concentration-dependent manner in HeLa cells. And the elevation of calcium induced by NO is due to calcium influx and calcium release from intracellular calcium stores. Moreover, calcium release from intracellular stores is dominant. Furthermore, calcium release from mitochondria is one of the modulation pathways of NO. These findings would contribute to recognizing the significance of NO in cancer cell proliferation and metastasis. © Wiley Periodicals, Inc.

  16. 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 ...

  17. Role of nitric oxide in pheromone-mediated intraspecific communication in mice.

    PubMed

    Agustín-Pavón, Carmen; Martínez-Ricós, Joana; Martínez-García, Fernando; Lanuza, Enrique

    2009-12-07

    Nitric oxide is known to take part in the control of sexual and agonistic behaviours. This is usually attributed to its role in neural transmission in the hypothalamus and other structures of the limbic system. However, socio-sexual behaviours in rodents are mainly directed by chemical signals detected by the vomeronasal system, and nitric oxide is abundant in key structures along the vomeronasal pathway. Thus, here we check whether pharmacological treatments interfering with nitrergic transmission could affect socio-sexual behaviour by impairing the processing of chemical signals. Treatment with an inhibitor of nitric oxide synthesis (Nomega-Nitro-l-arginine methyl ester hydrochloride, L-NAME, 100mg/kg) blocks the innate preference displayed by female mice for sexual pheromones contained in male-soiled bedding, with a lower dose of the drug (50mg/kg) having no effect. Animals treated with the high dose of L-NAME show no reduction of olfactory discrimination of male urine in a habituation-dishabituation test, thus suggesting that the effect of the drug on the preference for male pheromones is not due to an inability to detect male urine. Alternatively, it may result from an alteration in processing the reinforcing value of pheromones as sexual signals. These results add a new piece of evidence to our understanding of the neurochemistry of intraspecific chemical communication in rodents, and suggest that the role of nitric oxide in socio-sexual behaviours should be re-evaluated taking into account the involvement of this neuromodulator in the processing of chemical signals.

  18. The nitric oxide-sensitive p21Ras-ERK pathway mediates S-nitrosoglutathione-induced apoptosis.

    PubMed

    Tsujita, Maristela; Batista, Wagner L; Ogata, Fernando T; Stern, Arnold; Monteiro, Hugo P; Arai, Roberto J

    2008-05-16

    p21Ras protein plays a critical role in cellular signaling that induces either cell cycle progression or apoptosis. Nitric oxide (NO) has been consistently reported to activate p21Ras through the redox sensitive cysteine residue (118). In this study, we demonstrated that the p21Ras-ERK pathway regulates THP-1 monocyte/macrophage apoptosis induced by S-nitrosoglutathione (SNOG). This was apparent from studies in THP-1 cells expressing NO-insensitive p21Ras (p21Ras(C118S)) where the pro-apoptotic action of SNOG was almost abrogated. Three major MAP kinase pathways (ERK, JNK, and p38) that are downstream to p21Ras were investigated. It was observed that only the activation of ERK1/2 MAP kinases by SNOG in THP-1 cells was attributable to p21Ras. The inhibition of the ERK pathway by PD98059 markedly attenuated apoptosis in SNOG-treated THP-1 cells, but had a marginal effect on SNOG-treated THP-1 cells expressing NO-insensitive p21Ras. The inhibition of the JNK and p38 pathways by selective inhibitors had no marked effects on the percentage of apoptosis. The induction of p21Waf1 expression by SNOG was observed in THP-1 cells harboring mutant and wild-type p21Ras, however in cells expressing mutant Ras, the expression of p21Waf1 was significantly attenuated. The treatment of THP-1 cells expressing wild-type p21Ras with PD98059 resulted in significant attenuation of p21Waf1 expression. These results indicate that the redox sensitive p21Ras-ERK pathway plays a critical role in sensing and delivering the pro-apoptotic signaling mediated by SNOG.

  19. The nitric oxide-sensitive p21Ras-ERK pathway mediates S-nitrosoglutathione-induced apoptosis

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

    Tsujita, Maristela; Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo, SP; Batista, Wagner L.

    2008-05-16

    p21Ras protein plays a critical role in cellular signaling that induces either cell cycle progression or apoptosis. Nitric oxide (NO) has been consistently reported to activate p21Ras through the redox sensitive cysteine residue (118). In this study, we demonstrated that the p21Ras-ERK pathway regulates THP-1 monocyte/macrophage apoptosis induced by S-nitrosoglutathione (SNOG). This was apparent from studies in THP-1 cells expressing NO-insensitive p21Ras (p21Ras{sup C118S}) where the pro-apoptotic action of SNOG was almost abrogated. Three major MAP kinase pathways (ERK, JNK, and p38) that are downstream to p21Ras were investigated. It was observed that only the activation of ERK1/2 MAP kinasesmore » by SNOG in THP-1 cells was attributable to p21Ras. The inhibition of the ERK pathway by PD98059 markedly attenuated apoptosis in SNOG-treated THP-1 cells, but had a marginal effect on SNOG-treated THP-1 cells expressing NO-insensitive p21Ras. The inhibition of the JNK and p38 pathways by selective inhibitors had no marked effects on the percentage of apoptosis. The induction of p21Waf1 expression by SNOG was observed in THP-1 cells harboring mutant and wild-type p21Ras, however in cells expressing mutant Ras, the expression of p21Waf1 was significantly attenuated. The treatment of THP-1 cells expressing wild-type p21Ras with PD98059 resulted in significant attenuation of p21Waf1 expression. These results indicate that the redox sensitive p21Ras-ERK pathway plays a critical role in sensing and delivering the pro-apoptotic signaling mediated by SNOG.« less

  20. The Function of the Glutamate-Nitric Oxide-cGMP Pathway in Brain in Vivo and Learning Ability Decrease in Parallel in Mature Compared with Young Rats

    ERIC Educational Resources Information Center

    Piedrafita, Blanca; Cauli, Omar; Montoliu, Carmina; Felipo, Vicente

    2007-01-01

    Aging is associated with cognitive impairment, but the underlying mechanisms remain unclear. We have recently reported that the ability of rats to learn a Y-maze conditional discrimination task depends on the function of the glutamate-nitric oxide-cGMP pathway in brain. The aims of the present work were to assess whether the ability of rats to…

  1. Calcium and Superoxide-Mediated Pathways Converge to Induce Nitric Oxide-Dependent Apoptosis in Mycobacterium fortuitum-Infected Fish Macrophages.

    PubMed

    Datta, Debika; Khatri, Preeti; Banerjee, Chaitali; Singh, Ambika; Meena, Ramavatar; Saha, Dhira Rani; Raman, Rajagopal; Rajamani, Paulraj; Mitra, Abhijit; Mazumder, Shibnath

    2016-01-01

    Mycobacterium fortuitum causes 'mycobacteriosis' in wide range of hosts although the mechanisms remain largely unknown. Here we demonstrate the role of calcium (Ca+2)-signalling cascade on M. fortuitum-induced apoptosis in headkidney macrophages (HKM) of Clarias sp. M. fortuitum could trigger intracellular-Ca+2 influx leading to the activation of calmodulin (CaM), protein kinase C alpha (PKCα) and Calmodulin kinase II gamma (CaMKIIg). Gene silencing and inhibitor studies established the role of CaM in M. fortuitum pathogenesis. We noted that CaMKIIg activation is regulated by CaM as well as PKCα-dependent superoxide anions. This is altogether first report of oxidised CaMKIIg in mycobacterial infections. Our studies with targeted-siRNA and pharmacological inhibitors implicate CaMKIIg to be pro-apoptotic and critical for the activation of extra-cellular signal regulated kinase 1/2 (ERK1/2). Inhibiting the ERK1/2 pathway attenuated nitric oxide synthase 2 (NOS2)-induced nitric oxide (NO) production. Conversely, inhibiting the NOS2-NO axis by specific-siRNA and inhibitors down-regulated ERK1/2 activation suggesting the crosstalk between ERK1/2 and NO is essential for pathogenesis induced by the bacterium. Silencing the NOS2-NO axis enhanced intracellular bacterial survival and attenuated caspase-8 mediated activation of caspase-3 in the infected HKM. Our findings unveil hitherto unknown mechanism of M. fortuitum pathogenesis. We propose that M. fortuitum triggers intracellular Ca+2 elevations resulting in CaM activation and PKCα-mediated superoxide generation. The cascade converges in common pathway mediated by CaMKIIg resulting in the activation of ERK1/2-NOS2 axis. The crosstalk between ERK1/2 and NO shifts the balance in favour of caspase dependent apoptosis of M. fortuitum-infected HKM.

  2. 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.

  3. 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.

  4. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

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

    Grimes, Travis Shane; Mincher, Bruce Jay; Schmitt, Nicholas C

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show thatmore » the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.« less

  5. Recent developments in the effects of nitric oxide-donating statins on cardiovascular disease through regulation of tetrahydrobiopterin and nitric oxide.

    PubMed

    Ma, Sze; Ma, Christopher Cheng-Hwa

    2014-11-01

    Since the discovery of the importance of nitric oxide (NO) to the human body three decades ago, numerous laboratory and clinical studies have been done to explore its potential therapeutic actions on many organs. In the cardiovascular system, NO works as a volatile signaling molecule regulating the vascular permeability and vascular tone, preventing thrombosis and inflammation, as well as inhibiting the smooth muscle hyperplasia. Thus, NO is important in the prevention and treatment of cardiovascular disease. NO is synthesized by NO synthase (NOS) with tetrahydrobiopterin (BH4) as the crucial cofactor. Many studies have been done to form nitric oxide donors so as to deliver NO directly to the vessel walls. In addition, NO moieties have been incorporated into existing therapeutic agents to enhance the NO bioavailability, including statins. Statins are inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme (HMG-CoA), the rate-limiting enzyme of the mevalonate pathway. By inhibiting this pathway, statins lower blood cholesterol and exert their pleiotropic effects through activity in reaction cascades, such as Rho/ROCK and Rac 1/NADPH oxidase pathways. Statins have also been observed to implement their non-lipid effects by promoting BH4 synthesis with increase of NO bioavailability. Furthermore, NO-donating statins in laboratory studies have demonstrated to produce better therapeutic effects than their parent's drugs. They offer better anti-inflammatory, anti-proliferative and antithrombotic actions on cardiovascular system. They also cause better revascularization in peripheral ischemia and produce greater enhancement in limb reperfusion and salvage. In addition, it has been shown that NO-donating statin caused less myotoxicity, the most common side effect related to treatment with statins. The initial studies have demonstrated the superior therapeutic effects of NO-donating statins while producing fewer side effects. Crown Copyright © 2014. Published by Elsevier Inc. All

  6. 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.

  7. Nitric oxide signaling pathways involved in the inhibition of spontaneous activity in the guinea pig prostate.

    PubMed

    Dey, Anupa; Lang, Richard J; Exintaris, Betty

    2012-06-01

    We investigated nitric oxide mediated inhibition of spontaneous activity recorded in young and aging guinea pig prostates. Conventional intracellular microelectrode and tension recording techniques were used. The nitric oxide donor sodium nitroprusside (10 μM) abolished spontaneous contractions and slow wave activity in 5 young and 5 aging prostates. Upon adding the nitric oxide synthase inhibitor L-NAME (10 μM) the frequency of spontaneous contractile and electrical activity was significantly increased in each age group. This increase was significantly larger in 4 to 8 preparations of younger vs aging prostates (about 40% to 50% vs about 10% to 20%, 2-way ANOVA p<0.01). Other measured parameters, including the duration, amplitude and membrane potential of spontaneous electrical and contractile activity, were not altered from control values. The guanylate cyclase inhibitor ODQ (10 μM) significantly increased the frequency of spontaneous activity by 10% to 30% in 6 young guinea pig prostates (Student paired t test p<0.05). However, it had no effect on aging prostates. The cGMP analogue 8-Br-GMP (1 μM) and the PDE5 inhibitor dipyridamole (1 μM) significantly decreased the frequency of contractile activity by about 70% in 4 to 9 young and older prostates (Student paired t test p<0.05). The decrease in the response to L-NAME in spontaneous contractile and slow wave activity in aging prostate tissue compared to that in young prostates suggests that with age there is a decrease in nitric oxide production. This may further explain the increase in prostatic smooth muscle tone observed in age related prostate specific conditions, such as benign prostatic hyperplasia. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  8. Treatment of sunitinib-induced hypertension in solid tumor by nitric oxide donors☆

    PubMed Central

    León-Mateos, L.; Mosquera, J.; Antón Aparicio, L.

    2015-01-01

    Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) are overexpressed in the majority of renal cell carcinomas. This characteristic has supported the rationale of targeting VEGF-driven tumour vascularization, especially in clear cell RCC. VEGF-inhibiting strategies include the use of tyrosine kinase inhibitors (sunitinib, axitinib, pazopanib, and sorafenib) and neutralizing antibodies such as bevacizumab. Hypertension (HTN) is one of the most common adverse effects of angiogenesis inhibitors. HTN observed in clinical trials appears to correlate with the potency of VEGF kinase inhibitor against VEGFR-2: agents with higher potency are associated with a higher incidence of HTN. Although the exact mechanism by tyrosine kinase inhibitors induce HTN has not yet been completely clarified, two key hypotheses have been postulated. First, some studies have pointed to a VEGF inhibitors-induced decrease in nitric oxide synthase (NOS) and nitric oxide (NO) production, that can result in vasoconstriction and increased blood pressure. VEGF, mediated by PI3K/Akt and MAPK pathway, upregulates the endothelial nitric oxide synthase enzyme leading to up-regulation of NO production. So inhibition of signaling through the VEGF pathway would lead to a decrease in NO production, resulting in an increase in vascular resistance and blood pressure. Secondly a decrease in the number of microvascular endothelial cells and subsequent depletion of normal microvessel density (rarefaction) occurs upon VEGF signaling inhibition. NO donors could be successfully used not only for the treatment of developed angiogenesis-inhibitor-induced hypertension but also for preventive effects. PMID:26386874

  9. Genomic variants in the ASS1 gene, involved in the nitric oxide biosynthesis and signaling pathway, predict hydroxyurea treatment efficacy in compound sickle cell disease/β-thalassemia patients.

    PubMed

    Chalikiopoulou, Constantina; Tavianatou, Anastasia-Gerasimoula; Sgourou, Argyro; Kourakli, Alexandra; Kelepouri, Dimitra; Chrysanthakopoulou, Maria; Kanelaki, Vasiliki-Kaliopi; Mourdoukoutas, Evangelos; Siamoglou, Stavroula; John, Anne; Symeonidis, Argyris; Ali, Bassam R; Katsila, Theodora; Papachatzopoulou, Adamantia; Patrinos, George P

    2016-03-01

    Hemoglobinopathies exhibit a remarkable phenotypic diversity that restricts any safe association between molecular pathology and clinical outcomes. Herein, we explored the role of genes involved in the nitric oxide biosynthesis and signaling pathway, implicated in the increase of fetal hemoglobin levels and response to hydroxyurea treatment, in 119 Hellenic patients with β-type hemoglobinopathies. We show that two ASS1 genomic variants (namely, rs10901080 and rs10793902) can serve as pharmacogenomic biomarkers to predict hydroxyurea treatment efficacy in sickle cell disease/β-thalassemia compound heterozygous patients. These markers may exert their effect by inducing nitric oxide biosynthesis, either via altering splicing and/or miRNA binding, as predicted by in silico analysis, and ultimately, increase γ-globin levels, via guanylyl cyclase targeting.

  10. 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

  11. 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.

  12. Tetrahydrobiopterin improves hippocampal nitric oxide-linked long-term memory.

    PubMed

    Latini, Alexandra; de Bortoli da Silva, Lucila; da Luz Scheffer, Débora; Pires, Ananda Christina Staats; de Matos, Filipe José; Nesi, Renata T; Ghisoni, Karina; de Paula Martins, Roberta; de Oliveira, Paulo Alexandre; Prediger, Rui D; Ghersi, Marisa; Gabach, Laura; Pérez, Mariela Fernanda; Rubiales-Barioglio, Susana; Raisman-Vozari, Rita; Mongeau, Raymond; Lanfumey, Laurence; Aguiar, Aderbal Silva

    2018-06-11

    Tetrahydrobiopterin (BH4) is synthesized by the combined action of three metabolic pathways, namely de novo synthesis, recycling, and salvage pathways. The best-known function of BH4 is its mandatory action as a natural cofactor of the aromatic amino acid hydroxylases and nitric oxide synthases. Thus, BH4 is essential for the synthesis of nitric oxide, a retrograde neurotransmitter involved in learning and memory. We investigated the effect of BH4 (4-4000 pmol) intracerebroventricular administration on aversive memory, and on BH4 metabolism in the hippocampus of rodents. Memory-related behaviors were assessed in Swiss and C57BL/6 J mice, and in Wistar rats. It was consistently observed across all rodent species that BH4 facilitates aversive memory acquisition and consolidation by increasing the latency to step-down in the inhibitory avoidance task. This effect was associated with a reduced threshold to generate hippocampal long-term potentiation process. In addition, two inhibitors of memory formation (N(ω)-nitro-L-arginine methyl ester - L-Name - and dizocilpine - MK-801 -) blocked the enhanced effect of BH4 on memory, while the amnesic effect was not rescue by the co-administration of BH4 or a cGMP analog (8-Br-cGMP). The data strongly suggest that BH4 enhances aversive memory by activating the glutamatergic neurotransmission and the retrograde activity of NO. It was also demonstrated that BH2 can be converted into BH4 by activating the BH4 salvage pathway under physiological conditions in the hippocampus. This is the first evidence showing that BH4 enhances aversive memory and that the BH4 salvage pathway is active in the hippocampus. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. 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.

  14. 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

  15. 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...

  16. 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...

  17. The role of NMDA receptor and nitric oxide/cyclic guanosine monophosphate pathway in the antidepressant-like effect of dextromethorphan in mice forced swimming test and tail suspension test.

    PubMed

    Sakhaee, Ehsan; Ostadhadi, Sattar; Khan, Muhammad Imran; Yousefi, Farbod; Norouzi-Javidan, Abbas; Akbarian, Reyhaneh; Chamanara, Mohsen; Zolfaghari, Samira; Dehpour, Ahmad-Reza

    2017-01-01

    Depression is a devastating disorder which has a high impact on the wellbeing of overall society. As such, need for innovative therapeutic agents are always there. Most of the researchers focused on N-methyl-d-aspartate receptor to explore the antidepressant like activity of new therapeutic agents. Dextromethorphan is a cough suppressant agent with potential antidepressant activity reported in mouse force swimming test. Considering N-methyl-d-aspartate as a forefront in exploring antidepressant agents, here we focused to unpin the antidepressant mechanism of dextromethorphan targeting N-methyl-d-aspartate receptor induced nitric oxide-cyclic guanosine monophosphate signaling. Dextromethorphan administered at a dose of 10 and 30mg/kg i.p significantly reduced the immobility time. Interestingly, this effect of drug (30mg/kg) was inhibited when the animals were pretreated either with N-methyl-d-aspartate (75mg/kg), or l-arginine (750mg/kg) as a nitric oxide precursor and/or sildenafil (5mg/kg) as a phosphodiesterase 5 inhibitor. However, the antidepressant effect of Dextromethorphan subeffective dose (3mg/kg) was augmented when the animals were administered with either L-NG-Nitroarginine methyl ester (10mg/kg) non-specific nitric oxide synthase inhibitor, 7-Nitroindazole (30mg/kg) specific neural nitric oxide synthase inhibitor, MK-801 (0.05mg/kg) an N-methyl-d-aspartate receptor antagonist but not aminoguanidine (50mg/kg) which is specific inducible nitric oxide synthase inhibitor as compared to the drugs when administered alone. No remarkable effect on locomotor activity was observed during open field test when the drugs were administered at the above mentioned doses. Therefore, it is evident that the antidepressant like effect of Dextromethorphan is owed due to its inhibitory effect on N-methyl-d-aspartate receptor and NO- Cyclic guanosine monophosphate pathway. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Multifaceted role of nitric oxide in an in vitro mouse neuronal injury model: transcriptomic profiling defines the temporal recruitment of death signalling cascades

    PubMed Central

    Peng, Zhao Feng; Chen, Minghui Jessica; Manikandan, Jayapal; Melendez, Alirio J; Shui, Guanghou; Russo-Marie, Françoise; Whiteman, Matthew; Beart, Philip M; Moore, Philip K; Cheung, Nam Sang

    2012-01-01

    Abstract Nitric oxide is implicated in the pathogenesis of various neuropathologies characterized by oxidative stress. Although nitric oxide has been reported to be involved in the exacerbation of oxidative stress observed in several neuropathologies, existent data fail to provide a holistic description of how nitrergic pathobiology elicits neuronal injury. Here we provide a comprehensive description of mechanisms contributing to nitric oxide induced neuronal injury by global transcriptomic profiling. Microarray analyses were undertaken on RNA from murine primary cortical neurons treated with the nitric oxide generator DETA-NONOate (NOC-18, 0.5 mM) for 8–24 hrs. Biological pathway analysis focused upon 3672 gene probes which demonstrated at least a ±1.5-fold expression in a minimum of one out of three time-points and passed statistical analysis (one-way anova, P < 0.05). Numerous enriched processes potentially determining nitric oxide mediated neuronal injury were identified from the transcriptomic profile: cell death, developmental growth and survival, cell cycle, calcium ion homeostasis, endoplasmic reticulum stress, oxidative stress, mitochondrial homeostasis, ubiquitin-mediated proteolysis, and GSH and nitric oxide metabolism. Our detailed time-course study of nitric oxide induced neuronal injury allowed us to provide the first time a holistic description of the temporal sequence of cellular events contributing to nitrergic injury. These data form a foundation for the development of screening platforms and define targets for intervention in nitric oxide neuropathologies where nitric oxide mediated injury is causative. PMID:21352476

  19. Critical Role of Nitric Oxide-cGMP Cascade in the Formation of cAMP-Dependent Long-Term Memory

    ERIC Educational Resources Information Center

    Aonuma, Hitoshi; Mizunami, Makoto; Matsumoto, Yukihisa; Unoki, Sae

    2006-01-01

    Cyclic AMP pathway plays an essential role in formation of long-term memory (LTM). In some species, the nitric oxide (NO)-cyclic GMP pathway has been found to act in parallel and complementary to the cAMP pathway for LTM formation. Here we describe a new role of the NO-cGMP pathway, namely, stimulation of the cAMP pathway to induce LTM. We have…

  20. 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.

  1. Antidepressant-like effect of atorvastatin in the forced swimming test in mice: the role of PPAR-gamma receptor and nitric oxide pathway.

    PubMed

    Shahsavarian, Arash; Javadi, Shiva; Jahanabadi, Samane; Khoshnoodi, Mina; Shamsaee, Javad; Shafaroodi, Hamed; Mehr, Shahram Ejtemaei; Dehpour, Ahmadreza

    2014-12-15

    Atorvastatin is a synthetic and lipophilic statin which has been reported to have a positive role in reducing depression. The potential antidepressant-like effects of atorvastatin and the possible involvement of peroxisome proliferator-activated receptor gamma (PPAR_γ) and nitric oxide system were determined using forced swimming test (FST) in mice was studied. Atorvastatin (0.01, 0.1 and 1 mg/kg, p.o.) was administered 1 h before FST. To assess the involvement of PPAR_γ in the possible antidepressant effect of atorvastatin, pioglitazone, a PPAR_γ agonist (5 mg/kg), and GW-9662, a specific PPAR_γ antagonist (2 mg/kg), was co-administered with atorvastatin (0.01 mg/kg, p.o.) and then FST was performed. The possible role of nitric oxide pathway was determined by using co-administration of a non-specific NOS inhibitor, N-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg, i.p.), and a NO precursor, L-arginine (750 mg/kg, i.p.) with sub-effective doses of atorvastatin and pioglitazone. Immobility time was significantly decreased after atorvastatin administration (0.1 and 1 mg/kg, p.o.). Administration of pioglitazone or L-NAME in combination with the sub-effective dose of atorvastatin (0.01 mg/kg, p.o.) reduced the immobility time in the FST compared to drugs alone, showing the participation of these pathways; while co-administration of non-effective doses of atorvastatin and pioglitazone with GW9662 or L-arginine reversed antidepressant-like effect of atorvastatin in FST. Data from concurrent use of GW9662 and atorvastatin also demonstrated that the antidepressant effect of atorvastatin was significantly reversed by GW9662. The antidepressant-like effect of atorvastatin on mice in the FST is mediated at least in part through PPAR_γ receptors and NO pathway. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Novel Small Molecule Therapeutics for Sickle Cell Disease: Nitric Oxide, Carbon Monoxide, Nitrite, and Apolipoprotein A-I

    PubMed Central

    Kato, Gregory J.

    2009-01-01

    A hemolysis-linked subphenotype of sickle cell disease (SCD), characterized by pulmonary hypertension, stroke, priapism and leg ulcers, is associated with decreased nitric oxide bioavailability and vasculopathy. Vasculopathy appears to have a multifactorial etiology, including mechanisms primarily that involve deficient nitric oxide (NO) signaling, but also involving altered function of NO synthase related to substrate availability and cooperating factors such as apolipoproteins. Improved understanding of the vascular pathophysiology of SCD has led to new vascular targets for translational research in SCD. This growing vascular therapeutics field in SCD is complementary to the ongoing efforts to reduce the morbidity of vaso-occlusive pain crisis. This presentation will review the current biology and translational clinical development of novel small molecules targeting sickle cell vasculopathy. Strategies targeting the heme-oxygenase-carbon monoxide pathway, the arginine-NO synthase-cGMP-phosphodiesterase 5 pathway, the nitrate-nitrite-NO pathway, and the apolipoprotein A-I pathways will be reviewed. In this context, current clinical trials of inhaled NO, CO, nitrite, sildenafil and apoA-I mimetics will be discussed. PMID:19074079

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. Activation of neuronal nitric oxide synthase in cerebellum of chronic hepatic encephalopathy rats is associated with up-regulation of NADPH-producing pathway.

    PubMed

    Singh, Santosh; Trigun, Surendra K

    2010-09-01

    Cerebellum-associated functions get affected during mild hepatic encephalopathy (MHE) in patients with chronic liver failure (CLF). Involvement of nitrosative and antioxidant factors in the pathogenesis of chronic hepatic encephalopathy is an evolving concept and needs to be defined in a true CLF animal model. This article describes profiles of NADPH-dependent neuronal nitric oxide synthase (nNOS) and those of glutathione peroxidase and glutathione reductase (GR) vis-a-vis regulation of NADPH-producing pathway in the cerebellum of CLF rats induced by administration of thioacetamide (100 mg kg⁻¹ b.w., i.p.) up to 10 days and confirming MHE on Morris water maze tests. Significant increases in the expression of nNOS protein and nitric oxide (NOx) level coincided with a similar increment in NADPH-diaphorase activity in the cerebellum of CLF rats. Glutathione peroxidase and GR utilize NADPH to regenerate reduced glutathione (GSH) in the cells. Both these enzymes and GSH level were found to be static and thus suggested efficient turnover of GSH in the cerebellum of MHE rats. Relative levels of glucose-6-phosphate dehydrogenase (G6PD) vs. phosphofructokinase 2 (PFK2) determine the rate of pentose phosphate pathway (PPP) responsible to synthesize NADPH. The cerebellum of CLF rats showed overactivation of G6PD with a significant decline in the expression of PFK2 and thus suggested activation of PPP in the cerebellum during MHE. It is concluded that concordant activations of PPP and nNOS in cerebellum of MHE rats could be associated with the implication of NOx in the pathogenesis of MHE.

  8. Activation of cGMP/Protein Kinase G Pathway in Postconditioned Myocardium Depends on Reduced Oxidative Stress and Preserved Endothelial Nitric Oxide Synthase Coupling

    PubMed Central

    Inserte, Javier; Hernando, Victor; Vilardosa, Úrsula; Abad, Elena; Poncelas‐Nozal, Marcos; Garcia‐Dorado, David

    2013-01-01

    Background The cGMP/protein kinase G (PKG) pathway is involved in the cardioprotective effects of postconditioning (PoCo). Although PKG signaling in PoCo has been proposed to depend on the activation of the phosphatidylinositol 3‐kinase (PI3K)/Akt cascade, recent data bring into question a causal role of reperfusion injury signaling kinase (RISK) in PoCo protection. We hypothesized that PoCo increases PKG activity by reducing oxidative stress–induced endothelial nitric oxide synthase (NOS) uncoupling at the onset of reperfusion. Methods and Results Isolated rat hearts were submitted to 40 minutes of ischemia and reperfusion with and without a PoCo protocol. PoCo reduced infarct size by 48% and cGMP depletion. Blockade of cGMP synthesis (1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one) and inhibition of PKG (KT5823) or NOS (l‐NAME) abolished protection, but inhibition of PI3K/Akt cascade (LY294002) did not (n=5 to 7 per group). Phosphorylation of the RISK pathway was higher in PoCo hearts. However, this difference is due to increased cell death in control hearts because in hearts reperfused with the contractile inhibitor blebbistatin, a drug effective in preventing cell death at the onset of reperfusion, RISK phosphorylation increased during reperfusion without differences between control and PoCo groups. In these hearts, PoCo reduced the production of superoxide (O2−) and protein nitrotyrosylation and increased nitrate/nitrite levels in parallel with a significant decrease in the oxidation of tetrahydrobiopterin (BH4) and in the monomeric form of endothelial NOS. Conclusions These results demonstrate that PoCo activates the cGMP/PKG pathway via a mechanism independent of the PI3K/Akt cascade and dependent on the reduction of O2− production at the onset of reperfusion, resulting in attenuated oxidation of BH4 and reduced NOS uncoupling. PMID:23525447

  9. NITRIC OXIDE, MITOCHONDRIAL HYPERPOLARIZATION AND T-CELL ACTIVATION

    PubMed Central

    Nagy, Gyorgy; Koncz, Agnes; Fernandez, David; Perl, Andras

    2007-01-01

    T lymphocyte activation is associated with nitric oxide (NO) production that plays an essential role in multiple T cell functions. NO acts as a messenger, activating soluble guanyl cyclase and participating in the transduction signaling pathways involving cyclic GMP. NO modulates mitochondrial events that are involved in apoptosis and regulates mitochondrial membrane potential and mitochondrial biogenesis in many cell types, including lymphocytes. Mitochondrial hyperpolarization (MHP), an early and reversible event during both T lymphocyte activation and apoptosis, is regulated by NO. Here, we discuss recent evidence that NO-induced MHP represents a molecular switch in multiple T cell signaling pathways. Overproduction of NO in systemic lupus erythematosus (SLE) induces mitochondrial biogenesis and alters Ca2+ signaling. Thus, while NO plays a physiological role in lymphocyte cell signaling, its overproduction may disturb normal T cell function, contributing to the pathogenesis of autoimmunity. PMID:17462531

  10. Nitric oxide and mitochondria in metabolic syndrome

    PubMed Central

    Litvinova, Larisa; Atochin, Dmitriy N.; Fattakhov, Nikolai; Vasilenko, Mariia; Zatolokin, Pavel; Kirienkova, Elena

    2015-01-01

    Metabolic syndrome (MS) is a cluster of metabolic disorders that collectively increase the risk of cardiovascular disease. Nitric oxide (NO) plays a crucial role in the pathogeneses of MS components and is involved in different mitochondrial signaling pathways that control respiration and apoptosis. The present review summarizes the recent information regarding the interrelations of mitochondria and NO in MS. Changes in the activities of different NO synthase isoforms lead to the formation of metabolic disorders and therefore are highlighted here. Reduced endothelial NOS activity and NO bioavailability, as the main factors underlying the endothelial dysfunction that occurs in MS, are discussed in this review in relation to mitochondrial dysfunction. We also focus on potential therapeutic strategies involving NO signaling pathways that can be used to treat patients with metabolic disorders associated with mitochondrial dysfunction. The article may help researchers develop new approaches for the diagnosis, prevention and treatment of MS. PMID:25741283

  11. 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

  12. 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.

  13. Nitric Oxide and Anxiety.

    PubMed

    Gulati, K; Rai, N; Ray, A

    2017-01-01

    Anxiety is a common neuropsychiatric disorder which affects both physical and mental health. Complex neurobiological mechanisms are involved in the genesis of anxiety, and the drugs used to date, though effective, are not free from shortcomings. Conventional agents like the classical benzodiazepines and the atypical nonbenzodiazepine agents like buspirone have their own limitations. There is thus need to explore newer neurochemical pathways to develop efficacious and safer drugs for the disorder. Nitric oxide (NO) is a unique neuromodulator substance, with the ability to influence and modulate several other conventional messengers which play an important role in anxiety. The currently available experimental and clinical data indicate that NO may be involved in the regulation of anxiety-like behavior induced by a variety of stimuli. These studies have explored the pharmacological and biochemical basis of nitrergic mechanisms in anxiety, and the data available are equivocal. This chapter reviews the research data available in this specific area and suggests that in view of the nature of the existing data, there is considerable scope for future research in this field. © 2017 Elsevier Inc. All rights reserved.

  14. Role of the decreased nitric oxide bioavailability in the vascular complications of diabetes mellitus.

    PubMed

    Masha, Andi; Dinatale, Stefano; Allasia, Stefano; Martina, Valentino

    2011-09-01

    This mini-review takes into consideration the physiology, synthesis and mechanisms of action of the nitric oxide (NO) and, subsequently, the causes and effects of the NO bioavailability impairment. In diabetes mellitus the reduced NO bioavailability is caused by the increased free radicals production, secondary to hyperglycemia. The reactive oxygen species oxidize the cofactors of the nitric oxide synthase, diminishing their active forms and consequently leading to a decreased NO production. Furthermore the decreased concentration of reduced glutathione results in a diminished production of nitrosoglutathione. These molecules are important intermediates of the NO pathway and physiologically activate the soluble guanylate cyclase. Their decrease in oxidative states of the cell, therefore, leads to a reduced cGMP production which represents the principal molecule that carries out NO's major effects. Finally we considered the eventual therapeutic strategies to improve NO bioavailability by acting on the causes of its decrease. Therefore the treatments proposed are based on the possibility to counteract the oxidation and, in this context, the physiopathological mechanisms strongly support the treatment with thiols.

  15. 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.

  16. 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.

  17. Cholecystokinin-8-induced hypoplasia of the rat pancreas: influence of nitric oxide on cell proliferation and programmed cell death.

    PubMed

    Trulsson, Lena M; Gasslander, Thomas; Svanvik, Joar

    2004-10-01

    The background of cholecystokinin-8 (CCK-8)-induced hypoplasia in the pancreas is not known. In order to increase our understanding we studied the roles of nitric oxide and NF-kappaB in rats. CCK-8 was injected for 4 days, in a mode known to cause hypoplasia, and the nitric oxide formation was either decreased by means of N(omega)-nitro-L-arginine (L-NNA) or increased by S-nitroso-N-acetylpencillamine (SNAP). The activation of NF-kappaB was quantified by ELISA detection, apoptosis with caspase-3 and histone-associated DNA-fragmentation and mitotic activity in the acinar, centroacinar and ductal cells were visualized by the incorporation of [(3)H]-thymidine. Pancreatic histology and weight as well as protein- and DNA contents were also studied. Intermittent CCK injections reduced pancreatic weight, protein and DNA contents and increased apoptosis, acinar cell proliferation and nuclear factor kappaB (NF-kappaB) activation. It also caused vacuolisation of acinar cells. The inhibition of endogenous nitric oxide formation by L-NNA further increased apoptosis and NF-kappaB activation but blocked the increased proliferation and vacuolisation of acinar cells. The DNA content was not further reduced. SNAP given together with CCK-8 increased apoptosis and other pathways of cell death, raised proliferation of acinar cells and strongly reduced the DNA content in the pancreas. Histological examination showed no inflammation in any group. We conclude that during CCK-8-induced pancreatic hypoplasia, endogenously formed nitric oxide suppresses apoptosis but increases cell death along non-apoptotic pathways and stimulates regeneration of acinar cells. Exogenous nitric oxide enhances the acinar cell turnover by increasing both apoptotic and non-apoptotic cell death and cell renewal. In this situation NF-kappaB activation seems not to inhibit apoptosis nor promote cell proliferation.

  18. 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.

  19. Estimation of the nitric oxide formed from hydroxylamine by Nitrosomonas

    PubMed Central

    Anderson, J. H.

    1965-01-01

    1. Nitric oxide that was produced by reducing nitrite with an excess of acidified potassium iodide under nitrogen in Warburg respirometer flasks was rapidly absorbed by a solution of permanganate in sodium hydroxide held in the side arm. A small amount of nitrous oxide (or nitrogen) that was also produced was not absorbed. 2. By using a quantitative method for the recovery of nitrite from samples of the alkaline permanganate, it was found that the sum of the nitrite N formed and the residual nitrous oxide N was equivalent to the nitrite N used to generate the gases. These results showed that alkaline permanganate completely oxidized nitric oxide to nitrite. The method was suitable for determining 0·4–20 μmoles of nitric oxide. 3. The technique was used to determine the nitric oxide content of the nitrogenous gas that was produced anaerobically from hydroxylamine by an extract of the autotrophic nitrifying micro-organism Nitrosomonas in the presence of methylene blue as electron acceptor. PMID:14342235

  20. 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.

  1. Propofol restores TRPV1 sensitivity via a TRPA1-, nitric oxide synthase-dependent activation of PKCε

    PubMed Central

    Sinharoy, Pritam; Zhang, Hongyu; Sinha, Sayantani; Prudner, Bethany C; Bratz, Ian N; Damron, Derek S

    2015-01-01

    We previously demonstrated that the intravenous anesthetic, propofol, restores the sensitivity of transient receptor potential vanilloid channel subtype-1 (TRPV1) receptors via a protein kinase C epsilon (PKCε)-dependent and transient receptor potential ankyrin channel subtype-1 (TRPA1)-dependent pathway in sensory neurons. The extent to which the two pathways are directly linked or operating in parallel has not been determined. Using a molecular approach, our objectives of the current study were to confirm that TRPA1 activation directly results in PKCε activation and to elucidate the cellular mechanism by which this occurs. F-11 cells were transfected with complimentary DNA (cDNA) for TRPV1 only or both TRPV1 and TRPA1. Intracellular Ca2+ concentration was measured in individual cells via fluorescence microscopy. An immunoblot analysis of the total and phosphorylated forms of PKCε, nitric oxide synthase (nNOS), and TRPV1 was also performed. In F-11 cells containing both channels, PKCε inhibition prevented the propofol- and allyl isothiocyanate (AITC)-induced restoration of TRPV1 sensitivity to agonist stimulation as well as increased phosphorylation of PKCε and TRPV1. In cells containing TRPV1 only, neither agonist induced PKCε or TRPV1 phosphorylation. Moreover, NOS inhibition blocked propofol-and AITC-induced restoration of TRPV1 sensitivity and PKCε phosphorylation, and PKCε inhibition prevented the nitric oxide donor, SNAP, from restoring TRPV1 sensitivity. Also, propofol-and AITC-induced phosphorylation of nNOS and nitric oxide (NO) production were blocked with the TRPA1-antagonist, HC-030031. These data indicate that the AITC- and propofol-induced restoration of TRPV1 sensitivity is mediated by a TRPA1-dependent, nitric oxide synthase-dependent activation of PKCε. PMID:26171233

  2. Effects of exercise training on stress-induced vascular reactivity alterations: role of nitric oxide and prostanoids

    PubMed Central

    Bruder-Nascimento, Thiago; Silva, Samuel T.; Boer, Patrícia A.; Cordellini, Sandra

    2015-01-01

    Background: Physical exercise may modify biologic stress responses. Objective: To investigate the impact of exercise training on vascular alterations induced by acute stress, focusing on nitric oxide and cyclooxygenase pathways. Method: Wistar rats were separated into: sedentary, trained (60-min swimming, 5 days/week during 8 weeks, carrying a 5% body-weight load), stressed (2 h-immobilization), and trained/stressed. Response curves for noradrenaline, in the absence and presence of L-NAME or indomethacin, were obtained in intact and denuded aortas (n=7-10). Results: None of the procedures altered the denuded aorta reactivity. Intact aortas from stressed, trained, and trained/stressed rats showed similar reduction in noradrenaline maximal responses (sedentary 3.54±0.15, stressed 2.80±0.10*, trained 2.82±0.11*, trained/stressed 2.97± 0.21*, *P<0.05 relate to sedentary). Endothelium removal and L-NAME abolished this hyporeactivity in all experimental groups, except in trained/stressed rats that showed a partial aorta reactivity recovery in L-NAME presence (L-NAME: sedentary 5.23±0,26#, stressed 5.55±0.38#, trained 5.28±0.30#, trained/stressed 4.42±0.41, #P<0.05 related to trained/stressed). Indomethacin determined a decrease in sensitivity (EC50) in intact aortas of trained rats without abolishing the aortal hyporeactivity in trained, stressed, and trained/stressed rats. Conclusions: Exercise-induced vascular adaptive response involved an increase in endothelial vasodilator prostaglandins and nitric oxide. Stress-induced vascular adaptive response involved an increase in endothelial nitric oxide. Beside the involvement of the endothelial nitric oxide pathway, the vascular response of trained/stressed rats involved an additional mechanism yet to be elucidated. These findings advance on the understanding of the vascular processes after exercise and stress alone and in combination. PMID:26083604

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. Detoxification of nitric oxide by flavohemoglobin and the denitrification pathway in the maize pathogen Fusarium verticillioides

    USDA-ARS?s Scientific Manuscript database

    The ephemeral nitric oxide (NO) is a free radical, highly reactive, environmentally rare, and a potent signaling molecule in organisms across kingdoms of life. This gaseous small molecule can freely transverse membranes and has been implicated in aspects of pathogenicity both in animal and plant ho...

  11. 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

  12. 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.

  13. Nitric oxide signaling: systems integration of oxygen balance in defense of cell integrity.

    PubMed

    Gong, Li; Pitari, Giovanni M; Schulz, Stephanie; Waldman, Scott A

    2004-01-01

    Nitric oxide has emerged as a ubiquitous signaling molecule subserving diverse pathophysiologic processes, including cardiovascular homeostasis and its decompensation in atherogenesis. Recent insights into molecular mechanisms regulating nitric oxide generation and the rich diversity of mechanisms by which it propagates signals reveal the role of this simple gas as a principle mediator of systems integration of oxygen balance. The molecular lexicon by which nitric oxide propagates signals encompasses the elements of posttranslational modification of proteins by redox-based nitrosylation of transition metal centers and free thiols. Spatial and temporal precision and specificity of signal initiation, amplification, and propagation are orchestrated by dynamic assembly of supramolecular complexes coupling nitric oxide production to upstream and downstream components in specific subcellular compartments. The concept of local paracrine signaling by nitric oxide over subcellular distances for short durations has expanded to include endocrine-like effects over anatomic spatial and temporal scales. From these insights emerges a role for nitric oxide in integrating system responses controlling oxygen supply and demand to defend cell integrity in the face of ischemic challenge. In this context, nitric oxide coordinates the respiratory cycle to acquire and deliver oxygen to target tissues by regulating hemoglobin function and vascular smooth muscle contractility and matches energy supply and demand by down-regulating energy-requiring functions while shifting metabolism to optimize energy production. Insights into mechanisms regulating nitric oxide production and signaling and their integration into responses mediating homeostasis place into specific relief the role of those processes in pathophysiology. Indeed, endothelial dysfunction associated with altered production of nitric oxide regulating tissue integrity contributes to the pathogenesis underlying atherogenesis

  14. Caveolin-1 down-regulates inducible nitric oxide synthase via the proteasome pathway in human colon carcinoma cells

    PubMed Central

    Felley-Bosco, Emanuela; Bender, Florent C.; Courjault-Gautier, Françoise; Bron, Claude; Quest, Andrew F. G.

    2000-01-01

    To investigate whether caveolin-1 (cav-1) may modulate inducible nitric oxide synthase (iNOS) function in intact cells, the human intestinal carcinoma cell lines HT29 and DLD1 that have low endogenous cav-1 levels were transfected with cav-1 cDNA. In nontransfected cells, iNOS mRNA and protein levels were increased by the addition of a mix of cytokines. Ectopic expression of cav-1 in both cell lines correlated with significantly decreased iNOS activity and protein levels. This effect was linked to a posttranscriptional mechanism involving enhanced iNOS protein degradation by the proteasome pathway, because (i) induction of iNOS mRNA by cytokines was not affected and (ii) iNOS protein levels increased in the presence of the proteasome inhibitors N-acetyl-Leu-Leu-Norleucinal and lactacystin. In addition, a small amount of iNOS was found to cofractionate with cav-1 in Triton X-100-insoluble membrane fractions where also iNOS degradation was apparent. As has been described for endothelial and neuronal NOS isoenzymes, direct binding between cav-1 and human iNOS was detected in vitro. Taken together, these results suggest that cav-1 promotes iNOS presence in detergent-insoluble membrane fractions and degradation there via the proteasome pathway. PMID:11114180

  15. 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

  16. 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

  17. 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

  18. 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...

