Sample records for vascular nitric oxide

  1. Nitric oxide and reactive oxygen species in limb vascular function

    DEFF Research Database (Denmark)

    Gliemann, Lasse; Nyberg, Michael Permin; Hellsten, Ylva


    Abstract Nitric oxide (NO) is known to be one of the most important regulatory compounds within the cardiovascular system where it is central for functions such as regulation of blood pressure, blood flow and vascular growth. The bioavailability of NO is determined by a balance between, on one hand...... and xanthine oxidase and the degree of ROS removal through the antioxidant defense system. The development of cardiovascular disease has been proposed to be closely related to a reduced bioavailability of NO in parallel with an increased presence of ROS. Excessive levels of ROS not only lower....... Regular physical activity is therefore likely to be a highly useful tool in the treatment of cardiovascular disease. Future studies should focus on which form of exercise that may be most optimal for enhancing NO bioavailability and improving cardiovascular health....

  2. [Nitric oxide]. (United States)

    Rovira, I


    Nitric oxide was identified as the relaxing factor derived from the endothelium in 1987. Nitric oxide synthesis allows the vascular system to maintain a state of vasodilation, thereby regulating arterial pressure. Nitric oxide is also found in platelets, where it inhibits adhesion and aggregation; in the immune system, where it is responsible for the cytotoxic action of macrophages; and in the nervous system, where it acts as neurotransmitter. A deficit in endogenous synthesis of nitric oxide contributes to such conditions as essential arterial hypertension, pulmonary hypertension and heart disease. An excess of nitrous oxide induced by endotoxins and cytokinins, meanwhile, is believed to be responsible for hypotension in septic shock and for hyperdynamic circulatory state in cirrhosis of the liver. Nitric oxide has also been implicated in the rejection of transplanted organs and in cell damage after reperfusion. Inhaled nitrous oxide gas reduces pulmonary hypertension without triggering systemic hypotension in both experimental and clinical conditions. It also produces selective vasodilation when used to ventilate specific pulmonary areas, thereby improving the ventilation/perfusion ratio and, hence, oxygenation. Nitric oxide inhalation is effective in pulmonary hypertension-coincident with chronic obstructive lung disease, in persistent neonatal pulmonary hypertension and in pulmonary hypertension with congenital or acquired heart disease. Likewise, it reduces intrapulmonary shunt in acute respiratory failure and improves gas exchange. Under experimental conditions nitric oxide acts as a bronchodilator, although it seems to be less effective for this purpose in clinical use.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Cytoglobin regulates blood pressure and vascular tone through nitric oxide metabolism in the vascular wall (United States)

    Liu, Xiaoping; El-Mahdy, Mohamed A.; Boslett, James; Varadharaj, Saradhadevi; Hemann, Craig; Abdelghany, Tamer M.; Ismail, Raed S.; Little, Sean C.; Zhou, Danlei; Thuy, Le Thi Thanh; Kawada, Norifumi; Zweier, Jay L.


    The identity of the specific nitric oxide dioxygenase (NOD) that serves as the main in vivo regulator of O2-dependent NO degradation in smooth muscle remains elusive. Cytoglobin (Cygb) is a recently discovered globin expressed in fibroblasts and smooth muscle cells with unknown function. Cygb, coupled with a cellular reducing system, efficiently regulates the rate of NO consumption by metabolizing NO in an O2-dependent manner with decreased NO consumption in physiological hypoxia. Here we show that Cygb is a major regulator of NO degradation and cardiovascular tone. Knockout of Cygb greatly prolongs NO decay, increases vascular relaxation, and lowers blood pressure and systemic vascular resistance. We further demonstrate that downregulation of Cygb prevents angiotensin-mediated hypertension. Thus, Cygb has a critical role in the regulation of vascular tone and disease. We suggest that modulation of the expression and NOD activity of Cygb represents a strategy for the treatment of cardiovascular disease.

  4. Comparison Between the Acute Pulmonary Vascular Effects of Oxygen with Nitric Oxide and Sildenafil

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    Ronald W. Day


    Full Text Available Objective. Right heart catheterization is performed in patients with pulmonary arterial hypertension to determine the severity of disease and their pulmonary vascular reactivity. The acute pulmonary vascular effect of inhaled nitric oxide is frequently used to identify patients who will respond favorably to vasodilator therapy. This study sought to determine whether the acute pulmonary vascular effects of oxygen with nitric oxide and intravenous sildenafil are similar. Methods. A retrospective, descriptive study of 13 individuals with pulmonary hypertension who underwent heart catheterization and acute vasodilator testing was performed. The hemodynamic measurements during five phases (21% to 53% oxygen, 100% oxygen, 100% oxygen with 20 ppm nitric oxide, 21% to 51% oxygen, and 21% to 51% oxygen with 0.05 mg/kg to 0.29 mg/kg intravenous sildenafil of the procedures were compared.Results. Mean pulmonary arterial pressure and pulmonary vascular resistance acutely decreased with 100% oxygen with nitric oxide, and 21% to 51% oxygen with sildenafil. Mean pulmonary arterial pressure (mm Hg, mean ± standard error of the mean was 38 ± 4 during 21% to 53% oxygen, 32 ± 3 during 100% oxygen, 29 ± 2 during 100% oxygen with nitric oxide, 37 ± 3 during 21% to 51% oxygen, and 32 ± 2 during 21% to 51% oxygen with sildenafil. There was not a significant correlation between the percent change in pulmonary vascular resistance from baseline with oxygen and nitric oxide, and from baseline with sildenafil (r2 = 0.011, p = 0.738. Conclusions. Oxygen with nitric oxide and sildenafil decreased pulmonary vascular resistance. However, the pulmonary vascular effects of oxygen and nitric oxide cannot be used to predict the acute response to sildenafil. Additional studies are needed to determine whether the acute response to sildenafil can be used to predict the long-term response to treatment with an oral phosphodiesterase V inhibitor.

  5. Aspirin induces nitric oxide release from vascular endothelium: a novel mechanism of action


    Taubert, D; Berkels, R; Grosser, N; Schröder, H; Gründemann, D; Schömig, E


    The study was designed to test the hypothesis that aspirin may stimulate nitric oxide (NO) release from vascular endothelium, a pivotal factor for maintenance of vascular homeostasis.Clinical evidence suggests that low-dose aspirin may improve vascular endothelial function. Since other cyclooxygenase (COX) inhibitors showed no beneficial vascular effects, aspirin may exhibit a vasculoprotective, COX-independent mechanism.Luminal NO release was monitored in real time on dissected porcine coron...

  6. Endothelial Nitric Oxide Synthase Uncoupling: A Novel Pathway in OSA Induced Vascular Endothelial Dysfunction


    Varadharaj, Saradhadevi; Porter, Kyle; Pleister, Adam; Wannemacher, Jacob; Sow, Angela; Jarjoura, David; Zweier, Jay L.; Khayat, Rami N.


    The mechanism of vascular endothelial dysfunction (VED) and cardiovascular disease in obstructive sleep apnea (OSA) is unknown. We performed a comprehensive evaluation of endothelial nitric oxide synthase (eNOS) function directly in the microcirculatory endothelial tissue of OSA patients who have very low cardiovascular risk status. Nineteen OSA patients underwent gluteal biopsies before, and after effective treatment of OSA. We measured superoxide (O2−·) and nitric oxide (NO) in the microcir...