  19. Controlled nitric oxide production via O(1D) + N2O reactions for use in oxidation flow reactor studies

    NASA Astrophysics Data System (ADS)

    Lambe, Andrew; Massoli, Paola; Zhang, Xuan; Canagaratna, Manjula; Nowak, John; Daube, Conner; Yan, Chao; Nie, Wei; Onasch, Timothy; Jayne, John; Kolb, Charles; Davidovits, Paul; Worsnop, Douglas; Brune, William

    2017-06-01

    Oxidation flow reactors that use low-pressure mercury lamps to produce hydroxyl (OH) radicals are an emerging technique for studying the oxidative aging of organic aerosols. Here, ozone (O3) is photolyzed at 254 nm to produce O(1D) radicals, which react with water vapor to produce OH. However, the need to use parts-per-million levels of O3 hinders the ability of oxidation flow reactors to simulate NOx-dependent secondary organic aerosol (SOA) formation pathways. Simple addition of nitric oxide (NO) results in fast conversion of NOx (NO + NO2) to nitric acid (HNO3), making it impossible to sustain NOx at levels that are sufficient to compete with hydroperoxy (HO2) radicals as a sink for organic peroxy (RO2) radicals. We developed a new method that is well suited to the characterization of NOx-dependent SOA formation pathways in oxidation flow reactors. NO and NO2 are produced via the reaction O(1D) + N2O → 2NO, followed by the reaction NO + O3 → NO2 + O2. Laboratory measurements coupled with photochemical model simulations suggest that O(1D) + N2O reactions can be used to systematically vary the relative branching ratio of RO2 + NO reactions relative to RO2 + HO2 and/or RO2 + RO2 reactions over a range of conditions relevant to atmospheric SOA formation. We demonstrate proof of concept using high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) measurements with nitrate (NO3-) reagent ion to detect gas-phase oxidation products of isoprene and α-pinene previously observed in NOx-influenced environments and in laboratory chamber experiments.

  20. Controlled Nitric Oxide Production via O(1D) + N2O Reactions for Use in Oxidation Flow Reactor Studies

    NASA Technical Reports Server (NTRS)

    Lambe, Andrew; Massoli, Paola; Zhang, Xuan; Canagaratna, Manjula; Nowak, John; Daube, Conner; Yan, Chao; Nie, Wei; Onasch, Timothy; Jayne, John; hide

    2017-01-01

    Oxidation flow reactors that use low-pressure mercury lamps to produce hydroxyl (OH) radicals are an emerging technique for studying the oxidative aging of organic aerosols. Here, ozone (O3) is photolyzed at 254 nm to produce O(1D) radicals, which react with water vapor to produce OH. However, the need to use parts-per-million levels of O3 hinders the ability of oxidation flow reactors to simulate NOx-dependent secondary organic aerosol (SOA) formation pathways. Simple addition of nitric oxide (NO) results in fast conversion of NOx (NO+NO2) to nitric acid (HNO3), making it impossible to sustain NOx at levels that are sufficient to compete with hydroperoxy (HO2) radicals as a sink for organic peroxy (RO2) radicals. We developed a new method that is well suited to the characterization of NOx-dependent SOA formation pathways in oxidation flow reactors. NO and NO2 are produced via the reaction O(1D)+N2O->2NO, followed by the reaction NO+O3->NO2+O2. Laboratory measurements coupled with photochemical model simulations suggest that O(1D)+N2O reactions can be used to systematically vary the relative branching ratio of RO2 +NO reactions relative to RO2 +HO2 and/or RO2+RO2 reactions over a range of conditions relevant to atmospheric SOA formation. We demonstrate proof of concept using high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) measurements with nitrate (NO-3 ) reagent ion to detect gas-phase oxidation products of isoprene and -pinene previously observed in NOx-influenced environments and in laboratory chamber experiments.

  1. 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.

  2. 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

  3. 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.

  4. Ultraviolet A irradiation of the eye activates a nitric oxide-dependent hypothalamo-pituitary pro-opiomelanocortin pathway and modulates the functions of Langerhans cells.

    PubMed

    Hiramoto, Keiichi

    2009-06-01

    Ultraviolet A (UV-A) radiation decreases Langerhans cells (LC) in the skin specifically at the site of exposure. Unexpectedly, UV-A irradiation of the eye has been found systemically downregulating epidermal LC in mice. Male C57BL/6j mice and an inducible type of nitric oxide synthase knockout mice (iNOS(-/-)) were used in this study. The eye or ear was locally exposed to UV-A after covering the remaining body surface with aluminum foil at a dose of 110 kJ/m(2) using a sunlamp. Localized UV-A irradiation of the eye downregulated epidermal LC. The hypophysectomy strongly inhibited the UV-A-induced downregulation of LC. To elucidate the pathway by UV-A irradiation of the eye, the effect of a bilateral ciliary ganglionectomy and denervation of the optic nerves was examined. Optic nerve denervation strongly inhibited LC downregulation in response to localized irradiation of the eye. Furthermore, no LC downregulation in response to localized UV-A irradiation of the eye was observed in iNOS(-/-) mice. These results clearly indicate that a signal evoked by UV-A irradiation of the eye is transmitted in a nitric oxide-dependent manner through the optic nerves to the hypothalamo-pituitary pro-opiomelanocortin system.

  5. Nitric Oxide Synthase Inhibitors as Antidepressants

    PubMed Central

    Wegener, Gregers; Volke, Vallo

    2010-01-01

    Affective and anxiety disorders are widely distributed disorders with severe social and economic effects. Evidence is emphatic that effective treatment helps to restore function and quality of life. Due to the action of most modern antidepressant drugs, serotonergic mechanisms have traditionally been suggested to play major roles in the pathophysiology of mood and stress-related disorders. However, a few clinical and several pre-clinical studies, strongly suggest involvement of the nitric oxide (NO) signaling pathway in these disorders. Moreover, several of the conventional neurotransmitters, including serotonin, glutamate and GABA, are intimately regulated by NO, and distinct classes of antidepressants have been found to modulate the hippocampal NO level in vivo. The NO system is therefore a potential target for antidepressant and anxiolytic drug action in acute therapy as well as in prophylaxis. This paper reviews the effect of drugs modulating NO synthesis in anxiety and depression. PMID:27713253

  6. 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.

  7. 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.

  8. Antidepressant effect of pramipexole in mice forced swimming test: A cross talk between dopamine receptor and NMDA/nitric oxide/cGMP pathway.

    PubMed

    Ostadhadi, Sattar; Imran Khan, Muhammad; Norouzi-Javidan, Abbas; Dehpour, Ahmad-Reza

    2016-07-01

    Pramipexole is a dopamine D2 receptor agonist indicated for treating Parkinson disorder. This study was aimed to investigate the effect of pramipexole in forced swimming test (FST) in mice and the possible involvement of activation of D2 receptors and inhibition of N-methyl-d-aspartate (NMDA) receptors and nitric oxide-cyclic guanosine monophosphate (NO-cGMP) on this effect. Intraperitoneal administration of pramipexole (1-3mg/kg) reduced the immobility time in the FST similar to fluoxetine (20mg/kg, i.p.). This effect of pramipexole (1mg/kg, i.p.) was ceased when mice were pretreated with haloperidol (0.15mg/kg, i.p,) and sulpiride (5mg/kg, i.p) as D2 receptor antagonists, NMDA (75mg/kg,i.p.), l-arginine (750mg/kg, i.p., a substrate for nitric oxide synthase) or sildenafil (5mg/kg, i.p., a phosphodiesterase 5 inhibitor). The administration of MK-801 (0.05mg/kg, i.p., a NMDA receptor antagonist) l-NG-Nitro arginine methyl ester (l-NAME, 10mg/kg, i.p., a non-specific nitric oxide synthase (NOS) inhibitor), 7-nitroindazole (30mg/kg, i.p., a neuronal NOS inhibitor) and methylene blue (10mg/kg, i.p.), an inhibitor of both NOS and soluble guanylyl cyclase (sGC) in combination with the sub-effective dose of pramipexole (0.3mg/kg, i.p.) reduced the immobility. Altogether, our data suggest that the antidepressant-like effect of pramipexole is dependent on the activation of D2 receptor and inhibition of either NMDA receptors and/or NO-cGMP synthesis. These results contribute to the understanding of the mechanisms underlying the antidepressant-like effect of pramipexole and reinforce the role of D2 receptors, NMDA receptors and l-arginine-NO-GMP pathway in the antidepressant mechanism of this agent. Copyright © 2016. Published by Elsevier Masson SAS.

  9. Neuronal nitric oxide synthase mediates insulin- and oxidative stress-induced glucose uptake in skeletal muscle myotubes.

    PubMed

    Kellogg, Dean L; McCammon, Karen M; Hinchee-Rodriguez, Kathryn S; Adamo, Martin L; Roman, Linda J

    2017-09-01

    Previously published studies strongly suggested that insulin- and exercise-induced skeletal muscle glucose uptake require nitric oxide (NO) production. However, the signal transduction mechanisms by which insulin and contraction regulated NO production and subsequent glucose transport are not known. In the present study, we utilized the myotube cell lines treated with insulin or hydrogen peroxide, the latter to mimic contraction-induced oxidative stress, to characterize these mechanisms. We found that insulin stimulation of neuronal nitric oxide synthase (nNOS) phosphorylation, NO production, and GLUT4 translocation were all significantly reduced by inhibition of either nNOS or Akt2. Hydrogen peroxide (H 2 O 2 ) induced phosphorylation of nNOS at the same residue as did insulin, and also stimulated NO production and GLUT4 translocation. nNOS inhibition prevented H 2 O 2 -induced GLUT4 translocation. AMP activated protein kinase (AMPK) inhibition prevented H 2 O 2 activation and phosphorylation of nNOS, leading to reduced NO production and significantly attenuated GLUT4 translocation. We conclude that nNOS phosphorylation and subsequently increased NO production are required for both insulin- and H 2 O 2 -stimulated glucose transport. Although the two stimuli result in phosphorylation of the same residue on nNOS, they do so through distinct protein kinases. Thus, insulin and H 2 O 2 -activated signaling pathways converge on nNOS, which is a common mediator of glucose uptake in both pathways. However, the fact that different kinases are utilized provides a basis for the use of exercise to activate glucose transport in the face of insulin resistance. Copyright © 2017. Published by Elsevier Inc.

  10. Dysregulated nitric oxide signaling as a candidate mechanism of fragile X syndrome and other neuropsychiatric disorders.

    PubMed

    Colvin, Steven M; Kwan, Kenneth Y

    2014-01-01

    A mechanistic understanding of the pathophysiology underpinning psychiatric disorders is essential for the development of targeted molecular therapies. For fragile X syndrome (FXS), recent mechanistic studies have been focused on the metabotropic glutamate receptor (mGluR) signaling pathway. This line of research has led to the discovery of promising candidate drugs currently undergoing various phases of clinical trial, and represents a model of how biological insights can inform therapeutic strategies in neurodevelopmental disorders. Although mGluR signaling is a key mechanism at which targeted treatments can be directed, it is likely to be one of many mechanisms contributing to FXS. A more complete understanding of the molecular and neural underpinnings of the disorder is expected to inform additional therapeutic strategies. Alterations in the assembly of neural circuits in the neocortex have been recently implicated in genetic studies of autism and schizophrenia, and may also contribute to FXS. In this review, we explore dysregulated nitric oxide signaling in the developing neocortex as a novel candidate mechanism of FXS. This possibility stems from our previous work demonstrating that neuronal nitric oxide synthase 1 (NOS1 or nNOS) is regulated by the FXS protein FMRP in the mid-fetal human neocortex. Remarkably, in the mid-late fetal and early postnatal neocortex of human FXS patients, NOS1 expression is severely diminished. Given the role of nitric oxide in diverse neural processes, including synaptic development and plasticity, the loss of NOS1 in FXS may contribute to the etiology of the disorder. Here, we outline the genetic and neurobiological data that implicate neocortical dysfunction in FXS, review the evidence supporting dysregulated nitric oxide signaling in the developing FXS neocortex and its contribution to the disorder, and discuss the implications for targeting nitric oxide signaling in the treatment of FXS and other psychiatric illnesses.

  11. Arginase expression modulates nitric oxide production in Leishmania (Leishmania) amazonensis.

    PubMed

    Acuña, Stephanie Maia; Aoki, Juliana Ide; Laranjeira-Silva, Maria Fernanda; Zampieri, Ricardo Andrade; Fernandes, Juliane Cristina Ribeiro; Muxel, Sandra Marcia; Floeter-Winter, Lucile Maria

    2017-01-01

    Arginase is an enzyme that converts L-arginine to urea and L-ornithine, an essential substrate for the polyamine pathway supporting Leishmania (Leishmania) amazonensis replication and its survival in the mammalian host. L-arginine is also the substrate of macrophage nitric oxide synthase 2 (NOS2) to produce nitric oxide (NO) that kills the parasite. This competition can define the fate of Leishmania infection. The transcriptomic profiling identified a family of oxidoreductases in L. (L.) amazonensis wild-type (La-WT) and L. (L.) amazonensis arginase knockout (La-arg-) promastigotes and axenic amastigotes. We highlighted the identification of an oxidoreductase that could act as nitric oxide synthase-like (NOS-like), due to the following evidences: conserved domain composition, the participation of NO production during the time course of promastigotes growth and during the axenic amastigotes differentiation, regulation dependence on arginase activity, as well as reduction of NO amount through the NOS activity inhibition. NO quantification was measured by DAF-FM labeling analysis in a flow cytometry. We described an arginase-dependent NOS-like activity in L. (L.) amazonensis and its role in the parasite growth. The increased detection of NO production in the mid-stationary and late-stationary growth phases of La-WT promastigotes could suggest that this production is an important factor to metacyclogenesis triggering. On the other hand, La-arg- showed an earlier increase in NO production compared to La-WT, suggesting that NO production can be arginase-dependent. Interestingly, La-WT and La-arg- axenic amastigotes produced higher levels of NO than those observed in promastigotes. As a conclusion, our work suggested that NOS-like is expressed in Leishmania in the stationary growth phase promastigotes and amastigotes, and could be correlated to metacyclogenesis and amastigotes growth in a dependent way to the internal pool of L-arginine and arginase activity.

  12. [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%.

  13. Lysophosphatidylcholine up-regulates human endothelial nitric oxide synthase gene transactivity by c-Jun N-terminal kinase signalling pathway

    PubMed Central

    Xing, Feiyue; Liu, Jing; Mo, Yongyan; Liu, Zhifeng; Qin, Qinghe; Wang, Jingzhen; Fan, Zhenhua; Long, Yutian; Liu, Na; Zhao, Kesen; Jiang, Yong

    2009-01-01

    Human endothelial nitric oxide synthase (eNOS) plays a pivotal role in maintaining blood pressure homeostasis and vascular integrity. It has recently been reported that mitogen-activated protein kinases (MAPKs) are intimately implicated in expression of eNOS. However detailed mechanism mediated by them remains to be clarified. In this study, eNOS gene transactivity in human umbilical vein endothelial cells was up-regulated by stimulation of lysophosphatidylcholine (LPC). The stimulation of LPC highly activated both extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK), with differences in the dynamic processes of activation between them. Unexpectedly, p38 MAPK could not be activated by the stimulation of LPC. The activation of JNK signalling pathway by overexpression of JNK or its upstream kinase active mutant up-regulated the transactivity of eNOS significantly, but the activation of p38 signalling pathway down-regulated it largely. The inhibition of either ERK1/2 or JNK signalling pathway by kinase-selective inhibitors could markedly block the induction of the transactivity by LPC. It was observed by electrophoretic mobility shift assay that LPC stimulated both SP1 and AP1 DNA binding activity to go up. Additionally using decoy oligonucleotides proved that SP1 was necessary for maintaining the basal or stimulated transactivity, whereas AP1 contributed mainly to the increase of the stimulated transactivity. These findings indicate that the up-regulation of the eNOS gene transactivity by LPC involves the enhancement of SP1 transcription factor by the activation of JNK and ERK1/2 signalling pathways and AP1 transcription factor by the activation of JNK signalling pathway. PMID:18624763

  14. Endothelial Nitric Oxide Pathways in the Pathophysiology of Dengue: A Prospective Observational Study.

    PubMed

    Yacoub, Sophie; Lam, Phung Khanh; Huynh, Trieu Trung; Nguyen Ho, Hong Hanh; Dong Thi, Hoai Tam; Van, Nguyen Thu; Lien, Le Thi; Ha, Quyen Nguyen Than; Le, Duyen Huynh Thi; Mongkolspaya, Juthathip; Culshaw, Abigail; Yeo, Tsin Wen; Wertheim, Heiman; Simmons, Cameron; Screaton, Gavin; Wills, Bridget

    2017-10-16

    Dengue can cause increased vascular permeability that may lead to hypovolemic shock. Endothelial dysfunction may underlie this; however, the association of endothelial nitric oxide (NO) pathways with disease severity is unknown. We performed a prospective observational study in 2 Vietnamese hospitals, assessing patients presenting early (<72 hours of fever) and patients hospitalized with warning signs or severe dengue. The reactive hyperemic index (RHI), which measures endothelium-dependent vasodilation and is a surrogate marker of endothelial function and NO bioavailability, was evaluated using peripheral artery tonometry (EndoPAT), and plasma levels of l-arginine, arginase-1, and asymmetric dimethylarginine were measured at serial time-points. The main outcome of interest was plasma leakage severity. Three hundred fourteen patients were enrolled; median age of the participants was 21(interquartile range, 13-30) years. No difference was found in the endothelial parameters between dengue and other febrile illness. Considering dengue patients, the RHI was significantly lower for patients with severe plasma leakage compared to those with no leakage (1.46 vs 2.00; P < .001), over acute time-points, apparent already in the early febrile phase (1.29 vs 1.75; P = .012). RHI correlated negatively with arginase-1 and positively with l-arginine (P = .001). Endothelial dysfunction/NO bioavailability is associated with worse plasma leakage, occurs early in dengue illness and correlates with hypoargininemia and high arginase-1 levels. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  15. Endothelial Nitric Oxide Pathways in the Pathophysiology of Dengue: A Prospective Observational Study

    PubMed Central

    Yacoub, Sophie; Lam, Phung Khanh; Huynh, Trieu Trung; Nguyen Ho, Hong Hanh; Dong Thi, Hoai Tam; Van, Nguyen Thu; Lien, Le Thi; Ha, Quyen Nguyen Than; Le, Duyen Huynh Thi; Mongkolspaya, Juthathip; Culshaw, Abigail; Yeo, Tsin Wen; Wertheim, Heiman; Simmons, Cameron; Screaton, Gavin; Wills, Bridget

    2017-01-01

    Abstract Background Dengue can cause increased vascular permeability that may lead to hypovolemic shock. Endothelial dysfunction may underlie this; however, the association of endothelial nitric oxide (NO) pathways with disease severity is unknown. Methods We performed a prospective observational study in 2 Vietnamese hospitals, assessing patients presenting early (<72 hours of fever) and patients hospitalized with warning signs or severe dengue. The reactive hyperemic index (RHI), which measures endothelium-dependent vasodilation and is a surrogate marker of endothelial function and NO bioavailability, was evaluated using peripheral artery tonometry (EndoPAT), and plasma levels of l-arginine, arginase-1, and asymmetric dimethylarginine were measured at serial time-points. The main outcome of interest was plasma leakage severity. Results Three hundred fourteen patients were enrolled; median age of the participants was 21(interquartile range, 13–30) years. No difference was found in the endothelial parameters between dengue and other febrile illness. Considering dengue patients, the RHI was significantly lower for patients with severe plasma leakage compared to those with no leakage (1.46 vs 2.00; P < .001), over acute time-points, apparent already in the early febrile phase (1.29 vs 1.75; P = .012). RHI correlated negatively with arginase-1 and positively with l-arginine (P = .001). Conclusions Endothelial dysfunction/NO bioavailability is associated with worse plasma leakage, occurs early in dengue illness and correlates with hypoargininemia and high arginase-1 levels. PMID:28673038

  16. 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.

  17. Nitric oxide, stress, and depression.

    PubMed

    McLeod, T M; López-Figueroa, A L; López-Figueroa, M O

    2001-01-01

    Stress and depression have a significant impact on modern society. Even though their symptomatology is well characterized, little is known about the molecular mechanisms underlying these disturbing disorders. While the role of neurotransmitters such as serotonin, norepinephrine (NE), dopamine (DA), corticotropin-releasing hormone (CRH), and arginine vasopressin (AVP) has been extensively studied, new evidence suggests a role for the unique neurotransmitter nitric oxide (NO). This highly diffusible and reactive molecule is synthesized by at least three enzyme subtypes of NO synthase (NOS). The commonly known neuronal NOS subtype is localized in areas of the brain related to stress and depression. The limbic-hypothalamic-pituitary-adrenal (LHPA) axis is the core of this system. These interrelated pathways have in common the production, and negative feedback, of glucocorticoids. Within these areas, NO is suggested to play a role in modulating the release of other neurotransmitters, acting as a cellular communicator in plasticity and development, and/or acting as a vasodilator in regulation of blood flow. This article summarizes some of the recent advances in the understanding of the role of NO in stress and depression.

  18. 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.

  19. 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

  20. 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.

  1. Controlled nitric oxide production via O( 1D)+N 2O reactions for use in oxidation flow reactor studies

    DOE PAGES

    Lambe, Andrew; Massoli, Paola; Zhang, Xuan; ...

    2017-06-22

    Oxidation flow reactors that use low-pressure mercury lamps to produce hydroxyl (OH) radicals are an emerging technique for studying the oxidative aging of organic aerosols. Here, ozone (O 3) is photolyzed at 254 nm to produce O( 1D) radicals, which react with water vapor to produce OH. However, the need to use parts-per-million levels of O 3 hinders the ability of oxidation flow reactors to simulate NO x-dependent secondary organic aerosol (SOA) formation pathways. Simple addition of nitric oxide (NO) results in fast conversion of NO x (NO+NO 2) to nitric acid (HNO 3), making it impossible to sustain NOmore » x at levels that are sufficient to compete with hydroperoxy (HO 2) radicals as a sink for organic peroxy (RO 2) radicals. We developed a new method that is well suited to the characterization of NO x-dependent SOA formation pathways in oxidation flow reactors. NO and NO 2 are produced via the reaction O( 1D) + N 2O → 2NO, followed by the reaction NO + O 3 → NO 2+O 2. Laboratory measurements coupled with photochemical model simulations suggest that O( 1D) + N 2O reactions can be used to systematically vary the relative branching ratio of RO 2 + NO reactions relative to RO 2 + HO 2 and/or RO 2 + RO 2 reactions over a range of conditions relevant to atmospheric SOA formation. We demonstrate proof of concept using high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) measurements with nitrate (NO 3 -) reagent ion to detect gas-phase oxidation products of isoprene and α-pinene previously observed in NO x-influenced environments and in laboratory chamber experiments.« less

  2. Controlled nitric oxide production via O( 1D)+N 2O reactions for use in oxidation flow reactor studies

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

    Lambe, Andrew; Massoli, Paola; Zhang, Xuan

    Oxidation flow reactors that use low-pressure mercury lamps to produce hydroxyl (OH) radicals are an emerging technique for studying the oxidative aging of organic aerosols. Here, ozone (O 3) is photolyzed at 254 nm to produce O( 1D) radicals, which react with water vapor to produce OH. However, the need to use parts-per-million levels of O 3 hinders the ability of oxidation flow reactors to simulate NO x-dependent secondary organic aerosol (SOA) formation pathways. Simple addition of nitric oxide (NO) results in fast conversion of NO x (NO+NO 2) to nitric acid (HNO 3), making it impossible to sustain NOmore » x at levels that are sufficient to compete with hydroperoxy (HO 2) radicals as a sink for organic peroxy (RO 2) radicals. We developed a new method that is well suited to the characterization of NO x-dependent SOA formation pathways in oxidation flow reactors. NO and NO 2 are produced via the reaction O( 1D) + N 2O → 2NO, followed by the reaction NO + O 3 → NO 2+O 2. Laboratory measurements coupled with photochemical model simulations suggest that O( 1D) + N 2O reactions can be used to systematically vary the relative branching ratio of RO 2 + NO reactions relative to RO 2 + HO 2 and/or RO 2 + RO 2 reactions over a range of conditions relevant to atmospheric SOA formation. We demonstrate proof of concept using high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) measurements with nitrate (NO 3 -) reagent ion to detect gas-phase oxidation products of isoprene and α-pinene previously observed in NO x-influenced environments and in laboratory chamber experiments.« less

  3. Production of nitric oxide using a microwave plasma torch and its application to fungal cell differentiation

    NASA Astrophysics Data System (ADS)

    Na, Young Ho; Kumar, Naresh; Kang, Min-Ho; Cho, Guang Sup; Choi, Eun Ha; Park, Gyungsoon; Uhm, Han Sup

    2015-03-01

    The generation of nitric oxide by a microwave plasma torch is proposed for its application to cell differentiation. A microwave plasma torch was developed based on basic kinetic theory. The analytical theory indicates that nitric oxide density is nearly proportional to oxygen molecular density and that the high-temperature flame is an effective means of generating nitric oxide. Experimental data pertaining to nitric oxide production are presented in terms of the oxygen input in units of cubic centimeters per minute. The apparent length of the torch flame increases as the oxygen input increases. The various levels of nitric oxide are observed depending on the flow rate of nitrogen gas, the mole fraction of oxygen gas, and the microwave power. In order to evaluate the potential of nitric oxide as an activator of cell differentiation, we applied nitric oxide generated from the microwave plasma torch to a model microbial cell (Neurospora crassa: non-pathogenic fungus). Germination and hyphal differentiation of fungal cells were not dramatically changed but there was a significant increase in spore formation after treatment with nitric oxide. In addition, the expression level of a sporulation related gene acon-3 was significantly elevated after 24 h upon nitric oxide treatment. Increase in the level of nitric oxide, nitrite and nitrate in water after nitric oxide treatment seems to be responsible for activation of fungal sporulation. Our results suggest that nitric oxide generated by plasma can be used as a possible activator of cell differentiation and development.

  4. 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.

  5. 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

  6. Nitrosation of melatonin by nitric oxide: a computational study.

    PubMed

    Turjanski, A G; Sáenz, D A; Doctorovich, F; Estrin, D A; Rosenstein, R E

    2001-09-01

    Melatonin is being increasingly promoted as a therapeutic agent for the treatment of jet lag and insomnia, and is an efficient free radical scavenger. We have recently characterized a product for the reaction of melatonin with nitric oxide (NO), N-nitrosomelatonin. In the present work, reaction pathways with N1, C2, C4, C6 and C7 as possible targets for its reaction with NO that yield the respective nitroso derivatives have been investigated using semiempirical AM1 computational tools, both in vacuo and aqueous solution. Specifically, two different pathways were studied: a radical mechanism involving the hydrogen atom abstraction to yield a neutral radical followed by NO addition, and an ionic mechanism involving addition of nitrosonium ion to the indolic moiety. Our results show that the indolic nitrogen is the most probable site for nitrosation by the radical mechanism, whereas different targets are probable considering the ionic pathway. These results are in good agreement with previous experimental findings and provide a coherent picture for the interaction of melatonin with NO.

  7. Nitric oxide signaling pathway regulates potassium chloride cotransporter-1 mRNA expression in vascular smooth muscle cells.

    PubMed

    Di Fulvio, M; Lauf, P K; Adragna, N C

    2001-11-30

    Rat vascular smooth muscle cells (VSMCs) express at least two mRNAs for K-Cl cotransporters (KCC): KCC1 and KCC3. cGMP-dependent protein kinase I regulates KCC3 mRNA expression in these cells. Here, we show evidence implicating the nitric oxide (NO)/cGMP signaling pathway in the expression of KCC1 mRNA, considered to be the major cell volume regulator. VSMCs, expressing soluble guanylyl cyclase (sGC) and PKG-I isoforms showed a time- and concentration-dependent increase in KCC1 mRNA levels after treatment with sodium nitroprusside as demonstrated by semiquantitative RT-PCR. sGC-dependent regulation of KCC1 mRNA expression was confirmed using YC-1, a NO-independent sGC stimulator. The sGC inhibitor LY83583 blocked the effects of sodium nitroprusside and YC-1. Moreover, 8-Br-cGMP increased KCC1 mRNA expression in a concentration- and time-dependent fashion. The 8-Br-cGMP effect was partially blocked by KT5823 but not by actinomycin D. However, actinomycin D and cycloheximide increased basal KCC1 mRNA in an additive manner, suggesting different mechanisms of action for both drugs. These findings suggest that in VSMCs, the NO/cGMP-signaling pathway participates in KCC1 mRNA regulation at the post-transcriptional level.

  8. Nitric oxide-sensitive guanylyl cyclase is differentially regulated by nuclear and non-nuclear estrogen pathways in anterior pituitary gland.

    PubMed

    Cabilla, Jimena P; Nudler, Silvana I; Ronchetti, Sonia A; Quinteros, Fernanda A; Lasaga, Mercedes; Duvilanski, Beatriz H

    2011-01-01

    17β-estradiol (E2) regulates hormonal release as well as proliferation and cell death in the pituitary. The main nitric oxide receptor, nitric oxide sensitive- or soluble guanylyl cyclase (sGC), is a heterodimer composed of two subunits, α and β, that catalyses cGMP formation. α1β1 is the most abundant and widely expressed heterodimer, showing the greater activity. Previously we have shown that E2 decreased sGC activity but exerts opposite effects on sGC subunits increasing α1 and decreasing β1 mRNA and protein levels. In the present work we investigate the mechanisms by which E2 differentially regulates sGC subunits' expression on rat anterior pituitary gland. Experiments were performed on primary cultures of anterior pituitary cells from adult female Wistar rats at random stages of estrous cycle. After 6 h of E2 treatment, α1 mRNA and protein expression is increased while β1 levels are down-regulated. E2 effects on sGC expression are partially dependent on de novo transcription while de novo translation is fully required. E2 treatment decreased HuR mRNA stabilization factor and increased AUF1 p37 mRNA destabilization factor. E2-elicited β1 mRNA decrease correlates with a mRNA destabilization environment in the anterior pituitary gland. On the other hand, after 6 h of treatment, E2-BSA (1 nM) and E2-dendrimer conjugate (EDC, 1 nM) were unable to modify α1 or β1 mRNA levels, showing that nuclear receptor is involved in E2 actions. However, at earlier times (3 h), 1 nM EDC causes a transient decrease of α1 in a PI3k-dependent fashion. Our results show for the first time that E2 is able to exert opposite actions in the anterior pituitary gland, depending on the activation of classical or non-classical pathways. Thus, E2 can also modify sGC expression through membrane-initiated signals bringing to light a new point of regulation in NO/sGC pathway. © 2011 Cabilla et al.

  9. 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

  10. Nitric-oxide synthase trafficking inducer is a pleiotropic regulator of endothelial cell function and signaling

    PubMed Central

    2017-01-01

    Endothelial nitric-oxide synthase (eNOS) and its bioactive product, nitric oxide (NO), mediate many endothelial cell functions, including angiogenesis and vascular permeability. For example, vascular endothelial growth factor (VEGF)-mediated angiogenesis is inhibited upon reduction of NO bioactivity both in vitro and in vivo. Moreover, genetic disruption or pharmacological inhibition of eNOS attenuates angiogenesis during tissue repair, resulting in delayed wound closure. These observations emphasize that eNOS-derived NO can promote angiogenesis. Intriguingly, eNOS activity is regulated by nitric-oxide synthase trafficking inducer (NOSTRIN), which sequesters eNOS, thereby attenuating NO production. This has prompted significant interest in NOSTRIN's function in endothelial cells. We show here that NOSTRIN affects the functional transcriptome of endothelial cells by down-regulating several genes important for invasion and angiogenesis. Interestingly, the effects of NOSTRIN on endothelial gene expression were independent of eNOS activity. NOSTRIN also affected the expression of secreted cytokines involved in inflammatory responses, and ectopic NOSTRIN overexpression functionally restricted endothelial cell proliferation, invasion, adhesion, and VEGF-induced capillary tube formation. Furthermore, NOSTRIN interacted directly with TNF receptor-associated factor 6 (TRAF6), leading to the suppression of NFκB activity and inhibition of AKT activation via phosphorylation. Interestingly, TNF-α-induced NFκB pathway activation was reversed by NOSTRIN. We found that the SH3 domain of NOSTRIN is involved in the NOSTRIN-TRAF6 interaction and is required for NOSTRIN-induced down-regulation of endothelial cell proteins. These results have broad biological implications, as aberrant NOSTRIN expression leading to deactivation of the NFκB pathway, in turn triggering an anti-angiogenic cascade, might inhibit tumorigenesis and cancer progression. PMID:28235804

  11. 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

  12. 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.

  13. 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.

  14. Role of the nitric oxide/cyclic GMP/Ca2+ signaling pathway in the pyrogenic effect of interleukin-1beta.

    PubMed

    Palmi, Mitri; Meini, Antonella

    2002-04-01

    Interleukin-1beta (IL-1beta) has a wide spectrum of inflammatory, metabolic, haemopoietic, and immunological properties. Because it produces fever when injected into animals and humans, it is considered an endogenous pyrogen. There is evidence to suggest that Ca2+ plays a critical role in the central mechanisms of thermoregulation, and in the intracellular signaling pathways controlling fever induced by IL-1beta and other pyrogens. Data from different labs indicate that Ca2+ and Na+ determine the temperature set point in the posterior hypothalamus (PH) of various mammals and that changes in Ca2+ and PGE2 concentrations in the cerebrospinal fluid (CSF) of these animals are associated with IL-1beta-induced fever. Antipyretic drugs such as acetylsalicylic acid, dexamethasone, and lipocortin 5-(204-212) peptide counteract IL-1beta-induced fever and abolish changes in Ca2+ and PGE2 concentrations in CSF. In vitro studies have established that activation of the nitric oxide (NO)/cyclic GMP (cGMP) pathway is part of the signaling cascade transducing Ca2+ mobilization in response to IL-1beta and that the ryanodine (RY)- and inositol-(1,4,5)-trisphosphate (IP3)-sensitive pools are the main source of the mobilized Ca2+. It is concluded that the NO/cGMP/Ca2+ pathway is part of the signaling cascade subserving some of the multiple functions of IL-1beta.

  15. 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

  16. Nitric oxide pathway presumably does not contribute to antianxiety and memory retrieval effects of losartan.

    PubMed

    Aghaei, Iraj; Arjmand, Shokouh; Yousefzadeh Chabok, Shahrokh; Tondar, Mahdi; Shabani, Mohammad

    2017-09-01

    Nitric oxide (NO) and angiotensin (AT) receptors have demonstrated well-established interactions in various physiological phenomena. AT1 receptors can play a part in stress-induced activation of the hypothalamic-pituitary-adrenal axis; also, angiotensinergic neurotransmission plays a pivotal role in stress-evoked physiological responses. On the basis of the stress-modulating characteristics of NO, AT1, and AT2 receptors, the present study evaluated the roles of NO and AT1 receptors in the attenuation of stress-induced anxiety-like behaviors after administration of losartan, an AT1 antagonist. Male Wistar rats were exposed to the communication stress box, using a novel method to induce physical or emotional stress, and losartan (10 mg/kg), losartan+L-NG-nitroargininemethyl ester (L-NAME), L-NAME (1, 10, and 100 mg/kg), and normal saline-treated groups were compared. Losartan had reduced behavioral changes induced by both types of stressor and enhanced memory retrieval. Anxiety-like behaviors were significantly attenuated by administration of losartan, to a greater extent in the emotional rather than physical stress group. None of the injected dosages of L-NAME reversed the antianxiety and memory retrieval effects of losartan. Our results indicate that losartan probably improves memory retrieval and lessens anxiety-like behaviors through mechanisms other than the NO pathway.

  17. 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

  18. Effect of Blockade of Nitric Oxide Synthesis on the Renin Secretory Response to Frusemide in Conscious Rabbits

    NASA Technical Reports Server (NTRS)

    Reid, Ian A.; Chou, Lance

    1995-01-01

    The enzyme nitric oxide synthase is present in the macula densa and may participate in the control of renin secretion by the adjacent juxtagiomerular cells. In the present study, we investigated the effect of inhibiting nitric oxide synthase on the renin secretory response to frusemide, which stimulates renin secretion by blocking Na(+)-K(+)-2Cl(-) co-transport in the macula densa. Injection of frusemide in 12 conscious rabbits elicited a transient increase in mean arterial pressure from 84 +/- 2 to 92 +/-3 mm Hg at 5 min (P less than 0.01) and a sustained increase in heart rate from 246 +/- 6 to 281 +/- 10 beats/min at 45 min (P less than 0.01). Plasma renin activity increased from 8.0 +/- 1.2 to 14.3 +/- 1.8, 12.4 +/- 1.6 and 11.6 +/- 1.5 pmol/2h ml at 15, 30 and 45min respectively (P less than 0.01). There were no changes in plasma sodium and potassium concentrations or osmoiality. Inhibition of nitric oxide synthase with N(sup G)-nitro-L- arginine methyl ester increased mean arterial pressure by 9 mm Hg, decreased heart rate and plasma renin activity, and markedly suppressed the renin response to frusemide (from 4.6 +/- 0.7 to 7.6 +/- 1.7, 4.7 +/- 1.0 and 4.6 +/- 0.7pmol/2h ml at 15, 30 and 45 min respectively). By contrast, infusion of an equipressor dose of phenylephrine did not suppress the renin response to frusemide. Histochemical studies with the NADPH diaphorase technique confirmed the presence of nitric oxide synthase in the macula densa, and suggested that enzyme activity is increased by treatment with frusemide. These results are consistent with a role for the L- arginine-nitric oxide pathway in the modulation of renin secretion by the macula densa.

  19. 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.

  20. Hydrogen Sulfide Regulates Ca2+ Homeostasis Mediated by Concomitantly Produced Nitric Oxide via a Novel Synergistic Pathway in Exocrine Pancreas

    PubMed Central

    Moustafa, Amira

    2014-01-01

    Abstract Aim: The present study was designed to explore the effects of hydrogen sulfide (H2S) on Ca2+ homeostasis in rat pancreatic acini. Results: Sodium hydrosulfide (NaHS; an H2S donor) induced a biphasic increase in the intracellular Ca2+ concentration ([Ca2+]i) in a dose-dependent manner. The NaHS-induced [Ca2+]i elevation persisted with an EC50 of 73.3 μM in the absence of extracellular Ca2+ but was abolished by thapsigargin, indicating that both Ca2+ entry and Ca2+ release contributed to the increase. The [Ca2+]i increase was markedly inhibited in the presence of NG-monomethyl L-arginine or 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), and diaminofluorescein-2/diaminofluorescein-2 triazole (DAF-2/DAF-2T) fluorometry demonstrated that nitric oxide (NO) was also produced by H2S in a dose-dependent manner with an EC50 of 64.8 μM, indicating that NO was involved in the H2S effect. The H2S-induced [Ca2+]i increase was inhibited by pretreatment with U73122, xestospongin C, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, KT5823, and GP2A, indicating that phospholipase C (PLC), the inositol 1,4,5-trisphosphate (IP3) receptor, soluble guanylate cyclase (sGC), protein kinase G (PKG), and Gq-protein play roles as intermediate components in the H2S-triggered intracellular signaling. Innovation: To our knowledge, our study is the first one highlighting the effect of H2S on intracellular Ca2+ dynamics in pancreatic acinar cells. Moreover, a novel cascade was presumed to function via the synergistic interaction between H2S and NO. Conclusion: We conclude that H2S affects [Ca2+]i homeostasis that is mediated by H2S-evoked NO production via an endothelial nitric oxide synthase (eNOS)-NO-sGC-cyclic guanosine monophosphate-PKG-Gq-protein-PLC-IP3 pathway to induce Ca2+ release, and this pathway is identical to the one we recently proposed for a sole effect of NO and the two gaseous molecules synergistically function to regulate Ca2+ homeostasis

  1. Differences Between Tg2576 and Wild Type Mice in the NMDA Receptor-Nitric Oxide Pathway After Prolonged Application of a Diet High in Advanced Glycation End Products.

    PubMed

    Kristofikova, Zdena; Ricny, Jan; Sirova, Jana; Ripova, Daniela; Lubitz, Irit; Schnaider-Beeri, Michal

    2015-08-01

    It has been suggested that advanced glycation end (AGE) products, via cognate receptor activation, are implicated in several diseases, including Alzheimer's disease. The NMDA receptor-nitric oxide pathway appears to be influenced by AGE products and involved in the pathogenesis of this type of dementia. In this study, C57BL/6J (WT) and transgenic (Tg2576) mice expressing human mutant amyloid precursor protein were kept on prolonged (8 months) diets containing regular or high amounts of AGE products. After the decapitation of 11-months old mice, brain tissue analyses were performed [expressions of the NR1, NR2A and NR2B subunits of NMDA receptors, activities of neuronal, endothelial and inducible nitric oxide synthase (nNOS, eNOS and iNOS)]. Moreover, levels of malondialdehyde and of human amyloid β 1-42 were estimated. We found increased activity of nNOS in WT mice maintained on a high compared to regular AGE diet; however, no similar differences were found in Tg2576 mice. In addition, we observed an increase in NR1 expression in Tg2576 compared to WT mice, both kept on a diet high in AGE products. Correlation analyses performed on mice kept on the regular AGE diet supported close links between particular subunits (NR2A-NR2B, in WT as well as in Tg2576 mice), between subunits and synthase (NR2A/NR2B-nNOS, only in WT mice) or between particular synthases (nNOS-iNOS, only in WT). Correlation analysis also revealed differences between WT mice kept on both diets (changed correlations between NR2A/NR2B-nNOS, between nNOS-eNOS and between eNOS-iNOS). Malondialdehyde levels were increased in both Tg2576 groups when compared to the corresponding WT mice, but no effects of the diets were observed. Analogously, no significant effects of diets were found in the levels of soluble or insoluble amyloid β 1-42 in Tg2576 mice. Our results demonstrate that prolonged ingestion of AGE products can influence the NMDA receptor-nitric oxide pathway in the brain and that only WT mice

  2. Nitric oxide synthase immunoreactivity in the nematode Trichinella britovi. Evidence for nitric oxide production by the parasite.

    PubMed

    Masetti, Massimo; Locci, Teresa; Cecchettini, Antonella; Lucchesi, Paolo; Magi, Marta; Malvaldi, Gino; Bruschi, Fabrizio

    2004-05-01

    Nitric oxide has been extensively studied as an effector molecule of the host immune response against both protozoa and helminths, but parasites can also produce this molecule, through the action of nitric oxide (NO) synthases or NO synthases-like enzymes. The aim of this study was to verify the possible production of NO by Trichinella britovi L(1) larvae and the enzymes involved in this process. The NO synthase immunoreactivity and putative nitric oxide synthase-activity was analysed using antibodies to mammalian NO synthase III and to nitrotyrosine with immunohistochemistry, gold immunocytochemistry and immunoblot analysis and NADPH-diaphorase histochemistry. Our results show that T. britovi L(1) larvae possess an enzymatic activity capable of producing NO. The localisation of this activity, according to the NADPH-diaphorase histochemistry, is both at the cuticular and the internal level. This localisation is confirmed by nitrotyrosine immunohistochemistry both under optical and electron microscopy. Using the NO synthase III antibody, a similar pattern of labelling was found: in particular, electron microscopy showed a localisation of this immunoreactivity in the cuticle and in the stichocytes, where only the alpha2 granules contained gold particles, mainly concentrated at their periphery. Four polypeptides reacting to the NO synthase III antibody are revealed by Western blotting. Their molecular weight ranged from 38 to 50 kDa. A significant reaction of the anti-nitrotyrosine antibody to polypeptides 95, 60, 48 and 39 kDa from the same sample suggested the presence of different nitrosylated proteins.

  3. 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

  4. Physiologic ischaemic training induces endothelial progenitor cell mobilization and myocardial angiogenesis via endothelial nitric oxide synthase related pathway in rabbits.

    PubMed

    Xiao, Mingyue; Lu, Xiao; Li, Jianan; Li, Ling; Li, Yongxue

    2014-04-01

    Ischaemia-induced angiogenesis promises to improve neovascularization by delivery of angiogenic factors or endothelial progenitor cells (EPCs) to cardiac ischaemic areas. In order to avoid the risk of excessive myocardial ischaemia, therefore, we hypothesized that physiological ischaemic training (PIT) of normal skeletal muscle might contribute to myocardial angiogenesis via nitric oxide mediated mobilization of EPCs from the bone marrow in the established rabbit model of controllable myocardial ischaemia. The rabbits were grouped by sham-operation, myocardial ischaemia without PIT, PIT and PIT with pretreatment with the endothelial nitric oxide synthase (eNOS) inhibitor L-nitroarginine methyl ester (L-NAME). Controlled myocardial ischaemia was modelled by a water balloon constrictor implanted on the left ventricular branch in a rabbit. The PIT procedure included three cycles of 3 min of cuff inflation followed by 5 min of deflation on hind limbs of the rabbits for 4 weeks. At the endpoints, circulating EPCs (CD34/Flk-1) were measured by fluorescence-activated cell sorter; capillary density, by immunohistochemistry; blood flow, by a microsphere technique; endothelial nitric oxide synthase (eNOS) mRNA and protein, by real-time reverse transcriptase (RT)-PCR and Western blotting. The mRNA levels of eNOS were significantly higher in the PIT and L-NAME groups than in the sham-operation group (P < 0.05). Phospho-eNOS protein expression was higher in the PIT group than in the sham-operation and myocardial ischaemia without PIT groups (P < 0.05), and the effect was inhibited by L-NAME pretreatment (P < 0.05). Compared with sham-operation and myocardial ischaemia without PIT groups, the PIT group had the highest EPC count (P < 0.001), and the increase of capillary density (P < 0.01) and collateral blood flow (P < 0.05) in the ischaemic myocardium was consistent with the finding of EPC count. These effects were also inhibited by pretreatment with

  5. Role of nitric oxide in regulating stomatal apertures

    PubMed Central

    Ribeiro, Dimas M; Bright, Jo; Confraria, Ana; Harrison, Judith; Barros, Raimundo S; Desikan, Radhika; Neill, Steven J; Hancock, John T

    2009-01-01

    During stomatal closure, nitric oxide (NO) operates as one of the key intermediates in the complex, abscisic acid (ABA)-mediated, guard cell signaling network that regulates this process. However, data concerning the role of NO in stomatal closure that occurs in turgid vs. dehydrated plants is limited. The data presented demonstrate that, while there is a requirement for NO during the ABA-induced stomatal closure of turgid leaves, such a requirement does not exist for ABA-enhanced stomatal closure observed to occur during conditions of rapid dehydration. The data also indicate that the ABA signaling pathway must be both functional and to some degree activated for guard cell NO signaling to occur. These observations are in line with the idea that the effects of NO in guard cells are mediated via a Ca2+-dependent rather than a Ca2+-independent ABA signaling pathway. It appears that there is a role for NO in the fine tuning of the stomatal apertures of turgid leaves that occurs in response to fluctuations in the prevailing environment. PMID:19816112

  6. 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.