  7. Uncoupling of Vascular Nitric Oxide Synthase Caused by Intermittent Hypoxia

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    Mohammad Badran


    Full Text Available Objective. Obstructive sleep apnea (OSA, characterized by chronic intermittent hypoxia (CIH, is often present in diabetic (DB patients. Both conditions are associated with endothelial dysfunction and cardiovascular disease. We hypothesized that diabetic endothelial dysfunction is further compromised by CIH. Methods. Adult male diabetic (BKS.Cg-Dock7m +/+ Leprdb/J (db/db mice (10 weeks old and their heterozygote littermates were subjected to CIH or intermittent air (IA for 8 weeks. Mice were separated into 4 groups: IA (intermittent air nondiabetic, IH (intermittent hypoxia nondiabetic, IADB (intermittent air diabetic, and IHDB (intermittent hypoxia diabetic groups. Endothelium-dependent and endothelium-independent relaxation and modulation by basal nitric oxide (NO were analyzed using wire myograph. Plasma 8-isoprostane, interleukin-6 (IL-6, and asymmetric dimethylarginine (ADMA were measured using ELISA. Uncoupling of eNOS was measured using dihydroethidium (DHE staining. Results. Endothelium-dependent vasodilation and basal NO production were significantly impaired in the IH and IADB group compared to IA group but was more pronounced in IHDB group. Levels of 8-isoprostane, IL-6, ADMA, and eNOS uncoupling were ≈2-fold higher in IH and IADB groups and were further increased in the IHDB group. Conclusion. Endothelial dysfunction is more pronounced in diabetic mice subjected to CIH compared to diabetic or CIH mice alone. Oxidative stress, ADMA, and eNOS uncoupling were exacerbated by CIH in diabetic mice.

  8. Angiopoietins regulate vascular reactivity after haemorrhagic shock in rats through the Tie2-nitric oxide pathway. (United States)

    Xu, Jing; Lan, Dan; Li, Tao; Yang, Guangming; Liu, Liangming


    Vascular reactivity shows biphasic changes after severe trauma or shock. Our aim was to elucidate the mechanisms of biphasic-changed vascular reactivity after haemorrhagic shock by observing the regulation of angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) on it. Haemorrhagic-shock Sprague-Dawley rats, hypoxia-treated superior mesenteric arteries (SMAs) with intact endothelia, and a cell mixture of vascular smooth muscle cells (VSMCs) and vascular endothelial cells (VECs) were adopted to evaluate the regulatory effects of Ang-1 and Ang-2 on vascular reactivity and their relationship to Tie2 (receptor tyrosine kinase)-Akt-endothelial nitric oxide synthase (eNOS) and Tie2-extracellular signal-regulated kinase (Erk)-inducible nitric oxide synthase (iNOS) signal pathways. Ang-1 expression, Tie2 phosphorylation, and nitric oxide (NO) release were increased at early shock. Exogenous Ang-1 maintained the vascular reactivity of SMAs after early hypoxia. Tie2-blocking antibody and the antagonists of Akt and eNOS antagonized Ang-1-induced maintenance in vascular reactivity and a slight release in NO at the early stage of shock. Ang-2 expression, Tie2 phosphorylation, and NO release were greatly increased at late shock, but exogenous Ang-2 further decreased the vascular reactivity of SMAs after late hypoxia. Tie2-blocking antibody and the antagonists of Erk and iNOS andtagonized the Ang-2-induced decrease in vascular reactivity and a large release of NO at the late stage of shock. Ang-1 and Ang-2 participated in the regulation of vascular reactivity after haemorrhagic shock. Ang-1 was mainly responsible for the hyperreactivity at early shock through the Tie2-Akt-eNOS pathway and an appropriate amount of NO release. Ang-2 was mainly responsible for the hyporeactivity at late shock through the Tie2-Erk-iNOS pathway and the release of a large amount of NO.

  9. Nitric oxide-mediated changes in vascular reactivity in pregnancy in spontaneously hypertensive rats.


    Chu, Z. M.; Beilin, L. J.


    1. To examine the mechanisms which may account for pregnancy-induced vasodilatation in spontaneously hypertensive rats (SHR), we have investigated the changes in vascular reactivity and the effects of endothelial nitric oxide (NO) inhibition in the in situ blood-perfused, mesenteric resistance vessels of 18-20 day pregnant SHR. The effects of NG-nitro-L-arginine (L-NOARG) were compared in pregnant and nonpregnant SHR and gestation matched normotensive Wistar-Kyoto (WKY) rats. 2. Intra-arteria...

  10. Asymmetric dimethylarginine, oxidative stress, and vascular nitric oxide synthase in essential hypertension

    DEFF Research Database (Denmark)

    Wang, Dan; Strandgaard, Svend; Iversen, Jens


    We reported impaired endothelium-derived relaxation factor/nitric oxide (EDRF/NO) responses and constitutive nitric oxide synthase (cNOS) activity in subcutaneous vessels dissected from patients with essential hypertension (n = 9) compared with normal controls (n = 10). We now test the hypothesis...... and hypertensive subjects, the individual values for plasma levels of ADMA and HODE were both significantly (P oxidative stress in a group of hypertensive...

  11. The role of nitric oxide in the altered vascular reactivity of pregnancy in the rat.


    Nathan, L; Cuevas, J; Chaudhuri, G


    1. Pregnancy is characterized by a decrease in systemic vascular resistance and a blunting of the angiotensin II (AII) pressor response. We studied the role of nitric oxide (NO) and prostanoids in these vascular changes of pregnancy in anaesthesized, ganglion blocked non-pregnant and pregnant rats. 2. Inhibition of NO synthesis with NG-nitro-L-arginine methyl ester (L-NAME) led to an increase in mean arterial pressure (MAP) which was of a significantly greater magnitude in pregnant rats in la...

  12. Effect of a previous pregnancy on vascular function in endothelial nitric oxide synthase 3 knockout mice. (United States)

    Ghulmiyyah, Labib M; Tamayo, Esther; Clark, Shannon M; Hankins, Gary D V; Anderson, Garland D; Saade, George R; Longo, Monica


    Nitric oxide deficiency has been implicated in adverse pregnancy outcomes. Mice that lack endothelial nitric oxide synthase (NOS3) have abnormal in vitro vascular reactivity. Our objective was to assess the effect of a previous pregnancy on the abnormal vascular function of NOS3 knockout mice. Carotid arteries from pregnant NOS3 knockout (NOS3(-/-KO)) and wild-type control mice (NOS3(+/+WT)) from first and second pregnancy were obtained for in vitro vascular reactivity studies. Vascular responses to cumulative concentrations of the vasoconstrictors phenylephrine, serotonin, and thromboxane and the vasorelaxants acetylcholine, sodium nitroprusside, and isoproterenol were determined. In the first pregnancy, contractile responses were exaggerated in the knockout animals, compared with the wild-type animals. However, the second pregnancy in knockout animals was associated with normalization of responses to phenylephrine and serotonin and increased responses to the endothelium-independent relaxants. The vascular function of NOS3 knockout mice improves with subsequent pregnancy becoming comparable to wild-type animals.

  13. Post-translational regulation of endothelial nitric oxide synthase in vascular endothelium (United States)

    Qian, Jin; Fulton, David


    Nitric oxide (NO) is a short-lived gaseous signaling molecule. In blood vessels, it is synthesized in a dynamic fashion by endothelial nitric oxide synthase (eNOS) and influences vascular function via two distinct mechanisms, the activation of soluble guanylyl cyclase (sGC)/cyclic guanosine monophosphate (cGMP)-dependent signaling and the S-nitrosylation of proteins with reactive thiols (S-nitrosylation). The regulation of eNOS activity and NO bioavailability is critical to maintain blood vessel function. The activity of eNOS and ability to generate NO is regulated at the transcriptional, posttranscriptional, and posttranslational levels. Post-translational modifications acutely impact eNOS activity and dysregulation of these mechanisms compromise eNOS activity and foster the development of cardiovascular diseases (CVDs). This review will intergrate past and current literature on the post-translational modifications of eNOS in both health and disease. PMID:24379783

  14. Enhanced growth and improved vascular function in offspring from successive pregnancies in endothelial nitric oxide synthase knockout mice

    NARCIS (Netherlands)

    Longo, M; Jain, [No Value; Langenveld, J; Vedernikov, YP; Garfield, RE; Hankins, GDV; Anderson, GD; Saade, GR


    Objective: Transgenic mice that lack endothelial nitric oxide synthase have offspring with growth deficiency and abnormal vascular reactivity in later life. Our objective was to evaluate the role of parity in the modulation of the fetal programming of growth and vascular responses in these

  15. Trans fatty acids induce vascular inflammation and reduce vascular nitric oxide production in endothelial cells.

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    Naomi G Iwata

    Full Text Available Intake of trans fatty acids (TFA, which are consumed by eating foods made from partially hydrogenated vegetable oils, is associated with a higher risk of cardiovascular disease. This relation can be explained by many factors including TFA's negative effect on endothelial function and reduced nitric oxide (NO bioavailability. In this study we investigated the effects of three different TFA (2 common isomers of C18 found in partially hydrogenated vegetable oil and a C18 isomer found from ruminant-derived-dairy products and meat on endothelial NF-κB activation and nitric oxide (NO production. Human endothelial cells were treated with increasing concentrations of Elaidic (trans-C18:1 (9 trans, Linoelaidic (trans-C18:2 (9 trans, 12 trans, and Transvaccenic (trans-C18:1 (11 trans for 3 h. Both Elaidic and Linoelaidic acids were associated with increasing NF-κB activation as measured by IL-6 levels and phosphorylation of IκBα, and impairment of endothelial insulin signaling and NO production, whereas Transvaccenic acid was not associated with these responses. We also measured superoxide production, which has been hypothesized to be necessary in fatty acid-dependent activation of NF-κB. Both Elaidic acid and Linoelaidic acid are associated with increased superoxide production, whereas Transvaccenic acid (which did not induce inflammatory responses did not increase superoxide production. We observed differential activation of endothelial superoxide production, NF-κB activation, and reduction in NO production by different C18 isomers suggesting that the location and number of trans double bonds effect endothelial NF-κB activation.

  16. The effect of chronic nitric oxide inhibition on vascular reactivity and blood pressure in pregnant rats

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    Nilton Hideto Takiuti


    Full Text Available CONTEXT: The exact mechanism involved in changes in blood pressure and peripheral vascular resistance during pregnancy is unknown. OBJECTIVE:To evaluate the importance of endothelium-derivated relaxing factor (EDRF and its main component, nitric oxide, in blood pressure and vascular reactivity in pregnant rats. DESIGN: Clinical trial in experimentation animals. SETTING: University laboratory of Pharmacology. SAMPLE: Female Wistar rats with normal blood pressure, weight (152 to 227 grams and age (90 to 116 days. INTERVENTION: The rats were divided in to four groups: pregnant rats treated with L-NAME (13 rats; pregnant control rats (8 rats; virgin rats treated with L-NAME (10 rats; virgin control rats (12 rats. The vascular preparations and caudal blood pressure were obtained at the end of pregnancy, or after the administration of L-NAME in virgin rats. MAIN MEASUREMENTS: The caudal blood pressure and the vascular response to acetylcholine in pre-contracted aortic rings, both with and without endothelium, and the effect of nitric oxide inhibition, Nw-L-nitro-arginine methyl-ester (L-NAME, in pregnant and virgin rats. The L-NAME was administered in the drinking water over a 10-day period. RESULTS: The blood pressure decreased in pregnancy. Aortic rings of pregnant rats were more sensitive to acetylcholine than those of virgin rats. After L-NAME treatment, the blood pressure increased and relaxation was blocked in both groups. The fetal-placental unit weight of the L-NAME group was lower than that of the control group. CONCLUSION: Acetylcholine-induced vasorelaxation sensitivity was greater in pregnant rats and that blood pressure increased after L-NAME administration while the acetylcholine-induced vasorelaxation response was blocked.

  17. Inhaled nitric oxide prevents the increase in pulmonary vascular permeability caused by hydrogen peroxide. (United States)

    Poss, W B; Timmons, O D; Farrukh, I S; Hoidal, J R; Michael, J R


    Given the interest in using inhaled nitric oxide (NO.) to treat acute lung injury and the importance of oxygen radicals in its pathogenesis, we studied the effects, in buffer-perfused isolated rabbit lungs, of inhaled NO. (24 ppm) on the injury caused by generating hydrogen peroxide with glucose and glucose oxidase (GOX). Experiments were performed at a constant pulmonary arterial pressure. GOX substantially augmented vascular permeability, as demonstrated by an increase in the lung-to-perfusate 125I-labeled albumin ratio, lavage-to-perfusate 125I-albumin ratio, wet-to-dry lung weight ratio, and pulmonary vascular filtration coefficient. Lungs treated with inhaled NO. before perfusion with GOX had lung-to-perfusate and lavage-to-perfusate 125I-albumin ratios that were not significantly different from control values and intermediate between the control and GOX groups. Inhaled NO. also prevented the increase in wet-to-dry lung weight ratio and pulmonary vascular filtration coefficient caused by GOX.. Thus inhaled NO. substantially reduced in the isolated lung the increase in pulmonary vascular permeability produced by the intravascular generation of hydrogen peroxide.

  18. The role of nitric oxide in portal hypertensive systemic and portal vascular pathology. (United States)

    Hartleb, M; Michielsen, P P; Dziurkowska-Marek, A


    Hypotension, low systemic vascular resistance and reduced sensitivity to vasoconstrictor are features of hyperdynamic syndrome in portal hypertension (PH) and are pathogenetic factors triggering most serious clinical complications of liver cirrhosis. Nitric oxide (NO) is a powerful vasodilating agent, released from vascular endothelium cell and effecting relaxation of vascular smooth muscle. An increased release of NO has been proposed to play a role in the pathogenesis of vasodilation and vascular hypocontractility associated with PH. In agreement with this hypothesis, the whole-body production of NO has been found to be increased in PH, and the measurement of NOS mRNA expression in different organs suggest that the splanchnic vascular system is a major source of NO release. Consequently, NO could play a role in the development of the splanchnic hyperaemia, collateral circulation and portal hypertensive gastropathy. Furthermore, increased generation of NO in central circulation likely accounts for pulmonary vasorelaxation and cardiac dysfunction found in cirrhosis. By contrast, PH-associated endothelial dysfunction seems to invalidate the capability of intrahepatic and intrarenal vasculature to produce NO. A deficient NO release in these vascular territories might contribute to enhancement of PH and development of the hepatorenal syndrome. Overall NO hyperproduction is either the cause (induction of iNOS) or the consequence (stimulation of ecNOS) of the hyperdynamic syndrome. This incertitude results from the yet undefined significance of mild and transitory activation of the endotoxin-cytokines axis for iNOS induction and contradictory data on specific iNOS and ecNOS activities. A contribution of each isoform of NOS to pathogenesis of the hyperdynamic syndrome probably depends on the model of PH in animal studies and the aetiology or severity of cirrhosis in human studies.