  7. 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.

  8. Microinjection of l-glutamate into the nucleus ambiguus partially inhibits gastric motility through the NMDA receptor - nitric oxide pathway.

    PubMed

    Sun, Hong-Zhao; Zhao, Shu-Zhen; Ai, Hong-Bin

    2014-06-01

    We have previously reported that both l-glutamate (l-Glu) and nitric oxide (NO) modulate gastric motility in the nucleus ambiguus (NA). The aim of this study is to explore the potential correlation between the l-Glu and NO. A latex balloon connected to a pressure transducer was inserted into the pylorus through the fundus of anesthetized male Wistar rats to continuously record changes in gastric smooth muscle contractile curves. Pretreatment with the NO-synthase inhibitor N-nitro-l-arginine methylester (l-NAME) did not completely abolish the inhibitory effect of l-Glu on gastric motility, but intravenous injection of the ganglionic blocker hexamethonium bromide (Hb) did. By using a specific N-methyl-d-aspartic acid (NMDA) receptor antagonist, we blocked the inhibitory effect of the NO-donor sodium nitroprusside (SNP) on gastric motility. These results suggest that microinjections of l-Glu into the NA inhibits gastric motility by activating the cholinergic preganglionic neurons, partially through the NMDA receptor - NO pathway.

  9. Mechanism and Kinetics of Inducible Nitric Oxide Synthase Auto-S-Nitrosation and Inactivation†

    PubMed Central

    Smith, Brian C.; Fernhoff, Nathaniel B.; Marletta, Michael A.

    2012-01-01

    Nitric oxide (NO), the product of the nitric oxide synthase (NOS) reaction, was previously shown to result in S-nitrosation of the NOS Zn2+-tetrathiolate and inactivation of the enzyme. To probe the potential physiological significance of NOS S-nitrosation, the inactivation timescale of the inducible NOS isoform (iNOS) was determined and found to directly correlate with an increase in iNOS S-nitrosation. A kinetic model of NOS inactivation in which arginine is treated as a suicide substrate was developed. In this model, NO synthesized at the heme cofactor is partitioned between release into solution (NO release pathway) and NOS S-nitrosation followed by NOS inactivation (inactivation pathway). Experimentally determined progress curves of NO formation were fit to the model. The NO release pathway was perturbed through addition of the NO traps oxymyoglobin (MbO2) and β2 H-NOX, which yielded partition ratios between NO release and inactivation of ~100 at 4 μM MbO2 and ~22,000 at saturating trap concentrations. The results suggest that a portion of the NO synthesized at the heme cofactor reacts with the Zn2+-tetrathiolate without being released into solution. Perturbation of the inactivation pathway through addition of the reducing agents GSH or TCEP resulted in a concentration-dependent decrease in iNOS S-nitrosation that directly correlated with protection from iNOS inactivation. iNOS inactivation was most responsive to physiological concentrations of GSH with an apparent Km value of 13 mM. NOS turnover that leads to NOS S-nitrosation might be a mechanism to control NOS activity, and NOS S-nitrosation could play a role in the physiological generation of nitrosothiols. PMID:22242685

  10. Nitric oxide mediates the anticonvulsant effects of thalidomide on pentylenetetrazole-induced clonic seizures in mice.

    PubMed

    Payandemehr, Borna; Rahimian, Reza; Gooshe, Maziar; Bahremand, Arash; Gholizadeh, Ramtin; Berijani, Sina; Ahmadi-Dastgerdi, Mohammad; Aminizade, Mehdi; Sarreshte-Dari, Ali; Dianati, Vahid; Amanlou, Massoud; Dehpour, Ahmad Reza

    2014-05-01

    Thalidomide is an old glutamic acid derivative which was initially used as a sedative medication but withdrawn from the market due to the high incidence of teratogenicity. Recently, it has reemerged because of its potential for counteracting number of diseases, including neurodegenerative disorders. Other than the antiemetic and hypnotic aspects, thalidomide exerts some anticonvulsant properties in experimental settings. However, the underlying mechanisms of thalidomide actions are not fully realized yet. Some investigations revealed that thalidomide could elicit immunomodulatory or neuromodulatory properties by affecting different targets, including cytokines (such as TNF α), neurotransmitters, and nitric oxide (NO). In this regard, we used a model of clonic seizure induced by pentylenetetrazole (PTZ) in male NMRI mice to investigate whether the anticonvulsant effect of thalidomide is affected through modulation of the l-arginine-nitric oxide pathway or not. Injection of a single effective dose of thalidomide (10 mg/kg, i.p. or higher) significantly increased the seizure threshold (P<0.05). On the one hand, pretreatment with low and per se noneffective dose of l-arginine [NO precursor] (10, 30 and 60 mg/kg) prevented the anticonvulsant effect of thalidomide. On the other hand, NOS inhibitors [l-NAME and 7-NI] augmented the anticonvulsant effect of a subeffective dose of thalidomide (1 and 5 mg/kg, i.p.) at relatively low doses. Meanwhile, several doses of aminoguanidine [an inducible NOS inhibitor] (20, 50 and 100 mg/kg) failed to alter the anticonvulsant effect of thalidomide significantly. In summary, our findings demonstrated that the l-arginine-nitric oxide pathway can be involved in the anticonvulsant properties of thalidomide, and the role of constitutive nNOS is prominent in the reported neuroprotective feature. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. 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.

  12. Role of oxidative stress and nitric oxide in atherothrombosis

    PubMed Central

    Lubos, Edith; Handy, Diane E.; Loscalzo, Joseph

    2008-01-01

    During the last decade basic and clinical research has highlighted the central role of reactive oxygen species (ROS) in cardiovascular disease. Enhanced production or attenuated degradation of ROS leads to oxidative stress, a process that affects endothelial and vascular function, and contributes to vascular disease. Nitric oxide (NO), a product of the normal endothelium, is a principal determinant of normal endothelial and vascular function. In states of inflammation, NO production by the vasculature increases considerably and, in conjunction with other ROS, contributes to oxidative stress. This review examines the role of oxidative stress and NO in mechanisms of endothelial and vascular dysfunction with an emphasis on atherothrombosis. PMID:18508590

  13. Arginine affects appetite via nitric oxide in ducks.

    PubMed

    Wang, C; Hou, S S; Huang, W; Xu, T S; Rong, G H; Xie, M

    2014-08-01

    The objective of the study was to investigate the mechanism by which arginine regulates feed intake in Pekin ducks. In experiment 1, one hundred forty-four 1-d-old male Pekin ducks were randomly allotted to 3 dietary treatments with 6 replicate pens of 8 birds per pen. Birds in each group were fed a corn-corn gluten meal diet containing 0.65, 0.95, and 1.45% arginine. Ducks fed the diet containing 0.65% arginine had lower feed intake and plasma nitric oxide level (P < 0.05) than the other 2 groups. In experiment 2, twenty 11-d-old ducks were allotted to 1 of 2 treatments. After 2 h fasting, birds in the 2 groups were intraperitoneally administrated saline and l-NG-nitro-arginine methyl ester HCl (L-NAME) for 3 d, respectively. Feed intake (P < 0.07) and plasma nitric oxide concentration (P < 0.05) 2 h postinjection in the L-NAME administered group were lower than those of the control group. In conclusion, the study implied that arginine modifies feeding behavior possibly through controlling endogenous synthesis of nitric oxide in Pekin ducks. © Poultry Science Association Inc.

  14. Bioactive Fraction of Geopropolis from Melipona scutellaris Decreases Neutrophils Migration in the Inflammatory Process: Involvement of Nitric Oxide Pathway

    PubMed Central

    Franchin, Marcelo; da Cunha, Marcos Guilherme; Denny, Carina; Napimoga, Marcelo Henrique; Cunha, Thiago Mattar; Bueno-Silva, Bruno; Matias de Alencar, Severino; Ikegaki, Masaharu; Luiz Rosalen, Pedro

    2013-01-01

    The aim of this study was to evaluate the activity of the ethanolic extract of geopropolis (EEGP) from Melipona scutellaris and its fractions on the modulation of neutrophil migration in the inflammatory process, and the participation of nitric oxide (NO) pathway, as well as to check the chemical profile of the bioactive fraction. EEGP and its aqueous fraction decreased neutrophil migration in the peritoneal cavity and also the interaction of leukocytes (rolling and adhesion) with endothelial cells. The levels of chemokines CXCL1/KC and CXCL2/MIP-2 were not altered after treatment with EEGP and the aqueous fraction. It was found that the injection of NO pathway antagonists abolished the EEGP and the aqueous fraction inhibitory activity on the neutrophil migration. The expression of intercellular adhesion molecule type 1 (ICAM-1) was reduced, and nitrite levels increased after treatment with EEGP and aqueous fraction. In the carrageenan-induced paw edema model, EEGP and the aqueous fraction showed antiedema activity. No pattern of flavonoid and phenolic acid commonly found in propolis samples of Apis mellifera could be detected in the aqueous fraction samples. These data indicate that the aqueous fraction found has promising bioactive substances with anti-inflammatory activity. PMID:23737853

  15. Bioactive Fraction of Geopropolis from Melipona scutellaris Decreases Neutrophils Migration in the Inflammatory Process: Involvement of Nitric Oxide Pathway.

    PubMed

    Franchin, Marcelo; da Cunha, Marcos Guilherme; Denny, Carina; Napimoga, Marcelo Henrique; Cunha, Thiago Mattar; Bueno-Silva, Bruno; Matias de Alencar, Severino; Ikegaki, Masaharu; Luiz Rosalen, Pedro

    2013-01-01

    The aim of this study was to evaluate the activity of the ethanolic extract of geopropolis (EEGP) from Melipona scutellaris and its fractions on the modulation of neutrophil migration in the inflammatory process, and the participation of nitric oxide (NO) pathway, as well as to check the chemical profile of the bioactive fraction. EEGP and its aqueous fraction decreased neutrophil migration in the peritoneal cavity and also the interaction of leukocytes (rolling and adhesion) with endothelial cells. The levels of chemokines CXCL1/KC and CXCL2/MIP-2 were not altered after treatment with EEGP and the aqueous fraction. It was found that the injection of NO pathway antagonists abolished the EEGP and the aqueous fraction inhibitory activity on the neutrophil migration. The expression of intercellular adhesion molecule type 1 (ICAM-1) was reduced, and nitrite levels increased after treatment with EEGP and aqueous fraction. In the carrageenan-induced paw edema model, EEGP and the aqueous fraction showed antiedema activity. No pattern of flavonoid and phenolic acid commonly found in propolis samples of Apis mellifera could be detected in the aqueous fraction samples. These data indicate that the aqueous fraction found has promising bioactive substances with anti-inflammatory activity.

  16. 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...

  17. Triazine herbicides inhibit relaxin signaling and disrupt nitric oxide homeostasis

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

    Park, Si Eun; Lim, Sa Rang; Choi, Hyung-kyoon

    Triazines are herbicides that are widely used worldwide, and we previously observed that the maternal exposure of mice to simazine (50 or 500 μg/kg) resulted in smaller ovaries and uteri of their female offspring. Here, we investigated the underlying mechanism that may account for the reproductive dysfunction induced by simazine. We found that following maternal exposure, simazine is transmitted to the offspring, as evidenced by its presence in the offspring ovaries. Analyses of the simazine-exposed offspring revealed that the expression of the relaxin hormone receptor, relaxin-family peptide receptor 1 (RXFP1), prominently decreased in their ovaries and uteri. In addition, downstreammore » target genes of the relaxin pathway including nitric oxide (NO) synthase 2 (Nos2), Nos3, matrix metallopeptidase 9 (Mmp9), and vascular endothelial growth factor (Vegf) were downregulated in their ovaries. Moreover, AKT and extracellular signal-regulated kinases (ERK) levels and their phosphorylated active forms decreased in simazine-exposed ovaries. In vitro exposure of the human ovarian granulosa cells (KGN) and uterine endometrium cells (Hec-1A) to very low concentrations (0.001 to 1 nM) of triazines including atrazine, terbuthylazine, and propazine repressed NO production with a concurrent reduction in RXFP1, NOS2, and NOS3. The inhibitory action of triazines on NO release was dependent on RXFP1, phosphoinositol 3-kinase (PI3K)/AKT, and ERK. Radioligand-binding assay also confirmed that triazines competitively inhibited the binding of relaxin to its receptor. Therefore, the present study suggests that triazine herbicides act as endocrine disrupters by interfering with relaxin hormone signaling. Thus, further evaluation of their impact on human health is imperative. - Highlights: • Triazines downregulate critical molecules involved in the relaxin signaling pathway. • Triazines act as potent antagonists of binding of relaxin to its receptor. • Triazines disrupt nitric

  18. Participation of the nitric oxide-cyclic GMP-ATP-sensitive K(+) channel pathway in the antinociceptive action of ketorolac.

    PubMed

    Lázaro-Ibáñez, G G; Torres-López, J E; Granados-Soto, V

    2001-08-24

    The involvement of nitric oxide (NO), cyclic GMP and ATP-sensitive K(+) channels in the antinociceptive effect of ketorolac was assessed using the formalin test in the rat. Local administration of ketorolac in a formalin-injured paw produced a dose-dependent antinociceptive effect due to a local action, as drug administration in the contralateral paw was ineffective. Pretreatment of the injured paw with N(G)-L-nitro-arginine methyl ester (L-NAME, an NO synthesis inhibitor), 1H-(1,2,4)-oxadiazolo(4,2-a)quinoxalin-1-one (ODQ, a soluble guanylyl cyclase inhibitor) or glibenclamide (an ATP-sensitive K(+) channel blocker) prevented ketorolac-induced antinociception. However, pretreatment with saline or N(G)-D-nitro-arginine methyl ester (D-NAME) did not block antinociception. Local administration of S-nitroso-N-acetylpenicillamine (SNAP, an NO donor) was inactive by itself, but increased the effect of ketorolac. The present results suggest that the antinociceptive effect of ketorolac involves activation of the NO-cyclic GMP pathway, followed by an opening of ATP-sensitive K(+) channels at the peripheral level.

  19. 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

  20. Interactions between cytokines and nitric oxide.

    PubMed

    Liew, F Y

    1995-01-01

    There is now an impressive range of evidence supporting the important role of cytokines in sleep regulation (see Krueger et al., 1995; De Simoni et al., 1995). It has also been reported that inhibition of nitric oxide (NO) synthesis suppresses sleep in rabbits (Kapás et al., 1994). This is not surprising, since NO is closely involved in neurotransmission (Garthwaite, 1991; Schuman and Madison, 1994) and cytokines are the major inducers of NO synthesis (Hibbs et al., 1990). Further, it is now clear that NO plays an important role in modulating immune responses, possibly through the differential regulation of cytokine synthesis (Taylor-Robinson et al., 1994). In this article, I will provide evidence for the interactions between cytokines and nitric oxide, and discuss their implications in the regulation of immune responses. I shall illustrate these mainly with results from my coworkers and I, from our laboratory rather than attempting an exhaustive review of the subject.

  1. 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

  2. Nitric oxide signalling and neuronal nitric oxide synthase in the heart under stress.

    PubMed

    Zhang, Yin Hua

    2017-01-01

    Nitric oxide (NO) is an imperative regulator of the cardiovascular system and is a critical mechanism in preventing the pathogenesis and progression of the diseased heart. The scenario of bioavailable NO in the myocardium is complex: 1) NO is derived from both endogenous NO synthases (endothelial, neuronal, and/or inducible NOSs [eNOS, nNOS, and/or iNOS]) and exogenous sources (entero-salivary NO pathway) and the amount of NO from exogenous sources varies significantly; 2) NOSs are located at discrete compartments of cardiac myocytes and are regulated by distinctive mechanisms under stress; 3) NO regulates diverse target proteins through different modes of post-transcriptional modification (soluble guanylate cyclase [sGC]/cyclic guanosine monophosphate [cGMP]/protein kinase G [PKG]-dependent phosphorylation, S -nitrosylation, and transnitrosylation); 4) the downstream effectors of NO are multidimensional and vary from ion channels in the plasma membrane to signalling proteins and enzymes in the mitochondria, cytosol, nucleus, and myofilament; 5) NOS produces several radicals in addition to NO (e.g. superoxide, hydrogen peroxide, peroxynitrite, and different NO-related derivatives) and triggers redox-dependent responses. However, nNOS inhibits cardiac oxidases to reduce the sources of oxidative stress in diseased hearts. Recent consensus indicates the importance of nNOS protein in cardiac protection under pathological stress. In addition, a dietary regime with high nitrate intake from fruit and vegetables together with unsaturated fatty acids is strongly associated with reduced cardiovascular events. Collectively, NO-dependent mechanisms in healthy and diseased hearts are better understood and shed light on the therapeutic prospects for NO and NOSs in clinical applications for fatal human heart diseases.

  3. 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.

  4. Nitric Oxide Mediates Glutamate-Linked Enhancement of cGMP Levels in the Cerebellum

    NASA Astrophysics Data System (ADS)

    Bredt, David S.; Snyder, Solomon H.

    1989-11-01

    Nitric oxide, which mediates influences of numerous neurotransmitters and modulators on vascular smooth muscle and leukocytes, can be formed in the brain from arginine by an enzymatic activity that stoichiometrically generates citrulline. We show that glutamate and related amino acids, such as N-methyl-D-aspartate, markedly stimulate arginine-citrulline transformation in cerebellar slices stoichiometrically with enhancement of cGMP levels. Nω-monomethyl-L-arginine blocks the augmentation both of citrulline and cGMP with identical potencies. Arginine competitively reverses both effects of Nω-monomethyl-L-arginine with the same potencies. Hemoglobin, which complexes nitric oxide, prevents the stimulation by N-methyl-D-aspartate of cGMP levels, and superoxide dismutase, which elevates nitric oxide levels, increases cGMP formation. These data establish that nitric oxide mediates the stimulation by glutamate of cGMP formation.

  5. Nitric oxide provokes tumor necrosis factor-alpha expression in adult feline myocardium through a cGMP-dependent pathway.

    PubMed

    Kalra, D; Baumgarten, G; Dibbs, Z; Seta, Y; Sivasubramanian, N; Mann, D L

    2000-09-12

    The mechanism(s) responsible for the persistent coexpression of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) in the failing heart is unknown. To determine whether NO was sufficient to provoke TNF-alpha biosynthesis, we examined the effects of an NO donor, S-nitroso-N-acetyl penicillamine (SNAP), in buffer-perfused Langendorff hearts. SNAP (1 micromol/L) treatment resulted in a time- and dose-dependent increase in myocardial TNF-alpha mRNA and protein biosynthesis in adult cat hearts. The effects of SNAP were completely abrogated by a NO quenching agent, 2-(4-carboxyphenyl)-4, 4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (C-PTIO), and mimicked by sodium nitroprusside. Electrophoretic mobility shift assays demonstrated that SNAP treatment led to the rapid induction of nuclear factor kappa-beta (NF-kappaB) but not AP-1. The importance of the cGMP pathway in terms of mediating NO-induced TNF-alpha biosynthesis was shown by studies that demonstrated that 8-bromo-cGMP mimicked the effects of SNAP and that the effects of SNAP could be completely abrogated using a cGMP antagonist, 1H-(1,2, 4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ), or protein kinase G antagonist (Rp-8-Br-cGMPS). SNAP and 8-Br-cGMP were both sufficient to lead to the site-specific phosphorylation (serine 32) and degradation of IkappaBalpha in isolated cardiac myocytes. Finally, protein kinase G was sufficient to directly phosphorylate IkappaBalpha on serine 32, a critical step in the activation of NF-kappaB. These studies show that NO provokes TNF-alpha biosynthesis through a cGMP-dependent pathway, which suggests that the coincident expression of TNF-alpha and NO may foster self-sustaining positive autocrine/paracrine feedback inflammatory circuits within the failing heart.

  6. Demystified … Nitric oxide

    PubMed Central

    Stuart-Smith, K

    2002-01-01

    The discovery of nitric oxide (NO) demonstrated that cells could communicate via the manufacture and local diffusion of an unstable lipid soluble molecule. Since the original demonstration of the vascular relaxant properties of endothelium derived NO, this fascinating molecule has been shown to have multiple, complex roles within many biological systems. This review cannot hope to cover all of the recent advances in NO biology, but seeks to place the discovery of NO in its historical context, and show how far our understanding has come in the past 20 years. The role of NO in mitochondrial respiration, and consequently in oxidative stress, is described in detail because these processes probably underline the importance of NO in the development of disease. PMID:12456772

  7. 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

  8. 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.

  9. Olfactory ensheathing cells: nitric oxide production and innate immunity.

    PubMed

    Harris, Julie A; West, Adrian K; Chuah, Meng Inn

    2009-12-01

    Olfactory nerves extend from the nasal cavity to the central nervous system and provide therefore, a direct route for pathogenic infection of the brain. Since actual infection by this route remains relatively uncommon, powerful endogenous mechanisms for preventing microbial infection must exist, but these remain poorly understood. Our previous studies unexpectedly revealed that the unique glial cells that ensheath olfactory nerves, olfactory ensheathing cells (OECs), expressed components of the innate immune response. In this study, we show that OECs are able to detect and respond to bacterial challenge via the synthesis of nitric oxide. In vitro studies revealed that inducible nitric oxide synthase (iNOS) mRNA and protein were present in Escherichia coli- and Staphylococcus aureus-incubated OECs, but were barely detectable in untreated OECs. Neuronal NOS and endothelial NOS were not expressed by OECs pre- and post-bacterial incubation. Nuclear translocation of nuclear factor kappa B (NFkappaB), detectable in the majority of OECs 1 h following bacterial incubation, preceded iNOS induction which resulted in the production of nitric oxide. N(G)-methyl-L-arginine significantly attenuated nitric oxide (P < 0.001) and nitrite production (P < 0.001) by OECs. In rat olfactory mucosa which was compromised by irrigation with 0.17M zinc sulfate or 0.7% Triton X-100 to facilitate bacterial infiltration, OECs contributed to a robust synthesis of iNOS. These data strongly support the hypothesis that OECs are an essential component of the innate immune response against bacterial invasion of the central nervous system via olfactory nerves.

  10. 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...

  11. Relationship between endothelial nitric oxide synthase (eNOS) and natural history of intracranial aneurysms: meta-analysis.

    PubMed

    Paschoal, Eric Homero Albuquerque; Yamaki, Vitor Nagai; Teixeira, Renan Kleber Costa; Paschoal Junior, Fernando Mendes; Jong-A-Liem, Glaucia Suzanna; Teixeira, Manoel Jacobsen; Yamada, Elizabeth Sumi; Ribeiro-Dos-Santos, Ândrea; Bor-Seng-Shu, Edson

    2018-01-01

    The aneurysmal subarachnoid hemorrhage is a major public health problem described as a sudden drastic event with no warning symptoms and high morbidity and mortality rates. The role of the endothelial isoform of nitric oxide synthase gene polymorphism in intracranial aneurysms (IAs) is still a matter of controversy with divergent findings among European, American, and Asian populations. Our study purposed to test the association between intracranial aneurysms formation and nitric oxide gene polymorphisms through a systematic review and meta-analysis. Systematic search on Medline, Lilacs, and EMBASE was performed. The primary search resulted in 139 papers, out of which 9 met our inclusion criteria after a full text analysis. The dominant T786C model found a significant association with IA (OR 1.22, 95 % CI 1.04-1.44, p = 0.01), so did studies of the recessive T786C model (OR 0.37, 95 % CI 0.30-0.45, p < 0.0001) but with opposite effect. Our findings support the presence of the T786C polymorphism as a predictor for the development of intracranial aneurysm in the cerebral vascular system. More studies are necessary in order to elucidate the pathways of the endothelial nitric oxide synthase (eNOS) in cerebrovascular diseases and in defining how different allelic combinations of the eNOS gene single-nucleotide polymorphism (SNP) could favor this pathological process.

  12. 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

  13. 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.

  14. Transcriptional activation of the human inducible nitric-oxide synthase promoter by Kruppel-like factor 6.

    PubMed

    Warke, Vishal G; Nambiar, Madhusoodana P; Krishnan, Sandeep; Tenbrock, Klaus; Geller, David A; Koritschoner, Nicolas P; Atkins, James L; Farber, Donna L; Tsokos, George C

    2003-04-25

    Nitric oxide is a ubiquitous free radical that plays a key role in a broad spectrum of signaling pathways in physiological and pathophysiological processes. We have explored the transcriptional regulation of inducible nitric-oxide synthase (iNOS) by Krüppel-like factor 6 (KLF6), an Sp1-like zinc finger transcription factor. Study of serial deletion constructs of the iNOS promoter revealed that the proximal 0.63-kb region can support a 3-6-fold reporter activity similar to that of the full-length 16-kb promoter. Within the 0.63-kb region, we identified two CACCC sites (-164 to -168 and -261 to -265) that bound KLF6 in both electrophoretic mobility shift and chromatin immunoprecipitation assays. Mutation of both these sites abrogated the KLF6-induced enhancement of the 0.63-kb iNOS promoter activity. The binding of KLF6 to the iNOS promoter was significantly increased in Jurkat cells, primary T lymphocytes, and COS-7 cells subjected to NaCN-induced hypoxia, heat shock, serum starvation, and phorbol 12-myristate 13-acetate/ ionophore stimulation. Furthermore, in KLF6-transfected and NaCN-treated COS-7 cells, there was a 3-4-fold increase in the expression of the endogenous iNOS mRNA and protein that correlated with increased production of nitric oxide. These findings indicate that KLF6 is a potential transactivator of the human iNOS promoter in diverse pathophysiological conditions.

  15. 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

  16. Combined Cytological and Transcriptomic Analysis Reveals a Nitric Oxide Signaling Pathway Involved in Cold-Inhibited Camellia sinensis Pollen Tube Growth

    PubMed Central

    Wang, Weidong; Sheng, Xianyong; Shu, Zaifa; Li, Dongqin; Pan, Junting; Ye, Xiaoli; Chang, Pinpin; Li, Xinghui; Wang, Yuhua

    2016-01-01

    Nitric oxide (NO) as a signaling molecule plays crucial roles in many abiotic stresses in plant development processes, including pollen tube growth. Here, the signaling networks dominated by NO during cold stress that inhibited Camellia sinensis pollen tube growth are investigated in vitro. Cytological analysis show that cold-induced NO is involved in the inhibition of pollen tube growth along with disruption of the cytoplasmic Ca2+ gradient, increase in ROS content, acidification of cytoplasmic pH and abnormalities in organelle ultrastructure and cell wall component distribution in the pollen tube tip. Furthermore, differentially expressed genes (DEGs)-related to signaling pathway, such as NO synthesis, cGMP, Ca2+, ROS, pH, actin, cell wall, and MAPK cascade signal pathways, are identified and quantified using transcriptomic analyses and qRT-PCR, which indicate a potential molecular mechanism for the above cytological results. Taken together, these findings suggest that a complex signaling network dominated by NO, including Ca2+, ROS, pH, RACs signaling and the crosstalk among them, is stimulated in the C. sinensis pollen tube in response to cold stress, which further causes secondary and tertiary alterations, such as ultrastructural abnormalities in organelles and cell wall construction, ultimately resulting in perturbed pollen tube extension. PMID:27148289

  17. Neuropeptide Y stimulates retinal neural cell proliferation--involvement of nitric oxide.

    PubMed

    Alvaro, Ana Rita; Martins, João; Araújo, Inês M; Rosmaninho-Salgado, Joana; Ambrósio, António F; Cavadas, Cláudia

    2008-06-01

    Neuropeptide Y (NPY) is a 36 amino acid peptide widely present in the CNS, including the retina. Previous studies have demonstrated that NPY promotes cell proliferation of rat post-natal hippocampal and olfactory epithelium precursor cells. The aim of this work was to investigate the role of NPY on cell proliferation of rat retinal neural cells. For this purpose, primary retinal cell cultures expressing NPY, and NPY Y(1), Y(2), Y(4) and Y(5) receptors [Alvaro et al., (2007) Neurochem. Int., 50, 757] were used. NPY (10-1000 nM) stimulated cell proliferation through the activation of NPY Y(1), Y(2) and Y(5) receptors. NPY also increased the number of proliferating neuronal progenitor cells (BrdU(+)/nestin(+) cells). The intracellular mechanisms coupled to NPY receptors activation that mediate the increase in cell proliferation were also investigated. The stimulatory effect of NPY on cell proliferation was reduced by L-nitroarginine-methyl-esther (L-NAME; 500 microM), a nitric oxide synthase inhibitor, 1H-[1,2,4]oxadiazolo-[4, 3-a]quinoxalin-1-one (ODQ; 20 microM), a soluble guanylyl cyclase inhibitor or U0126 (1 microM), an inhibitor of the extracellular signal-regulated kinase 1/2 (ERK 1/2). In conclusion, NPY stimulates retinal neural cell proliferation, and this effect is mediated through nitric oxide-cyclic GMP and ERK 1/2 pathways.

  18. 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 ...

  19. 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.

  20. 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 ...

  1. 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

  2. Ex vivo immunomodulatory effect of ethanolic extract of propolis during Celiac Disease: involvement of nitric oxide pathway.

    PubMed

    Medjeber, Oussama; Touri, Kahina; Rafa, Hayet; Djeraba, Zineb; Belkhelfa, Mourad; Boutaleb, Amira Fatima; Arroul-Lammali, Amina; Belguendouz, Houda; Touil-Boukoffa, Chafia

    2018-03-07

    Celiac Disease (CeD) is a chronic immune-mediated enteropathy, in which dietary gluten induces an inflammatory reaction, predominantly in the duodenum. Propolis is a resinous hive product, collected by honeybees from various plant sources. Propolis is well-known for its anti-inflammatory, anti-oxidant and immunomodulatory effects, due to its major compounds, polyphenols and flavonoids. The aim of our study was to assess the ex vivo effect of ethanolic extract of propolis (EEP) upon the activity and expression of iNOS, along with IFN-γ and IL-10 production in Algerian Celiac patients. In this context, PBMCs isolated from peripheral blood of Celiac patients and healthy controls were cultured with different concentrations of EEP. NO production was measured using the Griess method, whereas quantitation of IFN-γ and IL-10 levels was performed by ELISA. Inducible nitric oxide synthase (iNOS) expression, NFκB and pSTAT-3 activity were analyzed by immunofluorescence assay. Our results showed that PBMCs from Celiac patients produced high levels of NO and IFN-γ compared with healthy controls (HC). Interestingly, EEP reduced significantly, NO and IFN-γ levels and significantly increased IL-10 levels at a concentration of 50 µg/mL. Importantly, EEP downmodulated the iNOS expression as well as the activity of NFκB and pSTAT-3 transcription factors. Altogether, our results highlight the immunomodulatory effect of propolis on NO pathway and on pro-inflammatory cytokines. Therefore, we suggest that propolis may constitute a potential candidate to modulate inflammation during Celiac Disease and has a potential therapeutic value.

  3. 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.

  4. Nitric oxide production from macrophages is regulated by arachidonic acid metabolites.

    PubMed

    Imai, Y; Kolb, H; Burkart, V

    1993-11-30

    In activated macrophages the inducible form of the enzyme nitric oxide (NO) synthase generates high amounts of the toxic mediator NO. After 20 h of treatment with LPS rat peritoneal macrophages release 12-16 nmol NO2-/10(5) cells which is detectable in the culture supernatant by the Griess reaction as a measure of NO formation. The addition of aminoguanidine (1 mM), a preferential inhibitor of the inducible NO-synthase, completely abolished NO2-accumulation. Incubation with indomethacin or acetyl-salicylic acid, preferential inhibitors of the cyclooxygenase pathway of the arachidonic acid metabolism, did not influence NO2- levels. Nordihydro-guaiaretic acid (50 microM), a preferential inhibitor of the lipoxygenase pathway, caused strong reduction of NO2- accumulation to 1.9 +/- 0.3 nmol/200 microliter. Simultaneous inhibition of cyclo- and lipoxygenase by BW755c resulted in an intermediate effect (7.3 +/- 1.1 nmol/200 microliter NO2-). These results show that the induction of NO production in activated macrophages is regulated by products of the lipoxygenase-pathway of the arachidonic acid metabolism.

  5. Agmatine attenuates reserpine-induced oral dyskinesia in mice: Role of oxidative stress, nitric oxide and glutamate NMDA receptors.

    PubMed

    Cunha, Andréia S; Matheus, Filipe C; Moretti, Morgana; Sampaio, Tuane B; Poli, Anicleto; Santos, Danúbia B; Colle, Dirleise; Cunha, Mauricio P; Blum-Silva, Carlos H; Sandjo, Louis P; Reginatto, Flávio H; Rodrigues, Ana Lúcia S; Farina, Marcelo; Prediger, Rui D

    2016-10-01

    Dyskinesia consists in a series of trunk, limbs and orofacial involuntary movements that can be observed following long-term pharmacological treatment in some psychotic and neurological disorders such as schizophrenia and Parkinson's disease, respectively. Agmatine is an endogenous arginine metabolite that emerges as neuromodulator and a promising agent to manage diverse central nervous system disorders by modulating nitric oxide (NO) pathway, glutamate NMDA receptors and oxidative stress. Herein, we investigated the effects of a single intraperitoneal (i.p.) administration of different agmatine doses (10, 30 or 100mg/kg) against the orofacial dyskinesia induced by reserpine (1mg/kg,s.c.) in mice by measuring the vacuous chewing movements and tongue protusion frequencies, and the duration of facial twitching. The results showed an orofacial antidyskinetic effect of agmatine (30mg/kg, i.p.) or the combined administration of sub-effective doses of agmatine (10mg/kg, i.p.) with the NMDA receptor antagonists amantadine (1mg/kg, i.p.) and MK801 (0.01mg/kg, i.p.) or the neuronal nitric oxide synthase (NOS) inhibitor 7-nitroindazole (7-NI; 0.1mg/kg, i.p.). Reserpine-treated mice displayed locomotor activity deficits in the open field and agmatine had no effect on this response. Reserpine increased nitrite and nitrate levels in cerebral cortex, but agmatine did not reverse it. Remarkably, agmatine reversed the decrease of dopamine and non-protein thiols (NPSH) levels caused by reserpine in the striatum. However, no changes were observed in striatal immunocontent of proteins related to the dopaminergic system including tyrosine hydroxylase, dopamine transporter, vesicular monoamine transporter type 2, pDARPP-32[Thr75], dopamine D1 and D2 receptors. These results indicate that the blockade of NO pathway, NMDAR and oxidative stress are possible mechanisms associated with the protective effects of agmatine against the orofacial dyskinesia induced by reserpine in mice

  6. Cuminum cyminum, a dietary spice, attenuates hypertension via endothelial nitric oxide synthase and NO pathway in renovascular hypertensive rats.

    PubMed

    Kalaivani, Periyathambi; Saranya, Ramesh Babu; Ramakrishnan, Ganapathy; Ranju, Vijayan; Sathiya, Sekar; Gayathri, Veeraraghavan; Thiyagarajan, Lakshmi Kantham; Venkhatesh, Jayakothanda Ramaswamy; Babu, Chidambaram Saravana; Thanikachalam, Sadagopan

    2013-01-01

    Cuminum cyminum (CC) is a commonly used spice in South Indian foods. It has been traditionally used for the treatment and management of sleep disorders, indigestion, and hypertension. The present study was carried out to scientifically evaluate the anti-hypertensive potential of standardized aqueous extract of CC seeds and its role in arterial endothelial nitric oxide synthase expression, inflammation, and oxidative stress in renal hypertensive rats. Renal hypertension was induced by the two-kidney one-clip (2K/1C) method in rats. Systolic blood pressure (SBP), plasma nitrate/nitrite, carotid-eNOS, renal-TNF-α, IL-6, Bax, Bcl-2, thioredoxin 1 (TRX1), and thioredoxin reductase 1 (TRXR1) mRNA expressions were studied to demonstrate the anti-hypertensive action of CC. Cuminum cyminum was administered orally (200 mg/kg b.wt) for a period of 9 weeks; it improved plasma nitric oxide and decreased the systolic blood pressure in hypertensive rats. It also up-regulated the gene expression of eNOS, Bcl-2, TRX1, and TRXR1; and down-regulated Bax, TNF-α, and IL-6. These data reveal that CC seeds augment endothelial functions and ameliorate inflammatory and oxidative stress in hypertensive rats. The present report is the first of its kind to demonstrate the mechanism of anti-hypertensive action of CC seeds in an animal model of renovascular hypertension.

  7. Nitric oxide balances osteoblast and adipocyte lineage differentiation via the JNK/MAPK signaling pathway in periodontal ligament stem cells.

    PubMed

    Yang, Shan; Guo, Lijia; Su, Yingying; Wen, Jing; Du, Juan; Li, Xiaoyan; Liu, Yitong; Feng, Jie; Xie, Yongmei; Bai, Yuxing; Wang, Hao; Liu, Yi

    2018-05-02

    Critical tissues that undergo regeneration in periodontal tissue are of mesenchymal origin; thus, investigating the regulatory mechanisms underlying the fate of periodontal ligament stem cells could be beneficial for application in periodontal tissue regeneration. Nitric oxide (NO) regulates many biological processes in developing embryos and adult stem cells. The present study was designed to investigate the effects of NO on the function of human periodontal ligament stem cells (PDLSCs) as well as to elucidate the underlying molecular mechanisms. Immunofluorescent staining and flow cytometry were used for stem cell identification. Western blot, reverse transcription polymerase chain reaction (RT-PCR), immunofluorescent staining, and flow cytometry were used to examine the expression of NO-synthesizing enzymes. The proliferative capacity of PDLSCs was determined by EdU assays. The osteogenic potential of PDLSCs was tested using alkaline phosphatase (ALP) staining, Alizarin Red staining, and calcium concentration detection. Oil Red O staining was used to analyze the adipogenic ability. Western blot, RT-PCR, and staining were used to examine the signaling pathway. Human PDLSCs expressed both inducible NO synthase (iNOS) and endothelial NO synthase (eNOS) and produced NO. Blocking the generation of NO with the NOS inhibitor L-N G -monomethyl arginine (L-NMMA) had no influence on PDLSC proliferation and apoptosis but significantly attenuated the osteogenic differentiation capacity and stimulated the adipogenic differentiation capacity of PDLSCs. Increasing the physiological level of NO with NO donor sodium nitroprusside (SNP) significantly promoted the osteogenic differentiation capacity but reduced the adipogenic differentiation capacity of PDLSCs. NO balances the osteoblast and adipocyte lineage differentiation in periodontal ligament stem cells via the c-Jun N-terminal kinase (JNK)/mitogen-activated protein kinase (MAPK) signaling pathway. NO is essential for

  8. [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.

  9. Role of nitric oxide in additive anticonvulsant effects of agmatine and morphine.

    PubMed

    Payandemehr, Borna; Rahimian, Reza; Bahremand, Arash; Ebrahimi, Ali; Saadat, Seyedehpariya; Moghaddas, Peiman; Fadakar, Kaveh; Derakhshanian, Hoda; Dehpour, Ahmad Reza

    2013-06-13

    The anticonvulsant effects of agmatine, an endogenous polyamine and a metabolite of l-arginine, have been shown in various experimental seizure models. Agmatine also potentiates the anti-seizure activity of morphine. The present study aimed to investigate a possible involvement of nitric oxide (NO) pathway in the protection by agmatine and morphine co-administration against pentylenetetrazole (PTZ) -induced seizure in male mice. To this end, the thresholds for the clonic seizures induced by the intravenous administration of PTZ, a GABA antagonist, were assessed. Intraperitoneal administration of morphine at lower dose (1mg/kg) increased the seizure threshold. Also intraperitoneal administration of agmatine (5 and 10mg/kg) increased the seizure threshold significantly. Combination of subeffective doses of morphine and agmatine led to potent anticonvulsant effects. Non-effective doses of morphine (0.1 and 0.5mg/kg) were able to induce anticonvulsant effects in mice pretreated with agmatine (3mg/kg). Concomitant administration of either the non-selective nitric oxide synthase (NOS) inhibitor L-NAME (1, 5mg/kg, i.p.) or the selective NOS inhibitor 7-NI (15, 30mg/kg, i.p.), with an ineffective combination of morphine (0.1mg/kg) plus agmatine (1mg/kg) produced significant anticonvulsant impacts. Moreover, the NO precursor, l-arginine (30, 60mg/kg, i.p.), inhibited the anticonvulsant action of agmatine (3mg/kg) plus morphine (0.5mg/kg) co-administration. Our results indicate that pretreatment of animals with agmatine enhances the anticonvulsant effects of morphine via a mechanism which may involve the NO pathway. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. 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...

  11. A shortcut to wide-ranging biological actions of dietary polyphenols: modulation of the nitrate-nitrite-nitric oxide pathway in the gut.

    PubMed

    Rocha, Bárbara S; Nunes, Carla; Pereira, Cassilda; Barbosa, Rui M; Laranjinha, João

    2014-08-01

    Dietary polyphenols are complex, natural compounds with recognized health benefits. Initially attractive to the biomedical area due to their in vitro antioxidant properties, the biological implications of polyphenols are now known to be far from their acute ability to scavenge free radicals but rather to modulate redox signaling pathways. Actually, it is now recognized that dietary polyphenols are extensively metabolized in vivo and that the chemical, biophysical and biological properties of their metabolites are, in most cases, quite different from the ones of the parent molecules. Hence, the study of the metabolic, absorptive and signaling pathways of both phenolics and derivatives has become a major issue. In this paper we propose a short-cut for the systemic effects of polyphenols in connection with nitric oxide (˙NO) biology. This free radical is a ubiquitous signaling molecule with pivotal functions in vivo. It is produced through an enzymatic pathway and also through the reduction of dietary nitrate and nitrite in the human stomach. At acidic gastric pH, dietary polyphenols, in the form they are conveyed in foods and at high concentration, not only promote nitrite reduction to ˙NO but also embark in a complex network of chemical reactions to produce higher nitrogen oxides with signaling functions, namely by inducing post-translational modifications. Modified endogenous molecules, such as nitrated proteins and lipids, acquire important physiological functions. Thus, local and systemic effects of ˙NO such as modulation of vascular tone, mucus production in the gut and protection against ischemia-reperfusion injury are, in this sense, triggered by dietary polyphenols. Evidence to support the signaling and biological effects of polyphenols by modulation of the nitrate-nitrite-NO pathway will be herein provided and discussed. General actions of polyphenols encompassing absorption and metabolism in the intestine/liver are short-cut via the production of

  12. Skeletal Muscle Function during Exercise—Fine-Tuning of Diverse Subsystems by Nitric Oxide

    PubMed Central

    Suhr, Frank; Gehlert, Sebastian; Grau, Marijke; Bloch, Wilhelm

    2013-01-01

    Skeletal muscle is responsible for altered acute and chronic workload as induced by exercise. Skeletal muscle adaptations range from immediate change of contractility to structural adaptation to adjust the demanded performance capacities. These processes are regulated by mechanically and metabolically induced signaling pathways, which are more or less involved in all of these regulations. Nitric oxide is one of the central signaling molecules involved in functional and structural adaption in different cell types. It is mainly produced by nitric oxide synthases (NOS) and by non-enzymatic pathways also in skeletal muscle. The relevance of a NOS-dependent NO signaling in skeletal muscle is underlined by the differential subcellular expression of NOS1, NOS2, and NOS3, and the alteration of NO production provoked by changes of workload. In skeletal muscle, a variety of highly relevant tasks to maintain skeletal muscle integrity and proper signaling mechanisms during adaptation processes towards mechanical and metabolic stimulations are taken over by NO signaling. The NO signaling can be mediated by cGMP-dependent and -independent signaling, such as S-nitrosylation-dependent modulation of effector molecules involved in contractile and metabolic adaptation to exercise. In this review, we describe the most recent findings of NO signaling in skeletal muscle with a special emphasis on exercise conditions. However, to gain a more detailed understanding of the complex role of NO signaling for functional adaptation of skeletal muscle (during exercise), additional sophisticated studies are needed to provide deeper insights into NO-mediated signaling and the role of non-enzymatic-derived NO in skeletal muscle physiology. PMID:23538841

  13. 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.