  19. Endothelial nitric oxide synthase uncoupling: a novel pathway in OSA induced vascular endothelial dysfunction. (United States)

    Varadharaj, Saradhadevi; Porter, Kyle; Pleister, Adam; Wannemacher, Jacob; Sow, Angela; Jarjoura, David; Zweier, Jay L; Khayat, Rami N


    The mechanism of vascular endothelial dysfunction (VED) and cardiovascular disease in obstructive sleep apnea (OSA) is unknown. We performed a comprehensive evaluation of endothelial nitric oxide synthase (eNOS) function directly in the microcirculatory endothelial tissue of OSA patients who have very low cardiovascular risk status. Nineteen OSA patients underwent gluteal biopsies before, and after effective treatment of OSA. We measured superoxide (O2(•-)) and nitric oxide (NO) in the microcirculatory endothelium using confocal microscopy. We evaluated the effect of the NOS inhibitor l-Nitroarginine-Methyl-Ester (l-NAME) and the NOS cofactor tetrahydrobiopterin (BH4) on endothelial O2(•-) and NO in patient endothelial tissue before and after treatment. We found that eNOS is dysfunctional in OSA patients pre-treatment, and is a source of endothelial O2(•-) overproduction. eNOS dysfunction was reversible with the addition of BH4. These findings provide a new mechanism of endothelial dysfunction in OSA patients and a potentially targetable pathway for treatment of cardiovascular risk in OSA. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. De novo lipogenesis maintains vascular homeostasis through endothelial nitric-oxide synthase (eNOS) palmitoylation. (United States)

    Wei, Xiaochao; Schneider, Jochen G; Shenouda, Sherene M; Lee, Ada; Towler, Dwight A; Chakravarthy, Manu V; Vita, Joseph A; Semenkovich, Clay F


    Endothelial dysfunction leads to lethal vascular complications in diabetes and related metabolic disorders. Here, we demonstrate that de novo lipogenesis, an insulin-dependent process driven by the multifunctional enzyme fatty-acid synthase (FAS), maintains endothelial function by targeting endothelial nitric-oxide synthase (eNOS) to the plasma membrane. In mice with endothelial inactivation of FAS (FASTie mice), eNOS membrane content and activity were decreased. eNOS and FAS were physically associated; eNOS palmitoylation was decreased in FAS-deficient cells, and incorporation of labeled carbon into eNOS-associated palmitate was FAS-dependent. FASTie mice manifested a proinflammatory state reflected as increases in vascular permeability, endothelial inflammatory markers, leukocyte migration, and susceptibility to LPS-induced death that was reversed with an NO donor. FAS-deficient endothelial cells showed deficient migratory capacity, and angiogenesis was decreased in FASTie mice subjected to hindlimb ischemia. Insulin induced FAS in endothelial cells freshly isolated from humans, and eNOS palmitoylation was decreased in mice with insulin-deficient or insulin-resistant diabetes. Thus, disrupting eNOS bioavailability through impaired lipogenesis identifies a novel mechanism coordinating nutritional status and tissue repair that may contribute to diabetic vascular disease.

  1. Characterisation and vascular expression of nitric oxide synthase 3 in amphibians. (United States)

    Cameron, Melissa S; Trajanovska, Sofie; Forgan, Leonard G; Donald, John A


    In mammals, nitric oxide (NO) produced by nitric oxide synthase 3 (NOS3) localised in vascular endothelial cells is an important vasodilator but the presence of NOS3 in the endothelium of amphibians has been concluded to be absent, based on physiological studies. In this study, a nos3 cDNA was sequenced from the toad, Rhinella marina. The open reading frame of R. marina nos3 encoded an 1170 amino acid protein that showed 81 % sequence identity to the recently cloned Xenopus tropicalis nos3. Rhinella marina nos3 mRNA was expressed in a range of tissues and in the dorsal aorta and pulmonary, mesenteric, iliac and gastrocnemius arteries. Furthermore, nos3 mRNA was expressed in the aorta of Xenopus laevis and X. tropicalis. Quantitative real-time PCR showed that removal of the endothelium of the lateral aorta of R. marina significantly reduced the expression of nos3 mRNA compared to control aorta with the endothelium intact. However, in situ hybridisation was not able to detect any nos3 mRNA in the dorsal aorta of R. marina. Immunohistochemistry using a homologous R. marina NOS3 antibody showed immunoreactivity (IR) within the basal region of many endothelial cells of the dorsal aorta and iliac artery. NOS3-IR was also observed in the proximal tubules and collecting ducts of the kidney but not within the capillaries of the glomeruli. This is the first study to demonstrate that vascular endothelial cells of an amphibian express NOS3.

  2. Aspirin induces nitric oxide release from vascular endothelium: a novel mechanism of action. (United States)

    Taubert, D; Berkels, R; Grosser, N; Schröder, H; Gründemann, D; Schömig, E


    1. The study was designed to test the hypothesis that aspirin may stimulate nitric oxide (NO) release from vascular endothelium, a pivotal factor for maintenance of vascular homeostasis. 2. Clinical evidence suggests that low-dose aspirin may improve vascular endothelial function. Since other cyclooxygenase (COX) inhibitors showed no beneficial vascular effects, aspirin may exhibit a vasculoprotective, COX-independent mechanism. 3. Luminal NO release was monitored in real time on dissected porcine coronary arteries (PCA) by an amperometric, NO-selective sensor. Additionally, endothelial NO synthase (eNOS) activity was measured in EA.hy 926 cell homogenates by an l-[(3)H]citrulline/l-[(3)H]arginine conversion assay. Superoxide scavenging capacity was assessed by lucigenin-enhanced luminescence. 4. Aspirin induced an immediate concentration-dependent NO release from PCA with an EC(50) of 50 nm and potentiated the NO stimulation by the receptor-dependent agonist substance P. These effects were independent of an increase in intracellular calcium and could be mimicked by stimulation with acetylating aspirin derivatives. The aspirin metabolite salicylic acid or the reversible cyclooxygenase inhibitor indomethacin failed to modulate NO release. Incubation of soluble eNOS for 15 min with 100 microm aspirin or acetylating aspirin analogues increased the l-[(3)H]citrulline yield by 40-80%, while salicylic acid had no effect. Aspirin and salicylic acid showed a similar, but only modest, magnitude and velocity of superoxide scavenging. 5. Our findings demonstrate that therapeutically relevant concentrations of aspirin elicit NO release from vascular endothelium. This effect appears to be due to a direct acetylation of the eNOS protein, but is independent of COX inhibition or inhibition of superoxide-mediated NO degradation.

  3. Dependence of Golgi apparatus integrity on nitric oxide in vascular cells: implications in pulmonary arterial hypertension (United States)

    Lee, Jason E.; Patel, Kirit; Almodóvar, Sharilyn; Tuder, Rubin M.; Flores, Sonia C.