  14. 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.

  15. Pharmacological Prevention and Reversion of Erectile Dysfunction After Radical Prostatectomy, by Modulation of Nitric Oxide/cGMP Pathways

    DTIC Science & Technology

    2009-03-01

    then sacrificed, body weights obtained, and paraffin-embedded tissue sections from the skin - denuded penile shaft were subjected to Masson trichrome...responsible for vasculogenic erectile dysfunction (ED) associated with aging , smoking, diabetes, hypertension, and post-radical prostatectomy. These...Pending. PI: Gonzalez-Cadavid NF (2009). Erectile Dysfunction and Nitric Oxide Synthase in Aging . RO1 DK53069-07 (resubmission). 11/09-10/14. No

  16. Microglia P2Y₆ receptors mediate nitric oxide release and astrocyte apoptosis.

    PubMed

    Quintas, Clara; Pinho, Diana; Pereira, Clara; Saraiva, Lucília; Gonçalves, Jorge; Queiroz, Glória

    2014-09-03

    During cerebral inflammation uracil nucleotides leak to the extracellular medium and activate glial pyrimidine receptors contributing to the development of a reactive phenotype. Chronically activated microglia acquire an anti-inflammatory phenotype that favors neuronal differentiation, but the impact of these microglia on astrogliosis is unknown. We investigated the contribution of pyrimidine receptors to microglia-astrocyte signaling in a chronic model of inflammation and its impact on astrogliosis. Co-cultures of astrocytes and microglia were chronically treated with lipopolysaccharide (LPS) and incubated with uracil nucleotides for 48 h. The effect of nucleotides was evaluated in methyl-[3H]-thymidine incorporation. Western blot and immunofluorescence was performed to detect the expression of P2Y6 receptors and the inducible form of nitric oxide synthase (iNOS). Nitric oxide (NO) release was quantified through Griess reaction. Cell death was also investigated by the LDH assay and by the TUNEL assay or Hoechst 33258 staining. UTP, UDP (0.001 to 1 mM) or PSB 0474 (0.01 to 10 μM) inhibited cell proliferation up to 43 ± 2% (n = 10, P <0.05), an effect prevented by the selective P2Y6 receptor antagonist MRS 2578 (1 μM). UTP was rapidly metabolized into UDP, which had a longer half-life. The inhibitory effect of UDP (1 mM) was abolished by phospholipase C (PLC), protein kinase C (PKC) and nitric oxide synthase (NOS) inhibitors. Both UDP (1 mM) and PSB 0474 (10 μM) increased NO release up to 199 ± 20% (n = 4, P <0.05), an effect dependent on P2Y6 receptors-PLC-PKC pathway activation, indicating that this pathway mediates NO release. Western blot and immunocytochemistry analysis indicated that P2Y6 receptors were expressed in the cultures being mainly localized in microglia. Moreover, the expression of iNOS was mainly observed in microglia and was upregulated by UDP (1 mM) or PSB 0474 (10 μM). UDP-mediated NO release induced apoptosis in astrocytes

  17. Nicorandil, a Nitric Oxide Donor and ATP-Sensitive Potassium Channel Opener, Protects Against Dystrophin-Deficient Cardiomyopathy

    PubMed Central

    Afzal, Muhammad Z.; Reiter, Melanie; Gastonguay, Courtney; McGivern, Jered V.; Guan, Xuan; Ge, Zhi-Dong; Mack, David L.; Childers, Martin K.; Ebert, Allison D.; Strande, Jennifer L.

    2016-01-01

    Background Dystrophin-deficient cardiomyopathy is a growing clinical problem without targeted treatments. We investigated whether nicorandil promotes cardioprotection in human dystrophin-deficient induced pluripotent stem cell (iPSC)-derived cardiomyocytes and the muscular dystrophy mdx mouse heart. Methods and Results Dystrophin-deficient iPSC-derived cardiomyocytes had decreased levels of endothelial nitric oxide synthase and neuronal nitric oxide synthase. The dystrophin-deficient cardiomyocytes had increased cell injury and death after 2 hours of stress and recovery. This was associated with increased levels of reactive oxygen species and dissipation of the mitochondrial membrane potential. Nicorandil pretreatment was able to abolish these stress-induced changes through a mechanism that involved the nitric oxide–cyclic guanosine monophosphate pathway and mitochondrial adenosine triphosphate-sensitive potassium channels. The increased reactive oxygen species levels in the dystrophin-deficient cardiomyocytes were associated with diminished expression of select antioxidant genes and increased activity of xanthine oxidase. Furthermore, nicorandil was found to improve the restoration of cardiac function after ischemia and reperfusion in the isolated mdx mouse heart. Conclusion Nicorandil protects against stress-induced cell death in dystrophin-deficient cardiomyocytes and preserves cardiac function in the mdx mouse heart subjected to ischemia and reperfusion injury. This suggests a potential therapeutic role for nicorandil in dystrophin-deficient cardiomyopathy. PMID:26940570

  18. 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

  19. S-Nitrosylation of Ras Mediates Nitric Oxide-Dependent Post-Injury Neurogenesis in a Seizure Model.

    PubMed

    Santos, Ana Isabel; Carreira, Bruno Pereira; Izquierdo-Álvarez, Alicia; Ramos, Elena; Lourenço, Ana Sofia; Filipa Santos, Daniela; Morte, Maria Inês; Ribeiro, Luís Filipe; Marreiros, Ana; Sánchez-López, Nuria; Marina, Anabel; Carvalho, Caetana Monteiro; Martínez-Ruiz, Antonio; Araújo, Inês Maria

    2018-01-01

    Nitric oxide (NO) is involved in the upregulation of endogenous neurogenesis in the subventricular zone and in the hippocampus after injury. One of the main neurogenic pathways activated by NO is the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway, downstream of the epidermal growth factor receptor. However, the mechanism by which NO stimulates cell proliferation through activation of the ERK/MAPK pathway remains unknown, although p21Ras seems to be one of the earliest targets of NO. Here, we aimed at studying the possible neurogenic action of NO by post-translational modification of p21Ras as a relevant target for early neurogenic events promoted by NO in neural stem cells (NSCs). We show that NO caused S-nitrosylation (SNO) of p21Ras in Cys118, which triggered downstream activation of the ERK/MAPK pathway and proliferation of NSC. Moreover, in cells overexpressing a mutant Ras in which Cys118 was replaced by a serine-C118S-, cells were insensitive to NO, and no increase in SNO, in ERK phosphorylation, or in cell proliferation was observed. We also show that, after seizures, in the presence of NO derived from inducible nitric oxide synthase, there was an increase in p21Ras cysteine modification that was concomitant with the previously described stimulation of proliferation in the dentate gyrus. Our work identifies p21Ras and its SNO as an early target of NO during signaling events that lead to NSC proliferation and neurogenesis. Our data highlight Ras SNO as an early event leading to NSC proliferation, and they may provide a target for NO-induced stimulation of neurogenesis with implications for brain repair. Antioxid. Redox Signal. 28, 15-30.

  20. Modulation of endothelial nitric oxide by plant-derived products.

    PubMed

    Schmitt, Christoph A; Dirsch, Verena M

    2009-09-01

    Nitric oxide (NO), produced by endothelial nitric oxide synthase (eNOS), is recognised as a central anti-inflammatory and anti-atherogenic principle in the vasculature. Decreased availability of NO in the vasculature promotes the progression of cardiovascular diseases. Epidemiological and clinical studies have demonstrated that a growing list of natural products, as components of the daily diet or phytomedical preparations, may improve vascular function by enhancing NO bioavailability. In this article we first outline common pathways modulating endothelial NO production or bioavailability to provide a basis for subsequent mechanistic discussions. Then we comprehensively review natural products and plant extracts known to positively influence eNOS activity and/or endothelial function in vitro or in vivo. We will discuss red wine, highlighting polyphenols, oligomeric procyanidins (OPC) and resveratrol as modulators of endothelial NO production. Other dietary products and their active components known to activate eNOS include cocoa (OPC and its monomer (-)-epicatechin), pomegranates (polyphenols), black and green tea (flavanoids, especially epigallocatechin gallate), olive oil (oleic acid and polyphenols), soy (genistein), and quercetin, one of the most abundant flavonoids in plants. In addition, phytomedical preparations made from ginkgo, hawthorn and ginseng, as well as formulations used in traditional Chinese Medicine, have been shown to affect endothelial NO production. Recurring phytochemical patterns among active fractions and purified compounds are discussed. In summary, there is increasing evidence that several single natural products and plant extracts influence endothelial NO production. Identification of such compounds and characterisation of their cellular actions may increase our knowledge of the regulation of endothelial NO production and could provide valuable clues for the prevention or treatment of cardiovascular diseases.

  1. Inducible Nitric Oxide Synthase in Heart Tissue and Nitric Oxide in Serum of Trypanosoma cruzi-Infected Rhesus Monkeys: Association with Heart Injury

    PubMed Central

    Carvalho, Cristiano Marcelo Espinola; Silverio, Jaline Coutinho; da Silva, Andrea Alice; Pereira, Isabela Resende; Coelho, Janice Mery Chicarino; Britto, Constança Carvalho; Moreira, Otacílio Cruz; Marchevsky, Renato Sergio; Xavier, Sergio Salles; Gazzinelli, Ricardo Tostes; da Glória Bonecini-Almeida, Maria; Lannes-Vieira, Joseli

    2012-01-01

    Background The factors contributing to chronic Chagas' heart disease remain unknown. High nitric oxide (NO) levels have been shown to be associated with cardiomyopathy severity in patients. Further, NO produced via inducible nitric oxide synthase (iNOS/NOS2) is proposed to play a role in Trypanosoma cruzi control. However, the participation of iNOS/NOS2 and NO in T. cruzi control and heart injury has been questioned. Here, using chronically infected rhesus monkeys and iNOS/NOS2-deficient (Nos2 −/−) mice we explored the participation of iNOS/NOS2-derived NO in heart injury in T. cruzi infection. Methodology Rhesus monkeys and C57BL/6 and Nos2 −/− mice were infected with the Colombian T. cruzi strain. Parasite DNA was detected by polymerase chain reaction, T. cruzi antigens and iNOS/NOS2+ cells were immunohistochemically detected in heart sections and NO levels in serum were determined by Griess reagent. Heart injury was assessed by electrocardiogram (ECG), echocardiogram (ECHO), creatine kinase heart isoenzyme (CK-MB) activity levels in serum and connexin 43 (Cx43) expression in the cardiac tissue. Results Chronically infected monkeys presented conduction abnormalities, cardiac inflammation and fibrosis, which resembled the spectrum of human chronic chagasic cardiomyopathy (CCC). Importantly, chronic myocarditis was associated with parasite persistence. Moreover, Cx43 loss and increased CK-MB activity levels were primarily correlated with iNOS/NOS2+ cells infiltrating the cardiac tissue and NO levels in serum. Studies in Nos2 −/− mice reinforced that the iNOS/NOS2-NO pathway plays a pivotal role in T. cruzi-elicited cardiomyocyte injury and in conduction abnormalities that were associated with Cx43 loss in the cardiac tissue. Conclusion T. cruzi-infected rhesus monkeys reproduce features of CCC. Moreover, our data support that in T. cruzi infection persistent parasite-triggered iNOS/NOS2 in the cardiac tissue and NO overproduction might contribute to CCC

  2. 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)

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. Microglial activation and the nitric oxide/cGMP/PKG pathway underlie enhanced neuronal vulnerability to mitochondrial dysfunction in experimental multiple sclerosis.

    PubMed

    Mancini, Andrea; Tantucci, Michela; Mazzocchetti, Petra; de Iure, Antonio; Durante, Valentina; Macchioni, Lara; Giampà, Carmela; Alvino, Alessandra; Gaetani, Lorenzo; Costa, Cinzia; Tozzi, Alessandro; Calabresi, Paolo; Di Filippo, Massimiliano

    2018-05-01

    During multiple sclerosis (MS), a close link has been demonstrated to occur between inflammation and neuro-axonal degeneration, leading to the hypothesis that immune mechanisms may promote neurodegeneration, leading to irreversible disease progression. Energy deficits and inflammation-driven mitochondrial dysfunction seem to be involved in this process. In this work we investigated, by the use of striatal electrophysiological field-potential recordings, if the inflammatory process associated with experimental autoimmune encephalomyelitis (EAE) is able to influence neuronal vulnerability to the blockade of mitochondrial complex IV, a crucial component for mitochondrial activity responsible of about 90% of total cellular oxygen consumption. We showed that during the acute relapsing phase of EAE, neuronal susceptibility to mitochondrial complex IV inhibition is markedly enhanced. This detrimental effect was counteracted by the pharmacological inhibition of microglia, of nitric oxide (NO) synthesis and its intracellular pathway (involving soluble guanylyl cyclase, sGC, and protein kinase G, PKG). The obtained results suggest that mitochondrial complex IV exerts an important role in maintaining neuronal energetic homeostasis during EAE. The pathological processes associated with experimental MS, and in particular the activation of microglia and of the NO pathway, lead to an increased neuronal vulnerability to mitochondrial complex IV inhibition, representing promising pharmacological targets. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. 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

  9. Effect of Electrode Configuration on Nitric Oxide Gas Sensor Behavior.

    PubMed

    Cui, Ling; Murray, Erica P

    2015-09-23

    The influence of electrode configuration on the impedancemetric response of nitric oxide (NO) gas sensors was investigated for solid electrochemical cells [Au/yttria-stabilized zirconia (YSZ)/Au)]. Fabrication of the sensors was carried out at 1050 °C in order to establish a porous YSZ electrolyte that enabled gas diffusion. Two electrode configurations were studied where Au wire electrodes were either embedded within or wrapped around the YSZ electrolyte. The electrical response of the sensors was collected via impedance spectroscopy under various operating conditions where gas concentrations ranged from 0 to 100 ppm NO and 1%-18% O₂ at temperatures varying from 600 to 700 °C. Gas diffusion appeared to be a rate-limiting mechanism in sensors where the electrode configuration resulted in longer diffusion pathways. The temperature dependence of the NO sensors studied was independent of the electrode configuration. Analysis of the impedance data, along with equivalent circuit modeling indicated the electrode configuration of the sensor effected gas and ionic transport pathways, capacitance behavior, and NO sensitivity.

  10. 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.

  11. 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.

  12. Nitric oxide signaling and the cross talk with prostanoids pathways in vascular system.

    PubMed

    Silva, Bruno R; Paula, Tiago D; Paulo, Michele; Bendhack, Lusiane M

    2016-12-28

    This review provides an overview of the cellular signaling of nitric oxide (NO) and prostanoids in vascular cells and the possible cross talk between their pathways, mainly in hypertension, since the imbalance of these two systems has been attributed to development of some cardiovascular diseases. It also deals with the modulation of vasodilation induced by NO donors. NO is a well-known second messenger involved in many cellular functions. In the vascular system, the NO produced by endothelial NO-synthase (eNOS) or released by NO donors acts in vascular smooth muscle cells, the binding of NO to Fe2+-heme of soluble guanylyl-cyclase (sGC) activates sGC and the production of cyclic guanosine-3-5-monophosphate (cGMP). The second messenger (cGMP) activates protein kinase G and the signaling cascade, including K+ channels. Activation of K+ channels leads to cell membrane hyperpolarization and Ca2+ channels blockade, which induce vascular relaxation. Moreover, the enzyme cyclooxygenase (COX) is also an important regulator of the vascular function by prostanoids production such as thromboxane A2 (TXA2) and prostacyclin (PGI2), which classically induce contraction and relaxation, respectively. Additionaly, studies indicate that the activity of both enzymes can be modulated by their products and reactive oxygen species (ROS) in cardiovascular diseases such as hypertension. The interaction of NO with cellular molecules, particularly the reaction of NO with ROS, determines the biological mechanisms of action and short half-life of NO. We have been working on the vascular effects of ruthenium-derived complexes that release NO. Our research group has published works on the vasodilating effects of ruthenium-derived NO donors and the mechanisms of vascular cells involved in the relaxation of the vascular smooth muscle in health and hypertensive rats. In our previous studies, we have compared the new NO donors synthesized by our group to SNP. It shows the cellular signaling of NO

  13. 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.

  14. 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.

  15. Ascending neural pathways in the rat ileum in vitro--effect of capsaicin and involvement of nitric oxide.

    PubMed

    Allescher, H D; Sattler, D; Piller, C; Schusdziarra, V; Classen, M

    1992-07-07

    The aim of the present study was to develop and characterize an in vitro model of the rat ileum in which activation of the orally projecting neural excitatory pathway of the myenteric reflex is produced by electrical field stimulation anally to the recording site. The motility of a 10-cm segment of rat ileum was recorded using a perfused manometric assembly with side holes 2 and 4 cm orally to the stimulation site. Electrical field stimulation caused a contractile response in the oral but not in the aboral direction of the stimulation site. The contractile response, which was maximal using low stimulus frequencies (3 or 5 pulses per second (pps)) and decreased with higher frequencies (10 or 20 pps), was blocked by atropine (10(-6) M) at all frequencies tested after acute and after prolonged (greater than 30 min) treatment. The maximal contractile response at 3 pps was abolished by hexamethonium (10(-4) M), tetrodotoxin (5 x 10(-7) M) and by complete transection of the muscular wall between the stimulation and the recording site. Acute administration of capsaicin (8 x 10(-7) M) to the bath reduced the lag between the start of the electrical stimulation and the onset of the contractile response. Higher concentrations of capsaicin (10(-5) M) reduced the contractile response, but this was partly due to an unspecific effect of capsaicin. Blockade of nitric oxide (NO) synthesis by L-NG-nitro-arginine-methyl ester (L-NAME) (3 x 10(-4) M) augmented the contractile response to anal stimulation by 222.4% and reduced the lag period by 54.5%, whereas the stereoisomer D-NAME had no significant effect. The potentiating effects of L-NAME were reversed in the presence of L-arginine (3 x 10(-3) M) but not in the presence of the stereoisomer D-arginine (3 x 10(-3) M). This model can be used to study ascending neural pathways in the rat small intestine. The ascending excitatory response is abolished by atropine and hexamethonium and is modulated by capsicin-sensitive fibers. The

  16. 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...

  17. Nitric oxide alleviates wheat yield reduction by protecting photosynthetic system from oxidation of ozone pollution.

    PubMed

    Li, Caihong; Song, Yanjie; Guo, Liyue; Gu, Xian; Muminov, Mahmud A; Wang, Tianzuo

    2018-05-01

    Accelerated industrialization has been increasing releases of chemical precursors of ozone. Ozone concentration has risen nowadays, and it's predicted that this trend will continue in the next few decades. The yield of many ozone-sensitive crops suffers seriously from ozone pollution, and there are abundant reports exploring the damage mechanisms of ozone to these crops, such as winter wheat. However, little is known on how to alleviate these negative impacts to increase grain production under elevated ozone. Nitric oxide, as a bioactive gaseous, mediates a variety of physiological processes and plays a central role in response to biotic and abiotic stresses. In the present study, the accumulation of endogenous nitric oxide in wheat leaves was found to increase in response to ozone. To study the functions of nitric oxide, its precursor sodium nitroprusside was spayed to wheat leaves under ozone pollution. Wheat leaves spayed with sodium nitroprusside accumulated less hydrogen peroxide, malondialdehyde and electrolyte leakage under ozone pollution, which can be accounted for by the higher activities of superoxide dismutase and peroxidase than in leaves treated without sodium nitroprusside. Consequently, net photosynthetic rate of wheat treated using sodium nitroprusside was much higher, and yield reduction was alleviated under ozone fumigation. These findings are important for our understanding of the potential roles of nitric oxide in responses of crops in general and wheat in particular to ozone pollution, and provide a viable method to mitigate the detrimental effects on crop production induced by ozone pollution, which is valuable for keeping food security worldwide. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Yomogin, an inhibitor of nitric oxide production in LPS-activated macrophages.

    PubMed

    Ryu, J H; Lee, H J; Jeong, Y S; Ryu, S Y; Han, Y N

    1998-08-01

    In activated macrophages the inducible form of nitric oxide synthase (i-NOS) generates high amounts of toxic mediator, nitric oxide (NO) which contributes to the circulatory failure associated with septic shock. A sesquiterpene lactone compound (yomogin) isolated from medicinal plant Artemisia princeps Pampan inhibited the production of NO in LPS-activated RAW 264.7 cells by suppressing i-NOS enzyme expression. Thus, yomogin may be a useful candidate for the development of new drugs to treat endotoxemia and inflammation accompanied by the overproduction of NO.

  19. 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.

  20. Association of a neuronal nitric oxide synthase gene polymorphism with levodopa-induced dyskinesia in Parkinson's disease.

    PubMed

    Santos-Lobato, Bruno Lopes; Borges, Vanderci; Ferraz, Henrique Ballalai; Mata, Ignacio Fernandez; Zabetian, Cyrus P; Tumas, Vitor

    2018-04-01

    Levodopa-induced dyskinesia (LID) is a common complication of advanced Parkinson's disease (PD). PD physiopathology is associated with dopaminergic and non-dopaminergic pathways, including the nitric oxide system. The present study aims to examine the association of a neuronal nitric oxide synthase gene (NOS1) single nucleotide polymorphism (rs2682826) with LID in PD patients. We studied 186 PD patients using levodopa. The presence of LID was defined as a MDS-UPDRS Part IV score ≥1 on item 4.1. We tested for association between NOS1 rs2682826 and the presence, daily frequency, and functional impact of LID using regression models, adjusting for important covariates. There was no significant association between genotype and any of the LID-related variables examined. Our results suggest that this NOS1 polymorphism does not contribute to LID susceptibility or severity. However, additional studies that include a comprehensive set of NOS1 variants will be needed to fully define the role of this gene in LID. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Evaluation of endogenous nitric oxide synthesis in congenital urea cycle enzyme defects.

    PubMed

    Nagasaka, Hironori; Tsukahara, Hirokazu; Yorifuji, Tohru; Miida, Takashi; Murayama, Kei; Tsuruoka, Tomoko; Takatani, Tomozumi; Kanazawa, Masaki; Kobayashi, Kunihiko; Okano, Yoshiyuki; Takayanagi, Masaki

    2009-03-01

    Nitric oxide (NO) is synthesized from arginine and O(2) by nitric oxide synthase (NOS). Citrulline, which is formed as a by-product of the NOS reaction, can be recycled to arginine by the 2 enzymes acting in the urea cycle: argininosuccinate synthetase (ASS) and argininosuccinate lyase (ASL). Although the complete urea cycle is expressed only in the liver, ASS and ASL are expressed in other organs including the kidney and vascular endothelium. To examine possible alterations of the NO pathway in urea cycle defects, we measured plasma concentrations of arginine and citrulline and serum concentrations of nitrite/nitrate (NOx(-), stable NO metabolites) and asymmetric dimethylarginine (ADMA, an endogenous NOS inhibitor) in patients with congenital urea cycle disorders of 3 types: ornithine transcarbamylase (OTC) deficiency, ASS deficiency, and ASL deficiency. All were receiving oral arginine replacement at the time of this study. The same parameters were also measured in healthy subjects, who participated as controls. The OTC-deficient patients had significantly high NOx(-) and nonsignificantly high ADMA concentrations. Their NOx(-) was significantly positively correlated with arginine. The ASS-deficient patients had significantly low NOx(-) and significantly high ADMA concentrations. The ASL-deficient patients had normal NOx(-) and nonsignificantly high ADMA concentrations. In ASS-deficient and ASL-deficient patients, the NOx(-) was significantly inversely correlated with citrulline. These results suggest that NO synthesis is enhanced in OTC-deficient patients while receiving arginine but that NO synthesis remains low in ASS-deficient patients despite receiving arginine. They also suggest that endogenous NO synthesis is negatively affected by citrulline and ADMA in ASS-deficient and ASL-deficient patients. Although the molecular mechanisms remain poorly understood, we infer that the NO pathway might play a role in the pathophysiology related to congenital urea cycle

  2. 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.

  3. (-)-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.

  4. Pharmacological Prevention and Reversion of Erectile Dysfunction After Radical Prostatectomy, by Modulation of Nitric Oxide/cGMP Pathways

    DTIC Science & Technology

    2010-03-01

    cancer in men. Now, we have shown that much lower doses of sildenafil, combined or not with a nitric oxide donor, molsidomine, also correct the CVOD...ED) subsequent to radical prostatectomy for prostate cancer can be prevented and even reversed by long-term sustained treatment with PDE5...erectile dysfunction subsequent to radical prostatectomy for prostate cancer , based on the long term sustained administration of PDE5 inhibitors. Our

  5. 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

  6. 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

  7. Nitric oxide selective electrodes.

    PubMed

    Davies, Ian R; Zhang, Xueji

    2008-01-01

    Since nitric oxide (NO) was identified as the endothelial-derived relaxing factor in the late 1980s, many approaches have attempted to provide an adequate means for measuring physiological levels of NO. Although several techniques have been successful in achieving this aim, the electrochemical method has proved the only technique that can reliably measure physiological levels of NO in vitro, in vivo, and in real time. We describe here the development of electrochemical sensors for NO, including the fabrication of sensors, the detection principle, calibration, detection limits, selectivity, and response time. Furthermore, we look at the many experimental applications where NO selective electrodes have been successfully used.

  8. Nitric oxide and gene regulation in plants.

    PubMed

    Grün, S; Lindermayr, C; Sell, S; Durner, J

    2006-01-01

    There is increasing evidence that nitric oxide (NO), which was first identified as a unique diffusible molecular messenger in animals, plays an important role in diverse physiological processes in plants. Recent progress that has deepened our understanding of NO signalling functions in plants, with special emphasis on defence signalling, is discussed here. Several studies, based on plants with altered NO-levels, have recently provided genetic evidence for the importance of NO in gene induction. For a general overview of which gene expression levels are altered by NO, two studies, involving large-scale transcriptional analyses of Arabidopsis thaliana using custom-made or commercial DNA-microarrays, were performed. Furthermore, a comprehensive transcript profiling by cDNA-amplification fragment length polymorphism (AFLP) revealed a number of Arabidopsis thaliana genes that are involved in signal transduction, disease resistance and stress response, photosynthesis, cellular transport, and basic metabolism. In addition, NO affects the expression of numerous genes in other plant species such as tobacco or soybean. The NO-dependent intracellular signalling pathway(s) that lead to the activation or suppression of these genes have not yet been defined. Several lines of evidence point to an interrelationship between NO and salicylic acid (SA) in plant defence. Recent evidence suggests that NO also plays a role in the wounding/jasmonic acid (JA) signalling pathway. NO donors affect both wounding-induced H2O2 synthesis and wounding- or JA-induced expression of defence genes. One of the major challenges ahead is to determine how the correct specific response is evoked, despite shared use of the NO signal and, in some cases, its downstream second messengers.

  9. 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...

  10. 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

  11. Bench-to-bedside review: Inhaled nitric oxide therapy in adults

    PubMed Central

    Creagh-Brown, Benedict C; Griffiths, Mark JD; Evans, Timothy W

    2009-01-01

    Nitric oxide (NO) is an endogenous mediator of vascular tone and host defence. Inhaled nitric oxide (iNO) results in preferential pulmonary vasodilatation and lowers pulmonary vascular resistance. The route of administration delivers NO selectively to ventilated lung units so that its effect augments that of hypoxic pulmonary vasoconstriction and improves oxygenation. This 'Bench-to-bedside' review focuses on the mechanisms of action of iNO and its clinical applications, with emphasis on acute lung injury and the acute respiratory distress syndrome. Developments in our understanding of the cellular and molecular actions of NO may help to explain the hitherto disappointing results of randomised controlled trials of iNO. PMID:19519946

  12. 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...

  13. Inducible nitric oxide synthase (iNOS) drives mTOR pathway activation and proliferation of human melanoma by reversible nitrosylation of TSC2

    PubMed Central

    Lopez-Rivera, Esther; Jayaraman, Padmini; Parikh, Falguni; Davies, Michael A.; Ekmekcioglu, Suhendan; Izadmehr, Sudeh; Milton, Denái R.; Chipuk, Jerry E.; Grimm, Elizabeth A.; Estrada, Yeriel; Aguirre-Ghiso, Julio; Sikora, Andrew G.

    2014-01-01

    Melanoma is one of the cancers of fastest-rising incidence in the world. iNOS is overexpressed in melanoma and other cancers, and previous data suggest that iNOS and nitric oxide (NO) drive survival and proliferation of human melanoma cells. However, specific mechanisms through which this occurs are poorly defined. One candidate is the PI3K/AKT/mTOR pathway, which plays a major role in proliferation, angiogenesis, and metastasis of melanoma and other cancers. We used the chick embryo chorioallantoic membrane (CAM) assay to test the hypothesis that melanoma growth is regulated by iNOS-dependent mTOR pathway activation. Both pharmacologic inhibition and siRNA-mediated gene silencing of iNOS suppressed melanoma proliferation and in vivo growth on the CAM in human melanoma models. This was associated with strong downregulation of mTOR pathway activation by Western blot analysis of p-mTOR, p-P70S6K, p-S6RP, and p-4EBP1. iNOS expression and NO were associated with reversible nitrosylation of TSC2, and inhibited dimerization of TSC2 with its inhibitory partner TSC1, enhancing GTPase activity of its target Rheb, a critical activator of mTOR signaling. Immunohistochemical analysis of tumor specimens from stage III melanoma patients showed a significant correlation between iNOS expression levels and expression of mTOR pathway members. Exogenously-supplied NO was also sufficient to reverse mTOR pathway inhibition by the B-Raf inhibitor Vemurafenib. In summary, covalent modification of TSC2 by iNOS-derived NO is associated with impaired TSC2/TSC1 dimerization, mTOR pathway activation, and proliferation of human melanoma. This model is consistent with the known association of iNOS overexpression and poor prognosis in melanoma and other cancers. PMID:24398473

  14. An ancient role for nitric oxide in regulating the animal pelagobenthic life cycle: evidence from a marine sponge

    PubMed Central

    Ueda, Nobuo; Richards, Gemma S.; Degnan, Bernard M.; Kranz, Alexandrea; Adamska, Maja; Croll, Roger P.; Degnan, Sandie M.

    2016-01-01

    In many marine invertebrates, larval metamorphosis is induced by environmental cues that activate sensory receptors and signalling pathways. Nitric oxide (NO) is a gaseous signalling molecule that regulates metamorphosis in diverse bilaterians. In most cases NO inhibits or represses this process, although it functions as an activator in some species. Here we demonstrate that NO positively regulates metamorphosis in the poriferan Amphimedon queenslandica. High rates of A. queenslandica metamorphosis normally induced by a coralline alga are inhibited by an inhibitor of nitric oxide synthase (NOS) and by a NO scavenger. Consistent with this, an artificial donor of NO induces metamorphosis even in the absence of the alga. Inhibition of the ERK signalling pathway prevents metamorphosis in concert with, or downstream of, NO signalling; a NO donor cannot override the ERK inhibitor. NOS gene expression is activated late in embryogenesis and in larvae, and is enriched in specific epithelial and subepithelial cell types, including a putative sensory cell, the globular cell; DAF-FM staining supports these cells being primary sources of NO. Together, these results are consistent with NO playing an activating role in induction of A. queenslandica metamorphosis, evidence of its highly conserved regulatory role in metamorphosis throughout the Metazoa. PMID:27874071

  15. Nitric oxide-mediated modulation of the murine locomotor network

    PubMed Central

    Foster, Joshua D.; Dunford, Catherine; Sillar, Keith T.

    2013-01-01

    Spinal motor control networks are regulated by neuromodulatory systems to allow adaptability of movements. The present study aimed to elucidate the role of nitric oxide (NO) in the modulation of mammalian spinal locomotor networks. This was investigated with isolated spinal cord preparations from neonatal mice in which rhythmic locomotor-related activity was induced pharmacologically. Bath application of the NO donor diethylamine NONOate (DEA/NO) decreased the frequency and modulated the amplitude of locomotor-related activity recorded from ventral roots. Removal of endogenous NO with coapplication of a NO scavenger (PTIO) and a nitric oxide synthase (NOS) blocker [nitro-l-arginine methyl ester (l-NAME)] increased the frequency and decreased the amplitude of locomotor-related activity. This demonstrates that endogenously derived NO can modulate both the timing and intensity of locomotor-related activity. The effects of DEA/NO were mimicked by the cGMP analog 8-bromo-cGMP. In addition, the soluble guanylyl cyclase (sGC) inhibitor ODQ blocked the effects of DEA/NO on burst amplitude and frequency, although the frequency effect was only blocked at low concentrations of DEA/NO. This suggests that NO-mediated modulation involves cGMP-dependent pathways. Sources of NO were studied within the lumbar spinal cord during postnatal development (postnatal days 1–12) with NADPH-diaphorase staining. NOS-positive cells in the ventral horn exhibited a rostrocaudal gradient, with more cells in rostral segments. The number of NOS-positive cells was also found to increase during postnatal development. In summary, we have shown that NO, derived from sources within the mammalian spinal cord, modulates the output of spinal motor networks and is therefore likely to contribute to the fine-tuning of locomotor behavior. PMID:24259545

  16. Vasodilator responses to nitric oxide are enhanced in mesenteric arteries of portal hypertensive rats.

    PubMed

    Heinemann, A; Stauber, R E

    1996-09-01

    Nitric oxide (NO) is discussed as a mediator of the splanchnic hyperaemia in portal hypertension. We assessed the vasorelaxation by the NO-dependent vasodilator acetylcholine, the NO donor 3-morpholino-sydnonimine (SIN-1) and forskolin, a stimulator of the adenylate cyclase pathway in potassium-preconstricted isolated perfused mesenteric arteries of portal vein-ligated and sham-operated rats. Dilator responses to acetylcholine and SIN-1 were significantly enhanced in vessels of portal vein-ligated rats as compared to sham-operated rats, whereas no difference was found in forskolin-induced vasodilatation. This suggests enhanced reactivity of the vasculature to NO in experimental portal hypertension.

  17. 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

  18. Nitric oxide synthesis leads to vascular endothelial growth factor synthesis via the NO/cyclic guanosine 3',5'-monophosphate (cGMP) pathway in human corpus cavernosal smooth muscle cells.

    PubMed

    Komori, Kazuhiko; Tsujimura, Akira; Takao, Tetsuya; Matsuoka, Yasuhiro; Miyagawa, Yasushi; Takada, Shingo; Nonomura, Norio; Okuyama, Akihiko

    2008-07-01

    Vascular smooth muscle cells express endothelial nitric oxide synthase (eNOS) and produce nitric oxide (NO). Recently, increased NO production has been reported to induce the synthesis and secretion of vascular endothelial growth factor (VEGF) via the NO/cyclic guanosine 3',5'-monophosphate (cGMP) pathway. L-arginine (L-arg), the precursor of NO, and selective phosphodiesterase type 5 (PDE-5) inhibitors that increase levels of intracellular cGMP may complementarily enhance VEGF synthesis in corpus cavernosal smooth muscle cells (CCSMCs), and may consequently restore impaired endothelial function. Expression of eNOS in corpus cavernosal smooth muscle has also been reported. However, it is unclear whether CCSMCs can generate NO. To elucidate whether CCSMCs can synthesize NO and whether NO synthesis enhances VEGF synthesis via the NO/cGMP pathway. Corpus cavernosal cells were cultured and characterized by immunocytochemistry and immunoblotting. CCSMCs were treated with L-arg. CCSMCs were also incubated with L-arg and with vardenafil, an inhibitor of PDE-5. Release of NO from cells was confirmed by assay of NO metabolites (NOx). Intracellular cGMP concentration and VEGF concentration in the medium were measured. Isolated cells were determined to be CCSMCs. The expression of eNOS by CCSMCs was also identified. NOx and cGMP levels in the L-arg-treated group were significantly greater than those in the control group. VEGF and cGMP levels in the L-arg-treated group were also significantly greater than those in the control group. VEGF and cGMP levels in the L-arg + vardenafil-treated group were significantly greater than those in the L-arg-treated group and the control group. CCSMCs express eNOS and synthesize NO. NO synthesis leads to enhancement of VEGF synthesis via the NO/cGMP pathway. Combined L-arg and vardenafil treatment, which can enhance VEGF production, may provide a novel therapeutic strategy for the treatment of erectile dysfunction as well as endothelial

  19. Constitutive Expression of Mammalian Nitric Oxide Synthase in Tobacco Plants Triggers Disease Resistance to Pathogens

    PubMed Central

    Chun, Hyun Jin; Park, Hyeong Cheol; Koo, Sung Cheol; Lee, Ju Huck; Park, Chan Young; Choi, Man Soo; Kang, Chang Ho; Baek, Dongwon; Cheong, Yong Hwa; Yun, Dae-Jin; Chung, Woo Sik; Cho, Moo Je; Kim, Min Chul

    2012-01-01

    Nitric oxide (NO) is known for its role in the activation of plant defense responses. To examine the involvement and mode of action of NO in plant defense responses, we introduced calmodulin-dependent mammalian neuronal nitric oxide synthase (nNOS), which controls the CaMV35S promoter, into wild-type and NahG tobacco plants. Constitutive expression of nNOS led to NO production and triggered spontaneous induction of leaf lesions. Transgenic plants accumulated high amounts of H2O2, with catalase activity lower than that in the wild type. nNOS transgenic plants contained high levels of salicylic acid (SA), and they induced an array of SA-, jasmonic acid (JA)-, and/or ethylene (ET)-related genes. Consequently, NahG co-expression blocked the induction of systemic acquired resistance (SAR)-associated genes in transgenic plants, implying SA is involved in NO-mediated induction of SAR genes. The transgenic plants exhibited enhanced resistance to a spectrum of pathogens, including bacteria, fungi, and viruses. Our results suggest a highly ranked regulatory role for NO in SA-, JA-, and/or ET-dependent pathways that lead to disease resistance. PMID:23124383

  20. Minocycline Attenuates Depressive-Like Behaviour Induced by Rat Model of Testicular Torsion: Involvement of Nitric Oxide Pathway.

    PubMed

    Saravi, Seyed Soheil Saeedi; Mousavi, Seyyedeh Elaheh; Saravi, Seyed Sobhan Saeedi; Dehpour, Ahmad Reza

    2016-04-01

    Testicular torsion/detorsion (T/D) can induce depression in pre- and post-pubertal patients. This study was conducted to investigate the psychological impact of testicular torsion and mechanism underlying its depressive-like behaviour, as well as antidepressant-like activity of minocycline and possible involvement of nitric oxide (NO)/cyclic GMP pathway in this paradigm in male rats undergoing testicular T/D. Unilateral T/D was performed in 36 male adult Wistar rats, and different doses of minocycline were injected alone or combined with N(ω) -nitro-l-arginine methyl ester (l-NAME), non-specific NO synthase (NOS) inhibitor; aminoguanidine (AG), specific inducible NOS inhibitor; l-arginine, an NO precursor; and selective PDE5I, sildenafil. After assessment of locomotor activity in open-field test, immobility times were recorded in the forced swimming test (FST). Moreover, 30 days after testicular T/D, testicular venous testosterone and serum nitrite concentrations were measured. A correlation was observed between either a decrease in plasma testosterone or an increase in serum nitrite concentrations with prolongation in immobility time in the testicular T/D-operated rats FST. Minocycline (160 mg/kg) exerted the highest significant antidepressant-like effect in the operated rats in the FST (p < 0.001). Furthermore, combination of subeffective doses of minocycline (80 mg/kg) and either l-NAME (10 mg/kg) or AG (50 mg/kg) demonstrated a significant robust antidepressant-like activity in T/D group (p < 0.01). Consequently, NO/cGMP pathway was involved in testicular T/D-induced depressive-like behaviour and antidepressant-like activity of minocycline in the animal model. Moreover, a contribution was observed between either decreased testosterone or elevated serum nitrite levels and depressive-like behaviour following testicular T/D. © 2015 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  1. 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

  2. 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

  3. 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...

  4. 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.

  5. 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.

  6. Venlafaxine prevents morphine antinociceptive tolerance: The role of neuroinflammation and the l-arginine-nitric oxide pathway.

    PubMed

    Mansouri, Mohammad Taghi; Naghizadeh, Bahareh; Ghorbanzadeh, Behnam; Alboghobeish, Soheila; Amirgholami, Neda; Houshmand, Gholamreza; Cauli, Omar

    2018-05-01

    Opioid-induced neuroinflammation and the nitric oxide (NO) signal-transduction pathway are involved in the development of opioid analgesic tolerance. The antidepressant venlafaxine (VLF) modulates NO in nervous tissues, and so we investigated its effect on induced tolerance to morphine, neuroinflammation, and oxidative stress in mice. Tolerance to the analgesic effects of morphine were induced by injecting mice with morphine (50 mg/kg) once a day for three consecutive days; the effect of co-administration of VLF (5 or 40 mg/kg) with morphine was similarly tested in a separate group. To determine if the NO precursor l-arginine hydrochloride (l-arg) or NO are involved in the effects rendered by VLF, animals were pre-treated with l-arg (200 mg/kg), or the NO synthesis inhibitors N(ω)-nitro-l-arginine methyl ester (L-NAME; 30 mg/kg) or aminoguanidine hydrochloride (AG; 100 mg/kg), along with VLF (40 mg/kg) for three days before receiving morphine for another three days. Nociception was assessed with a hot-plate test on the fourth day, and the concentration of tumor necrosis factor alpha (TNF-α), interleukin-1beta (IL-1β), interleukin-6 (IL-6), interleukin-10, brain-derived neurotrophic factor, NO, and oxidative stress factors such as total thiol, malondialdehyde content, and glutathione peroxidase (GPx) activity in the brain was also determined. Co-administration of VLF with morphine attenuated morphine-induced analgesic tolerance and prevented the upregulation of proinflammatory cytokines (TNF-α, IL-1β, and IL-6), NO, and malondialdehyde in brains of mice with induced morphine tolerance; chronic VLF administration inhibited this decrease in brain-derived neurotrophic factor, total thiol, and GPx levels. Moreover, repeated administration of l-arg before receipt of VLF antagonized the effects induced by VLF, while L-NAME and AG potentiated these effects. VLF attenuates morphine-induced analgesic tolerance, at least partly because of its anti

  7. Photoinduced fluorescence activation and nitric oxide release with biocompatible polymer nanoparticles.

    PubMed

    Deniz, Erhan; Kandoth, Noufal; Fraix, Aurore; Cardile, Venera; Graziano, Adriana C E; Lo Furno, Debora; Gref, Ruxandra; Raymo, Françisco M; Sortino, Salvatore

    2012-12-03

    A viable strategy to encapsulate a fluorophore/photochrome dyad and a nitric oxide photodonor within supramolecular assemblies of a cyclodextrin-based polymer in water was developed. The two photoresponsive guests do not interact with each other within their supramolecular container and can be operated in parallel under optical control. Specifically, the dyad permits the reversible switching of fluorescence on a microsecond timescale for hundreds of cycles, and the photodonor enables the irreversible release of nitric oxide. Furthermore, these supramolecular assemblies cross the membrane of human melanoma cancer cells and transport their cargo in the cytosol. The fluorescence of one component allows the visualization of the labeled cells, and its switchable character could, in principle, be used to acquire super-resolution images, while the release of nitric oxide from the other induces significant cell mortality. Thus, our design logic for the construction of biocompatible nanoparticles with dual functionality might evolve into the realization of valuable photoresponsive probes for imaging and therapeutic applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Role of inducible nitric oxide synthase in transplant arteriosclerosis.

    PubMed

    Lee, P C; Shears, L L; Billiar, T R

    1999-12-01

    1. Transplant arteriosclerosis is a major obstacle to long-term allograft survival. Nitric oxide (NO) has been implicated as a mediator in the development of this disease. 2. We and others have shown that inducible nitric oxide synthase (iNOS) is up-regulated in allografts with transplant arteriosclerosis. Despite the acute cytotoxic effects produced by high levels of NO, a chronic increase in NO availability is protective against neointimal hyperplasia, mainly by suppressing the inflammatory cell recruitment and neointimal smooth muscle cell accumulation. 3. Currently, we have the technology to directly transfer the iNOS gene to allografts. We have demonstrated that this exciting strategy is feasible and therapeutic and may improve the long-term survival and function of allografts. Future challenges include optimizing the methods and the vectors of gene delivery.

  9. Nitric oxide donors rescue diabetic nephropathy through oxidative-stress-and nitrosative-stress-mediated Wnt signaling pathways

    PubMed Central

    Hsu, Yung-Chien; Lee, Pei-Hsien; Lei, Chen-Chou; Ho, Cheng; Shih, Ya-Hsueh; Lin, Chun-Liang

    2015-01-01

    Aims/Introduction The role of the renal nitric oxide (NO) system in the pathophysiology of diabetic nephropathy constitutes a very challenging and fertile field for future investigation. The purpose of the present study was to investigate whether NO donors can attenuate diabetic renal fibrosis and apoptosis through modulating oxidative-and nitrosative-stress, and Wnt signaling using in vivo diabetic models. Materials and Methods Diabetic rat was induced by a single intraperitoneal injection of streptozotocin. Rats in each group were intraperitoneally given 2,2′-(hydroxynitrosohydrazino)bis-ethanamine (1 U/kg/day) and vehicle for 28 and 56 consecutive days. Expression of the oxidative-and nitrosative-stress, and Wnt signaling components were examined in kidneys from diabetic animals by quantitative reverse transcription polymerase chain reaction, western blot analysis and immunohistochemical staining. Results NO donor treatment significantly reduced the ratio of kidney weight to bodyweight and proteinuria. This treatment also significantly restored the suppressive effect of diabetes on urinary NO2 + NO3 levels. Immunohistochemistry showed that NO donor treatment significantly reduced transforming growth factor (TGF)-β1, fibronectin, cleaved caspase-3 and triphosphate-biotin nick end-labeling expression in the glomeruli of diabetic rats. We found that diabetes promoted 8-hydroxy-2′-deoxyguanosine, and peroxynitrite expression coincided with reduced endothelial NO synthase expression in glomeruli. Interestingly, NO donor treatment completely removed oxidative stress and nitrosative stress, and restored endothelial NO synthase expression in diabetic renal glomeruli. Immunohistomorphometry results showed that NO donor treatment significantly restored suppressed Wnt5a expression and β-catenin immunoreactivities in glomeruli. Based on laser-captured microdissection for quantitative reverse transcription polymerase chain reaction, diabetes significantly increased

  10. Modulation of taurine release by glutamate receptors and nitric oxide.

    PubMed

    Oja, S S; Saransaari, P

    2000-11-01

    Taurine is held to function as a modulator and osmoregulator in the central nervous system, being of particular importance in the immature brain. In view of the possible involvement of excitatory pathways in the regulation of taurine function in the brain, the interference of glutamate receptors with taurine release from different tissue preparations in vitro and from the brain in vivo is of special interest. The release of taurine from the brain is enhanced by glutamate receptor agonists. This enhancement is inhibited by the respective receptor antagonists both in vitro and in vivo. The ionotropic N-methyl-D-aspartate (NMDA) and 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor agonists appear to be the most effective in enhancing taurine release, their effects being receptor-mediated. Kainate is less effective, particularly in adults. Of the glutamate receptors, the NMDA class seems to be the most susceptible to modulation by nitric oxide. Nitric oxide also modulates taurine release, enhancing the basal release in both immature and mature hippocampus, whereas the K(+)-stimulated release is generally inhibited. Metabotropic glutamate receptors also participate in the regulation of taurine release, group I metabotropic glutamate receptors potentiating the release in the developing hippocampus, while group III receptors may be involved in the adult. Under various cell-damaging conditions, including ischemia, hypoxia and hypoglycemia, taurine release is enhanced, together with an enhanced release of excitatory amino acids. The increase in extracellular taurine upon excessive stimulation of glutamate receptors and under cell-damaging conditions may serve as an important protective mechanism against excitotoxicity, being particularly effective in the immature brain.

  11. 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.

  12. Heterogeneous distribution of type I nitric oxide synthase in pulmonary vasculature of ovine fetus.

    PubMed

    Tzao, C; Nickerson, P A; Russell, J A; Noble, B K; Steinhorn, R H

    2000-11-01

    The nitric oxide/guanosine 3',5'-cyclic monophosphate pathway plays an essential role in mediating pulmonary vasodilation at birth. Small resistance arteries in the fetal lung are vessels of major significance in the regulation of pulmonary vascular tone. The present study is to determine that type I nitric oxide synthase (NOS-I) is present in ovine fetal pulmonary vasculature and that NOS-I is distributed heterogeneously in ovine fetal pulmonary circulation. We used reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry and NOS-I immunohistochemistry to localize NOS-I in fetal sheep lungs and showed a colocalization for NADPH-d activity with NOS-I immunoreactivity. Strong NOS-I immunoreactivity was observed exclusively in the endothelium of the terminal bronchiole and respiratory bronchiole-associated arteries. As a comparison, adult sheep lung did not show positive immunoreactivity in the pulmonary endothelium. NOS-I was absent in the umbilical or systemic arteries from the ovine fetus, whereas abundant NOS-III immunoreactivity was present in these arteries. We conclude that NOS-I is present uniquely in the ovine fetal pulmonary circulation as opposed to the adult pulmonary or the fetal systemic circulation. NOS-I is distributed heterogeneously in the ovine pulmonary vasculature. We speculate that NOS-I plays an active role in the regulation of perinatal pulmonary circulation.

  13. Apple fruit responses following exposure to nitric oxide

    USDA-ARS?s Scientific Manuscript database

    Exogenous nitric oxide (.NO) applied as gas or generated from .NO releasing compounds has physiological activity in cut apple fruit tissues. Studies were conducted to characterize .NO production by whole fruit as well as to assess responses of whole fruit to exogenous .NO. .NO and ethylene product...

  14. Activation by nitric oxide of an oxidative-stress response that defends Escherichia coli against activated macrophages.

    PubMed Central

    Nunoshiba, T; deRojas-Walker, T; Wishnok, J S; Tannenbaum, S R; Demple, B

    1993-01-01

    Nitric oxide is a free radical (NO) formed biologically through the oxidation of L-arginine by nitric oxide synthases. NO is produced transiently in mammalian cells for intercellular signaling and in copious quantities to cause cytostasis and cytotoxicity. In the latter situation, NO is a deliberate cytotoxic product of activated macrophages, along with other reactive oxygen species such as hydrogen peroxide (H2O2) and superoxide (O2-). Escherichia coli has a complex set of responses to H2O2 and O2- that involves approximately 80 inducible proteins; we wondered whether these bacteria might induce analogous defenses against nitric oxide. We show here that a multigene system controlled by the redox-sensitive transcriptional regulator SoxR is activated by NO in vivo. This induction confers bacterial resistance to activated murine macrophages with kinetics that parallel the production of NO by these cells. Elimination of specific SoxR-regulated genes diminishes the resistance of these bacteria to the cytotoxic macrophages. The required functions include manganese-containing superoxide dismutase, endonuclease IV (a DNA-repair enzyme for oxidative damage), and micF, an antisense regulator of the outer membrane porin OmpF. These results demonstrate that SoxR is a sensor for cellular exposure to NO, and that the soxRS response system may contribute to bacterial virulence. PMID:8234347

  15. 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

  16. Fumagillin Prodrug Nanotherapy Suppresses Macrophage Inflammatory Response via Endothelial Nitric Oxide

    PubMed Central

    2015-01-01

    Antiangiogenesis has been extensively explored for the treatment of a variety of cancers and certain inflammatory processes. Fumagillin, a mycotoxin produced by Aspergillus fumigatus that binds methionine aminopeptidase 2 (MetAP-2), is a potent antiangiogenic agent. Native fumagillin, however, is poorly soluble and extremely unstable. We have developed a lipase-labile fumagillin prodrug (Fum-PD) that eliminated the photoinstability of the compound. Using αvβ3-integrin-targeted perfluorocarbon nanocarriers to deliver Fum-PD specifically to angiogenic vessels, we effectively suppressed clinical disease in an experimental model of rheumatoid arthritis (RA). The exact mechanism by which Fum-PD-loaded targeted nanoparticles suppressed inflammation in experimental RA, however, remained unexplained. We herein present evidence that Fum-PD nanotherapy indirectly suppresses inflammation in experimental RA through the local production of endothelial nitric oxide (NO). Fum-PD-induced NO activates AMP-activated protein kinase (AMPK), which subsequently modulates macrophage inflammatory response. In vivo, NO-induced AMPK activation inhibits mammalian target of rapamycin (mTOR) activity and enhances autophagic flux, as evidenced by p62 depletion and increased autolysosome formation. Autophagy in turn mediates the degradation of IkappaB kinase (IKK), suppressing the NF-κB p65 signaling pathway and inflammatory cytokine release. Inhibition of NO production by NG-nitro-l-arginine methyl ester (l-NAME), a nitric oxide synthase inhibitor, reverses the suppression of NF-κB-mediated inflammatory response induced by Fum-PD nanotherapy. These unexpected results uncover an activity of Fum-PD nanotherapy that may be further explored in the treatment of angiogenesis-dependent diseases. PMID:24941020

  17. N-acetylcysteine restores nitric oxide-mediated effects in the fetoplacental circulation of preeclamptic patients.

    PubMed

    Bisseling, Tanya M; Maria Roes, Eva; Raijmakers, Maarten T M; Steegers, Eric A P; Peters, Wilbert H M; Smits, Paul

    2004-07-01

    Preeclampsia is associated with an imbalance between oxidants and antioxidants, resulting in reduced effects of the endothelium-derived, relaxing-factor nitric oxide (NO). Antioxidants, like N-acetylcysteine (NAC), remove reactive oxygen species, resulting in an improvement of endothelial function. We aimed to investigate the effect of NAC on the NO-pathway in the human fetoplacental circulation in preeclampsia and control pregnancies. The NO-pathway was investigated by use of the NO-synthase inhibitor L-NAME in an ex vivo cotyledon perfusion model. At baseline, fetoplacental arterial pressure was comparable in preeclamptic pregnancies (n=8) and control pregnancies (n=8), and increased dose-dependently after L-NAME. The maximal L-NAME-induced rise in fetoplacental arterial pressure was attenuated in preeclamptic versus control pregnancies (20.8 +/- 2.0 mm Hg vs 36.7 +/- 3.5 mm Hg, P<.05). Addition of NAC increased the L-NAME-induced rise in fetoplacental arterial pressure to 36.4 +/- 3.4 mm Hg in preeclampsia pregnancies (P<.05) and to 49.2 +/- 2.6 mm Hg in control pregnancies (P<.05). Preeclampsia is associated with a dysfunction of the NO-pathway. N-acetylcysteine increases NO-mediated effects in the fetoplacental circulation in preeclamptic placentas as well as in healthy control placentas.

  18. 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.

  19. Badger macrophages fail to produce nitric oxide, a key anti-mycobacterial effector molecule.

    PubMed

    Bilham, Kirstin; Boyd, Amy C; Preston, Stephen G; Buesching, Christina D; Newman, Chris; Macdonald, David W; Smith, Adrian L

    2017-04-06

    The European badger is recognised as a wildlife reservoir for bovine tuberculosis (bTB); the control of which is complex, costly and controversial. Despite the importance of badgers in bTB and the well-documented role for macrophages as anti-mycobacterial effector cells, badger macrophage (bdMφ) responses remain uncharacterised. Here, we demonstrate that bdMφ fail to produce nitric oxide (NO) or upregulate inducible nitric oxide synthase (iNOS) mRNA following Toll-like receptor (TLR) agonist treatment. BdMφ also failed to make NO after stimulation with recombinant badger interferon gamma (bdIFNγ) or a combination of bdIFNγ and lipopolysaccharide. Exposure of bdMφ to TLR agonists and/or bdIFNγ resulted in upregulated cytokine (IL1β, IL6, IL12 and TNFα) mRNA levels indicating that these critical pathways were otherwise intact. Although stimulation with most TLR agonists resulted in strong cytokine mRNA responses, weaker responses were evident after exposure to TLR9 agonists, potentially due to very low expression of TLR9 in bdMφ. Both NO and TLR9 are important elements of innate immunity to mycobacteria, and these features of bdMφ biology would impair their capacity to resist bTB infection. These findings have significant implications for the development of bTB management strategies, and support the use of vaccination to reduce bTB infection in badgers.

  20. Sensor materials for an intravascular fiber optic nitric oxide sensor

    NASA Astrophysics Data System (ADS)

    Soller, Babs R.; Parikh, Bhairavi R.; Stahl, Russell F.

    1996-04-01

    Nitric oxide (NO) is an important regulatory molecule in physiological processes including neurotransmission and the control of blood pressure. It is produced in excess during septic shock, the profound hypotensive state which accompanies severe infections. In-vivo measurement of NO would enhance the understanding of its varied biological roles. Our goal is the development of an intravascular fiber-optic sensor for the continuous measurement of NO. This study evaluated nitric oxide sensitive compounds as potential sensing materials in the presence and absence of oxygen. Using absorption spectroscopy we studied both the Fe II and Fe III forms of three biologically active hemes known to rapidly react with NO: hemoglobin, myoglobin, and cytochrome-c. The Fe II forms of hemoglobin and myoglobin and the Fe III form of cytochrome-c were found to have the highest sensitivity to NO. Cytochrome c (Fe III) is selective for NO even at high oxygen levels, while myoglobin is selective only under normal oxygen levels. NO concentrations as low as 1 (mu) M can be detected with our fiber-optic spectrometer using cytochrome c, and as low as 300 nM using myoglobin. Either of these materials would be adequate to monitor the increase in nitric oxide production during the onset of septic shock.

  1. Enhanced nitric oxide generation from nitric oxide synthases as the cause of increased peroxynitrite formation during acute restraint stress: Effects on carotid responsiveness to angiotensinergic stimuli in type-1 diabetic rats.

    PubMed

    Moreira, Josimar D; Pernomian, Larissa; Gomes, Mayara S; Moreira, Rafael P; do Prado, Alejandro F; da Silva, Carlos H T P; de Oliveira, Ana M

    2016-07-15

    Diabetes mellitus is associated with reactive oxygen and nitrogen species accumulation. Behavioral stress increases nitric oxide production, which may trigger a massive impact on vascular cells and accelerate cardiovascular complications under oxidative stress conditions such as Diabetes. For this study, type-1 Diabetes mellitus was induced in Wistar rats by intraperitoneal injection of streptozotocin. After 28 days, cumulative concentration-response curves for angiotensin II were obtained in endothelium-intact carotid rings from diabetic rats that underwent to acute restraint stress for 3h. The contractile response evoked by angiotensin II was increased in carotid arteries from diabetic rats. Acute restraint stress did not alter angiotensin II-induced contraction in carotid arteries from normoglycaemic rats. However acute stress combined with Diabetes increased angiotensin II-induced contraction in carotid rings. Western blot experiments and the inhibition of nitric oxide synthases in functional assays showed that neuronal, endothelial and inducible nitric oxide synthase isoforms contribute to the increased formation of peroxynitrite and contractile hyperreactivity to angiotensin II in carotid rings from stressed diabetic rats. In summary, these findings suggest that the increased superoxide anion generation in carotid arteries from diabetic rats associated to the increased local nitric oxide synthases expression and activity induced by acute restrain stress were responsible for exacerbating the local formation of peroxynitrite and the contraction induced by angiotensin II. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Nitric oxide rescues thalidomide mediated teratogenicity

    PubMed Central

    Siamwala, Jamila H.; Veeriah, Vimal; Priya, M. Krishna; Rajendran, Saranya; Saran, Uttara; Sinha, Swaraj; Nagarajan, Shunmugam; T, Pradeep; Chatterjee, Suvro

    2012-01-01

    Thalidomide, a sedative drug given to pregnant women, unfortunately caused limb deformities in thousands of babies. Recently the drug was revived because of its therapeutic potential; however the search is still ongoing for an antidote against thalidomide induced limb deformities. In the current study we found that nitric oxide (NO) rescues thalidomide affected chick (Gallus gallus) and zebrafish (Danio rerio) embryos. This study confirms that NO reduced the number of thalidomide mediated limb deformities by 94% and 80% in chick and zebrafish embryos respectively. NO prevents limb deformities by promoting angiogenesis, reducing oxidative stress and inactivating caspase-3 dependent apoptosis. We conclude that NO secures angiogenesis in the thalidomide treated embryos to protect them from deformities. PMID:22997553

  3. 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.

  4. [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.

  5. 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.

  6. 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).

  7. Nitric oxide-dependent pigment migration induced by ultraviolet radiation in retinal pigment cells of the crab Neohelice granulata.

    PubMed

    Filgueira, Daza de Moraes Vaz Batista; Guterres, Laís Pereira; Votto, Ana Paula de Souza; Vargas, Marcelo Alves; Boyle, Robert Tew; Trindade, Gilma Santos; Nery, Luiz Eduardo Maia

    2010-01-01

    The purpose of this study was to verify the occurrence of pigment dispersion in retinal pigment cells exposed to UVA and UVB radiation, and to investigate the possible participation of a nitric oxide (NO) pathway. Retinal pigment cells from Neohelice granulata were obtained by cellular dissociation. Cells were analyzed for 30 min in the dark (control) and then exposed to 1.1 and 3.3 J cm(-2) UVA, 0.07 and 0.9 J cm(-2) UVB, 20 nmβ-PDH (pigment dispersing hormone) or 10 μm SIN-1 (NO donor). Histological analyses were performed to verify the UV effect in vivo. Cultured cells were exposed to 250 μm L-NAME (NO synthase blocker) and afterwards were treated with UVA, UVB or β-PDH. The retinal cells in culture displayed significant pigment dispersion in response to UVA, UVB and β-PDH. The same responses to UVA and UVB were observed in vivo. SIN-1 did not induce pigment dispersion in the cell cultures. L-NAME significantly decreased the pigment dispersion induced by UVA and UVB but not by β-PDH. All retinal cells showed an immunopositive reaction against neuronal nitric oxide synthases. Therefore, UVA and UVB radiation are capable of inducing pigment dispersion in retinal pigment cells of Neohelice granulata and this dispersion may be nitric oxide synthase dependent. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.

  8. Low concentrations of salicylic acid delay methyl jasmonate-induced leaf senescence by up-regulating nitric oxide synthase activity.

    PubMed

    Ji, Yingbin; Liu, Jian; Xing, Da

    2016-09-01

    In plants, extensive efforts have been devoted to understanding the crosstalk between salicylic acid (SA) and jasmonic acid (JA) signaling in pathogen defenses, but this crosstalk has scarcely been addressed during senescence. In this study, the effect of SA application on methyl jasmonate (MeJA)-induced leaf senescence was assessed. We found that low concentrations of SA (1-50 μM) played a delayed role against the senescence promoted by MeJA. Furthermore, low concentrations of SA enhanced plant antioxidant defenses and restricted reactive oxygen species (ROS) accumulation in MeJA-treated leaves. When applied simultaneously with MeJA, low concentrations of SA triggered a nitric oxide (NO) burst, and the elevated NO levels were linked to the nitric oxide associated 1 (NOA1)-dependent pathway via nitric oxide synthase (NOS) activity. The ability of SA to up-regulate plant antioxidant defenses, reduce ROS accumulation, and suppress leaf senescence was lost in NO-deficient Atnoa1 plants. In a converse manner, exogenous addition of NO donors increased the plant antioxidant capacity and lowered the ROS levels in MeJA-treated leaves. Taken together, the results indicate that SA at low concentrations counteracts MeJA-induced leaf senescence through NOA1-dependent NO signaling and strengthening of the antioxidant defense. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. Melatonin influences NO/NOS pathway and reduces oxidative and nitrosative stress in a model of hypoxic-ischemic brain damage.

    PubMed

    Blanco, Santos; Hernández, Raquel; Franchelli, Gustavo; Ramos-Álvarez, Manuel Miguel; Peinado, María Ángeles

    2017-01-30

    In this work, using a rat model combining ischemia and hypobaric hypoxia (IH), we evaluate the relationships between the antioxidant melatonin and the cerebral nitric oxide/nitric oxide synthase (NO/NOS) system seeking to ascertain whether melatonin exerts its antioxidant protective action by balancing this key pathway, which is highly involved in the cerebral oxidative and nitrosative damage underlying these pathologies. The application of the IH model increases the expression of the three nitric oxide synthase (NOS) isoforms, as well as nitrogen oxide (NOx) levels and nitrotyrosine (n-Tyr) impacts on the cerebral cortex. However, melatonin administration before IH makes nNOS expression response earlier and stronger, but diminishes iNOS and n-Tyr expression, while both eNOS and NOx remain unchanged. These results were corroborated by nicotine adenine dinucleotide phosphate diaphorase (NADPH-d) staining, as indicative of in situ NOS activity. In addition, the rats previously treated with melatonin exhibited a reduction in the oxidative impact evaluated by thiobarbituric acid reactive substances (TBARS). Finally, IH also intensified glial fibrillary acidic protein (GFAP) expression, reduced hypoxia-inducible factor-1alpha (HIF-1α), but did not change nuclear factor kappa B (NF-κB); meanwhile, melatonin did not significantly affect any of these patterns after the application of the IH model. The antioxidant melatonin acts on the NO/NOS system after IH injury balancing the release of NO, reducing peroxynitrite formation and protecting from nitrosative/oxidative damage. In addition, this paper raises questions concerning the classical role of some controversial molecules such as NO, which are of great consequence in the final fate of hypoxic neurons. We conclude that melatonin protects the brain from hypoxic/ischemic-derived damage in the first steps of the ischemic cascade, influencing the NO/NOS pathway and reducing oxidative and nitrosative stress. Copyright

  10. 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

  11. Cytosolic NADP(+)-dependent isocitrate dehydrogenase protects macrophages from LPS-induced nitric oxide and reactive oxygen species.

    PubMed

    Maeng, Oky; Kim, Yong Chan; Shin, Han-Jae; Lee, Jie-Oh; Huh, Tae-Lin; Kang, Kwang-il; Kim, Young Sang; Paik, Sang-Gi; Lee, Hayyoung

    2004-04-30

    Macrophages activated by microbial lipopolysaccharides (LPS) produce bursts of nitric oxide and reactive oxygen species (ROS). Redox protection systems are essential for the survival of the macrophages since the nitric oxide and ROS can be toxic to them as well as to pathogens. Using suppression subtractive hybridization (SSH) we found that cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) is strongly upregulated by nitric oxide in macrophages. The levels of IDPc mRNA and of the corresponding enzymatic activity were markedly increased by treatment of RAW264.7 cells or peritoneal macrophages with LPS or SNAP (a nitric oxide donor). Over-expression of IDPc reduced intracellular peroxide levels and enhanced the survival of H2O2- and SNAP-treated RAW264.7 macrophages. IDPc is known to generate NADPH, a cellular reducing agent, via oxidative decarboxylation of isocitrate. The expression of enzymes implicated in redox protection, superoxide dismutase (SOD) and catalase, was relatively unaffected by LPS and SNAP. We propose that the induction of IDPc is one of the main self-protection mechanisms of macrophages against LPS-induced oxidative stress.

  12. Biogenic nitric oxide from wastewater land application

    NASA Astrophysics Data System (ADS)

    Rammon, Desirée A.; Peirce, J. Jeffrey

    The importance of municipal wastewater land application to nitric oxide production and transport in soil was studied through the formulation and conduct of a comprehensive laboratory testing protocol. Nitric oxide (NO) is a precursor in the formation of tropospheric ozone which can directly impact public health and the environment. It is the uncertainty in the NO budget, and its relation to O 3, that motivates the need for measurements and modeling of NO flux from soils. Wastewater-amended soil is potentially one important component of that budget. NO emissions reported here were measured from: a well-characterized unamended soil, water-amended soil, and wastewater-amended soil in the laboratory in a dynamic test chamber. Laboratory results indicate that NO emissions from the selected sandy loam soil ranged from 0.3 to 0.4 ng N m -2 s -1 per cm 2 of unamended soil, while water-amended soil emissions ranged from 0.4 to 0.7 ng N m -2 s -1 per cm 2. NO flux from wastewater-amended soil ranged from 1.0 to 1.2 ng N m -2 s -1 per cm 2 of applied soil.

  13. 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

  14. Biological nitric oxide signalling: chemistry and terminology

    PubMed Central

    Heinrich, Tassiele A; da Silva, Roberto S; Miranda, Katrina M; Switzer, Christopher H; Wink, David A; Fukuto, Jon M

    2013-01-01

    Biological nitrogen oxide signalling and stress is an area of extreme clinical, pharmacological, toxicological, biochemical and chemical research interest. The utility of nitric oxide and derived species as signalling agents is due to their novel and vast chemical interactions with a variety of biological targets. Herein, the chemistry associated with the interaction of the biologically relevant nitrogen oxide species with fundamental biochemical targets is discussed. Specifically, the chemical interactions of nitrogen oxides with nucleophiles (e.g. thiols), metals (e.g. hemeproteins) and paramagnetic species (e.g. dioxygen and superoxide) are addressed. Importantly, the terms associated with the mechanisms by which NO (and derived species) react with their respective biological targets have been defined by numerous past chemical studies. Thus, in order to assist researchers in referring to chemical processes associated with nitrogen oxide biology, the vernacular associated with these chemical interactions is addressed. PMID:23617570

  15. 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

  16. Constitutive nitric oxide synthase activation is a significant route for nitroglycerin-mediated vasodilation

    PubMed Central

    Bonini, Marcelo G.; Stadler, Krisztian; de Oliveira Silva, Sueli; Corbett, Jean; Dore, Michael; Petranka, John; Fernandes, Denise C.; Tanaka, Leonardo Y.; Duma, Danielle; Laurindo, Francisco R. M.; Mason, Ronald P.

    2008-01-01

    The physiological effects of nitroglycerin as a potent vasodilator have long been documented. However, the molecular mechanisms by which nitroglycerin exerts its biological functions are still a matter of intense debate. Enzymatic pathways converting nitroglycerin to vasoactive compounds have been identified, but none of them seems to fully account for the reported clinical observations. Here, we demonstrate that nitroglycerin triggers constitutive nitric oxide synthase (NOS) activation, which is a major source of NO responsible for low-dose (1–10 nM) nitroglycerin-induced vasorelaxation. Our studies in cell cultures, isolated vessels, and whole animals identified endothelial NOS activation as a fundamental requirement for nitroglycerin action at pharmacologically relevant concentrations in WT animals. PMID:18562300

  17. Homocysteine impaired endothelial function through compromised vascular endothelial growth factor/Akt/endothelial nitric oxide synthase signalling.

    PubMed

    Yan, Ting-Ting; Li, Qian; Zhang, Xuan-Hong; Wu, Wei-Kang; Sun, Juan; Li, Lin; Zhang, Quan; Tan, Hong-Mei

    2010-11-01

    1. Hyperhomocysteinaemia (HHcy) is associated with endothelial dysfunction and has been recognized as a risk factor of cardiovascular disease. The present study aimed to investigate the effect of homocysteine (Hcy) on endothelial function in vivo and in vitro, and the underlying signalling pathways. 2. The HHcy animal model was established by intragastric administration with l-methionine in rats. Plasma Hcy and nitric oxide (NO) concentration were measured by fluorescence immunoassay or nitrate reductase method, respectively. Vasorelaxation in response to acetylcholine and sodium nitroprusside were carried out on aortic rings. Human umbilical vein endothelial cells (HUVEC) were treated with indicated concentrations of Hcy in the in vitro experiments. Intracellular NO level and NO concentration in culture medium were assayed. The alterations of possible signalling proteins were detected by western blot analysis. 3. l-methionine administration induced a significant increase in plasma Hcy and decrease in plasma NO. Endothelium-dependent relaxation of aortic rings in response to acetylcholine was impaired in l-methionine-administrated rats. The in vitro study showed that Hcy reduced both intracellular and culture medium NO levels. Furthermore, Hcy decreased phosphorylation of endothelial nitric oxide synthase (eNOS) at serine-1177 and phosphorylation of Akt at serine-473. Hcy-induced dephosphorylation of eNOS at Ser-1177 was partially reversed by insulin (Akt activator) and GF109203X (PKC inhibitor). Furthermore, Hcy reduced vascular endothelial growth factor (VEGF) expression in a dose-dependent manner. 4. In conclusion, Hcy impaired endothelial function through compromised VEGF/Akt/endothelial nitric oxide synthase signalling. These findings will be beneficial for further understanding the role of Hcy in cardiovascular disease. © 2010 Blackwell Publishing Asia Pty Ltd.

  18. 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.

  19. Exploring the Role of CYP3A4 Mediated Drug Metabolism in the Pharmacological Modulation of Nitric Oxide Production

    PubMed Central

    Pérez-del Palacio, José; Díaz, Caridad; Vergara, Noemí; Algieri, Francesca; Rodríguez-Nogales, Alba; de Pedro, Nuria; Rodríguez-Cabezas, M. Elena; Genilloud, Olga; Gálvez, Julio; Vicente, Francisca

    2017-01-01

    Nitric-oxide synthase, the enzyme responsible for mammalian nitric oxide generation, and cytochrome P450, the major enzymes involved in drug metabolism, share striking similarities. Therefore, it makes sense that cytochrome P450 drug mediated biotransformations might play an important role in the pharmacological modulation of nitric oxide synthase. In this work, we have undertaken an integrated in vitro assessment of the hepatic metabolism and nitric oxide modulation of previously described dual inhibitors (imidazoles and macrolides) of these enzymes in order assess the implication of CYP450 activities over production of nitric oxide. In vitro systems based in human liver microsomes and activated mouse macrophages were developed for these purposes. Additionally in vitro production the hepatic metabolites of dual inhibitor, roxithromycin, was investigated achieving the identification and isolation of main hepatic biotransformation products. Our results suggested that for some macrolide compounds, the cytochrome P450 3A4 derived drug metabolites have an important effect on nitric oxide production and might critically contribute to the pharmacological immunomodulatory activity observed. PMID:28446877

  20. 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.

  1. 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.

  2. Genetic polymorphisms in nitric oxide synthase genes modify the relationship between vegetable and fruit intake and risk of non-Hodgkin lymphoma

    PubMed Central

    Han, Xuesong; Zheng, Tongzhang; Lan, Qing; Zhang, Yaqun; Kilfoy, Briseis A.; Qin, Qin; Rothman, Nathaniel; Zahm, Shelia H.; Holford, Theodore R.; Leaderer, Brian; Zhang, Yawei

    2010-01-01

    Oxidative damage caused by reactive oxygen species (ROS) and other free radicals is involved in carcinogenesis. It has been suggested that high vegetable and fruit intake may reduce the risk of non-Hodgkin lymphoma (NHL) as vegetables and fruit are rich in antioxidants. The aim of this study is to evaluate the interaction of vegetable and fruit intake with genetic polymorphisms in oxidative stress pathway genes and NHL risk. This hypothesis was investigated in a population-based case-control study of NHL and NHL histological subtype in Connecticut women including 513 histologically confirmed incident cases and 591 randomly selected controls. Gene-vegetable/fruit joint effects were estimated using unconditional logistic regression model. The false discovery rate method was applied to adjust for multiple comparisons. Significant interactions with vegetable and fruit intake were mainly found for genetic polymorphisms on nitric oxide synthase (NOS) genes among those with diffuse large B-cell lymphoma (DLBCL) and Follicular lymphoma (FL). Two single nucleotide polymorphisms (SNPs) in the NOS1 gene were found to significantly modify the association between total vegetable and fruit intake and risk of NHL overall, as well as the risk of follicular lymphoma (FL). When vegetables, bean vegetables, cruciferous vegetables, green leafy vegetables, red vegetables, yellow/orange vegetables, fruit, and citrus fruit were examined separately, strong interaction effects were narrowed to vegetable intake among DLBCL patients. Our results suggest that genetic polymorphisms in oxidative stress pathway genes, especially in the nitric oxide synthase genes, modify the association between vegetable and fruit intake and risk of NHL. PMID:19423521

  3. 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.

  4. Role of nitric oxide in methamphetamine neurotoxicity: protection by 7-nitroindazole, an inhibitor of neuronal nitric oxide synthase.

    PubMed

    Di Monte, D A; Royland, J E; Jakowec, M W; Langston, J W

    1996-12-01

    The role of nitric oxide (NO.) in the neurotoxic effects of methamphetamine (METH) was evaluated using 7-nitroindazole (7-NI), a potent inhibitor of neuronal nitric oxide synthase. Treatment of mice with 7-NI (50 mg/kg) almost completely counteracted the loss of dopamine, 3,4-dihydroxyphenylacetic acid, and tyrosine hydroxylase immunoreactivity observed 5 days after four injections of 10 or 7.5 mg/kg METH. With the higher dose of METH, this protection at 5 days occurred despite the fact that combined administration of METH and 7-NI significantly increased lethality and exacerbated METH-induced dopamine release (as indicated by a greater dopamine depletion at 90 min and 1 day). Combined treatment with 4 x 10 mg/kg METH and 7-NI also slightly increased the body temperature of mice as compared with METH alone. Thus, the neuroprotective effects of 7-NI are independent from lethality, are not likely to be related to a reduction of METH-induced dopamine release, and are not due to a decrease in body temperature. These results indicate that NO. formation is an important step leading to METH neurotoxicity, and suggest that the cytotoxic properties of NO. may be directly involved in dopaminergic terminal damage.

  5. 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.

  6. The production of nitric oxide in EL4 lymphoma cells overexpressing growth hormone.

    PubMed

    Arnold, Robyn E; Weigent, Douglas A

    2003-01-01

    Growth hormone (GH) is produced by immunocompetent cells and has been implicated in the regulation of a multiplicity of functions in the immune system involved in growth and activation. However, the actions of endogenous or lymphocyte GH and its contribution to immune reactivity when compared with those of serum or exogenous GH are still unclear. In the present study, we overexpressed lymphocyte GH in EL4 lymphoma cells, which lack the GH receptor (GHR), to determine the role of endogenous GH in nitric oxide (NO) production and response to genotoxic stress. Western blot analysis demonstrated that the levels of GH increased approximately 40% in cells overexpressing GH (GHo) when compared with cells with vector alone. The results also show a substantial increase in NO production in cells overexpressing GH that could be blocked by N(G)-monomethyl-L-arginine (L-NMMA), an L-arginine analogue that competitively inhibits all three isoforms of nitric oxide synthase (NOS). No evidence was obtained to support an increase in peroxynitrite in cells overexpressing GH. Overexpression of GH increased NOS activity, inducible nitric oxide synthase (iNOS) promoter activity, and iNOS protein expression, whereas endothelial nitric oxide synthase and neuronal nitric oxide synthase protein levels were essentially unchanged. In addition, cells overexpressing GH showed increased arginine transport ability and intracellular arginase activity when compared with control cells. GH overexpression appeared to protect cells from the toxic effects of the DNA alkylating agent methyl methanesulfonate. This possibility was suggested by maintenance of the mitochondrial transmembrane potential in cells overexpressing GH when compared with control cells that could be blocked by L-NMMA. Taken together, the data support the notion that lymphocyte GH, independently of the GH receptor, may play a key role in the survival of lymphocytes exposed to stressful stimuli via the production of NO.

  7. 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.

  8. Anti-allodynic effect of mangiferin in neuropathic rats: Involvement of nitric oxide-cyclic GMP-ATP sensitive K+ channels pathway and serotoninergic system.

    PubMed

    de Los Monteros-Zuñiga, Antonio Espinosa; Izquierdo, Teresa; Quiñonez-Bastidas, Geovanna Nallely; Rocha-González, Héctor Isaac; Godínez-Chaparro, Beatriz

    The neurobiology of neuropathic pain is caused by injury in the central or peripheral nervous system. Recent evidence points out that mangiferin shows anti-nociceptive effect in inflammatory pain. However, its role in inflammatory and neuropathic pain and the possible mechanisms of action are not yet established. The purpose of this study was to determine the possible anti-allodynic effect of mangiferin in rats with spinal nerve ligation (SNL). Furthermore, we sought to investigate the possible mechanisms of action that contribute to these effects. Mechanical allodynia to stimulation with the von Frey filaments was measured by the up and down method. Intrathecal administration of mangiferin prevented, in a dose-dependent fashion, SNL-induced mechanical allodynia. Mangiferin-induced anti-allodynia was prevented by the intrathecal administration of L-NAME (100μg/rat, non-selective nitric oxide synthase inhibitor), ODQ (10μg/rat, inhibitor of guanylate-cyclase) and glibenclamide (50μg/rat, channel blocker of ATP-sensitive K + channels). Moreover, methiothepin (30μg/rat, non-selective 5-HT receptor antagonist), WAY-100635 (6μg/rat, selective 5-HT 1A receptor antagonist), SB-224289 (5μg/rat, selective 5-HT 1B receptor antagonist), BRL-15572 (4μg/rat, selective 5-HT 1D receptor antagonist) and SB-659551 (6μg/rat, selective 5-HT 5A receptor antagonist), but not naloxone (50μg/rat, non-selective opioid receptor antagonist), were able to prevent mangiferin-induced anti-allodynic effect. These data suggest that the anti-allodynic effect induced by mangiferin is mediated at least in part by the serotoninergic system, involving the activation of 5-HT 1A/1B/1D/5A receptors, as well as the nitric oxide-cyclic GMP-ATP-sensitive K + channels pathway, but not by the opioidergic system, in the SNL model of neuropathic pain in rats. Copyright © 2016. Published by Elsevier Inc.

  9. Breast cancer drugs dampen vascular functions by interfering with nitric oxide signaling in endothelium

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

    Gajalakshmi, Palanivel; Priya, Mani Krishna; Pradeep, Thangaraj

    Widely used chemotherapeutic breast cancer drugs such as Tamoxifen citrate (TC), Capecitabine (CP) and Epirubicin (EP) are known to cause various cardiovascular side-effects among long term cancer survivors. Vascular modulation warrants nitric oxide (NO) signal transduction, which targets the vascular endothelium. We hypothesize that TC, CP and EP interference with the nitric oxide downstream signaling specifically, could lead to cardiovascular dysfunctions. The results demonstrate that while all three drugs attenuate NO and cyclic guanosine mono-phosphate (cGMP) production in endothelial cells, they caused elevated levels of NO in the plasma and RBC. However, PBMC and platelets did not show any significantmore » changes under treatment. This implies that the drug effects are specific to the endothelium. Altered eNOS and phosphorylated eNOS (Ser-1177) localization patterns in endothelial cells were observed following drug treatments. Similarly, the expression of phosphorylated eNOS (Ser-1177) protein was decreased under the treatment of drugs. Altered actin polymerization was also observed following drug treatment, while addition of SpNO and 8Br-cGMP reversed this effect. Incubation with the drugs decreased endothelial cell migration whereas addition of YC-1, SC and 8Br-cGMP recovered the effect. Additionally molecular docking studies showed that all three drugs exhibited a strong binding affinity with the catalytic domain of human sGC. In conclusion, results indicate that TC, CP and EP cause endothelial dysfunctions via the NO–sGC–cGMP pathway and these effects could be recovered using pharmaceutical agonists of NO signaling pathway. Further, the study proposes a combination therapy of chemotherapeutic drugs and cGMP analogs, which would confer protection against chemotherapy mediated vascular dysfunctions in cancer patients. - Highlights: • NO production is reduced in endothelial cells under breast cancer drug treatment. • Cellular cGMP level is

  10. Effect of fuel/air nonuniformity on nitric oxide emissions

    NASA Technical Reports Server (NTRS)

    Lyons, V. J.

    1979-01-01

    A flame tube combustor holding jet A fuel was used in experiments performed at a pressure of .3 Mpa and a reference velocity of 25 meters/second for three inlet air temperatures of 600, 700, and 800 K. The gas sample measurements were taken at locations 18 cm and 48 cm downstream of the perforated plate flameholder. Nonuniform fuel/air profiles were produced using a fuel injector by separately fueling the inner five fuel tubes and the outer ring of twelve fuel tubes. Six fuel/air profiles were produced for nominal overall equivalence ratios of .5 and .6. An example of three of three of these profiles and their resultant nitric oxide NOx emissions are presented. The uniform fuel/air profile cases produced uniform and relatively low profile levels. When the profiles were either center-peaked or edge-peaked, the overall mass-weighted nitric oxide levels increased.

  11. 5-HT1D receptor inhibits renal sympathetic neurotransmission by nitric oxide pathway in anesthetized rats.

    PubMed

    García-Pedraza, José-Ángel; García, Mónica; Martín, María-Luisa; Morán, Asunción

    2015-09-01

    Although serotonin has been shown to inhibit peripheral sympathetic outflow, serotonin regulation on renal sympathetic outflow has not yet been elucidated. This study investigated which 5-HT receptor subtypes are involved. Wistar rats were anesthetized (sodium pentobarbital; 60mg/kg, i.p.), and prepared for in situ autoperfused rat kidney, which allows continuous measurement of systemic blood pressure (SBP), heart rate (HR) and renal perfusion pressure (PP). Electrical stimulation of renal sympathetic nerves resulted in frequency-dependent increases in PP (18.3±1.0, 43.7±2.7 and 66.7±4.0 for 2, 4 and 6Hz, respectively), without altering SBP or HR. 5-HT, 5-carboxamidotryptamine (5-HT1/7 agonist) (0.00000125-0.1μg/kg each) or l-694,247 (5-HT1D agonist; 0.0125μg/kg) i.a. bolus inhibited vasopressor responses by renal nerve electrical stimulation, unlike i.a. bolus of agonists α-methyl-5-HT (5-HT2), 1-PBG (5-HT3), cisapride (5-HT4), AS-19 (5-HT7), CGS-12066B (5-HT1B) or 8-OH-DPAT (5-HT1A) (0.0125μg/kg each). The effect of l-694,247 did not affect the exogenous norepinephrine-induced vasoconstrictions, whereas was abolished by antagonist LY310762 (5-HT1D; 1mg/kg) or l-NAME (nitric oxide; 10mg/kg), but not by indomethacin (COX1/2; 2mg/kg) or glibenclamide (ATP-dependent K(+) channel; 20mg/kg). These results suggest that 5-HT mechanism-induced inhibition of rat vasopressor renal sympathetic outflow is mainly mediated by prejunctional 5-HT1D receptors via nitric oxide release. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. 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.

  13. 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.

  14. 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.

  15. Nitric Oxide Signaling in Hypergravity-Induced Neuronal Plasticity

    NASA Technical Reports Server (NTRS)

    Holstein, Gay R.

    2003-01-01

    The goal of this research project was to identify the neurons and circuits in the vestibular nuclei and nucleus prepositus hypoglossi that utilize nitric oxide (NO) for intercellular signaling during gravity-induced plasticity. This objective was pursued using histochemical and immunocytochemical approaches to localize NO-producing neurons and characterize the fine morphology of the cells in ground-based studies of normal rats, rats adapted to hypergravity, and rats adapted to hypergravity and then re-adapted to the 1G environment. NO-producing neurons were identified and studied using four methodologies: i) immunocytochemistry employing polyclonal antibodies directed against neuronal nitric oxide synthase (nNOS), to provide an indication of the capacity of a cell for NO production; ii) immunocytochemistry employing a monoclonal antibody directed against L-citrulline, to provide an indirect index of the enzyme's activity; iii) histochemistry based on the NADPH-diaphorase reaction, for fuI1 cytological visualization of neurons; and iv) double immunofluorescence to co-localize nNOS and L-citrulline in individual vestibular nuclei (VN) and neurons.

  16. 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.

  17. Umbelliferone prevents oxidative stress, inflammation and hematological alterations, and modulates glutamate-nitric oxide-cGMP signaling in hyperammonemic rats.

    PubMed

    Germoush, Mousa O; Othman, Sarah I; Al-Qaraawi, Maha A; Al-Harbi, Hanan M; Hussein, Omnia E; Al-Basher, Gadh; Alotaibi, Mohammed F; Elgebaly, Hassan A; Sandhu, Mansur A; Allam, Ahmed A; Mahmoud, Ayman M

    2018-06-01

    Hepatic encephalopathy (HE) is a serious neuropsychiatric complication that occurs as a result of liver failure. Umbelliferone (UMB; 7-hydroxycoumarin) is a natural product with proven hepatoprotective activity; however, nothing has yet been reported on its protective effect against hyperammonemia, the main culprit behind the symptoms of HE. Here, we evaluated the effect of UMB against ammonium chloride (NH 4 Cl)-induced hyperammonemia, oxidative stress, inflammation and hematological alterations in rats. We demonstrated the modulatory role of UMB on the glutamate-nitric oxide (NO)-cGMP pathways in the cerebrum of rats. Rats received intraperitoneal injections of NH 4 Cl (3 times/week) for 8 weeks and concomitantly received 50 mg/kg UMB. NH 4 Cl-induced rats showed significantly elevated blood ammonia and liver function markers. Lipid peroxidation and NO were increased in the liver and cerebrum of rats while the antioxidant defenses were declined. UMB significantly reduced blood ammonia, liver function markers, lipid peroxidation and NO, and enhanced the antioxidant defenses in NH 4 Cl-induced rats. UMB significantly prevented anemia, leukocytosis, thrombocytopenia and prolongation of PT and aPTT. Hyperammonemic rats showed elevated levels of cerebral TNF-α, IL-1β and glutamine as well as increased activity and expression of Na + /K + -ATPase, effects that were significantly reversed by UMB. In addition, UMB down-regulated nitric oxide synthase and soluble guanylate cyclase in the cerebrum of hyperammonemic rats. In conclusion, this study provides evidence that UMB protects against hyperammonemia via attenuation of oxidative stress and inflammation. UMB prevents hyperammonemia associated hematological alterations and therefore represents a promising protective agent against the deleterious effects of excess ammonia. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  18. Nitric Oxide-Related Biological Pathways in Patients with Major Depression

    PubMed Central

    Baranyi, Andreas; Amouzadeh-Ghadikolai, Omid; Rothenhäusler, Hans-Bernd; Theokas, Simon; Robier, Christoph; Baranyi, Maria; Koppitz, Michael; Reicht, Gerhard; Hlade, Peter; Meinitzer, Andreas

    2015-01-01

    Background Major depression is a well-known risk factor for cardiovascular diseases and increased mortality following myocardial infarction. However, biomarkers of depression and increased cardiovascular risk are still missing. The aim of this prospective study was to evaluate, whether nitric-oxide (NO) related factors for endothelial dysfunction, such as global arginine bioavailability, arginase activity, L-arginine/ADMA ratio and the arginine metabolites asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) might be biomarkers for depression-induced cardiovascular risk. Methods In 71 in-patients with major depression and 48 healthy controls the Global Arginine Bioavailability Ratio (GABR), arginase activity (arginine/ornithine ratio), the L-arginine/ADMA ratio, ADMA, and SDMA were determined by high-pressure liquid chromatography. Psychiatric and laboratory assessments were obtained at baseline at the time of in-patient admittance and at the time of hospital discharge. Results The ADMA concentrations in patients with major depression were significantly elevated and the SDMA concentrations were significantly decreased in comparison with the healthy controls. Even after a first improvement of depression, ADMA and SDMA levels remained nearly unchanged. In addition, after a first improvement of depression at the time of hospital discharge, a significant decrease in arginase activity, an increased L-arginine/ADMA ratio and a trend for increased global arginine bioavailability were observed. Conclusions Our study results are evidence that in patients with major depression ADMA and SDMA might be biomarkers to indicate an increased cardiovascular threat due to depression-triggered NO reduction. GABR, the L-arginine/ADMA ratio and arginase activity might be indicators of therapy success and increased NO production after remission. PMID:26581044

  19. 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

  20. Nitric oxide nanoparticles

    PubMed Central

    Schairer, David O.; Martinez, Luis R.; Blecher, Karin; Chouake, Jason S.; Nacharaju, Parimala; Gialanella, Philip; Friedman, Joel M.; Nosanchuk, Joshua D.; Friedman, Adam J.