    Although reduced bioavailability of nitric oxide (NO) has been implicated in the pathogenesis of pulmonary arterial hypertension (PAH), its consequences on organellar structure and function within vascular cells is largely unexplored. We investigated the effect of reduced NO on the structure of the Golgi apparatus as assayed by giantin or GM130 immunofluorescence in human pulmonary arterial endothelial (HPAECs) and smooth muscle (HPASMCs) cells, bovine PAECs, and human EA.hy926 endothelial cells. Golgi structure was also investigated in cells in tissue sections of pulmonary vascular lesions in idiopathic PAH (IPAH) and in macaques infected with a chimeric simian immunodeficiency virus containing the human immunodeficiency virus (HIV)-nef gene (SHIV-nef) with subcellular three-dimensional (3D) immunoimaging. Compounds with NO scavenging activity including 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO), methylene blue, N-acetylcysteine, and hemoglobin markedly fragmented the Golgi in all cell types evaluated as did monocrotaline pyrrole, while LY-83583, sildenafil, fasudil, Y-27632, Tiron, Tempol, or H2O2 did not. Golgi fragmentation by NO scavengers was inhibited by diethylamine NONOate, was evident in HPAECs after selective knockdown of endothelial nitric oxide synthase using small interfering RNA (siRNA), was independent of microtubule organization, required the GTPase dynamin 2, and was accompanied by depletion of α-soluble N-ethylmaleimide-sensitive factor (NSF) acceptor protein (α-SNAP) from Golgi membranes and codispersal of the SNAP receptor (SNARE) Vti1a with giantin. Golgi fragmentation was confirmed in endothelial and smooth muscle cells in pulmonary arterial lesions in IPAH and the SHIV-nef-infected macaque with subcellular 3D immunoimaging. In SHIV-nef-infected macaques Golgi fragmentation was observed in cells containing HIV-nef-bearing endosomes. The observed Golgi fragmentation suggests that NO plays a significant role in

  4. Construction and biofunctional evaluation of electrospun vascular graft loaded with selenocystamine for in situ catalytic generation of nitric oxide

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    Chen, Siyuan; An, Jun; Weng, Lei [State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials for Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Li, Yandong [Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071 (China); Xu, Han; Wang, Yaping; Ding, Dan; Kong, Deling [State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials for Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Wang, Shufang, E-mail: [State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials for Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China)


    Construction and biofunctional evaluation of a novel vascular graft with in situ catalytic generation of nitric oxide were described in this paper. Poly α-lysine and poly (γ-glutamic acid) were deposited alternately onto the surface of an electrospun poly ε-caprolactone matrix via electrostatic layer-by-layer self-assembly, and then selenocystamine was loaded as a catalyst. Measurement of in vitro catalytic generation of nitric oxide demonstrated that this catalyst-loaded material could considerably accelerate the release of nitric oxide from S-nitrosoglutathione. A fibroblast proliferation assay showed that the material possessed satisfactory cellular compatibility. The catalyst-loaded material could inhibit the spread of smooth muscle cells in the presence of nitric oxide donors. In arteriovenous-shunt experiment, the catalyst-loaded graft exhibited good anti-thrombotic property where it could prevent acute thrombosis by decreasing the adhesion and activation of platelets and other blood cells. These data suggest a new method of building vascular grafts with improved hemocompatibility and biological functions. - Highlights: • A porous small-diameter vascular graft was prepared by electrospinning. • Selenocystamine was loaded for in situ catalytic and sustained NO generation. • There was a significant catalytic NO generation on the catalyst-loaded sample. • The spread of smooth muscle cells was inhibited on the catalyst-loaded sample. • The catalyst-loaded sample showed anti-thrombotic property in AV-shunt experiment.

  5. Nitric Oxide: The Wonder Molecule

    Indian Academy of Sciences (India)

    (heart attack) and hypertension. Nitric oxide (NO), an inorganic molecule formed by vascular endothelial cells is now thought to be a messenger molecule that is believed to playa crucial role in various biological processes of both physiological and pathological importance. Nitric oxide is a simple heterodiatomic molecule ...

  6. Nitric oxide and TNFα are critical regulators of reversible lymph node vascular remodeling and adaptive immune response.

    Directory of Open Access Journals (Sweden)

    Stephanie L Sellers

    Full Text Available Lymph node (LN vascular growth, at the level of the main arteriole, was recently characterized for the first time during infection. Arteriole diameter was shown to increase for at least seven days and to occur via a CD4(+ T cell dependent mechanism, with vascular expansion playing a critical role in regulating induction of adaptive immune response. Here, using intravital microscopy of the inguinal LN during herpes simplex type II (HSV-2 infection, the data provides the first studies that demonstrate arteriole expansion during infection is a reversible vascular event that occurs via eutrophic outward remodeling. Furthermore, using genetic ablation models, and pharmacological blockade, we reveal arteriole remodeling and LN hypertrophy to be dependent upon both endothelial nitric oxide synthase (eNOS and TNFα expression. Additionally, we reveal transient changes in nitric oxide (NO levels to be a notable feature of response to viral infection and LN vascular remodeling and provide evidence that mast cells are the critical source of TNFα required to drive arteriole remodeling. Overall, this study is the first to fully characterize LN arteriole vascular changes throughout the course of infection. It effectively reveals a novel role for NO and TNFα in LN cellularity and changes in LN vascularity, which represent key advances in understanding LN vascular physiology and adaptive immune response.

  7. Arginase Inhibitor 2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-Glucoside Activates Endothelial Nitric Oxide Synthase and Improves Vascular Function. (United States)

    Yi, Bonggu; Nguyen, Minh Cong; Won, Moo-Ho; Kim, Young Myeong; Ryoo, Sungwoo


    Endothelial arginase constrains the activity of endothelial nitric oxide synthase by reducing nitric oxide bioavailability, which contributes to vascular diseases. During screening, we identified a novel compound from the rhizome of Polygonum multiflorum (Polygonaceae), 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (THSG), which inhibited arginase activity. THSG exhibited noncompetitive inhibition of arginase II and inhibited both arginases I and II in a dose-dependent manner. THSG-dependent arginase inhibition reciprocally increased nitric oxide production and decreased reactive oxygen species generation in aortic endothelia. These effects were associated with increased dimerization of endothelial nitric oxide synthase without changes in the protein expression levels of arginase I, arginase II, or endothelial nitric oxide synthase. In vascular tension assays, when aortic vessels from wild-type mice are incubated with THSG, responses to the nitric oxide-dependent vasorelaxant acetylcholine were augmented, but responses to an nitric oxide donor, sodium nitroprusside, were not affected. On the other hand, phenylephrine-dependent vasoconstriction was significantly retarded in THSG-treated vessels. In a high-cholesterol diet-fed atherogenic model mice (ApoE-/-), THSG improved endothelial function by enhancement of the nitric oxide-cGMP pathway. Taken together, these results suggest that THSG may exert vasoprotective effects through augmentation of nitric oxide signaling by inhibiting arginase. Therefore, THSG may be useful in the treatment of vascular diseases that are derived from endothelial dysfunction, such as atherosclerosis. Georg Thieme Verlag KG Stuttgart · New York.