    2012-01-01

    Nitric oxide (NO) is a critical component of host defense against invading pathogens; however, its therapeutic utility is limited due to a lack of practical delivery systems. Recently, a NO-releasing nanoparticulate platform (NO-np) was shown to have in vitro broad-spectrum antimicrobial activity and in vivo pre-clinical efficacy in a dermal abscess model. To extend these findings, both topical (TP) and intralesional (IL) NO-np administration was evaluated in a MRSA intramuscular murine abscess model and compared with vancomycin. All treatment arms accelerated abscess clearance clinically, histologically, and by microbiological assays on both days 4 and 7 following infection. However, abscesses treated with NO-np via either route demonstrated a more substantial, statistically significant decrease in bacterial survival based on colony forming unit assays and histologically revealed less inflammatory cell infiltration and preserved muscular architecture. These data suggest that the NO-np may be an effective addition to our armament for deep soft tissue infections. PMID:22286699

  1. 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.

  2. Violent suicidal behaviour in bipolar disorder is associated with nitric oxide synthase 3 gene polymorphism.

    PubMed

    Oliveira, J; Debnath, M; Etain, B; Bennabi, M; Hamdani, N; Lajnef, M; Bengoufa, D; Fortier, C; Boukouaci, W; Bellivier, F; Kahn, J-P; Henry, C; Charron, D; Krishnamoorthy, R; Leboyer, M; Tamouza, R

    2015-09-01

    Given the importance of nitric oxide system in oxidative stress, inflammation, neurotransmission and cerebrovascular tone regulation, we postulated its potential dysfunction in bipolar disorder (BD) and suicide. By simultaneously analysing variants of three isoforms of nitric oxide synthase (NOS) genes, we explored interindividual genetic liability to suicidal behaviour in BD. A total of 536 patients with BD (DSM-IV) and 160 healthy controls were genotyped for functionally relevant NOS1, NOS2 and NOS3 polymorphisms. History of suicidal behaviour and violent suicide attempt was documented for 511 patients with BD. Chi-squared test was used to perform genetic association analyses and logistic regression to test for gene-gene interactions. NOS3 rs1799983 T homozygous state was associated with violent suicide attempts (26.4% vs. 10.8%, in patients and controls, P = 0.002, corrected P (Pc) = 0.004, OR: 2.96, 95% CI = 1.33-6.34), and this association was restricted to the early-onset BD subgroup (37.9% vs. 10.8%, in early-onset BD and controls, P = 0.0003, Pc = 0.0006 OR: 5.05, 95% CI: 1.95-12.45), while we found no association with BD per se and no gene-gene interactions. Our results bring further evidence for the potential involvement of endothelial NOS gene variants in susceptibility to suicidal behaviour. Future exploration of this pathway on larger cohort of suicidal behaviour is warranted. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Cross sections for electron collisions with nitric oxide

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

    Itikawa, Yukikazu, E-mail: yukitikawa@nifty.com

    Cross section data are reviewed for electron collisions with nitric oxide. Collision processes considered are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states, ionization, and dissociative electron attachment. After a survey of the literature (up to the end of 2015), recommended values of the cross section are determined, as far as possible.

  4. 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.

  5. Differential regulation of metabolism by nitric oxide and S-nitrosothiols in endothelial cells

    PubMed Central

    Diers, Anne R.; Broniowska, Katarzyna A.; Darley-Usmar, Victor M.

    2011-01-01

    S-nitrosation of thiols in key proteins in cell signaling pathways is thought to be an important contributor to nitric oxide (NO)-dependent control of vascular (patho)physiology. Multiple metabolic enzymes are targets of both NO and S-nitrosation, including those involved in glycolysis and oxidative phosphorylation. Thus it is important to understand how these metabolic pathways are integrated by NO-dependent mechanisms. Here, we compared the effects of NO and S-nitrosation on both glycolysis and oxidative phosphorylation in bovine aortic endothelial cells using extracellular flux technology to determine common and unique points of regulation. The compound S-nitroso-l-cysteine (l-CysNO) was used to initiate intracellular S-nitrosation since it is transported into cells and results in stable S-nitrosation in vitro. Its effects were compared with the NO donor DetaNONOate (DetaNO). DetaNO treatment caused only a decrease in the reserve respiratory capacity; however, l-CysNO impaired both this parameter and basal respiration in a concentration-dependent manner. In addition, DetaNO stimulated extracellular acidification rate (ECAR), a surrogate marker of glycolysis, whereas l-CysNO stimulated ECAR at low concentrations and inhibited it at higher concentrations. Moreover, a temporal relationship between NO- and S-nitrosation-mediated effects on metabolism was identified, whereby NO caused a rapid impairment in mitochondrial function, which was eventually overwhelmed by S-nitrosation-dependent processes. Taken together, these results suggest that severe pharmacological nitrosative stress may differentially regulate metabolic pathways through both intracellular S-nitrosation and NO-dependent mechanisms. Moreover, these data provide insight into the role of NO and related compounds in vascular (patho)physiology. PMID:21685262

  6. Differential regulation of metabolism by nitric oxide and S-nitrosothiols in endothelial cells.

    PubMed

    Diers, Anne R; Broniowska, Katarzyna A; Darley-Usmar, Victor M; Hogg, Neil

    2011-09-01

    S-nitrosation of thiols in key proteins in cell signaling pathways is thought to be an important contributor to nitric oxide (NO)-dependent control of vascular (patho)physiology. Multiple metabolic enzymes are targets of both NO and S-nitrosation, including those involved in glycolysis and oxidative phosphorylation. Thus it is important to understand how these metabolic pathways are integrated by NO-dependent mechanisms. Here, we compared the effects of NO and S-nitrosation on both glycolysis and oxidative phosphorylation in bovine aortic endothelial cells using extracellular flux technology to determine common and unique points of regulation. The compound S-nitroso-L-cysteine (L-CysNO) was used to initiate intracellular S-nitrosation since it is transported into cells and results in stable S-nitrosation in vitro. Its effects were compared with the NO donor DetaNONOate (DetaNO). DetaNO treatment caused only a decrease in the reserve respiratory capacity; however, L-CysNO impaired both this parameter and basal respiration in a concentration-dependent manner. In addition, DetaNO stimulated extracellular acidification rate (ECAR), a surrogate marker of glycolysis, whereas L-CysNO stimulated ECAR at low concentrations and inhibited it at higher concentrations. Moreover, a temporal relationship between NO- and S-nitrosation-mediated effects on metabolism was identified, whereby NO caused a rapid impairment in mitochondrial function, which was eventually overwhelmed by S-nitrosation-dependent processes. Taken together, these results suggest that severe pharmacological nitrosative stress may differentially regulate metabolic pathways through both intracellular S-nitrosation and NO-dependent mechanisms. Moreover, these data provide insight into the role of NO and related compounds in vascular (patho)physiology.

  7. 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.

  8. Effects of short term and long term Extremely Low Frequency Magnetic Field on depressive disorder in mice: Involvement of nitric oxide pathway.

    PubMed

    Madjid Ansari, Alireza; Farzampour, Shahrokh; Sadr, Ali; Shekarchi, Babak; Majidzadeh-A, Keivan

    2016-02-01

    Previous reports on the possible effects of Extremely Low Frequency Magnetic Fields (ELF MF) on mood have been paradoxical in different settings while no study has yet been conducted on animal behavior. In addition, it was shown that ELF MF exposure makes an increase in brain nitric oxide level. Therefore, in the current study, we aimed to assess the possible effect(s) of ELF MF exposure on mice Forced Swimming Test (FST) and evaluate the probable role of the increased level of nitric oxide in the observed behavior. Male adult mice NMRI were recruited to investigate the short term and long term ELF MF exposure (0.5 mT and 50 Hz, single 2h and 2 weeks 2h a day). Locomotor behavior was assessed by using open-field test (OFT) followed by FST to evaluate the immobility time. Accordingly, NΩ-nitro-l-arginine methyl ester 30 mg/kg was used to exert anti-depressant like effect. According to the results, short term exposure did not alter the immobility time, whereas long term exposure significantly reduces immobility time (p<0.01). However, it was revealed that the locomotion did not differ among all experimental groups. Short term exposure reversed the anti-depressant like effect resulting from 30 mg/kg of NΩ-nitro-l-arginine methyl ester (p<0.01). It has been concluded that long term exposure could alter the depressive disorder in mice, whereas short term exposure has no significant effect. Also, reversing the anti-depressant activity of L-NAME indicates a probable increase in the brain nitric oxide. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Mechanisms of cell signaling by nitric oxide and peroxynitrite: from mitochondria to MAP kinases

    NASA Technical Reports Server (NTRS)

    Levonen, A. L.; Patel, R. P.; Brookes, P.; Go, Y. M.; Jo, H.; Parthasarathy, S.; Anderson, P. G.; Darley-Usmar, V. M.

    2001-01-01

    Many of the biological and pathological effects of nitric oxide (NO) are mediated through cell signaling pathways that are initiated by NO reacting with metalloproteins. More recently, it has been recognized that the reaction of NO with free radicals such as superoxide and the lipid peroxyl radical also has the potential to modulate redox signaling. Although it is clear that NO can exert both cytotoxic and cytoprotective actions, the focus of this overview are those reactions that could lead to protection of the cell against oxidative stress in the vasculature. This will include the induction of antioxidant defenses such as glutathione, activation of mitogen-activated protein kinases in response to blood flow, and modulation of mitochondrial function and its impact on apoptosis. Models are presented that show the increased synthesis of glutathione in response to shear stress and inhibition of cytochrome c release from mitochondria. It appears that in the vasculature NO-dependent signaling pathways are of three types: (i) those involving NO itself, leading to modulation of mitochondrial respiration and soluble guanylate cyclase; (ii) those that involve S-nitrosation, including inhibition of caspases; and (iii) autocrine signaling that involves the intracellular formation of peroxynitrite and the activation of the mitogen-activated protein kinases. Taken together, NO plays a major role in the modulation of redox cell signaling through a number of distinct pathways in a cellular setting.

  10. Malate and Aspartate Increase L-Arginine and Nitric Oxide and Attenuate Hypertension.

    PubMed

    Hou, Entai; Sun, Na; Zhang, Fuchang; Zhao, Chenyang; Usa, Kristie; Liang, Mingyu; Tian, Zhongmin

    2017-05-23

    Fumarase catalyzes the interconversion of fumarate and L-malate in the tricarboxylic acid cycle. The Dahl salt-sensitive (SS) rat, a model of salt-sensitive hypertension, exhibits fumarase insufficiencies. To investigate the mechanism mediating the effect of fumarase-related metabolites on hypertension, we considered the pathway in which L-malate can be converted to oxaloacetate, aspartate, argininosuccinate, and L-arginine, the substrate of nitric oxide (NO) synthase. The levels of aspartate, citrulline, L-arginine, and NO were significantly decreased in the kidneys of SS rats compared to salt-insensitive consomic SS.13 BN rats. Knockdown of fumarase in human kidney cells and vascular endothelial cells resulted in decreased levels of malate, aspartate, L-arginine, and NO. Supplementation of aspartate or malate increased renal levels of L-arginine and NO and attenuated hypertension in SS rats. These findings reveal a multi-step metabolic pathway important for hypertension in which malate and aspartate may modulate blood pressure by altering levels of L-arginine and NO. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  11. 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.

  12. 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.

  13. 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.

  14. Increased nitric oxide production in platelets from severe chronic renal failure patients.

    PubMed

    Siqueira, Mariana Alves de Sá; Brunini, Tatiana M C; Pereira, Natália Rodrigues; Martins, Marcela Anjos; Moss, Monique Bandeira; Santos, Sérgio F; Lugon, Jocemir R; Mendes-Ribeiro, Antônio C

    2011-02-01

    Nitric oxide (NO) production occurs through oxidation of the amino acid L-arginine by NO synthase (NOS). NO inhibits platelet activation by increasing the levels of cyclic guanosine monophosphate (cGMP), thus maintaining vascular homeostasis. Our group previously demonstrated (da Silva et al. 2005) an enhancement of the L-arginine-NO-cGMP pathway in platelets taken from chronic renal failure (CRF) patients on haemodialysis associated with reduced platelet aggregation. We investigate the platelet L-arginine-NO-cGMP pathway, platelet function, and inflammation from patients in CRF on conservative treatment. A total of 42 CRF patients and 42 controls (creatinine clearance = 27 ± 3 vs. 93 ± 1 mL per min per 1.73 m2, respectively) participated in this study. NOS activity and expression and cGMP concentration were measured in platelets. Platelet aggregation induced by collagen or ADP was evaluated and plasma levels of fibrinogen were determined by the Clauss method. A marked increase in basal NOS activity was seen in undialysed CRF patients compared with controls, accompanied by an elevation of fibrinogen plasma levels. There were no differences in expression of NOS and in cGMP levels. In this context, platelet aggregation was not affected. We provide the first evidence of increased intraplatelet NO biosynthesis in undialysed CRF patients, which can be an early marker of future haemostatic abnormalities during dialysis treatment.

  15. 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

  16. Nitric oxide in the stress axis.

    PubMed

    López-Figueroa, M O; Day, H E; Akil, H; Watson, S J

    1998-10-01

    In recent years nitric oxide (NO) has emerged as a unique biological messenger. NO is a highly diffusible gas, synthesized from L-arginine by the enzyme nitric oxide synthase (NOS). Three unique subtypes of NOS have been described, each with a specific distribution profile in the brain and periphery. NOS subtype I is present, among other areas, in the hippocampus, hypothalamus, pituitary and adrenal gland. Together these structures form the limbic-hypothalamic-pituitary-adrenal (LHPA) or stress axis, activation of which is one of the defining features of a stress response. Evidence suggests that NO may modulate the release of the stress hormones ACTH and corticosterone, and NOS activity and transcription is increased in the LHPA axis following various stressful stimuli. Furthermore, following activation of the stress axis, glucocorticoids are thought to down-regulate the transcription and activity of NOS via a feedback mechanism. Taken together, current data indicate a role for NO in the regulation of the LHPA axis, although at present this role is not well defined. It has been suggested that NO may act as a cellular communicator in plasticity and development, to facilitate the activation or the release of other neurotransmitters, to mediate immune responses, and/or as a vasodilator in the regulation of blood flow. In the following review we summarize some of the latest insights into the function of NO, with special attention to its relationship with the LHPA axis.

  17. Elucidating nitric oxide synthase domain interactions by molecular dynamics.

    PubMed

    Hollingsworth, Scott A; Holden, Jeffrey K; Li, Huiying; Poulos, Thomas L

    2016-02-01

    Nitric oxide synthase (NOS) is a multidomain enzyme that catalyzes the production of nitric oxide (NO) by oxidizing L-Arg to NO and L-citrulline. NO production requires multiple interdomain electron transfer steps between the flavin mononucleotide (FMN) and heme domain. Specifically, NADPH-derived electrons are transferred to the heme-containing oxygenase domain via the flavin adenine dinucleotide (FAD) and FMN containing reductase domains. While crystal structures are available for both the reductase and oxygenase domains of NOS, to date there is no atomic level structural information on domain interactions required for the final FMN-to-heme electron transfer step. Here, we evaluate a model of this final electron transfer step for the heme-FMN-calmodulin NOS complex based on the recent biophysical studies using a 105-ns molecular dynamics trajectory. The resulting equilibrated complex structure is very stable and provides a detailed prediction of interdomain contacts required for stabilizing the NOS output state. The resulting equilibrated complex model agrees well with previous experimental work and provides a detailed working model of the final NOS electron transfer step required for NO biosynthesis. © 2015 The Protein Society.

  18. The involvement of neuronal nitric oxide synthase in antiepileptic action of alpha-asarone on pentylenetetrazol molding rats.

    PubMed

    Su, Jing; Zhu, Wenting; Liu, Jing; Yin, Jian; Qin, Wei; Jiang, Changbin

    2014-01-01

    The aim of the present study was to research the role of nitric oxide (NO) as a mediator of alpha (α)-asarone effect at the pentylenetetrazol (PTZ)-induced epileptiform discharge in rat. α-Asarone that was injected intraperitoneally twenty minutes before PTZ injection suppressed the clonic discharge effectively and the significant actions lasted for 30 min with no change of clonic amplitude. Administration of α-asarone did not influence interictal discharge. Four kinds of NO regulators were administered, including non-selective NG-nitro-L-arginine methyl ester (L-NAME), selective neuronal nitric oxide synthase (nNOS) inhibitor, 7-nitroindazole (7-NI), inducible nitric oxide synthase (iNOS) inhibitor, aminoguanidine (AG) and NO substrate, L-arginine (ARG) and their influence on the actions of α-asarone were studied, and all of the regulators were administered fifteen minutes before α-asarone injection. L-NAME and 7-NI reversed the anticlonic activity of α-asarone, and a significant increase of clonic activity was induced by L-NAME later in L-NAME +.α-asarone + PTZ group. There were no significant differences between AG + α-asarone + PTZ and α-asarone + PTZ group. L-ARG played a dual role in this study. It aggravated clonic discharge in the early stage but relieved interictal discharge in the late stage compared with PTZ group alone, and the beneficial effect of α-asarone was also reversed. All the above results suggest that nNOS/NO pathway mediates the anticonvulsant effect of α-asarone, and NO played a biphasic role in PTZ modeling process, while iNOS was unrelated to the inhibition effect of α-asarone on PTZ induced epileptiform activity.

  19. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breath nitric oxide test system. 862.3080 Section 862.3080 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test...

  20. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Breath nitric oxide test system. 862.3080 Section 862.3080 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test...

  1. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Breath nitric oxide test system. 862.3080 Section 862.3080 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test...

  2. 21 CFR 862.3080 - Breath nitric oxide test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Breath nitric oxide test system. 862.3080 Section 862.3080 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test...

  3. Procedures of laboratory nitric oxide fumigation for pest control

    USDA-ARS?s Scientific Manuscript database

    Nitric oxide (NO) is a newly discovered fumigant and has the potential to be a safe and effective alternative for postharvest pest control. As NO reacts with oxygen spontaneously to produce nitrogen dioxide, NO fumigation must be conducted under ultralow oxygen (ULO) atmosphere and therefore has com...

  4. Nitric Oxide Metabolism in Neisseria meningitidis

    PubMed Central

    Anjum, Muna F.; Stevanin, Tânia M.; Read, Robert C.; Moir, James W. B.

    2002-01-01

    Neisseria meningitidis, the causative agent of meningococcal disease in humans, is likely to be exposed to nitrosative stress during natural colonization and disease. The genome of N. meningitidis includes the genes aniA and norB, predicted to encode nitrite reductase and nitric oxide (NO) reductase, respectively. These gene products should allow the bacterium to denitrify nitrite to nitrous oxide. We show that N. meningitidis can support growth microaerobically by the denitrification of nitrite via NO and that norB is required for anaerobic growth with nitrite. NorB and, to a lesser extent, the cycP gene product cytochrome c′ are able to counteract toxicity due to exogenously added NO. Expression of these genes by N. meningitidis during colonization and disease may confer protection against exogenous or endogenous nitrosative stress. PMID:12003939

  5. Nitric oxide signaling: classical, less classical, and nonclassical mechanisms.

    PubMed

    Martínez-Ruiz, Antonio; Cadenas, Susana; Lamas, Santiago

    2011-07-01

    Although nitric oxide (NO) was identified more than 150 years ago and its effects were clinically tested in the form of nitroglycerine, it was not until the decades of 1970-1990 that it was described as a gaseous signal transducer. Since then, a canonical pathway linked to cyclic GMP (cGMP) as its quintessential effector has been established, but other modes of action have emerged and are now part of the common body of knowledge within the field. Classical (or canonical) signaling involves the selective activation of soluble guanylate cyclase, the generation of cGMP, and the activation of specific kinases (cGMP-dependent protein kinases) by this cyclic nucleotide. Nonclassical signaling alludes to the formation of NO-induced posttranslational modifications (PTMs), especially S-nitrosylation, S-glutathionylation, and tyrosine nitration. These PTMs are governed by specific biochemical mechanisms as well as by enzymatic systems. In addition, a less classical but equally important pathway is related to the interaction between NO and mitochondrial cytochrome c oxidase, which might have important implications for cell respiration and intermediary metabolism. Cross talk trespassing these necessarily artificial conceptual boundaries is progressively being identified and hence an integrated systems biology approach to the comprehension of NO function will probably emerge in the near future. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Reactive oxygen species are key mediators of the nitric oxide apoptotic pathway in anterior pituitary cells.

    PubMed

    Machiavelli, Leticia I; Poliandri, Ariel H; Quinteros, Fernanda A; Cabilla, Jimena P; Duvilanski, Beatriz H

    2007-03-01

    We previously showed that long-term exposure of anterior pituitary cells to nitric oxide (NO) induces apoptosis. The intracellular signals underlying this effect remained unclear. In this study, we searched for possible mechanisms involved in the early stages of the NO apoptotic cascade. Caspase 3 was activated by NO with no apparent disruption of mitochondrial membrane potential. NO caused a rapid increase of reactive oxygen species (ROS), and this increase seems to be dependent of mitochondrial electron transport chain. The antioxidant N-acetyl-cysteine avoided ROS increase, prevented the NO-induced caspase 3 activation, and reduced the NO apoptotic effect. Catalase was inactivated by NO, while glutathione peroxidase (GPx) activity and reduced glutathione (GSH) were not modified at first, but increased at later times of NO exposure. The increase of GSH level is important for the scavenging of the NO-induced ROS overproduction. Our results indicate that ROS have an essential role as a trigger of the NO apoptotic cascade in anterior pituitary cells. The permanent inhibition of catalase may strengthen the oxidative damage induced by NO. GPx activity and GSH level augment in response to the oxidative damage, though this increase seems not to be enough to rescue the cells from the NO effect.

  7. Estimates of nitric oxide production for lifting spacecraft reentry

    NASA Technical Reports Server (NTRS)

    Park, C.

    1971-01-01

    The amount of nitric oxide which may be produced by heating of air during an atmospheric reentry of a lifting spacecraft is estimated by three different methods. Two assume nitrogen fixation by the process of sudden freezing, and the third is a computer calculation using chemical rate equations.

  8. 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.

  9. 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.

  10. 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.

  11. Nitric oxide in the upper stratosphere - Measurements and geophysical interpretation

    NASA Technical Reports Server (NTRS)

    Harvath, J. J.; Frederick, J. E.; Orsini, N.; Douglass, A. R.

    1983-01-01

    A rocket-borne parachute-deployed chemiluminescence instrument has obtained seven new measurements of atmospheric nitric oxide for altitudes between 30 and 50 km at mid-latitudes. These results, when combined with profiles measured by an earlier version of the instrument, cover all four seasons and provide a more comprehensive picture of upper stratospheric nitric oxide than has been available previously. At the highest altitudes studied, the vertical gradient in mixing ratio displays positive and negative values during different observations, with the largest values tending to appear at the greatest heights in summer. Examination of the differences among the profiles, which exceed a factor of 3 near the stratopause, suggests that they arise from the action of transport processes which carry air into the mid-latitude upper stratosphere from regions of the atmosphere that contain widely different odd-nitrogen abundances.

  12. Tolerance and withdrawal to anticonvulsant action of clonazepam: role of nitric oxide.

    PubMed

    Gupta, N; Bhargava, V K; Pandhi, P

    2000-05-01

    The use of clonazepam in the long-term treatment of epilepsy is greatly inhibited by its capacity to induce tolerance and dependence. A means of preventing or minimizing the tolerance and dependence inducing properties is required. Here the role of nitric oxide in preventing the development of tolerance and withdrawal hyperexcitability was studied. In Wistar rats, clonazepam at a dose of 0.25 mg/kg i.p. twice daily produced tolerance to its anticonvulsant action in 28 days. After sudden cessation of therapy it produced hyperexcitability. Tolerance was shown by a decrease in seizure threshold to near control value while withdrawal hyperexcitability was evidenced by a significant decrease in seizure threshold below the control value. L-Arginine (a donor of nitric oxide) and N omega-nitro-L-arginine (an inhibitor of nitric oxide synthase) were given in doses of 150 mg/kg and 8 mg/kg, respectively on day 1, 3, 7, 14, 21 and 28 with clonazepam. Withdrawal hyperexcitability was seen on day 1, 2 and 4 after cessation of drug therapy. Electroshock was used as a model of epilepsy and seizure thresholds were determined by an up and down method of Kimball et al. L-Arginine was found to inhibit the development tolerance as well as withdrawal hyperexcitability when administered with clonazepam while N omega-L-arginine did not prevent either the development of tolerance or withdrawal hyperexcitability in the electroshock model. In the PTZ model, however, L-arginine had no effect on the anticonvulsant action and withdrawal hyperexcitability while inhibition of nitric oxide synthesis prevented withdrawal hyperexcitability in PTZ-induced seizures.

  13. NITRIC OXIDE INHIBITORY ACTIVITY OF STRYCHNOS SPINOSA (LOGANIACEAE) LEAF EXTRACTS AND FRACTIONS

    PubMed Central

    AI, Isa; JP, Dzoyem; SA, Adebayo; MM, Suleiman; JN, Eloff

    2016-01-01

    Background: The study was aimed at determining the anti-inflammatory activity of fractions and extracts obtained from Strychnos spinosa leaves on a mediator of inflammation nitric oxide (NO). Materials and Methods: Leaves were extracted with acetone and separated into fractions with different polarities by solvent-solvent fractionation. The Griess assay was used to determine the nitric oxide (NO) inhibitory activity. Cellular toxicity was determined by “using the MTT reduction assay”. Results: With the exception of the ethyl acetate fraction which had an IC50 >750 μg/mL, all extracts and fractions had significant nitric oxide-inhibitory activity. The most active being the water fraction, chloroform fraction and the dichloromethane/methanol extracts with IC50 values of 88.43 μg/mL, 96.72 μg/mL and 115.62 μg/mL, respectively. The extracts and fractions had low cytotoxicity on macrophage U937 cell lines. Conclusion: Extracts and fractions of Strychnos spinosa leaves may be promising sources of natural anti-inflammatory agents. Findings obtained from this study showed that Strychnos spinosa leaves possess promising anti-inflammatory action and could be used in the treatment of inflammation-related conditions. PMID:28480356

  14. NITRIC OXIDE INHIBITORY ACTIVITY OF STRYCHNOS SPINOSA (LOGANIACEAE) LEAF EXTRACTS AND FRACTIONS.

    PubMed

    Ai, Isa; Jp, Dzoyem; Sa, Adebayo; Mm, Suleiman; Jn, Eloff

    2016-01-01

    The study was aimed at determining the anti-inflammatory activity of fractions and extracts obtained from Strychnos spinosa leaves on a mediator of inflammation nitric oxide (NO). Leaves were extracted with acetone and separated into fractions with different polarities by solvent-solvent fractionation. The Griess assay was used to determine the nitric oxide (NO) inhibitory activity. Cellular toxicity was determined by "using the MTT reduction assay". With the exception of the ethyl acetate fraction which had an IC 50 >750 μg/mL, all extracts and fractions had significant nitric oxide-inhibitory activity. The most active being the water fraction, chloroform fraction and the dichloromethane/methanol extracts with IC 50 values of 88.43 μg/mL, 96.72 μg/mL and 115.62 μg/mL, respectively. The extracts and fractions had low cytotoxicity on macrophage U937 cell lines. Extracts and fractions of Strychnos spinosa leaves may be promising sources of natural anti-inflammatory agents. Findings obtained from this study showed that Strychnos spinosa leaves possess promising anti-inflammatory action and could be used in the treatment of inflammation-related conditions.

  15. Anticonvulsant effect of minocycline on pentylenetetrazole-induced seizure in mice: involvement of nitric oxide and N-methyl-D-aspartate receptor.

    PubMed

    Amini-Khoei, Hossein; Kordjazy, Nastaran; Haj-Mirzaian, Arya; Amiri, Shayan; Haj-Mirzaian, Arvin; Shirzadian, Armin; Hasanvand, Amin; Balali-Dehkordi, Shima; Hassanipoor, Mahsa; Dehpour, Ahmad Reza

    2018-03-20

    Anticonvulsant effects of minocycline have been explored recently. This study was designed to examine the anticonvulsant effect of acute administration of minocycline on pentylenetetrazole (PTZ)-induced seizures in mouse considering the possible role of nitric oxide (NO)/NMDA pathway. We induced seizure using intravenous administration of PTZ. Our results showed that acute administration of minocycline increased the seizure threshold. Furthermore, co-administration of sub-effective doses of the non-selective nitric oxide synthase (NOS) inhibitor, L-NAME (10 mg/kg) and the neuronal NOS inhibitor, 7-nitroindazole (40 mg/kg) enhanced the anticonvulsant effect of sub-effective dose of minocycline (40 mg/kg). We found that inducible NOS inhibitor, aminoguanidine (100 mg/kg), had no effect on the anti-seizure effect of minocycline. Moreover, L-arginine (60 mg/kg), as a NOS substrate, reduced the anticonvulsant effect of minocycline. We also demonstrated that pretreatment with NMDA receptor antagonists, ketamine (0.5 mg/kg) and MK-801 (0.05 mg/kg) increased the anticonvulsant effect of sub-effective dose of minocycline. Results showed that minocycline significantly decreased the hippocampal nitrite level. Furthermore, co-administration of nNOS inhibitor like NMDA receptor antagonists augmented the effect of minocycline on the hippocampal nitrite level. In conclusion, we revealed that anticonvulsant effect of minocycline might be, at least in part, due to decline in constitutive hippocampal nitric oxide activity as well as inhibition of NMDA receptors.

  16. 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.

  17. [Effects of nitric oxide on peritoneal lymphatic stomata and lymph drainage via NO-cGMP-Ca2+ pathway].

    PubMed

    Li, Yan-Yuan; Li, Ji-Cheng

    2005-02-25

    To study the cell signal transduction mechanism of nitric oxide (NO) on the peritoneal lymphatic stomata and lymph drainage in the rat, cGMP content were measured by a commercially available radioimmunoassay kit, and the [Ca(2+)](i) were observed by a confocal laser scanning microscope in the cultured peritoneal mesothelial cell. Animal experiment was practiced to study the effect of NO-cGMP-Ca(2+) pathway on the lymphatic stomata and lymph absorption. The results showed that: (1) Sper/NO increased cGMP of the rat peritoneal mesothelial cell (RPMC) in a dose-dependent manner (P<0.01) compared to the control group. This effect was blocked by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) (P<0.05), a specific inhibitor of soluble guanylyl cyclase (sGC). The level of [Ca(2+)](i) in single RPMC decreased by adding Sper/NO (P<0.05). Pretreatment with ODQ for 10 min blocked the Sper/NO-induced decrease in [Ca(2+)](i). L-typed calcium channel blocker nifedipine induced an immediate and marked decrease in [Ca(2+)](i) (P<0.05).. After [Ca(2+)](i) reached a balance again, adding Sper/NO could not change [Ca(2+)](i) (P>0.05). (2) Sper/NO increased the area of the stomata (P<0.01) and the quantity of the tracer in a dose-dependent manner (P<0.05) compared to the control group. Pretreatment with ODQ significantly inhibited Sper/NO-induced change of lymphatic stomata and lymph drainage (P<0.01). Nifedipine increased the opening area of the lymphatic stomata (P< 0.01) and the concentration of absorbed trypan blue of the diaphragm (P<0.05). Sper/NO could not make a further change in the samples pretreated by nifedipine (P> 0.05). The results indicate that NO can decrease [Ca(2+)](i) in the RPMC through the NO-cGMP pathway. This procession is related with the L- type voltage-gated Ca(2+) channel. NO enlarges the opening area of the lymphatic stomata and enhances the lymph drainage of tracer by NO-cGMP-[Ca(2+)](i) pathway.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. Relationship between nitric oxide- and calcium-dependent signal transduction pathways in growth hormone release from dispersed goldfish pituitary cells.

    PubMed

    Chang, John P; Sawisky, Grant R; Davis, Philip J; Pemberton, Joshua G; Rieger, Aja M; Barreda, Daniel R

    2014-09-15

    Nitric oxide (NO) and Ca(2+) are two of the many intracellular signal transduction pathways mediating the control of growth hormone (GH) secretion from somatotropes by neuroendocrine factors. We have previously shown that the NO donor sodium nitroprusside (SNP) elicits Ca(2+) signals in identified goldfish somatotropes. In this study, we examined the relationships between NO- and Ca(2+)-dependent signal transduction mechanisms in GH secretion from primary cultures of dispersed goldfish pituitary cells. Morphologically identified goldfish somatotropes stained positively for an NO-sensitive dye indicating they may be a source of NO production. In 2h static incubation experiments, GH release responses to the NO donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP) were attenuated by CoCl2, nifedipine, verapamil, TMB-8, BHQ, and KN62. In column perifusion experiments, the ability of SNP to induce GH release was impaired in the presence of TMB-8, BHQ, caffeine, and thapsigargin, but not ryanodine. Caffeine-elicited GH secretion was not affected by the NO scavenger PTIO. These results suggest that NO-stimulated GH release is dependent on extracellular Ca(2+) availability and voltage-sensitive Ca(2+) channels, as well as intracellular Ca(2+) store(s) that possess BHQ- and/or thapsigargin-inhibited sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases, as well as TMB-8- and/or caffeine-sensitive, but not ryanodine-sensitive, Ca(2+)-release channels. Calmodulin kinase-II also likely participates in NO-elicited GH secretion but caffeine-induced GH release is not upstream of NO production. These findings provide insights into how NO actions many integrate with Ca(2+)-dependent signalling mechanisms in goldfish somatotropes and how such interactions may participate in the GH-releasing actions of regulators that utilize both NO- and Ca(2+)-dependent transduction pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Study on relationship of nitric oxide, oxidation, peroxidation, lipoperoxidation with chronic chole-cystitis

    PubMed Central

    Zhou, Jun-Fu; Cai, Dong; Zhu, You-Gen; Yang, Jin-Lu; Peng, Cheng-Hong; Yu, Yang-Hai

    2000-01-01

    AIM: To study relationship of injury induced by nitric oxide, oxidation, peroxidation, lipoperoxidation with chronic cholecystitis. METHODS: The values of plasma nitric oxide (P-NO), plasma vitamin C (P-VC), plasma vitamin E (P-VE), plasma β-carotene (P-β-CAR), plasma lipoperoxides (P-LPO), erythrocyte superoxide dismutase (E-SOD), erythrocyte catalase (E-CAT), erythrocyte glutathione peroxidase (E-GSH-Px) activities and erythrocyte lipoperoxides (E-LPO) level in 77 patients with chro nic cholecystitis and 80 healthy control subjects were determined, differences of the above average values between t he patient group and the control group and differences of the average values bet ween preoperative and postoperative patients were analyzed and compared, linear regression and correlation of the disease course with the above determination values as well as the stepwise regression and correlation of the course with th e values were analyzed. RESULTS: Compared with the control group, the average values of P-NO, P-LPO, E-LPO were significantly increased (P < 0.01), and of P-VC, P-VE, P-β-CAR, E-SOD, E-CAT and E-GSH-Px decreased (P < 0.01) in the patient group. The analysis of the lin ear regression and correlation s howed that with prolonging of the course, the values of P-NO, P-LPO and E-LPO in the patients were gradually ascended and the values of P-VC, P-VE, P-β-CAR, E-SOD, E-CAT and E-GSH-Px descended (P < 0.01). The analysis of the stepwise regression and correlation indicated that the correlation of the course with P-NO, P-VE and P-β-CAR values was the closest. Compared with the preoperative patients, the average values of P-NO, P-LPO and E-LPO were significantly decre ased (P < 0.01) and the average values of P-VC, E-SOD, E-CAT and E-GSH-Px in postoperative pa tients increased (P < 0.01) in postoperative patients. But there was no signif icant difference in the average values of P-VE, P-β-CAR preope rative and postoperative patients. CONCLUSION: Chronic

  4. 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.

  5. Roles of thioredoxin in nitric oxide-dependent preconditioning-induced tolerance against MPTP neurotoxin

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

    Chiueh, C.C.; Andoh, Tsugunobu; Chock, P. Boon

    2005-09-01

    Hormesis, a stress tolerance, can be induced by ischemic preconditioning stress. In addition to preconditioning, it may be induced by other means, such as gas anesthetics. Preconditioning mechanisms, which may be mediated by reprogramming survival genes and proteins, are obscure. A known neurotoxicant, 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), causes less neurotoxicity in the mice that are preconditioned. Pharmacological evidences suggest that the signaling pathway of {center_dot}NO-cGMP-PKG (protein kinase G) may mediate preconditioning phenomenon. We developed a human SH-SY5Y cell model for investigating {sup {center_dot}}NO-mediated signaling pathway, gene regulation, and protein expression following a sublethal preconditioning stress caused by a brief 2-h serum deprivation.more » Preconditioned human SH-SY5Y cells are more resistant against severe oxidative stress and apoptosis caused by lethal serum deprivation and 1-mehtyl-4-phenylpyridinium (MPP{sup +}). Both sublethal and lethal oxidative stress caused by serum withdrawal increased neuronal nitric oxide synthase (nNOS/NOS1) expression and {sup {center_dot}}NO levels to a similar extent. In addition to free radical scavengers, inhibition of nNOS, guanylyl cyclase, and PKG blocks hormesis induced by preconditioning. S-nitrosothiols and 6-Br-cGMP produce a cytoprotection mimicking the action of preconditioning tolerance. There are two distinct cGMP-mediated survival pathways: (i) the up-regulation of a redox protein thioredoxin (Trx) for elevating mitochondrial levels of antioxidant protein Mn superoxide dismutase (MnSOD) and antiapoptotic protein Bcl-2, and (ii) the activation of mitochondrial ATP-sensitive potassium channels [K(ATP)]. Preconditioning induction of Trx increased tolerance against MPP{sup +}, which was blocked by Trx mRNA antisense oligonucleotide and Trx reductase inhibitor. It is concluded that Trx plays a pivotal role in {sup {center_dot}}NO-dependent preconditioning hormesis

  6. 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.

  7. Effects of cyclooxygenase inhibitor pretreatment on nitric oxide production, nNOS and iNOS expression in rat cerebellum.

    PubMed

    Di Girolamo, G; Farina, M; Riberio, M L; Ogando, D; Aisemberg, J; de los Santos, A R; Martí, M L; Franchi, A M

    2003-07-01

    1. The therapeutic effect of nonsteroidal anti-inflammatory drugs (NSAIDs) is thought to be due mainly to its inhibition of cyclooxygenase (COX) enzymes, but there is a growing body of research that now demonstrates a variety of NSAIDs effects on cellular signal transduction pathways other than those involving prostaglandins. 2. Nitric oxide (NO) as a free radical and an agent that gives rise to highly toxic oxidants (peroxynitrile, nitric dioxide, nitron ion), becomes a cause of neuronal damage and death in some brain lesions such as Parkinson and Alzheimer disease, and Huntington's chorea. 3. In the present study, the in vivo effect of three NSAIDs (lysine clonixinate (LC), indomethacine (INDO) and meloxicam (MELO)) on NO production and nitric oxide synthase expression in rat cerebellar slices was analysed. Rats were treated with (a) saline, (b) lipopolysaccharide (LPS) (5 mg kg(-1), i.p.), (c) saline in combination with different doses of NSAIDs and (d) LPS in combination with different doses of NSAIDs and then killed 6 h after treatment. 4. NO synthesis, evaluated by Bred and Snyder technique, was increased by LPS. This augmentation was inhibited by coadministration of the three NSAIDs assayed. None of the NSAIDs tested was able to modify control NO synthesis. 5. Expression of iNOS and neural NOS (nNOS) was detected by Western blotting in control and LPS-treated rats. LC and INDO, but not MELO, were able to inhibit the expression of these enzymes. 6. Therefore, reduction of iNOS and nNOS levels in cerebellum may explain, in part, the anti-inflammatory effect of these NSAIDs and may also have importance in the prevention of NO-mediated neuronal injury.

  8. Effects of cyclooxygenase inhibitor pretreatment on nitric oxide production, nNOS and iNOS expression in rat cerebellum

    PubMed Central

    DiGirolamo, G; Farina, M; Riberio, M L; Ogando, D; Aisemberg, J; de los Santos, A R; Martí, M L; Franchi, A M

    2003-01-01

    The therapeutic effect of nonsteroidal anti-inflammatory drugs (NSAIDs) is thought to be due mainly to its inhibition of cyclooxygenase (COX) enzymes, but there is a growing body of research that now demonstrates a variety of NSAIDs effects on cellular signal transduction pathways other than those involving prostaglandins. Nitric oxide (NO) as a free radical and an agent that gives rise to highly toxic oxidants (peroxynitrile, nitric dioxide, nitron ion), becomes a cause of neuronal damage and death in some brain lesions such as Parkinson and Alzheimer disease, and Huntington's chorea. In the present study, the in vivo effect of three NSAIDs (lysine clonixinate (LC), indomethacine (INDO) and meloxicam (MELO)) on NO production and nitric oxide synthase expression in rat cerebellar slices was analysed. Rats were treated with (a) saline, (b) lipopolysaccharide (LPS) (5 mg kg−1, i.p.), (c) saline in combination with different doses of NSAIDs and (d) LPS in combination with different doses of NSAIDs and then killed 6 h after treatment. NO synthesis, evaluated by Bred and Snyder technique, was increased by LPS. This augmentation was inhibited by coadministration of the three NSAIDs assayed. None of the NSAIDs tested was able to modify control NO synthesis. Expression of iNOS and neural NOS (nNOS) was detected by Western blotting in control and LPS-treated rats. LC and INDO, but not MELO, were able to inhibit the expression of these enzymes. Therefore, reduction of iNOS and nNOS levels in cerebellum may explain, in part, the anti-inflammatory effect of these NSAIDs and may also have importance in the prevention of NO-mediated neuronal injury. PMID:12871835

  9. Isotope Effects Associated with N2O Production By Fungal and Bacterial Nitric Oxide Reductases: Implications for Tracing Microbial Production Pathways

    NASA Astrophysics Data System (ADS)

    Ostrom, N. E.; Yang, H.; Gandhi, H.; Hegg, E. L.

    2014-12-01

    Site preference (SP), the difference in δ15N between the central (α) and outer (β) N atoms in N2O, has emerged as a conservative tracer of microbial N2O production. The key advantages of SP relative to bulk isotopes are (1) that it is independent of the isotope composition of the substrates of nitrification and denitrification and (2) has not been shown to exhibit fractionation during production. In pure microbial culture distinct SP values for N2O production from bacterial denitrification, including nitrifier-denitrification (-10 to 0 ‰), relative to hydroxylamine oxidation and fungal denitrification (33-37 ‰) provide a promising basis to resolve production pathways. In this study, we determined the δ15N, δ18O, δ15Nα, and δ15Nβ of N2O generated by purified fungal (P450nor) and bacterial nitric oxide reductases. The isotope values were used to calculate SP values, enrichment factors (e), and kinetic isotope effects (KIEs). Both O and Nα displayed normal isotope effects during enzymatic NO reduction by the P450nor with e values of -25.7‰ (KIE = 1.0264) and -12.6‰ (KIE = 1.0127), respectively. However, bulk nitrogen (average δ15N of Nα and Nβ) and Nβ exhibited inverse isotope effects with e values of 14.0‰ (KIE = 0.9862) and 36.1‰ (KIE = 0.9651), respectively. The observed inverse isotope effect in δ15Nβ is consistent with reversible binding of the first NO in the P450nor reaction mechanism. Experiments with bacterial nitric oxide reductase are ongoing, however, preliminary data indicates a inverse isotope effect in the α and β positions and a normal isotope effect in δ18O. In contrast to the constant SP observed during N2O production observed in microbial cultures, the SP measured for purified P450nor was not constant, increasing from ~15‰ to ~29‰ during the course of the reaction. Our results clearly indicate that fractionation of SP during N2O production by P450nor is not zero, and that SP values higher and lower than the

  10. Evidence for a pathogenic role of nitric oxide in inflammation-induced osteoporosis.

    PubMed

    Armour, K E; Van'T Hof, R J; Grabowski, P S; Reid, D M; Ralston, S H

    1999-12-01

    Inflammatory disease is associated with increased production of nitric oxide (NO) and activation of the inducible nitric oxide synthase (iNOS) pathway. Several studies have addressed the role of NO as a mediator of cytokine effects on bone cell activity in vitro. Stimulatory and inhibitory actions have been found, however, depending on the concentrations produced and model system used. In view of this, it has been difficult to predict whether increased production of NO during inflammation is likely to increase bone loss or prevent it. We have investigated the pathogenic role of NO in an animal model of inflammation-induced osteoporosis (IMO). NO production was increased in IMO when compared with controls (+344%; p < 0.01), and this was accompanied by activation of inducible NOS (iNOS) in the bone marrow space. Bone mineral density (BMD) was reduced in IMO when compared with controls (-64%; p < 0.01), and this was found to be associated with reduced osteoblast numbers (-44%; p < 0.05) and increased osteoclast numbers (+38%; p < 0.01). The NOS inhibitor L-NMMA reversed the deleterious effects of IMO on bone mass and bone turnover, but L-NMMA had no effect on bone mass in control animals. This study has important implications for many inflammatory diseases such as rheumatoid arthritis, ankylosing spondylitis, and inflammatory bowel disease which are associated with increased NO production and osteoporosis. Our data not only suggest that iNOS activation and increased NO production contribute to the pathogenesis of osteoporosis in these situations, but also suggest that NOS inhibitors could be of therapeutic value in the prevention and treatment of such bone loss.