  8. Exhaled Nitric Oxide and Vascular Endothelial Growth Factor as Predictors of Cold Symptoms After Stress. (United States)

    Ritz, Thomas; Trueba, Ana F; Vogel, Pia D; Auchus, Richard J; Rosenfield, David


    Prior research has demonstrated that psychosocial stress is associated with respiratory infections. Immunologic, endocrine, and cardiovascular predictors of such infections have been explored with varying success. We therefore sought to study the unexplored role of airway mucosal immunity factors, nitric oxide (NO) and vascular endothelial growth factor (VEGF). NO is secreted by airway epithelial cells as part of the first line of defense against bacteria, viruses, and fungi. VEGF is expressed by mast cells in respiratory infections and recruits immune cells to infected sites, but in excess lead to vulnerability of the airway epithelium. In this proof-of-concept study we measured exhaled NO, exhaled breath condensate (EBC) VEGF, salivary VEGF, and salivary cortisol in 36 students undergoing final academic examinations at three occasions: a low-stress baseline during the term, an early phase of finals, and a late phase of finals. Participants also reported on cold symptoms at these time points and approximately 5 and 10days after their last academic examination. Higher baseline NO was associated with fewer cold symptoms after stress, whereas higher baseline VEGF in EBC and saliva were associated with more cold symptoms after stress. Perceived stress at baseline as well as salivary VEGF and cortisol late in the finals also contributed to the prediction of later cold symptoms. Basal levels of NO and VEGF may inform about mucosal immunocompetence and add to preventative treatments against airway infections from periods of stress in daily life. Copyright © 2017. Published by Elsevier B.V.

  9. Inhibition of nitric oxide synthases abrogates pregnancy-induced uterine vascular expansive remodeling. (United States)

    Osol, George; Barron, Carolyn; Gokina, Natalia; Mandala, Maurizio


    It was the aim of this study to test the hypothesis that hypertension and/or inhibition of nitric oxide (NO) synthases alters uterine vascular remodeling during pregnancy. Using a model of hypertension (NO synthase inhibition with L-NAME) in nonpregnant and pregnant rats, comparisons were made with age-matched controls, as well as with animals receiving hydralazine along with L-NAME to maintain normotension in the presence of NO synthase inhibition. Circumferential and axial remodeling of large (main uterine, MUA) and small (premyometrial radial) arteries were quantified and compared. L-NAME treatment prevented expansive circumferential remodeling of the MUA; cotreatment with hydralazine was without effect. Circumferential remodeling of smaller premyometrial radial arteries was also significantly attenuated in hypertensive pregnant animals, while premyometrial radial arteries from rats receiving hydralazine with L-NAME were of intermediate diameter. Neither hypertension nor NO synthase inhibition had any effect on the substantial (200-300%) axial growth of MUA or premyometrial radial arteries. NO plays a major role in facilitating pregnancy-induced expansive remodeling in the uterine circulation, particularly in larger arteries. Some beneficial effects of hydralazine on expansive circumferential remodeling were noted in smaller radial vessels, and these may be linked to its prevention of systemic hypertension and/or to local effects on the arterial wall. Neither NO synthase inhibition nor hypertension had any effect on arterial longitudinal growth.

  10. Critical role of exogenous nitric oxide in ROCK activity in vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Tatsuya Maruhashi

    Full Text Available Rho-associated kinase (ROCK signaling pathway has been shown to mediate various cellular functions including cell proliferation, migration, adhesion, apoptosis, and contraction, all of which may be involved in pathogenesis of atherosclerosis. Endogenous nitric oxide (NO is well known to have an anti-atherosclerotic effect, whereas the exogenous NO-mediated cardiovascular effect still remains controversial. The purpose of this study was to evaluate the effect of exogenous NO on ROCK activity in vascular smooth muscle cells (VSMCs in vitro and in vivo.VSMCs migration was evaluated using a modified Boyden chamber assay. ROCK activities were measured by Western blot analysis in murine and human VSMCs and aorta of mice treated with or without angiotensin II (Ang II and/or sodium nitroprusside (SNP, an NO donor.Co-treatment with SNP inhibited the Ang II-induced cell migration and increases in ROCK activity in murine and human VSMCs. Similarly, the increased ROCK activity 2 weeks after Ang II infusion in the mouse aorta was substantially inhibited by subcutaneous injection of SNP.These findings suggest that administration of exogenous NO can inhibit ROCK activity in VSMCs in vitro and in vivo.

  11. Role of folic acid in nitric oxide bioavailability and vascular endothelial function. (United States)

    Stanhewicz, Anna E; Kenney, W Larry


    Folic acid is a member of the B-vitamin family and is essential for amino acid metabolism. Adequate intake of folic acid is vital for metabolism, cellular homeostasis, and DNA synthesis. Since the initial discovery of folic acid in the 1940s, folate deficiency has been implicated in numerous disease states, primarily those associated with neural tube defects in utero and neurological degeneration later in life. However, in the past decade, epidemiological studies have identified an inverse relation between both folic acid intake and blood folate concentration and cardiovascular health. This association inspired a number of clinical studies that suggested that folic acid supplementation could reverse endothelial dysfunction in patients with cardiovascular disease (CVD). Recently, in vitro and in vivo studies have begun to elucidate the mechanism(s) through which folic acid improves vascular endothelial function. These studies, which are the focus of this review, suggest that folic acid and its active metabolite 5-methyl tetrahydrofolate improve nitric oxide (NO) bioavailability by increasing endothelial NO synthase coupling and NO production as well as by directly scavenging superoxide radicals. By improving NO bioavailability, folic acid may protect or improve endothelial function, thereby preventing or reversing the progression of CVD in those with overt disease or elevated CVD risk. © The Author(s) 2016. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail:

  12. Passive leg movement and nitric oxide-mediated vascular function: the impact of age. (United States)

    Trinity, Joel D; Groot, H Jonathan; Layec, Gwenael; Rossman, Matthew J; Ives, Stephen J; Morgan, David E; Gmelch, Ben S; Bledsoe, Amber; Richardson, Russell S


    In young healthy men, passive leg movement (PLM) elicits a robust nitric oxide (NO)-dependent increase in leg blood flow (LBF), thus providing a novel approach to assess NO-mediated vascular function. While the magnitude of the LBF response to PLM is markedly reduced with age, the role of NO in this attenuated response in the elderly is unknown. Therefore, this study sought to determine the contribution of NO in the PLM-induced LBF with age. Fourteen male subjects (7 young, 24 ± 1 yr; and 7 old, 75 ± 3 yr) underwent PLM with and without NO synthase (NOS) inhibition achieved by intra-arterial infusion of N(G)-monomethyl-L-arginine (L-NMMA). LBF was determined second-by-second by Doppler ultrasound, and central hemodynamics were measured by finger photoplethysmography. NOS inhibition blunted the PLM-induced peak increase in LBF in the young (control: 668 ± 106; 431 ± 95 Δml/min; P = 0.03) but had no effect in the old (control: 266 ± 98; 251 ± 92 Δml/min; P = 0.59). Likewise, the magnitude of the reduction in the overall (i.e., area under the curve) PLM-induced LBF response to NOS inhibition was less in the old (LBF: -31 ± 18 ml) than the young (LBF: -129 ± 21 ml; P PLM-induced LBF in the elderly is primarily due to a reduced contribution to vasodilation from NO and therefore support the use of PLM as a novel approach to assess NO-mediated vascular function across the lifespan.