  11. Nitric oxide acts as a positive regulator to induce metamorphosis of the ascidian Herdmania momus.

    PubMed

    Ueda, Nobuo; Degnan, Sandie M

    2013-01-01

    Marine invertebrates commonly have a biphasic life cycle in which the metamorphic transition from a pelagic larva to a benthic post-larva is mediated by the nitric oxide signalling pathway. Nitric oxide (NO) is synthesised by nitric oxide synthase (NOS), which is a client protein of the molecular chaperon heat shock protein 90 (HSP90). It is notable, then, that both NO and HSP90 have been implicated in regulating metamorphosis in marine invertebrates as diverse as urochordates, echinoderms, molluscs, annelids, and crustaceans. Specifically, the suppression of NOS activity by the application of either NOS- or HSP90-inhibiting pharmacological agents has been shown consistently to induce the initiation of metamorphosis, leading to the hypothesis that a negative regulatory role of NO is widely conserved in biphasic life cycles. Further, the induction of metamorphosis by heat-shock has been demonstrated for multiple species. Here, we investigate the regulatory role of NO in induction of metamorphosis of the solitary tropical ascidian, Herdmania momus. By coupling pharmacological treatments with analysis of HmNOS and HmHSP90 gene expression, we present compelling evidence of a positive regulatory role for NO in metamorphosis of this species, in contrast to all existing ascidian data that supports the hypothesis of NO as a conserved negative regulator of metamorphosis. The exposure of competent H. momus larvae to a NOS inhibitor or an NO donor results in an up-regulation of NOS and HSP90 genes. Heat shock of competent larvae induces metamorphosis in a temperature dependent manner, up to a thermal tolerance that approaches 35°C. Both larval/post-larval survival and the appearance of abnormal morphologies in H. momus post-larvae reflect the magnitude of up-regulation of the HSP90 gene in response to heat-shock. The demonstrated role of NO as a positive metamorphic regulator in H. momus suggests the existence of inter-specific adaptations of NO regulation in ascidian

  12. Nitric Oxide Acts as a Positive Regulator to Induce Metamorphosis of the Ascidian Herdmania momus

    PubMed Central

    Ueda, Nobuo; Degnan, Sandie M.

    2013-01-01

    Marine invertebrates commonly have a biphasic life cycle in which the metamorphic transition from a pelagic larva to a benthic post-larva is mediated by the nitric oxide signalling pathway. Nitric oxide (NO) is synthesised by nitric oxide synthase (NOS), which is a client protein of the molecular chaperon heat shock protein 90 (HSP90). It is notable, then, that both NO and HSP90 have been implicated in regulating metamorphosis in marine invertebrates as diverse as urochordates, echinoderms, molluscs, annelids, and crustaceans. Specifically, the suppression of NOS activity by the application of either NOS- or HSP90-inhibiting pharmacological agents has been shown consistently to induce the initiation of metamorphosis, leading to the hypothesis that a negative regulatory role of NO is widely conserved in biphasic life cycles. Further, the induction of metamorphosis by heat-shock has been demonstrated for multiple species. Here, we investigate the regulatory role of NO in induction of metamorphosis of the solitary tropical ascidian, Herdmania momus. By coupling pharmacological treatments with analysis of HmNOS and HmHSP90 gene expression, we present compelling evidence of a positive regulatory role for NO in metamorphosis of this species, in contrast to all existing ascidian data that supports the hypothesis of NO as a conserved negative regulator of metamorphosis. The exposure of competent H. momus larvae to a NOS inhibitor or an NO donor results in an up-regulation of NOS and HSP90 genes. Heat shock of competent larvae induces metamorphosis in a temperature dependent manner, up to a thermal tolerance that approaches 35°C. Both larval/post-larval survival and the appearance of abnormal morphologies in H. momus post-larvae reflect the magnitude of up-regulation of the HSP90 gene in response to heat-shock. The demonstrated role of NO as a positive metamorphic regulator in H. momus suggests the existence of inter-specific adaptations of NO regulation in ascidian

  13. The role of nitric oxide in low level light therapy

    NASA Astrophysics Data System (ADS)

    Hamblin, Michael R.

    2008-02-01

    The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing tissue damage by reducing cellular apoptosis has been known for almost forty years since the invention of lasers. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial. Firstly the biochemical mechanisms underlying the positive effects are incompletely understood, and secondly the complexity of choosing amongst a large number of illumination parameters has led to the publication of a number of negative studies as well as many positive ones. This review will focus on the role of nitric oxide in the cellular and tissue effects of LLLT. Red and near-IR light is primarily absorbed by cytochrome c oxidase (unit four in the mitochondrial respiratory chain). Nitric oxide produced in the mitochondria can inhibit respiration by binding to cytochrome c oxidase and competitively displacing oxygen, especially in stressed or hypoxic cells. If light absorption displaced the nitric oxide and thus allowed the cytochrome c oxidase to recover and cellular respiration to resume, this would explain many of the observations made in LLLT. Why the effect is only seen in hypoxic, stressed or damaged cells or tissues? How the effects can keep working for some time (hours or days) postillumination? Why increased NO concentrations are sometimes measured in cell culture or in animals? How blood flow can be increased? Why angiogenesis is sometimes increased after LLLT in vivo?

  14. Role of nitric oxide in adenosine-induced vasodilation in humans

    NASA Technical Reports Server (NTRS)

    Costa, F.; Biaggioni, I.; Robertson, D. (Principal Investigator)

    1998-01-01

    Vasodilation is one of the most prominent effects of adenosine and one of the first to be recognized, but its mechanism of action is not completely understood. In particular, there is conflicting information about the potential contribution of endothelial factors. The purpose of this study was to explore the role of nitric oxide in the vasodilatory effect of adenosine. Forearm blood flow responses to intrabrachial adenosine infusion (125 microg/min) were assessed with venous occlusion plethysmography during intrabrachial infusion of saline or the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA) (12.5 mg/min). Intrabrachial infusions of acetylcholine (50 microg/min) and nitroprusside (3 microg/min) were used as a positive and negative control, respectively. These doses were chosen to produce comparable levels of vasodilation. In a separate study, a second saline infusion was administered instead of L-NMMA to rule out time-related effects. As expected, pretreatment with L-NMMA reduced acetylcholine-induced vasodilation; 50 microg/min acetylcholine increased forearm blood flow by 150+/-43% and 51+/-12% during saline and L-NMMA infusion, respectively (P<.01, n=6). In contrast, L-NMMA did not affect the increase in forearm blood flow produced by 3 microg/min nitroprusside (165+/-30% and 248+/-41% during saline and L-NMMA, respectively) or adenosine (173+/-48% and 270+/-75% during saline and L-NMMA, respectively). On the basis of our observations, we conclude that adenosine-induced vasodilation is not mediated by nitric oxide in the human forearm.

  15. Modulation of Lung Function by Increased Nitric Oxide Production

    PubMed Central

    Yadav, Ram Lochan; Yadav, Prakash Kumar

    2017-01-01

    Introduction Cigarette smoking reduces endogenous Nitric Oxide (NO) production by reducing Nitric Oxide Synthase (NOS) activity, which is one of the probable reason for increased rate of pulmonary diseases in smokers. Nitric oxide/oxygen blends are used in critical care to promote capillary and pulmonary dilation to treat several pulmonary vascular diseases. Among several supplements, the highest NOS activation has been proved for garlic with its unique mechanism of action. Aim To investigate the effect of dietary supplementation of NO producing garlic on pulmonary function of smokers. Materials and Methods The study was conducted on 40 healthy non-smoker (Group A) and 40 chronic smoker (Group B) males with matched age, height and weight. The pulmonary function tests- Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), FEV1/FVC ratio and Peak Expiratory Flow Rate (PEFR) were performed in non-smokers (Group A), smokers (Group B) and smokers after supplementation of approximately 4 gm of raw garlic (2 garlic cloves) per day for three months (Group C). Endogenous NO production was studied in smokers before and after garlic supplementation and in non-smokers without supplementation. The data obtained were compared between the groups using unpaired student’s t-test. The p-value considered significant at <0.05. Results Our results showed that FVC, FEV1, FEV1/FVC ratio and PEFR were reduced significantly along with a significant decreased NOS activity among smokers (Group B) when compared with non-smokers (Group A). Garlic supplementation significantly improved the pulmonary function tests in Group C in comparison to Group B by increasing NOS activity. Conclusion Dietary supplementation of garlic, which might be by increasing NOS activity, has significantly improved pulmonary functions in smokers. PMID:28764150

  16. 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.

  17. Calycosin and formononetin from astragalus root enhance dimethylarginine dimethylaminohydrolase 2 and nitric oxide synthase expressions in Madin Darby Canine Kidney II cells.

    PubMed

    Bai, Fan; Makino, Toshiaki; Kono, Keiko; Nagatsu, Akito; Ono, Takahiko; Mizukami, Hajime

    2013-10-01

    Nitric oxide (NO) is a crucial vasodilator produced by nitric oxide synthase (NOS). Asymmetric dimethylarginine (ADMA) is an endogenous NOS inhibitor and mainly catabolized by dimethylarginine dimethylaminohydrolase (DDAH). As we reported, the antihypertensive effect of shichimotsukokato (SKT), a formula of Japanese traditional kampo medicine consisting of 7 crude drugs, in 5/6 nephrectomized rats, is mediated by the DDAH-ADMA-NO pathway. Our present study aimed to explore the effective compounds of SKT using Madin Darby Canine Kidney (MDCK) II cells. We isolated two isoflavones, calycosin and formononetin from astragalus root, one of the components of SKT, which can promote DDAH2 protein and mRNA expressions in MDCK II cells. The neuronal NOS levels were also upregulated by the treatment of calycosin and formononetin. These results suggest that calycosin and formononetin could be the active ingredients of astragalus root and SKT that cause antihypertensive effects. The increased levels of DDAH2 and NOS may enhance NO production, decrease ADMA level and improve endothelial and cardiovascular dysfunction.

  18. Detection of nitric oxide in the dark cloud L134N

    NASA Technical Reports Server (NTRS)

    Mcgonagle, D.; Irvine, W. M.; Minh, Y. C.; Ziurys, L. M.

    1990-01-01

    The first detection of interstellar nitric oxide (NO) in a cold dark cloud, L134N is reported. Nitric oxide was observed by means of its two 2 Pi 1/2, J = 3/2 - 1/2, rotational transitions at 150.2 and 150.5 GHz, which occur because of Lambda-doubling. The inferred column density for L134N is about 5 x 10 to the 14th/sq cm toward the SO peak in that cloud. This value corresponds to a fractional abundance relative to molecular hydrogen of about 6 x 10 to the -8th and is in good agreement with predictions of quiescent cloud ion-molecule chemistry. NO was not detected toward the dark cloud TMC-1 at an upper limit of 3 x 10 to the -8th or less.

  19. Ribavirin in Cancer Immunotherapies: Controlling Nitric Oxide Augments Cytotoxic Lymphocyte Function

    PubMed Central

    Kast, Richard E

    2003-01-01

    Abstract Either ribavirin (RBV) or cyclophosphamide (CY) can shift an immune response from Th2 toward a Th1 cytokine profile. CY is used in this role in various current cancer immunotherapy attempts but with mixed success. More potent and reliable immunoadjuvants and Th1 response biasing methods are needed. RBV is used today mainly to augment interferon-alpha treatment of hepatitis C. RBV shifts an immune response from Th2 toward Th1 more effectively than CY and may be a safe and useful adjuvant for current cancer immunotherapeutic efforts. RBV is thought to act by inhibition of tetrahydrobiopterin synthesis. Tetrahydrobiopterin is an essential cofactor for all known isoforms of nitric oxide synthase. Lowered nitric oxide favors Th1 development as high levels favor Th2 weighting. PMID:12659664

  20. 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.

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

    NASA Technical Reports Server (NTRS)

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

    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 six months following the burn. Simultaneous measurements indicate enhanced levels of exchangeable ammonium in the soil following the burn. Biomass burning is known to be an instantaneous source of NO and N2O resulting from high-temperature combustion. Now it is found that biomass burning also results in significantly enhanced biogenic emissions of these gases, which persist for months following the burn.

  2. Diurnal variation of nitric oxide in the upper stratosphere

    NASA Technical Reports Server (NTRS)

    Kondo, Y.; Aimedieu, P.; Pirre, M.; Ramaroson, R.; Matthews, W. A.

    1990-01-01

    Two recent measurements of the temporal variation of nitric oxide at constant altitude near 40 km are reported. The observations were made at float altitude with a balloon-borne chemiluminescence detector together with in situ ozone measurements. The first measurement was made at 44 N on September 17, 1987, at an altitude of 40 km from before sunrise until 1000 LT. The second observation was made at the same latitude on June 18, 1988, at 39 km from 0800 to 1230 LT. At an altitude of 40 km, nitric oxide was observed to start increasing very rapidly at sunrise when the solar zenith angle reached about 95 deg. After the rapid initial buildup, the rate of NO increase stabilized for 3 hours at about 1.2 ppbv/hour. Near 1100 LT at 39 km in summer, the NO mixing ratio was observed to become nearly constant. These features of the diurnal variation of NO are in accord with the temporal variation expected from a time-dependent zero-dimensional photochemical model.

  3. Requirement of argininosuccinate lyase for systemic nitric oxide production.

    PubMed

    Erez, Ayelet; Nagamani, Sandesh C S; Shchelochkov, Oleg A; Premkumar, Muralidhar H; Campeau, Philippe M; Chen, Yuqing; Garg, Harsha K; Li, Li; Mian, Asad; Bertin, Terry K; Black, Jennifer O; Zeng, Heng; Tang, Yaoping; Reddy, Anilkumar K; Summar, Marshall; O'Brien, William E; Harrison, David G; Mitch, William E; Marini, Juan C; Aschner, Judy L; Bryan, Nathan S; Lee, Brendan

    2011-11-13

    Nitric oxide (NO) is crucial in diverse physiological and pathological processes. We show that a hypomorphic mouse model of argininosuccinate lyase (encoded by Asl) deficiency has a distinct phenotype of multiorgan dysfunction and NO deficiency. Loss of Asl in both humans and mice leads to reduced NO synthesis, owing to both decreased endogenous arginine synthesis and an impaired ability to use extracellular arginine for NO production. Administration of nitrite, which can be converted into NO in vivo, rescued the manifestations of NO deficiency in hypomorphic Asl mice, and a nitric oxide synthase (NOS)-independent NO donor restored NO-dependent vascular reactivity in humans with ASL deficiency. Mechanistic studies showed that ASL has a structural function in addition to its catalytic activity, by which it contributes to the formation of a multiprotein complex required for NO production. Our data demonstrate a previously unappreciated role for ASL in NOS function and NO homeostasis. Hence, ASL may serve as a target for manipulating NO production in experimental models, as well as for the treatment of NO-related diseases.

  4. AMPK and Endothelial Nitric Oxide Synthase Signaling Regulates K-Ras Plasma Membrane Interactions via Cyclic GMP-Dependent Protein Kinase 2

    PubMed Central

    Cho, Kwang-jin; Casteel, Darren E.; Prakash, Priyanka; Tan, Lingxiao; van der Hoeven, Dharini; Salim, Angela A.; Kim, Choel; Capon, Robert J.; Lacey, Ernest; Cunha, Shane R.; Gorfe, Alemayehu A.

    2016-01-01

    K-Ras must localize to the plasma membrane and be arrayed in nanoclusters for biological activity. We show here that K-Ras is a substrate for cyclic GMP-dependent protein kinases (PKGs). In intact cells, activated PKG2 selectively colocalizes with K-Ras on the plasma membrane and phosphorylates K-Ras at Ser181 in the C-terminal polybasic domain. K-Ras phosphorylation by PKG2 is triggered by activation of AMP-activated protein kinase (AMPK) and requires endothelial nitric oxide synthase and soluble guanylyl cyclase. Phosphorylated K-Ras reorganizes into distinct nanoclusters that retune the signal output. Phosphorylation acutely enhances K-Ras plasma membrane affinity, but phosphorylated K-Ras is progressively lost from the plasma membrane via endocytic recycling. Concordantly, chronic pharmacological activation of AMPK → PKG2 signaling with mitochondrial inhibitors, nitric oxide, or sildenafil inhibits proliferation of K-Ras-positive non-small cell lung cancer cells. The study shows that K-Ras is a target of a metabolic stress-signaling pathway that can be leveraged to inhibit oncogenic K-Ras function. PMID:27697864

  5. 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.

  6. 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

  7. 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

  8. The Role of Nitric Oxide during Sonoreperfusion of Microvascular Obstruction

    PubMed Central

    Yu, Francois T.H.; Chen, Xucai; Straub, Adam C.; Pacella, John J.

    2017-01-01

    Rationale: Microembolization during PCI for acute myocardial infarction can cause microvascular obstruction (MVO). MVO severely limits the success of reperfusion therapies, is associated with additional myonecrosis, and is linked to worse prognosis, including death. We have shown, both in in vitro and in vivo models, that ultrasound (US) and microbubble (MB) therapy (termed “sonoreperfusion” or “SRP”) is a theranostic approach that relieves MVO and restores perfusion, but the underlying mechanisms remain to be established. Objective: In this study, we investigated the role of nitric oxide (NO) during SRP. Methods and results: We first demonstrated in plated cells that US-stimulated MB oscillations induced a 6-fold increase in endothelial nitric oxide synthase (eNOS) phosphorylation in vitro. We then monitored the kinetics of intramuscular NO and perfusion flow rate responses following 2-min of SRP therapy in the rat hindlimb muscle, with and without blockade of eNOS with LNAME. Following SRP, we found that starting at 6 minutes, intramuscular NO increased significantly over 30 min and was higher than baseline after 13 min. Concomitant contrast enhanced burst reperfusion imaging confirmed that there was a marked increase in perfusion flow rate at 6 and 10 min post SRP compared to baseline (>2.5 fold). The increases in intramuscular NO and perfusion rate were blunted with LNAME. Finally, we tested the hypothesis that NO plays a role in SRP by assessing reperfusion efficacy in a previously described rat hindlimb model of MVO during blockade of eNOS. After US treatment 1, microvascular blood volume was restored to baseline in the MB+US group, but remained low in the LNAME group. Perfusion rates increased in the MB+US group after US treatment 2 but not in the MB+US+LNAME group. Conclusions: These data strongly support that MB oscillations can activate the eNOS pathway leading to increased blood perfusion and that NO plays a significant role in SRP efficacy. PMID

  9. Novel therapeutic applications of nitric oxide donors in cancer: roles in chemo- and immunosensitization to apoptosis and inhibition of metastases.

    PubMed

    Bonavida, Benjamin; Baritaki, Stavroula; Huerta-Yepez, Sara; Vega, Mario I; Chatterjee, Devasis; Yeung, Kam

    2008-09-01

    The treatment of primary tumors results in an initial response to approved conventional therapeutics. However, recurrences and malignancies develop as a result of tumors' acquisition of anti-apoptotic mechanisms of resistance. Hence, there is an urgent need of novel therapeutics that can reverse resistance. One approach of interest is the inhibition of cell survival and anti-apoptotic pathways by sensitizing agents that can render resistant tumor cells sensitive to respond to various cytotoxic therapies. We have found that nitric oxide donors, similar to DETANONOate, inhibit cell survival anti-apoptotic pathways, such as the constitutively activated NF-kappaB and sensitize drug-resistant tumor cells to apoptosis by both chemotherapy and immunotherapy. Sensitization by DETANONOate was shown to inhibit the transcription repressor Yin Yang1 (YY1) shown to regulate resistance to both Fas ligand and TRAIL. In addition, DETANONOate-induced inhibition of NF-kappaB results downstream in the inhibition of several anti-apoptotic gene products, thus facilitating the activation of the apoptotic pathways with both chemotherapy and immunotherapy. In addition, DETANONOate induces the expression of the metastatic tumor suppressor gene product, Raf-1 Kinase Inhibitor Protein (RKIP), which inhibits the survival pathways induced by NF-kappaB and Raf-1/MEK which also contributes to the sensitizing activity. This indicates a novel finding that RKIP may also play an important role in the prevention of metastasis. Inhibition of NF-kappaB activation by DETANONOate results downstream in the inhibition of the RKIP transcription repressor Snail, resulting in upregulation of RKIP. Inhibition of Snail results in downstream inhibition of the metastatic cascade initiated by the epithelial-mesenchymal transition (EMT). Thus, nitric oxide donors have the dual functions of both sensitizing tumor cells to chemotherapy and immunotherapy and are also involved in the regulation and inhibition of

  10. 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.

  11. 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

  12. Review of Federal Reference Method for Ozone: Nitric Oxide-Chemiluminescence

    EPA Science Inventory

    •The proposed new FRM measurement principle for ozone is based on quantitative measurement of the chemiluminescence emission from the gas-phase reaction of ozone in an air sample with nitric oxide (NO).•The chemiluminescence from the NO-O3 reaction (with excess NO) is p...

  13. Penile Erection Induced by Scoparone from Artemisia capillaris through the Nitric Oxide-Cyclic Guanosine Monophosphate Signaling Pathway.

    PubMed

    Choi, Bo Ram; Kim, Hye Kyung; Park, Jong Kwan

    2017-12-01

    The objective of this study was to evaluate the relaxant effect of scoparone from Artemisia capillaris on rabbit penile corpus cavernosum smooth muscle (PCCSM) and to elucidate the mechanism of action of scoparone for the treatment of erectile dysfunction (ED). PCCSM that had been precontracted with phenylephrine was treated with 3 Artemisia herbs (A. princeps, A. capillaris, and A. iwayomogi) and 3 fractions (n-hexane, ethyl acetate, and n-butanol) with different concentrations (0.1, 0.5, 1.0, and 2.0 mg/mL). Four components (esculetin, scopoletin, capillarisin, and scoparone) isolated from A. capillaris were also evaluated. The PCCSM was preincubated with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) and 1H-[1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (ODQ). Cyclic nucleotides in the perfusate were measured by a radioimmunoassay. The interactions of scoparone with udenafil and rolipram were also evaluated. A. capillaris extract relaxed PCCSM in a concentration-dependent manner. Scoparone had the highest relaxant effect on PCCSM among the 4 components (esculetin, scopoletin, capillarisin, and scoparone) isolated from the ethyl acetate fraction. The application of scoparone on PCCSM pretreated with L-NAME and ODQ led to significantly less relaxation. Scoparone also increased the cyclic guanosine monophosphate (cGMP) levels in the perfusate in a concentration-dependent manner. Furthermore, scoparone enhanced udenafil- and rolipram-induced relaxation of the PCCSM. Scoparone relaxed the PCCSM mainly by activating the nitric oxide-cGMP signaling pathway, and it may be a new promising treatment for ED patients who do not completely respond to udenafil. Copyright © 2017 Korean Society for Sexual Medicine and Andrology

  14. Penile Erection Induced by Scoparone from Artemisia capillaris through the Nitric Oxide-Cyclic Guanosine Monophosphate Signaling Pathway

    PubMed Central

    2017-01-01

    Purpose The objective of this study was to evaluate the relaxant effect of scoparone from Artemisia capillaris on rabbit penile corpus cavernosum smooth muscle (PCCSM) and to elucidate the mechanism of action of scoparone for the treatment of erectile dysfunction (ED). Materials and Methods PCCSM that had been precontracted with phenylephrine was treated with 3 Artemisia herbs (A. princeps, A. capillaris, and A. iwayomogi) and 3 fractions (n-hexane, ethyl acetate, and n-butanol) with different concentrations (0.1, 0.5, 1.0, and 2.0 mg/mL). Four components (esculetin, scopoletin, capillarisin, and scoparone) isolated from A. capillaris were also evaluated. The PCCSM was preincubated with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) and 1H-[1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (ODQ). Cyclic nucleotides in the perfusate were measured by a radioimmunoassay. The interactions of scoparone with udenafil and rolipram were also evaluated. Results A. capillaris extract relaxed PCCSM in a concentration-dependent manner. Scoparone had the highest relaxant effect on PCCSM among the 4 components (esculetin, scopoletin, capillarisin, and scoparone) isolated from the ethyl acetate fraction. The application of scoparone on PCCSM pretreated with L-NAME and ODQ led to significantly less relaxation. Scoparone also increased the cyclic guanosine monophosphate (cGMP) levels in the perfusate in a concentration-dependent manner. Furthermore, scoparone enhanced udenafil- and rolipram-induced relaxation of the PCCSM. Conclusions Scoparone relaxed the PCCSM mainly by activating the nitric oxide-cGMP signaling pathway, and it may be a new promising treatment for ED patients who do not completely respond to udenafil. PMID:29164835

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Nitric oxide: a multitasked signaling gas in plants.

    PubMed

    Domingos, Patricia; Prado, Ana Margarida; Wong, Aloysius; Gehring, Christoph; Feijo, Jose A

    2015-04-01

    Nitric oxide (NO) is a gaseous reactive oxygen species (ROS) that has evolved as a signaling hormone in many physiological processes in animals. In plants it has been demonstrated to be a crucial regulator of development, acting as a signaling molecule present at each step of the plant life cycle. NO has also been implicated as a signal in biotic and abiotic responses of plants to the environment. Remarkably, despite this plethora of effects and functional relationships, the fundamental knowledge of NO production, sensing, and transduction in plants remains largely unknown or inadequately characterized. In this review we cover the current understanding of NO production, perception, and action in different physiological scenarios. We especially address the issues of enzymatic and chemical generation of NO in plants, NO sensing and downstream signaling, namely the putative cGMP and Ca(2+) pathways, ion-channel activity modulation, gene expression regulation, and the interface with other ROS, which can have a profound effect on both NO accumulation and function. We also focus on the importance of NO in cell-cell communication during developmental processes and sexual reproduction, namely in pollen tube guidance and embryo sac fertilization, pathogen defense, and responses to abiotic stress. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  20. Arctigenin, a Potent Ingredient of Arctium lappa L., Induces Endothelial Nitric Oxide Synthase and Attenuates Subarachnoid Hemorrhage-Induced Vasospasm through PI3K/Akt Pathway in a Rat Model

    PubMed Central

    Chang, Chih-Zen; Wu, Shu-Chuan; Chang, Chia-Mao; Kwan, Aij-Lie

    2015-01-01

    Upregulation of protein kinase B (PKB, also known as Akt) is observed within the cerebral arteries of subarachnoid hemorrhage (SAH) animals. This study is of interest to examine Arctigenin, a potent antioxidant, on endothelial nitric oxide synthase (eNOS) and Akt pathways in a SAH in vitro study. Basilar arteries (BAs) were obtained to examine phosphatidylinositol-3-kinase (PI3K), phospho-PI3K, Akt, phospho-Akt (Western blot) and morphological examination. Endothelins (ETs) and eNOS evaluation (Western blot and immunostaining) were also determined. Arctigenin treatment significantly alleviates disrupted endothelial cells and tortured internal elastic layer observed in the SAH groups (p < 0.01). The reduced eNOS protein and phospho-Akt expression in the SAH groups were relieved by the treatment of Arctigenin (p < 0.01). This result confirmed that Arctigenin might exert dural effects in preventing SAH-induced vasospasm through upregulating eNOS expression via the PI3K/Akt signaling pathway and attenuate endothelins after SAH. Arctigenin shows therapeutic promise in the treatment of cerebral vasospasm following SAH. PMID:26539501

  1. Arctigenin, a Potent Ingredient of Arctium lappa L., Induces Endothelial Nitric Oxide Synthase and Attenuates Subarachnoid Hemorrhage-Induced Vasospasm through PI3K/Akt Pathway in a Rat Model.

    PubMed

    Chang, Chih-Zen; Wu, Shu-Chuan; Chang, Chia-Mao; Lin, Chih-Lung; Kwan, Aij-Lie

    2015-01-01

    Upregulation of protein kinase B (PKB, also known as Akt) is observed within the cerebral arteries of subarachnoid hemorrhage (SAH) animals. This study is of interest to examine Arctigenin, a potent antioxidant, on endothelial nitric oxide synthase (eNOS) and Akt pathways in a SAH in vitro study. Basilar arteries (BAs) were obtained to examine phosphatidylinositol-3-kinase (PI3K), phospho-PI3K, Akt, phospho-Akt (Western blot) and morphological examination. Endothelins (ETs) and eNOS evaluation (Western blot and immunostaining) were also determined. Arctigenin treatment significantly alleviates disrupted endothelial cells and tortured internal elastic layer observed in the SAH groups (p < 0.01). The reduced eNOS protein and phospho-Akt expression in the SAH groups were relieved by the treatment of Arctigenin (p < 0.01). This result confirmed that Arctigenin might exert dural effects in preventing SAH-induced vasospasm through upregulating eNOS expression via the PI3K/Akt signaling pathway and attenuate endothelins after SAH. Arctigenin shows therapeutic promise in the treatment of cerebral vasospasm following SAH.

  2. Nitric oxide synthase inhibition reduces muscle inflammation and necrosis in modified muscle use

    NASA Technical Reports Server (NTRS)

    Pizza, F. X.; Hernandez, I. J.; Tidball, J. G.

    1998-01-01

    The objective of this study was to determine the role of nitric oxide in muscle inflammation, fiber necrosis, and apoptosis of inflammatory cells in vivo. The effects of nitric oxide synthase (NOS) inhibition on the concentrations of neutrophils, ED1+ and ED2+ macrophages, apoptotic inflammatory cells, and necrotic muscle fibers in rats subjected to 10 days of hindlimb unloading and 2 days of reloading were determined. Administration of NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) significantly reduced the concentrations of neutrophils, ED1+ and ED2+ macrophages, and necrotic fibers in soleus muscle relative to water-treated controls. The concentration of apoptotic inflammatory cells was also significantly lower for L-NAME-treated animals compared with water-treated controls. However, the proportion of the inflammatory cell population that was apoptotic did not differ between L-NAME-treated and control animals, suggesting that L-NAME treatment did not decrease inflammatory cell populations by increasing the frequency of apoptosis. Thus, nitric oxide or one of its intermediates promotes muscle inflammation and fiber necrosis during modified muscle use and plays no more than a minor role in the resolution of muscle inflammation by inducing apoptosis of inflammatory cells.

  3. Immune-relevant thrombocytes of common carp undergo parasite-induced nitric oxide-mediated apoptosis.

    PubMed

    Fink, Inge R; Ribeiro, Carla M S; Forlenza, Maria; Taverne-Thiele, Anja; Rombout, Jan H W M; Savelkoul, Huub F J; Wiegertjes, Geert F

    2015-06-01

    Common carp thrombocytes account for 30-40% of peripheral blood leukocytes and are abundant in the healthy animals' spleen, the thrombopoietic organ. We show that, ex vivo, thrombocytes from healthy carp express a large number of immune-relevant genes, among which several cytokines and Toll-like receptors, clearly pointing at immune functions of carp thrombocytes. Few studies have described the role of fish thrombocytes during infection. Carp are natural host to two different but related protozoan parasites, Trypanoplasma borreli and Trypanosoma carassii, which reside in the blood and tissue fluids. We used the two parasites to undertake controlled studies on the role of fish thrombocytes during these infections. In vivo, but only during infection with T. borreli, thrombocytes were massively depleted from the blood and spleen leading to severe thrombocytopenia. Ex vivo, addition of nitric oxide induced a clear and rapid apoptosis of thrombocytes from healthy carp, supporting a role for nitric oxide-mediated control of immune-relevant thrombocytes during infection with T. borreli. The potential advantage for parasites to selectively deplete the host of thrombocytes via nitric oxide-induced apoptosis is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Auxin-induced nitric oxide, cGMP and gibberellins were involved in the gravitropism

    NASA Astrophysics Data System (ADS)

    Cai, Weiming; Hu, Liwei; Hu, Xiangyang; Cui, Dayong; Cai, Weiming

    Gravitropism is the asymmetric growth or curvature of plant organs in response to gravistimulation. There is a complex signal transduction cascade which involved in the differential growth of plants in response to changes in the gravity vector. The role of auxin in gravitropism has been demonstrated by many experiments, but little is known regarding the molecular details of such effects. In our studies before, mediation of the gravitropic bending of soybean roots and rice leaf sheath bases by nitric oxide, cGMP and gibberellins, are induced by auxin. The asymmetrical distribution of nitric oxide, cGMP and gibberellins resulted from the asymmetrical synthesis of them in bending sites. In soybean roots, inhibitions of NO and cGMP synthesis reduced differential NO and cGMP accumulation respectively, which both of these effects can lead to the reduction of gravitropic bending. Gibberellin-induced OsXET, OsEXPA4 and OsRWC3 were also found involved in the gravitropic bending. These data indicated that auxin-induced nitric oxide, cGMP and gibberellins were involved in the gravitropism. More experiments need to prove the more detailed mechanism of them.

  5. Processes regulating nitric oxide emissions from soils.

    PubMed

    Pilegaard, Kim

    2013-07-05

    Nitric oxide (NO) is a reactive gas that plays an important role in atmospheric chemistry by influencing the production and destruction of ozone and thereby the oxidizing capacity of the atmosphere. NO also contributes by its oxidation products to the formation of acid rain. The major sources of NO in the atmosphere are anthropogenic emissions (from combustion of fossil fuels) and biogenic emission from soils. NO is both produced and consumed in soils as a result of biotic and abiotic processes. The main processes involved are microbial nitrification and denitrification, and chemodenitrification. Thus, the net result is complex and dependent on several factors such as nitrogen availability, organic matter content, oxygen status, soil moisture, pH and temperature. This paper reviews recent knowledge on processes forming NO in soils and the factors controlling its emission to the atmosphere. Schemes for simulating these processes are described, and the results are discussed with the purpose of scaling up to global emission.

  6. Additive effects of nicotine and high-fat diet on hepatocellular apoptosis in mice: involvement of caspase 2 and inducible nitric oxide synthase-mediated intrinsic pathway signaling.

    PubMed

    Ivey, R; Desai, M; Green, K; Sinha-Hikim, I; Friedman, T C; Sinha-Hikim, A P

    2014-07-01

    Smoking is a major risk factor for diabetes and cardiovascular disease and may contribute to nonalcoholic fatty liver disease (NAFLD). The health risk associated with smoking is exaggerated by obesity and is the leading causes of morbidity and mortality worldwide. We recently demonstrated that combined treatment with nicotine and a high-fat diet (HFD) triggers greater oxidative stress, activates hepatocellular apoptosis, and exacerbates HFD-induced hepatic steatosis. Given that hepatocellular apoptosis plays a pivotal role in the pathogenesis of NAFLD, using this model of exacerbated hepatic steatosis, we elucidated the signal transduction pathways involved in HFD plus nicotine-induced liver cell death. Adult C57BL6 male mice were fed a normal chow diet or HFD with 60% of calories derived from fat and received twice daily IP injections of 0.75 mg/kg BW of nicotine or saline for 10 weeks. High-resolution light microscopy revealed markedly higher lipid accumulation in hepatocytes from mice received HFD plus nicotine, compared to mice on HFD alone. Addition of nicotine to HFD further resulted in an increase in the incidence of hepatocellular apoptosis and was associated with activation of caspase 2, induction of inducible nitric oxide synthase (iNOS), and perturbation of the BAX/BCL-2 ratio. Together, our data indicate the involvement of caspase 2 and iNOS-mediated apoptotic signaling in nicotine plus HFD-induced hepatocellular apoptosis. Targeting the caspase 2-mediated death pathway may have a protective role in development and progression of NAFLD. © Georg Thieme Verlag KG Stuttgart · New York.

  7. 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.

  8. Nitric oxide system and diabetic nephropathy

    PubMed Central

    2014-01-01

    About 30% of patients with type 2 diabetes mellitus develop clinically overt nephropathy. Hyperglycemia is necessary, but not sufficient, to cause the renal damage that leads to kidney failure. Diabetic nephropathy (DN) is a multifactorial disorder that results from interaction between environmental and genetic factors. In the present article we will review the role of the nitric oxide synthase (NOS) in the pathogenesis of DN. Nitric oxide (NO) is a short-lived gaseous lipophilic molecule produced in almost all tissues, and it has three distinct genes that encode three NOS isoforms: neuronal (nNOS), inducible (iNOS) and endothelial (eNOS). The correct function of the endothelium depends on NO, participating in hemostasis control, vascular tone regulation, proliferation of vascular smooth muscle cells and blood pressure homeostasis, among other features. In the kidney, NO plays many different roles, including control of renal and glomerular hemodynamics. The net effect of NO in the kidney is to promote natriuresis and diuresis, along with renal adaptation to dietary salt intake. The eNOS gene has been considered a potential candidate gene for DN susceptibility. Three polymorphisms have been extensively researched: G894T missense mutation (rs1799983), a 27-bp repeat in intron 4, and the T786C single nucleotide polymorphism (SNP) in the promoter (rs2070744). However, the potential link between eNOS gene variants and the induction and progression of DN yielded contradictory results in the literature. In conclusion, NOS seems to be involve in the development and progression of DN. Despite the discrepant results of many studies, the eNOS gene is also a good candidate gene for DN. PMID:24520999

  9. 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.

  10. REGULATION OF OBESITY AND INSULIN RESISTANCE BY NITRIC OXIDE

    PubMed Central

    Sansbury, Brian E.; Hill, Bradford G.

    2014-01-01

    Obesity is a risk factor for developing type 2 diabetes and cardiovascular disease and has quickly become a world-wide pandemic with few tangible and safe treatment options. While it is generally accepted that the primary cause of obesity is energy imbalance, i.e., the calories consumed are greater than are utilized, understanding how caloric balance is regulated has proven a challenge. Many “distal” causes of obesity, such as the structural environment, occupation, and social influences, are exceedingly difficult to change or manipulate. Hence, molecular processes and pathways more proximal to the origins of obesity—those that directly regulate energy metabolism or caloric intake—appear to be more feasible targets for therapy. In particular, nitric oxide (NO) is emerging as a central regulator of energy metabolism and body composition. NO bioavailability is decreased in animal models of diet-induced obesity and in obese and insulin resistant patients, and increasing NO output has remarkable effects on obesity and insulin resistance. This review discusses the role of NO in regulating adiposity and insulin sensitivity and places its modes of action into context with the known causes and consequences of metabolic disease. PMID:24878261

  11. Cross state-dependency of learning between tramadol and MK-801 in the mouse dorsal hippocampus: involvement of nitric oxide (NO) signaling pathway.

    PubMed

    Jafari-Sabet, Majid; Amiri, Shiva; Ataee, Ramin

    2018-04-21

    Tramadol, an atypical μ-opioid receptor agonist, as a psychoactive drug, is frequently abused by human beings. Understanding the neurobiological mechanisms of drug-associated learning and memory formation may help prevent drug addiction and relapse. Previous study revealed that dorsal hippocampus (CA1) plays a crucial role in the retrieval of tramadol-associated memory and that its role depends on the expression of CA1 N-methyl-D-aspartate (NMDA) receptors (Jafari-Sabet et al. Can J Physiol Pharmacol 96:45-50, 2018). To clarify the exact mechanisms involved, the activation of CA1 nitric oxide (NO) signaling pathway by L-arginine (a nitric oxide precursor) on the interaction between tramadol and MK-801 in memory retrieval was examined. The dorsal hippocampal CA1 regions of adult male NMRI mice were bilaterally cannulated and a single-trial step-down inhibitory avoidance apparatus was used for the assessment of memory retrieval. Post-training and/or pre-test microinjection of tramadol (0.5 and 1 μg/mouse) and/or a non-competitive NMDA receptor antagonist, MK-801 (0.25 and 0.5 μg/mouse), induced amnesia which were reversed when the same doses of the drugs were administered 24 h later in a pre-test session, suggesting tramadol state-dependent learning (SDL) and MK-801 SDL. The amnesia induced by post-training microinjection of tramadol (1 μg/mouse) was reversed by pre-test microinjection of MK-801 (0.25 and 0.5 μg/mouse). Pre-test microinjection of MK-801 (0.125 and 0.25 μg/mouse) with an ineffective dose of tramadol (0.25 μg/mouse) potentiated tramadol SDL. The amnesia induced by post-training microinjection of MK-801 (0.5 μg/mouse) was reversed by pre-test microinjection of tramadol (0.5 and 1 μg/mouse). Pre-test microinjection of tramadol (0.25 and 0.5 μg/mouse) with an ineffective dose of MK-801 (0.125 μg/mouse) potentiated MK-801 SDL. Pre-test microinjection of ineffective doses of L-arginine (0.125, 025, and 0.5 μg/mouse) improved amnesia

  12. 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

  13. Daily life negative mood and exhaled nitric oxide in asthma.

    PubMed

    Ritz, Thomas; Kullowatz, Antje; Bill, Michelle N; Rosenfield, David

    2016-07-01

    Psychosocial stress and negative affect have been linked to asthma exacerbations, but longitudinal studies demonstrating a daily life association between negative affect and airway nitric oxide are missing. The longitudinal association between negative mood fluctuations, exhaled nitric oxide, and lung function in asthma was examined. Self-assessments of the fraction of exhaled nitric oxide (FeNO), spirometry (forced expiratory volume in the first second, FEV1), negative mood, and daily activities were obtained from 20 patients with asthma for 2 months, resulting in 1108 assessments for the analyses (approximately 55 per patient). Concurrent and prospective associations between FeNO, FEV1, and negative mood were analyzed using mixed effects regression models for longitudinal data. Negative mood was positively associated with changes in FeNO during the same day, and to a stronger extent when prior day negative mood was included in the prediction. FeNO and negative mood were positively associated with same-day FEV1, with the latter relation being partially mediated by changes in FeNO. Associations between FeNO and FEV1 were stronger in younger patients, with earlier onset of asthma, or with lower asthma control. Findings were not changed when controlling for physical activity, medication, cold symptoms, air pollution, and hours spent outside. Daily life changes of negative mood in asthma are positively associated with FeNO changes and FeNO increases are associated with a mild bronchodilation. These findings indicate that psychological influences need to be considered when using FeNO as indicator of airway inflammation and guide for treatment decisions. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Defective bone formation and anabolic response to exogenous estrogen in mice with targeted disruption of endothelial nitric oxide synthase.

    PubMed

    Armour, K E; Armour, K J; Gallagher, M E; Gödecke, A; Helfrich, M H; Reid, D M; Ralston, S H

    2001-02-01

    Nitric oxide (NO) is a pleiotropic signaling molecule that is produced by bone cells constitutively and in response to diverse stimuli such as proinflammatory cytokines, mechanical strain, and sex hormones. Endothelial nitric oxide synthase (eNOS) is the predominant NOS isoform expressed in bone, but its physiological role in regulating bone metabolism remains unclear. Here we studied various aspects of bone metabolism in female mice with targeted disruption of the eNOS gene. Mice with eNOS deficiency (eNOS KO) had reduced bone mineral density, and cortical thinning when compared with WT controls and histomorphometric analysis of bone revealed profound abnormalities of bone formation, with reduced osteoblast numbers, surfaces and mineral apposition rate. Studies in vitro showed that osteoblasts derived from eNOS KO mice had reduced rates of growth when compared with WT and were less well differentiated as reflected by lower levels of alkaline phosphatase activity. Mice with eNOS deficiency lost bone normally following ovariectomy but exhibited a significantly blunted anabolic response to high dose exogenous estrogen. We conclude that the eNOS pathway plays an essential role in regulating bone mass and bone turnover by modulating osteoblast function.

  15. 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...

  16. Nitric Oxide--Some Old and New Perspectives

    NASA Astrophysics Data System (ADS)

    Ainscough, Eric W.; Brodie, Andrew M.

    1995-08-01

    The discovery and early use of NO is recalled followed by some of its chemical reactions to give useful products such as nitric acid and fertilizers. However NO produced from the internal combustion engine results in photochemical smog production and ozone depletion. A rebirth of interest in NO has occurred because of its unexpected roles in physiology and neurobiology. Its production can lead to biological responses such as vasodilation, cell adhesion, neurotransmission and immune regulation. Finally the ways denitrifying bacteria convert NO and other oxides of nitrogen to dinitrogen are discussed.