  13. Slow and sustained nitric oxide releasing compounds inhibit multipotent vascular stem cell proliferation and differentiation without causing cell death

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Brandon M.; Leix, Kyle Alexander [Department of Chemistry, Central Michigan University, Mount Pleasant, MI 48859 (United States); Ji, Yajing [Department of Biomedical Science and Medicine, Michigan State University, East Lansing, MI 48824 (United States); Glaves, Richard Samuel Elliot [Department of Biology, Central Michigan University, Mount Pleasant, MI 48859 (United States); Ash, David E. [Department of Chemistry, Central Michigan University, Mount Pleasant, MI 48859 (United States); Mohanty, Dillip K., E-mail: [Department of Chemistry, Central Michigan University, Mount Pleasant, MI 48859 (United States)


    Highlights: • Multipotent vascular stem cells (MVSCs) proliferate and differentiate. • Nitric oxide inhibits proliferation of MVSCs. • Nitric oxide inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs). • Smooth muscle cells (SMCs) neither de-differentiate nor proliferate. - Abstract: Atherosclerosis is the leading cause of cerebral and myocardial infarction. It is believed that neointimal growth common in the later stages of atherosclerosis is a result of vascular smooth muscle cell (SMC) de-differentiation in response to endothelial injury. However, the claims of the SMC de-differentiation theory have not been substantiated by monitoring the fate of mature SMCs in response to such injuries. A recent study suggests that atherosclerosis is a consequence of multipotent vascular stem cell (MVSC) differentiation. Nitric oxide (NO) is a well-known mediator against atherosclerosis, in part because of its inhibitory effect on SMC proliferation. Using three different NO-donors, we have investigated the effects of NO on MVSC proliferation. Results indicate that NO inhibits MVSC proliferation in a concentration dependent manner. A slow and sustained delivery of NO proved to inhibit proliferation without causing cell death. On the other hand, larger, single-burst NO concentrations, inhibits proliferation, with concurrent significant cell death. Furthermore, our results indicate that endogenously produced NO inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs) and subsequently to SMC as well.

  14. Vascular gene transfer of the human inducible nitric oxide synthase: characterization of activity and effects on myointimal hyperplasia.


    E.; Tzeng; Shears, L. L.; Robbins, P. D.; Pitt, B.R.; Geller, D. A.; Watkins, S C; Simmons, R.L.; Billiar, T R


    BACKGROUND: Nitric oxide (NO) has been shown to decrease myointimal hyperplasia in injured blood vessels. We hypothesize inducible No synthase (iNOS) gene transfer even at low efficiency will provide adequate local no production to achieve this goal. MATERIALS AND METHODS: A retroviral vector containing the human iNOS cDNA (DFGiNOS) was used to transfer the iNOS gene into vascular cells and isolated blood vessels to answer the following questions: can vascular endothelial and smooth muscle ce...

  15. Vascular endothelial growth factor and nitric oxide synthase expression in human tooth germ development. (United States)

    Mastrangelo, F; Sberna, M T; Tettamanti, L; Cantatore, G; Tagliabue, A; Gherlone, E


    Vascular Endothelia Growth Factor (VEGF) and Nitric Oxide Synthase (NOS) expression, were evaluated in human tooth germs at two different stages of embryogenesis, to clarify the role of angiogenesis during tooth tissue differentiation and growth. Seventy-two third molar germ specimens were selected during oral surgery. Thirty-six were in the early stage and 36 in the later stage of tooth development. The samples were evaluated with Semi-quantitative Reverse Transcription-Polymerase chain Reaction analyses (RT-PcR), Western blot analysis (WB) and immunohistochemical analysis. Western blot and immunohistochemical analysis showed a VEGF and NOS 1-2-3 positive reaction in all samples analysed. VEGF high positive decrease reaction was observed in stellate reticulum cells, ameloblast and odontoblast clusters in early stage compared to later stage of tooth germ development. Comparable VEGF expression was observed in endothelial cells of early and advanced stage growth. NOS1 and NOS3 expressions showed a high increased value in stellate reticulum cells, and ameloblast and odontoblast clusters in advanced stage compared to early stage of development. The absence or only moderate positive reaction of NOS2 was detected in all the different tissues. Positive NOS2 expression showed in advanced stage of tissue development compared to early stage. The action of VEGF and NOS molecules are important mediators of angiogenesis during dental tissue development. VEGF high positive expression in stellate reticulum cells in the early stage of tooth development compared to the later stage and the other cell types, suggests a critical role of the stellate reticulum during dental embryo-morphogenesis.

  16. Oxidant-redox regulation of pulmonary vascular responses to hypoxia and nitric oxide-cGMP signaling. (United States)

    Wolin, Michael S; Gupte, Sachin A; Neo, Boon Hwa; Gao, Qun; Ahmad, Mansoor


    Most current theories for the mechanism of hypoxic pulmonary vasoconstriction (HPV) include a role for reactive oxygen species and/or changes in redox regulation, but extreme controversy exists regarding which systems and redox changes mediate the HPV response. Nitric oxide (NO) appears to help to maintain low pulmonary arterial pressure, suppress HPV, and prevent the development of pulmonary hypertension. Our studies have found a key role for glucose-6-phosphate dehydrogenase in bovine pulmonary arterial smooth muscle functioning to maintain elevated levels of cytosolic NADPH which fuels the generation of vasodilator levels of hydrogen peroxide. HPV results from hypoxia removing vasodilation by peroxide. Decreased superoxide generation by Nox4 oxidase and its conversion to peroxide by Cu,Zn-SOD appear to be potential factors in sensing hypoxia, and decreased cGMP-associated vasodilation and removal of redox controlled vasodilator mechanisms by increased cytosolic NADPH may be key coordinators of the HPV response. Oxidant generation associated with vascular disease processes, including the removal of NO by superoxide, and attenuation of its ability to stimulate cGMP production by oxidation of the heme and thiols of soluble guanylate cyclase attenuate potential beneficial actions of NO on pulmonary arterial function. While pulmonary hypertension appears to have multiple poorly understood effects on redox-associated processes, potentially influencing responses to hypoxia and NO-cGMP signaling, much remains to be elucidated regarding how these processes may be important factors in the progression, expression and therapeutic treatment of pulmonary hypertension.

  17. Protective role of endothelial nitric oxide synthase

    NARCIS (Netherlands)

    Albrecht, Ester W J A; Stegeman, Coen A; Heeringa, Peter; Henning, Robert; van Goor, Harry

    Nitric oxide is a versatile molecule, with its actions ranging from haemodynamic regulation to anti-proliferative effects on vascular smooth muscle cells. Nitric oxide is produced by the nitric oxide synthases, endothelial NOS (eNOS), neural NOS (nNOS), and inducible NOS (iNOS). Constitutively

  18. Nitric oxide supersensitivity

    DEFF Research Database (Denmark)

    Olesen, J; Iversen, Helle Klingenberg; Thomsen, L L


    Nitroglycerin, which may be regarded as a prodrug for nitric oxide, induces a mild to moderate headache in healthy subjects. In order to study whether migraine patients are more sensitive to nitric oxide than non-migrainous subjects, four different doses of intravenous nitroglycerin were given...... previously shown a similar supersensitivity to histamine which in human cerebral arteries activates endothelial H1 receptors and causes endothelial production of nitric oxide. Migraine patients are thus supersensitive to exogenous nitric oxide from nitroglycerin as well as to endothelially produced nitric...... oxide. It is suggested that nitric oxide may be partially or completely responsible for migraine pain....