  17. Copper Complex in Poly(vinyl chloride) as a Nitric Oxide-Generating Catalyst for the Control of Nitrifying Bacterial Biofilms.

    PubMed

    Wonoputri, Vita; Gunawan, Cindy; Liu, Sanly; Barraud, Nicolas; Yee, Lachlan H; Lim, May; Amal, Rose

    2015-10-14

    In this study, catalytic generation of nitric oxide by a copper(II) complex embedded within a poly(vinyl chloride) matrix in the presence of nitrite (source of nitric oxide) and ascorbic acid (reducing agent) was shown to effectively control the formation and dispersion of nitrifying bacteria biofilms. Amperometric measurements indicated increased and prolonged generation of nitric oxide with the addition of the copper complex when compared to that with nitrite and ascorbic acid alone. The effectiveness of the copper complex-nitrite-ascorbic acid system for biofilm control was quantified using protein analysis, which showed enhanced biofilm suppression when the copper complex was used in comparison to that with nitrite and ascorbic acid treatment alone. Confocal laser scanning microscopy (CLSM) and LIVE/DEAD staining revealed a reduction in cell surface coverage without a loss of viability with the copper complex and up to 5 mM of nitrite and ascorbic acid, suggesting that the nitric oxide generated from the system inhibits proliferation of the cells on surfaces. Induction of nitric oxide production by the copper complex system also triggered the dispersal of pre-established biofilms. However, the addition of a high concentration of nitrite and ascorbic acid to a pre-established biofilm induced bacterial membrane damage and strongly decreased the metabolic activity of planktonic and biofilm cells, as revealed by CLSM with LIVE/DEAD staining and intracellular adenosine triphosphate measurements, respectively. This study highlights the utility of the catalytic generation of nitric oxide for the long-term suppression and removal of nitrifying bacterial biofilms.

  18. 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.

  19. Nitric Oxide and Mitochondrial Function in Neurological Diseases.

    PubMed

    Ghasemi, Mehdi; Mayasi, Yunis; Hannoun, Anas; Eslami, Seyed Majid; Carandang, Raphael

    2018-04-15

    Mitochondria are key cellular organelles that play crucial roles in the energy production and regulation of cellular metabolism. Accumulating evidence suggests that mitochondrial activity can be modulated by nitric oxide (NO). As a key neurotransmitter in biologic systems, NO mediates the majority of its function through activation of the cyclic guanylyl cyclase (cGC) signaling pathway and S-nitrosylation of a variety of proteins involved in cellular functioning including those involved in mitochondrial biology. Moreover, excess NO or the formation of reactive NO species (RNS), e.g., peroxynitrite (ONOO - ), impairs mitochondrial functioning and this, in conjunction with nuclear events, eventually affects neuronal cell metabolism and survival, contributing to the pathogenesis of several neurodegenerative diseases. In this review we highlight the possible mechanisms underlying the noxious effects of excess NO and RNS on mitochondrial function including (i) negative effects on electron transport chain (ETC); (ii) ONOO - -mediated alteration in mitochondrial permeability transition; (iii) enhanced mitochondrial fragmentation and autophagy through S-nitrosylation of key proteins involved in this process such as dynamin-related protein 1 (DRP-1) and Parkin/PINK1 (protein phosphatase and tensin homolog-induced kinase 1) complex; (iv) alterations in the mitochondrial metabolic pathways including Krebs cycle, glycolysis, fatty acid metabolism, and urea cycle; and finally (v) mitochondrial ONOO - -induced nuclear toxicity and subsequent release of apoptosis-inducing factor (AIF) from mitochondria, causing neuronal cell death. These proposed mechanisms highlight the multidimensional nature of NO and its signaling in the mitochondrial function. Understanding the mechanisms by which NO mediates mitochondrial (dys)function can provide new insights into the treatment of neurodegenerative diseases. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Nitric oxide-sphingolipid interplays in plant signalling: a new enigma from the Sphinx?

    PubMed

    Guillas, Isabelle; Puyaubert, Juliette; Baudouin, Emmanuel

    2013-09-12

    Nitric oxide (NO) emerged as one of the major signaling molecules operating during plant development and plant responses to its environment. Beyond the identification of the direct molecular targets of NO, a series of studies considered its interplay with other actors of signal transduction and the integration of NO into complex signaling networks. Beside the close relationships between NO and calcium or phosphatidic acid signaling pathways that are now well-established, recent reports paved the way for interplays between NO and sphingolipids (SLs). This mini-review summarizes our current knowledge of the influence NO and SLs might exert on each other in plant physiology. Based on comparisons with examples from the animal field, it further indicates that, although SL-NO interplays are common features in signaling networks of eukaryotic cells, the underlying mechanisms and molecular targets significantly differ.

  1. Nitric oxide-sphingolipid interplays in plant signalling: a new enigma from the Sphinx?

    PubMed Central

    Guillas, Isabelle; Puyaubert, Juliette; Baudouin, Emmanuel

    2013-01-01

    Nitric oxide (NO) emerged as one of the major signaling molecules operating during plant development and plant responses to its environment. Beyond the identification of the direct molecular targets of NO, a series of studies considered its interplay with other actors of signal transduction and the integration of NO into complex signaling networks. Beside the close relationships between NO and calcium or phosphatidic acid signaling pathways that are now well-established, recent reports paved the way for interplays between NO and sphingolipids (SLs). This mini-review summarizes our current knowledge of the influence NO and SLs might exert on each other in plant physiology. Based on comparisons with examples from the animal field, it further indicates that, although SL–NO interplays are common features in signaling networks of eukaryotic cells, the underlying mechanisms and molecular targets significantly differ. PMID:24062754

  2. Molecular Pathways: Inflammation-associated nitric-oxide production as a cancer-supporting redox mechanism and a potential therapeutic target

    PubMed Central

    Grimm, Elizabeth A.; Sikora, Andrew G.; Ekmekcioglu, Suhendan

    2013-01-01

    It is widely accepted that many cancers express features of inflammation, driven by both microenvironmental cells and factors, and the intrinsic production of inflammation-associated mediators from malignant cells themselves. Inflammation results in intracellular oxidative stress, with the ultimate biochemical oxidants composed of reactive nitrogens and oxygens. Although the role of inflammation in carcinogensis is well accepted, we now present data that inflammatory processes are also active in the maintenance phase of many aggressive forms of cancer. The oxidative stress of inflammation is proposed to drive a continuous process of DNA adducts and crosslinks, as well as posttranslational modifications to lipids and proteins that we argue support growth and survival. In this Perspective we introduce data on the emerging science of inflammation-driven posttranslational modifications on proteins responsible for driving growth, angiogenesis, immunosuppression, and inhibition of apoptosis. Examples include data from human melanoma, breast, head and neck, lung, and colon cancers. Fortunately, numerous anti-oxidant agents are clinically available, and we further propose that the pharmacological attenuation of these inflammatory processes, particularly the reactive nitrogen species, will restore the cancer cells to an apoptosis-permissive and growth inhibitory state. Our mouse model data using an arginine antagonist that prevents enzymatic production of nitric oxide, directly supports this view. We contend that selected antioxidants be considered as part of the cancer treatment approach, as they are likely to provide a novel and mechanistically justified addition for therapeutic benefit. PMID:23868870

  3. Studies on the oxidation of hexamethylbenzene 1: Oxidation of hexamethylbenzene with nitric acid

    NASA Technical Reports Server (NTRS)

    Chiba, K.; Tomura, S.; Mizuno, T.

    1986-01-01

    The oxidative reaction of hexamethylbenzene (HMB) with nitric acid was studied, and the hitherto unknown polymethylbenzenepolycarboxylic acids were isolated: tetramethylphthalic anhydride, tetramethylisophthalic acid, 1,3,5-, 1,2,4- and 1,2,3-trimethylbenzenetricarboxylic acids. When HMB was warmed with 50% nitric acid at about 80 C, tetramethylphthalic anhydride and tetramethylisophthalic acid were initially produced. The continued reaction led to the production of trimethylbenzenetricarboxylic acids, but only slight amounts of dimethylbenzenetetracarboxylic acids were detected in the reaction mixture. Whereas tetramethylphthalic anydride and tetramethylisophthalic acid were obtained, pentamethylbenzoic acid, a possible precursor of them, was scarcely produced. On the other hand, a yellow material extracted with ether from the initial reaction mixture contained bis-(nitromethyl)prehnitene (CH3)4C6(CH2NO2)2, which was easily converted into the phthalic anhydride.

  4. 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.

  5. 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

  6. Sesquiterpenes from Curcuma wenyujin with their inhibitory activities on nitric oxide production in RAW 264.7 cells.

    PubMed

    Gao, Suyu; Xia, Guiyang; Wang, Liqing; Zhou, Li; Zhao, Feng; Huang, Jian; Chen, Lixia

    2017-03-01

    One new sesquiterpene, 7α,11-epoxy-6α-hydroxy-carabrane-4,8-dione, along with 10 known ones were isolated from the essential oil of Curcuma wenyujin Y.H. Chen et C. Ling. Their structures were established based on extensive spectroscopic analysis. The absolute configuration of compound 1 was determined by the CD analysis of the insitu formed [Rh 2 (OCOCF 3 ) 4 ] complex, and the CD data analysis based on the octane rule of cyclohexanone. The inhibitory effects of these sesquiterpenes on nitric oxide production in lipopolysaccharide-activated macrophages were also evaluated. Furthermore, the biosynthesis pathway of the isolated compounds was proposed.

  7. 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

  8. Ginsenoside Rg3 attenuates myocardial ischemia/reperfusion injury via Akt/endothelial nitric oxide synthase signaling and the B‑cell lymphoma/B‑cell lymphoma‑associated X protein pathway.

    PubMed

    Wang, Yiping; Hu, Zhaohui; Sun, Bing; Xu, Jiahong; Jiang, Jinfa; Luo, Ming

    2015-06-01

    Previous studies have suggested that ginsenoside Rg3 (GSRg3) extract from the medicinal plant Panax ginseng, may increase nitric oxide production via increases in the phosphorylation and expression of endothelial nitric oxide synthase (eNOS). The present study used an in vitro neonatal rat cardiomyocyte (NRC) model of anoxia‑reoxygenation injury and an in vivo rat model of myocardial ischemia/reperfusion (MI/R) injury. Hemodynamic, histopathological and biochemical assessment of the myocardial injury was performed and the expression levels of lactate dehydrogenase (LDH), superoxide dismutase and creatine kinase (CK) were measured in serum from the animal model, which may reflect myocardial injury. NRC injury was determined using a Cell Counting kit‑8. The GSRg3 anti‑apoptotic effects were assessed using flow cytometry to investigate the number of early‑late apoptotic cells and western blot analysis was performed to analyze the protein expression levels of caspase‑3, caspase‑9, B‑cell lymphoma‑2 (Bcl‑2), phosphorylated (p‑)Akt and eNOS. The results suggested that pretreatment with GSRg3 (60 mg/kg) significantly improved rat cardiac function, as demonstrated by increased left ventricular systolic pressure, heart rate and first derivative of left ventricular pressure. GSRg3 also reduced the size of the myocardial infarct and LDH/CK levels in the blood following MI/R. In vitro investigations revealed that GSRg3 (10 mM) decreased NRC apoptosis through inhibiting the activation of caspase‑3 and caspase‑9, and increasing the expression levels of p‑Akt, eNOS and the ratio of Bcl‑2/Bcl‑2‑associated X protein (Bax). Overall, the present study revealed that GSRg3 mediated a cardioprotective effect against MI/R‑induced apoptosis via Akt/eNOS signaling and the Bcl‑2/Bax pathway.

  9. 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.

  10. Inhibition of inducible nitric oxide synthesis by azathioprine in a macrophage cell line.

    PubMed

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

    2006-06-20

    Azathioprine is used as an anti-inflammatory agent. Although there are numerous data demonstrating cytotoxic and immunosuppressive properties of azathioprine and its metabolite 6-mercaptopurine, the mechanism of the anti-inflammatory action of azathioprine has not yet been fully clarified. During our study, we investigated the effects of azathioprine on the inducible nitric oxide synthase (iNOS) in lipopolysaccharide stimulated murine macrophages (RAW 264.7) by measurement of iNOS protein (immunoblotting), iNOS mRNA (semiquantitative competitive RT-PCR), and NO production (nitrite levels). Azathioprine (0-210 muM) induces a concentration dependent inhibition of inducible nitric oxide synthesis (IC50: 33.5 muM). iNOS protein expression showed a concentration dependent reduction as revealed by immunoblotting when cells were incubated with increasing amounts of azathioprine. Azathioprine decreases iNOS mRNA levels as shown by semiquantitative competitive RT-PCR. In contrast, 6-mercaptopurine showed no inhibition of inducible nitric oxide synthesis. Azathioprine did not reduce iNOS mRNA stability after the addition of actinomycin D. Enzymatic activity assays with increasing concentrations of azathioprine (0-210 muM) showed no statistically significant inhibition of iNOS enzyme activity compared to cell lysates without azathioprine. Nuclear translocation of NF-kappaB p65 subunit and binding of NF-kappaB p50 subunit from nuclear extracts to a biotinylated-consensus sequence was unaffected by azathioprine treatment. iNOS inhibition by azathioprine was associated with a decreased expression of IRF-1 (interferon regulatory factor 1) and IFN-beta (beta-interferon) mRNA. Azathioprine induced iNOS inhibition seems to be associated with an action of the methylnitroimidazolyl substituent. This suggests a route to the rational design of nontoxic anti-inflammatory agents by replacing the 6-mercaptopurine component of azathioprine with other substituents. The inhibition of

  11. 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…

  12. 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.

  13. 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.

  14. 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.

  15. Relevance of Chemical Kinetics for Medicine: The Case of Nitric Oxide

    NASA Astrophysics Data System (ADS)

    Balaban, Alexandru T.; Seitz, William

    2003-06-01

    Nitric oxide, NO, is central to many physiological processes including regulation of blood pressure and nerve signal transmission. Enzymes in endothelial cells and in the brain of mammals continuously synthesize it—generally in low and carefully regulated concentrations. The well known reaction of NO with oxygen to produce toxic nitrogen dioxide, NO2, has a rate which is bimolecular in NO. High concentrations of NO, as are found often in industrial plants or cigarettes, react rapidly with oxygen to produce toxic NO2. However, the half-life of NO at low NO concentrations as found in solutions and gases occurring in blood vessels, brains, and lungs is sufficiently long for biochemical purposes. Kinetics, then, determines the harmful versus helpful aspects of nitric oxide. At concentrations below 80 ppm NO is used in hospitals for lung vasodilation of preterm newborns and patients with pulmonary distress.

  16. Vascular endothelial growth factor inhibitor-induced hypertension: from pathophysiology to prevention and treatment based on long-acting nitric oxide donors.

    PubMed

    Kruzliak, Peter; Novák, Jan; Novák, Miroslav

    2014-01-01

    Hypertension is the most common adverse effect of the inhibitors of vascular endothelial growth factor (VEGF) pathway-based therapy (VEGF pathway inhibitors therapy, VPI therapy) in cancer patients. VPI includes monoclonal antibodies against VEGF, tyrosine kinase inhibitors, VEGF Traps, and so-called aptamers that may become clinically relevant in the future. All of these substances inhibit the VEGF pathway, which in turn causes a decrease in nitric oxide (NO) and an increase in blood pressure, with the consequent development of hypertension and its final events (e.g., myocardial infarction or stroke). To our knowledge, there is no current study on how to provide an optimal therapy for patients on VPI therapy with hypertension. This review summarizes the roles of VEGF and NO in vessel biology, provides an overview of VPI agents, and suggests a potential treatment procedure for patients with VPI-induced hypertension.

  17. Nitric oxide and heat shock protein 90 co-regulate temperature-induced bleaching in the soft coral Eunicea fusca

    NASA Astrophysics Data System (ADS)

    Ross, Cliff

    2014-06-01

    Coral bleaching represents a complex physiological process that is affected not only by environmental conditions but by the dynamic internal cellular biology of symbiotic dinoflagellates ( Symbiodinium spp.) and their cnidarian hosts. Recently, nitric oxide (NO) has emerged as a key molecule involved with the expulsion of Symbiodinium from host cnidarian cells. However, the site of production remains under debate, and the corresponding signaling pathways within and between host and endosymbiont remain elusive. In this study, using freshly isolated Symbiodinium from the soft coral Eunicea fusca, I demonstrate that thermally induced stress causes an upregulation in Symbiodinium heat shock protein 90 (Hsp90). In turn, Hsp90 shows a concomitant ability to enhance the activity of a constitutively expressed isoform of NO synthase. The resulting production of NO constitutes a signaling molecule capable of inducing Symbiodinium expulsion. Using nitric oxide synthase (NOS) and Hsp90 polyclonal antibodies, thermal stress-induced Hsp90 was shown to co-immunoprecipitate with a constitutive isoform of NOS. The specific blocking of Hsp90 activity, with the Hsp90 inhibitor geldanamycin, was capable of inhibiting NO production implicating the involvement of a coordinated regulatory system. These results have strong evolutionary implications for Hsp90-NOS chaperone complexes among biological kingdoms and provide evidence for a new functional role in symbiotic associations.

  18. Manganese-induced effects on cerebral trace element and nitric oxide of Hyline cocks.

    PubMed

    Liu, Xiaofei; Zuo, Nan; Guan, Huanan; Han, Chunran; Xu, Shi Wen

    2013-08-01

    Exposure to Manganese (Mn) is a common phenomenon due to its environmental pervasiveness. To investigate the Mn-induced toxicity on cerebral trace element levels and crucial nitric oxide parameters on brain of birds, 50-day-old male Hyline cocks were fed either a commercial diet or a Mn-supplemented diet containing 600, 900, 1,800 mg kg(-1). After being treated with Mn for 30, 60, and 90 days, the following were determined: the changes in contents of copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), selenium (Se) in brain; inducible nitric oxide synthase-nitric oxide (iNOS-NO) system activity in brain; and histopathology and ultrastructure changes of cerebral cortex. The results showed that Mn was accumulated in brain and the content of Cu and Fe increased. However, the levels of Zn and Se decreased and the Ca content presented no obvious regularity. Exposure to Mn significantly elevated the content of NO and the expression of iNOS mRNA. Activity of total NO synthase (T NOS) and iNOS appeared with an increased tendency. These findings suggested that Mn exposure resulted in the imbalance of cerebral trace elements and influenced iNOS in the molecular level, which are possible underlying nervous system injury mechanisms induced by Mn exposure.

  19. 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.

  20. Nitric oxide-releasing porous silicon nanoparticles

    PubMed Central

    2014-01-01

    In this study, the ability of porous silicon nanoparticles (PSi NPs) to entrap and deliver nitric oxide (NO) as an effective antibacterial agent is tested against different Gram-positive and Gram-negative bacteria. NO was entrapped inside PSi NPs functionalized by means of the thermal hydrocarbonization (THC) process. Subsequent reduction of nitrite in the presence of d-glucose led to the production of large NO payloads without reducing the biocompatibility of the PSi NPs with mammalian cells. The resulting PSi NPs demonstrated sustained release of NO and showed remarkable antibacterial efficiency and anti-biofilm-forming properties. These results will set the stage to develop antimicrobial nanoparticle formulations for applications in chronic wound treatment. PMID:25114633

  1. Nitric oxide-releasing porous silicon nanoparticles.

    PubMed

    Kafshgari, Morteza Hasanzadeh; Cavallaro, Alex; Delalat, Bahman; Harding, Frances J; McInnes, Steven Jp; Mäkilä, Ermei; Salonen, Jarno; Vasilev, Krasimir; Voelcker, Nicolas H

    2014-01-01

    In this study, the ability of porous silicon nanoparticles (PSi NPs) to entrap and deliver nitric oxide (NO) as an effective antibacterial agent is tested against different Gram-positive and Gram-negative bacteria. NO was entrapped inside PSi NPs functionalized by means of the thermal hydrocarbonization (THC) process. Subsequent reduction of nitrite in the presence of d-glucose led to the production of large NO payloads without reducing the biocompatibility of the PSi NPs with mammalian cells. The resulting PSi NPs demonstrated sustained release of NO and showed remarkable antibacterial efficiency and anti-biofilm-forming properties. These results will set the stage to develop antimicrobial nanoparticle formulations for applications in chronic wound treatment.

  2. Nitric oxide and plant iron homeostasis.

    PubMed

    Buet, Agustina; Simontacchi, Marcela

    2015-03-01

    Like all living organisms, plants demand iron (Fe) for important biochemical and metabolic processes. Internal imbalances, as a consequence of insufficient or excess Fe in the environment, lead to growth restriction and affect crop yield. Knowledge of signals and factors affecting each step in Fe uptake from the soil and distribution (long-distance transport, remobilization from old to young leaves, and storage in seeds) is necessary to improve our understanding of plant mineral nutrition. In this context, the role of nitric oxide (NO) is discussed as a key player in maintaining Fe homeostasis through its cross talk with hormones, ferritin, and frataxin and the ability to form nitrosyl-iron complexes. © 2015 New York Academy of Sciences.

  3. Nitric oxide-releasing porous silicon nanoparticles

    NASA Astrophysics Data System (ADS)

    Kafshgari, Morteza Hasanzadeh; Cavallaro, Alex; Delalat, Bahman; Harding, Frances J.; McInnes, Steven JP; Mäkilä, Ermei; Salonen, Jarno; Vasilev, Krasimir; Voelcker, Nicolas H.

    2014-07-01

    In this study, the ability of porous silicon nanoparticles (PSi NPs) to entrap and deliver nitric oxide (NO) as an effective antibacterial agent is tested against different Gram-positive and Gram-negative bacteria. NO was entrapped inside PSi NPs functionalized by means of the thermal hydrocarbonization (THC) process. Subsequent reduction of nitrite in the presence of d-glucose led to the production of large NO payloads without reducing the biocompatibility of the PSi NPs with mammalian cells. The resulting PSi NPs demonstrated sustained release of NO and showed remarkable antibacterial efficiency and anti-biofilm-forming properties. These results will set the stage to develop antimicrobial nanoparticle formulations for applications in chronic wound treatment.

  4. Nitric oxide in microgravity-induced orthostatic intolerance: relevance to spinal cord injury

    NASA Technical Reports Server (NTRS)

    Vaziri, N. D.; Purdy, R. E. (Principal Investigator)

    2003-01-01

    Prolonged exposure to microgravity results in cardiovascular deconditioning which is marked by orthostatic intolerance in the returning astronauts and recovering bed-ridden patients. Recent studies conducted in our laboratories at University of California, Irvine have revealed marked elevation of nitric oxide (NO) production in the kidney, heart, brain, and systemic arteries coupled with significant reduction of NO production in the cerebral arteries of microgravity-adapted animals. We have further demonstrated that the observed alteration of NO metabolism is primarily responsible for the associated cardiovascular deconditioning. Recovery from acute spinal cord injury (SCI) is frequently complicated by orthostatic intolerance that is due to the combined effects of the disruption of efferent sympathetic pathway and cardiovascular deconditioning occasioned by prolonged confinement to bed. In this presentation, I will review the nature of altered NO metabolism and its role in the pathogenesis of microgravity-induced cardiovascular deconditioning. The possible relevance of the new findings to orthostatic intolerance in patients with acute SCI and its potential therapeutic implications will be discussed.

  5. Rhus coriaria suppresses angiogenesis, metastasis and tumor growth of breast cancer through inhibition of STAT3, NFκB and nitric oxide pathways

    PubMed Central

    El Hasasna, Hussain; Saleh, Alaaeldin; Samri, Halima Al; Athamneh, Khawlah; Attoub, Samir; Arafat, Kholoud; Benhalilou, Nehla; Alyan, Sofyan; Viallet, Jean; Dhaheri, Yusra Al; Eid, Ali; Iratni, Rabah

    2016-01-01

    Recently, we reported that Rhus coriaria exhibits anticancer activities by promoting cell cycle arrest and autophagic cell death of the metastatic triple negative MDA-MB-231 breast cancer cells. Here, we investigated the effect of Rhus coriaria on the migration, invasion, metastasis and tumor growth of TNBC cells. Our current study revealed that non-cytotoxic concentrations of Rhus coriaria significantly inhibited migration and invasion, blocked adhesion to fibronectin and downregulated MMP-9 and prostaglandin E2 (PgE2). Not only did Rhus coriaria decrease their adhesion to HUVECs and to lung microvascular endothelial (HMVEC-L) cells, but it also inhibited the transendothelial migration of MDA-MB-231 cells through TNF-α-activated HUVECs. Furthermore, we found that Rhus coriaria inhibited angiogenesis, reduced VEGF production in both MDA-MB-231 and HUVECs and downregulated the inflammatory cytokines TNF-α, IL-6 and IL-8. The underlying mechanism for Rhus coriaria effects appears to be through inhibiting NFκB, STAT3 and nitric oxide (NO) pathways. Most importantly, by using chick embryo tumor growth assay, we showed that Rhus coriaria suppressed tumor growth and metastasis in vivo. The results described in the present study identify Rhus coriaria as a promising chemopreventive and therapeutic candidate that modulate triple negative breast cancer growth and metastasis. PMID:26888313

  6. The lethal effects of cytokine-induced nitric oxide on cardiac myocytes are blocked by nitric oxide synthase antagonism or transforming growth factor beta.

    PubMed Central

    Pinsky, D J; Cai, B; Yang, X; Rodriguez, C; Sciacca, R R; Cannon, P J

    1995-01-01

    Inducible nitric oxide (NO) produced by macrophages is cytotoxic to invading organisms and has an important role in host defense. Recent studies have demonstrated inducible NO production within the heart, and that cytokine-induced NO mediates alterations in cardiac contractility, but the cytotoxic potential of nitric oxide with respect to the heart has not been defined. To evaluate the role of inducible nitric oxide synthase (iNOS) on cardiac myocyte cytotoxicity, we exposed adult rat cardiac myocytes to either cytokines alone or to activated J774 macrophages in coculture. Increased expression of both iNOS message and protein was seen in J774 macrophages treated with IFN gamma and LPS and cardiac myocytes treated with TNF-alpha, IL-1 beta, and IFN gamma. Increased NO synthesis was confirmed in both the coculture and isolated myocyte preparations by increased nitrite production. Increased NO synthesis was associated with a parallel increase in myocyte death as measured by CPK release into the culture medium as well as by loss of membrane integrity, visualized by trypan blue staining. Addition of the competitive NO synthase inhibitor L-NMMA to the culture medium prevented both the increased nitrite production and the cytotoxicity observed after cytokine treatment in both the isolated myocyte and the coculture experiments. Because transforming growth-factor beta modulates iNOS expression in other cell types, we evaluated its effects on cardiac myocyte iNOS expression and NO-mediated myocyte cytotoxicity. TGF-beta reduced expression of cardiac myocyte iNOS message and protein, reduced nitrite production, and reduced NO-mediated cytotoxicity in parallel. Taken together, these experiments show the cytotoxic potential of endogenous NO production within the heart, and suggest a role for TGF-beta or NO synthase antagonists to mute these lethal effects. These findings may help explain the cardiac response to sepsis or allograft rejection, as well as the progression of

  7. Nitric Oxide Accumulation: The Evolutionary Trigger for Phytopathogenesis

    PubMed Central

    Santana, Margarida M.; Gonzalez, Juan M.; Cruz, Cristina

    2017-01-01

    Many publications highlight the importance of nitric oxide (NO) in plant–bacteria interactions, either in the promotion of health and plant growth or in pathogenesis. However, the role of NO in the signaling between bacteria and plants and in the fate of their interaction, as well as the reconstruction of their interactive evolution, remains largely unknown. Despite the complexity of the evolution of life on Earth, we explore the hypothesis that denitrification and aerobic respiration were responsible for local NO accumulation, which triggered primordial antagonistic biotic interactions, namely the first phytopathogenic interactions. N-oxides, including NO, could globally accumulate via lightning synthesis in the early anoxic ocean and constitute pools for the evolution of denitrification, considered an early step of the biological nitrogen cycle. Interestingly, a common evolution may be proposed for components of denitrification and aerobic respiration pathways, namely for NO and oxygen reductases, a theory compatible with the presence of low amounts of oxygen before the great oxygenation event (GOE), which was generated by Cyanobacteria. During GOE, the increase in oxygen caused the decrease of Earth’s temperature and the consequent increase of oxygen dissolution and availability, making aerobic respiration an increasingly dominant trait of the expanding mesophilic lifestyle. Horizontal gene transfer was certainly important in the joint expansion of mesophily and aerobic respiration. First denitrification steps lead to NO formation through nitrite reductase activity, and NO may further accumulate when oxygen binds NO reductase, resulting in denitrification blockage. The consequent transient NO surplus in an oxic niche could have been a key factor for a successful outcome of an early denitrifying prokaryote able to scavenge oxygen by NO/oxygen reductase or by an independent heterotrophic aerobic respiration pathway. In fact, NO surplus could result in toxicity

  8. The role of nitric oxide radicals in removal of hyper-radiosensitivity by priming irradiation

    PubMed Central

    Edin, Nina Jeppesen; Sandvik, Joe Alexander; Vollan, Hilde Synnøve; Reger, Katharina; Görlach, Agnes; Pettersen, Erik Olai

    2013-01-01

    In this study, a mechanism in which low-dose hyper-radiosensitivity (HRS) is permanently removed, induced by low-dose-rate (LDR) (0.2–0.3 Gy/h for 1 h) but not by high-dose-rate priming (0.3 Gy at 40 Gy/h) was investigated. One HRS-negative cell line (NHIK 3025) and two HRS-positive cell lines (T-47D, T98G) were used. The effects of different pretreatments on HRS were investigated using the colony assay. Cell-based ELISA was used to measure nitric oxide synthase (NOS) levels, and microarray analysis to compare gene expression in primed and unprimed cells. The data show how permanent removal of HRS, previously found to be induced by LDR priming irradiation, can also be induced by addition of nitric oxide (NO)-donor DEANO combined with either high-dose-rate priming or exposure to prolonged cycling hypoxia followed by reoxygenation, a treatment not involving radiation. The removal of HRS appears not to involve DNA damage induced during priming irradiation as it was also induced by LDR irradiation of cell-conditioned medium without cells present. The permanent removal of HRS in LDR-primed cells was reversed by treatment with inducible nitric oxide synthase (iNOS) inhibitor 1400W. Furthermore, 1400W could also induce HRS in an HRS-negative cell line. The data suggest that LDR irradiation for 1 h, but not 15 min, activates iNOS, and also that sustained iNOS activation is necessary for the permanent removal of HRS by LDR priming. The data indicate that nitric oxide production is involved in the regulatory processes determining cellular responses to low-dose-rate irradiation. PMID:23685670

  9. β-Adrenergic-mediated vasodilation in young men and women: cyclooxygenase restrains nitric oxide synthase

    PubMed Central

    Limberg, Jacqueline K.; Johansson, Rebecca E.; Peltonen, Garrett L.; Harrell, John W.; Kellawan, J. Mikhail; Eldridge, Marlowe W.; Sebranek, Joshua J.

    2016-01-01

    We tested the hypothesis that women exhibit greater vasodilator responses to β-adrenoceptor stimulation compared with men. We further hypothesized women exhibit a greater contribution of nitric oxide synthase and cyclooxygenase to β-adrenergic-mediated vasodilation compared with men. Forearm blood flow (Doppler ultrasound) was measured in young men (n = 29, 26 ± 1 yr) and women (n = 33, 25 ± 1 yr) during intra-arterial infusion of isoproterenol (β-adrenergic agonist). In subset of subjects, isoproterenol responses were examined before and after local inhibition of nitric oxide synthase [NG-monomethyl-l-arginine (l-NMMA); 6 male/10 female] and/or cyclooxygenase (ketorolac; 5 male/5 female). Vascular conductance (blood flow ÷ mean arterial pressure) was calculated to assess vasodilation. Vascular conductance increased with isoproterenol infusion (P < 0.01), and this effect was not different between men and women (P = 0.41). l-NMMA infusion had no effect on isoproterenol-mediated dilation in men (P > 0.99) or women (P = 0.21). In contrast, ketorolac infusion markedly increased isoproterenol-mediated responses in both men (P < 0.01) and women (P = 0.04) and this rise was lost with subsequent l-NMMA infusion (men, P < 0.01; women, P < 0.05). β-Adrenergic vasodilation is not different between men and women and sex differences in the independent contribution of nitric oxide synthase and cyclooxygenase to β-mediated vasodilation are not present. However, these data are the first to demonstrate β-adrenoceptor activation of cyclooxygenase suppresses nitric oxide synthase signaling in human forearm microcirculation and may have important implications for neurovascular control in both health and disease. PMID:26747505

  10. Enhancement of fracture healing in the rat, modulated by compounds that stimulate inducible nitric oxide synthase: Acceleration of fracture healing via inducible nitric oxide synthase.

    PubMed

    Rajfer, R A; Kilic, A; Neviaser, A S; Schulte, L M; Hlaing, S M; Landeros, J; Ferrini, M G; Ebramzadeh, E; Park, S-H

    2017-02-01

    We investigated the effects on fracture healing of two up-regulators of inducible nitric oxide synthase (iNOS) in a rat model of an open femoral osteotomy: tadalafil, a phosphodiesterase inhibitor, and the recently reported nutraceutical, COMB-4 (consisting of L-citrulline, Paullinia cupana, ginger and muira puama), given orally for either 14 or 42 days. Unilateral femoral osteotomies were created in 58 male rats and fixed with an intramedullary compression nail. Rats were treated daily either with vehicle, tadalafil or COMB-4. Biomechanical testing of the healed fracture was performed on day 42. The volume, mineral content and bone density of the callus were measured by quantitative CT on days 14 and 42. Expression of iNOS was measured by immunohistochemistry. When compared with the control group, the COMB-4 group exhibited 46% higher maximum strength ( t -test, p = 0.029) and 92% higher stiffness ( t -test, p = 0.023), but no significant changes were observed in the tadalafil group. At days 14 and 42, there was no significant difference between the three groups with respect to callus volume, mineral content and bone density. Expression of iNOS at day 14 was significantly higher in the COMB-4 group which, as expected, had returned to baseline levels at day 42. This study demonstrates an enhancement in fracture healing by an oral natural product known to augment iNOS expression. Cite this article: R. A. Rajfer, A. Kilic, A. S. Neviaser, L. M. Schulte, S. M. Hlaing, J. Landeros, M. G. Ferrini, E. Ebramzadeh, S-H. Park. Enhancement of fracture healing in the rat, modulated by compounds that stimulate inducible nitric oxide synthase: Acceleration of fracture healing via inducible nitric oxide synthase. Bone Joint Res 2017:6:-97. DOI: 10.1302/2046-3758.62.BJR-2016-0164.R2. © 2017 Park et al.

  11. Release of nitric oxide during the T cell-independent pathway of macrophage activation

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

    Beckerman, K.P.; Rogers, H.W.; Corbett, J.A.

    1993-02-01

    Immunodeficient mice are remarkably resistant to Listeria monocytogenes (LM) infection. The authors examined the role that nitric oxide (NO) plays in the CB-17/lcr SCID (SCID) response to LM. SCID spleen cells produced large quantities of NO (as measured by nitrite formation) when incubated in the presence of heat-killed LM. NO produced large quantities of nitrite in response to LM, but only in the presence of IFN-[gamma]. The production of NO induced by LM was not affected by neutralizing antibodies to TNF or IL-1. The production of NO was inhibited by addition of either of two inhibitors of NO synthase, N[supmore » G]-monomethyl arginine, or aminoguanidine. In a different situation, NK cells that were stimulated by TNF and Listeria products to release IFN-[gamma] did not produce NO. Macrophages cultured with IFN-[gamma] killed live LM. This increased killing of LM was significantly inhibited by amino-guanidine. In vivo, administration of aminoguanidine resulted in a marked increase in the mortality and spleen bacterial loads of LM-infected SCID or immunocompetent control mice. It is concluded that NO is a critical effector molecule of T cell-independent natural resistence of LM as studied in the SCID mouse, and that the NO-mediated response is essential for both SCID and immunocompetent host to survive after LM infection. 37 refs., 7 figs.« less

  12. 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

  13. Effect of fluoroquinolone on the enhanced nitric oxide-induced peripheral vasodilation seen in cirrhosis.

    PubMed

    Chin-Dusting, J P; Rasaratnam, B; Jennings, G L; Dudley, F J

    1997-12-01

    In patients with cirrhosis, portosystemic shunts allow intestinal bacteria and endotoxin to enter the systemic circulation. Endotoxemia may induce increased synthesis of nitric oxide, thereby contributing to arterial vasodilation. To test the hypothesis that the antibiotic norfloxacin blocks the effects of nitric oxide. Placebo-controlled, double-blind, crossover study. Alfred Hospital, Melbourne, Australia. 9 patients with alcohol-related cirrhosis and 10 healthy controls. Norfloxacin, 400 mg twice daily, for 4 weeks. Peripheral blood flow was measured by using forearm venous occlusion plethysmography. Basal forearm blood flow was higher in patients with cirrhosis than in controls (3.69 +/- 0.27 mL/100 mL per minute and 2.47 +/- 0.40 mL/100 mL per minute; P = 0.014) but returned toward normal after norfloxacin was given (2.64 +/- 0.31 mL/100 mL of tissue per minute in patients with cirrhosis). Responses to NG-monomethyl-L-arginine were greater in patients with cirrhosis but returned to normal after norfloxacin was given. Bacterial endotoxemia in patients with cirrhosis induces increased synthesis of nitric oxide that can be corrected with norfloxacin.

  14. Intrathecal oxotremorine affects formalin-induced behavior and spinal nitric oxide synthase immunoreactivity in rats.

    PubMed

    Przewlocka, B; Mika, J; Capone, F; Machelska, H; Pavone, F

    1999-03-01

    The present research was undertaken to investigate, by behavioral and immunohistochemical methods, the effects of intrathecal (i.th.) injection of the muscarinic agonist oxotremorine on the response to the long-lasting nociceptive stimulus induced by injection of formalin into the rat hind paw. Formalin injection induced a biphasic, pain-induced behavioral response (paw jerks), as well as an increase in the number of nitric oxide (NO) synthase-labeled neurons in laminae I-III, IV, and X, but not in laminae V-VI. Oxotremorine (0.1-10 ng, i.th.) inhibited paw-jerk frequency in both phases of formalin-induced behavior. The immunohistochemical results showed that i.th.-injected oxotremorine differently affected the level of NO synthase in lumbar part of the spinal cord: no change or increase after the dose of 1 ng, and a significant reduction of nitric oxide synthase neurons after the higher dose (10 ng). These results evidenced a role of cholinergic system in the modulation of tonic pain and in nitric oxide synthase expression at the spinal cord level, which further suggests that these two systems could be involved in phenomena induced by long-lasting nociceptive stimulation.

  15. Inducible nitric oxide synthase in T cells regulates T cell death and immune memory

    PubMed Central

    Vig, Monika; Srivastava, Smita; Kandpal, Usha; Sade, Hadassah; Lewis, Virginia; Sarin, Apurva; George, Anna; Bal, Vineeta; Durdik, Jeannine M.; Rath, Satyajit

    2004-01-01

    The progeny of T lymphocytes responding to immunization mostly die rapidly, leaving a few long-lived survivors functioning as immune memory. Thus, control of this choice of death versus survival is critical for immune memory. There are indications that reactive radicals may be involved in this death pathway. We now show that, in mice lacking inducible nitric oxide synthase (iNOS), higher frequencies of both CD4 and CD8 memory T cells persist in response to immunization, even when iNOS+/+ APCs are used for immunization. Postactivation T cell death by neglect is reduced in iNOS–/– T cells, and levels of the antiapoptotic proteins Bcl-2 and Bcl-xL are increased. Inhibitors of the iNOS-peroxynitrite pathway also enhance memory responses and block postactivation death by neglect in both mouse and human T cells. However, early primary immune responses are not enhanced, which suggests that altered survival, rather than enhanced activation, is responsible for the persistent immunity observed. Thus, in primary immune responses, iNOS in activated T cells autocrinely controls their susceptibility to death by neglect to determine the level of persisting CD4 and CD8 T cell memory, and modulation of this pathway can enhance the persistence of immune memory in response to vaccination. PMID:15199408

  16. The effects of nitric oxide-cGMP pathway stimulation on dopamine in the medial preoptic area and copulation in DHT-treated castrated male rats

    PubMed Central

    Sato, Satoru M.; Wersinger, Scott R.; Hull, Elaine M.

    2007-01-01

    Dopamine (DA) in the medial preoptic area (MPOA) provides important facilitative influence on male rat copulation. We have shown that the nitric oxide-cGMP (NO-cGMP) pathway modulates MPOA DA levels and copulation. We have also shown that systemic estradiol (E2) maintains neuronal NO synthase (nNOS) immunoreactivity in the MPOA of castrates, as well as relatively normal DA levels. This effect of E2 on nNOS probably accounts for at least some of the previously demonstrated behavioral facilitation by intra-MPOA E2 administration in castrates. Therefore, we hypothesized that stimulation of the MPOA NO-cGMP pathway in dihydrotestosterone (DHT)-treated castrates should restore DA levels and copulatory behaviors. Reverse-dialysis of a NO donor, sodium nitroprusside (SNP), increased extracellular DA in the MPOA of DHT-treated castrates and restored the ability to copulate to ejaculation in half of the animals. A cGMP analog, 8-Br-cGMP, also increased extracellular DA, though not as robustly, but did not restore copulatory ability. The effectiveness of the NO donor in restoring copulation and MPOA DA levels is consistent with our hypothesis. However, the lack of behavioral effects of 8-Br-cGMP, despite its increase in MPOA DA, suggests that NO may have additional mediators in the MPOA in the regulation of copulation. Furthermore, the suboptimal copulation seen in the NO donor-treated animals suggests the importance of extra-MPOA systems in the regulation of copulation. PMID:17467707

  17. Human endogenous retrovirus W env increases nitric oxide production and enhances the migration ability of microglia by regulating the expression of inducible nitric oxide synthase.

    PubMed

    Xiao, Ran; Li, Shan; Cao, Qian; Wang, Xiuling; Yan, Qiujin; Tu, Xiaoning; Zhu, Ying; Zhu, Fan

    2017-06-01

    Human endogenous retrovirus W env (HERV-W env) plays a critical role in many neuropsychological diseases such as schizophrenia and multiple sclerosis (MS). These diseases are accompanied by immunological reactions in the central nervous system (CNS). Microglia are important immunocytes in brain inflammation that can produce a gasotransmitter-nitric oxide (NO). NO not only plays a role in the function of neuronal cells but also participates in the pathogenesis of various neuropsychological diseases. In this study, we reported increased NO production in CHME-5 microglia cells after they were transfected with HERV-W env. Moreover, HERV-W env increased the expression and function of human inducible nitric oxide synthase (hiNOS) and enhanced the promoter activity of hiNOS. Microglial migration was also enhanced. These data revealed that HERV-W env might contribute to increase NO production and microglial migration ability in neuropsychological disorders by regulating the expression of inducible NOS. Results from this study might lead to the identification of novel targets for the treatment of neuropsychological diseases, including neuroinflammatory diseases, stroke, and neurodegenerative diseases.

  18. Detoxification of nitric oxide by Fusarium verticillioides is linked to denitrification

    USDA-ARS?s Scientific Manuscript database

    Nitric oxide (NO) is a potent cellular signaling molecule and a byproduct of nitrogen metabolism. High concentrations of NO are a form of nitrosative stress, and to alleviate this stress, organisms utilize flavohemoglobins to convert NO into nontoxic nitrate ions. We have investigated the capacity o...

  19. Involvement of the nitric oxide in melatonin-mediated protection against injury.

    PubMed

    Fan, Wenguo; He, Yifan; Guan, Xiaoyan; Gu, Wenzhen; Wu, Zhi; Zhu, Xiao; Huang, Fang; He, Hongwen

    2018-05-01

    Melatonin is a hormone mainly synthesized by the pineal gland in vertebrates and known well as an endogenous regulator of circadian and seasonal rhythms. It has been demonstrated that melatonin is involved in many physiological and pathophysiological processes showing antioxidant, anti-apoptotic and anti-inflammatory properties. Nitric oxide (NO) is a free radical gas in the biological system, which is produced by nitric oxide synthase (NOS) family. NO acts as a biological mediator and plays important roles in different systems in humans. The NO/NOS system exerts a broad spectrum of signaling functions. Accumulating evidence has clearly revealed that melatonin regulates NO/NOS system through multiple mechanisms that may influence physiological and pathophysiological processes. This article reviews the latest evidence for the effects of melatonin on NO/NOS regulation in different organs and disease conditions, the potential cellular mechanisms by which melatonin is involved in organ protection are discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Activity of nitric oxide-generating compounds against encephalomyocarditis virus.

    PubMed Central

    Guillemard, E; Geniteau-Legendre, M; Kergot, R; Lemaire, G; Petit, J F; Labarre, C; Quero, A M

    1996-01-01

    Nitric oxide (NO) generated by two NO donors (sodium nitroprusside or S-nitroso-L-glutathione) was shown to exert a dose-dependent inhibition of encephalomyocarditis virus growth in L-929 cells. This activity was not due to the cytotoxic or direct virucidal effects of NO donors. L-929 cells were shown to produce NO endogenously, but this low level of production did not counter encephalomyocarditis virus replication. PMID:8849231