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

    Directory of Open Access Journals (Sweden)

    Thiago Bruder-Nascimento


    Full Text Available 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.

  20. Influence of cholesterol and fish oil dietary intake on nitric oxide-induced apoptosis in vascular smooth muscle cells. (United States)

    Perales, Sonia; Alejandre, Ma José; Palomino-Morales, Rogelio; Torres, Carolina; Linares, Ana


    Apoptosis of vascular smooth muscle cells (SMC) is critically involved in the progression of atherosclerosis. We previously reported that dietary cholesterol intake induces changes in SMC at molecular and gene expression levels. The objectives of the present study were to investigate the differential response to nitric oxide of vascular SMC obtained from chicks after cholesterol and fish oil dietary intake and to examine effects on the main pro-apoptotic and anti-apoptotic genes. Dietary cholesterol intake reduced the Bcl-2/Bax (anti-apoptotic/pro-apoptotic) protein ratio in SMC, making them more susceptible to apoptosis. When cholesterol was withdrawn and replaced with a fish oil-enriched diet, the Bcl-xl/Bax protein ratio significantly increased, reversing the changes induced by cholesterol. The decrease in c-myc gene expression after apoptotic stimuli and the increase in Bcl-xl/Bax ratio indicate that fish oil has a protective role against apoptosis in SMC. Nitroprussiate-like nitric oxide donors exerted an intensive action on vascular SMC cultures. However, SMC-C (isolated from animals fed with control diet) and SMC-Ch (isolated from animals fed with cholesterol-enriched diet) responded differently to nitric oxide, especially in their bcl-2 and bcl-xl gene expression. SMC isolated from animals fed with cholesterol-enriched and then fish oil-enriched diet (SMC-Ch-FO cultures) showed an intermediate apoptosis level (Bcl-2/Bax ratio) between SMC-C and SMC-Ch, induction of c-myc expression and elevated p53 expression. These findings indicate that fish oil protects SMC against apoptosis. Copyright 2009 Elsevier Inc. All rights reserved.

  1. Anti-Vascular Endothelial Growth Factors Protect Retinal Pigment Epithelium Cells Against Oxidation by Modulating Nitric Oxide Release and Autophagy

    Directory of Open Access Journals (Sweden)

    Stefano De Cillà


    Full Text Available Background/Aims: the anti-vascular endothelial growth factors (VEGF, Aflibercept and Ranibizumab, are used for the treatment of macular degeneration. Here we examined the involvement of nitric oxide (NO, mitochondria function and of apoptosis/autophagy in their antioxidant effects in human retinal pigment epithelium cells (RPE. Methods: RPE were exposed to Ranibizumab/Aflibercept in the absence or presence of NO synthase (NOS inhibitor and of autophagy activator/blocker, rapamicyn/3-methyladenine. Specific kits were used for cell viability, NO and reactive oxygen species detection and mitochondrial membrane potential measurement, whereas Western Blot was performed for apoptosis/ autophagy markers and other kinases detection. Results: In RPE cultured in physiological conditions, Aflibercept/Ranibizumab increased NO release in a dose and time-dependent way. Opposite results were obtained in RPE pretreated with hydrogen peroxide. Moreover, both the anti-VEGF agents were able to prevent the fall of cell viability and of mitochondrial membrane potential. Those effects were reduced by the NOS inhibitor and 3-methyladenine and were potentiated by rapamycin. Finally, Aflibercept and Ranibizumab counteracted the changes of apoptosis/autophagy markers, NOS, Phosphatidylinositol-3-Kinase/Protein Kinase B and Extracellular signal–regulated kinases 1/2 caused by peroxidation. Conclusion: Aflibercept and Ranibizumab protect RPE against peroxidation through the modulation of NO release, apoptosis and autophagy.

  2. Arginase inhibition reduces interleukin-1β-stimulated vascular smooth muscle cell proliferation by increasing nitric oxide synthase-dependent nitric oxide production

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeongyeon; Ryoo, Sungwoo, E-mail:


    Highlights: •Arginase inhibition suppressed proliferation of IL-1β-stimulated VSMCs in dose-dependent manner. •NO production from IL-1β-induced iNOS expression was augmented by arginase inhibition, reducing VSMC proliferation. •Incubation with cGMP analogues abolished IL-1β-dependent proliferation of VSMCs. -- Abstract: We investigated whether arginase inhibition suppressed interleukin (IL)-1β-stimulated proliferation in vascular smooth muscle cells (VSMCs) and the possible mechanisms involved. IL-1β stimulation increased VSMC proliferation, while the arginase inhibitor BEC and transfection of the antisense (AS) oligonucleotide against arginase I decreased VSMC proliferation and was associated with increased protein content of the cell cycle regulator p21Waf1/Cip1. IL-1β incubation induced inducible nitric oxide synthase (iNOS) mRNA expression and protein levels in a dose-dependent manner, but did not affect arginase I and II expression. Consistent with this data, IL-1β stimulation resulted in increase in NO production that was significantly augmented by arginase inhibition. The specific iNOS inhibitor 1400W abolished IL-1β-mediated NO production and further accentuated IL-1β-stimulated cell proliferation. Incubation with NO donors GSNO and DETA/NO in the presence of IL-1β abolished VSMCs proliferation and increased p21Waf1/Cip1 protein content. Furthermore, incubation with the cGMP analogue 8-Br-cGMP prevented IL-1β-induced VSMCs proliferation. In conclusion, arginase inhibition augmented iNOS-dependent NO production that resulted in suppression of IL-1β-induced VSMCs proliferation in a cGMP-dependent manner.

  3. iNOS-Derived Nitric Oxide Induces Integrin-Linked Kinase Endocytic Lysosome-Mediated Degradation in the Vascular Endothelium. (United States)

    Reventun, Paula; Alique, Matilde; Cuadrado, Irene; Márquez, Susana; Toro, Rocío; Zaragoza, Carlos; Saura, Marta


    ILK (integrin-linked kinase) plays a key role in controlling vasomotor tone and is decreased in atherosclerosis. The objective of this study is to test whether nitric oxide (NO) regulates ILK in vascular remodeling. We found a striking correlation between increased levels of inducible nitric oxide and decreased ILK levels in human atherosclerosis and in a mouse model of vascular remodeling (carotid artery ligation) comparing with iNOS (inducible NO synthase) knockout mice. iNOS induction produced the same result in mouse aortic endothelial cells, and these effects were mimicked by an NO donor in a time-dependent manner. We found that NO decreased ILK protein stability by promoting the dissociation of the complex ILK/Hsp90 (heat shock protein 90)/eNOS (endothelial NO synthase), leading to eNOS uncoupling. NO also destabilized ILK signaling platform and lead to decreased levels of paxillin and α-parvin. ILK phosphorylation of its downstream target GSK3-β (glycogen synthase kinase 3 beta) was decreased by NO. Mechanistically, NO increased ILK ubiquitination mediated by the E3 ubiquitin ligase CHIP (C terminus of HSC70-interacting protein), but ILK ubiquitination was not followed by proteasome degradation. Alternatively, NO drove ILK to degradation through the endocytic-lysosomal pathway. ILK colocalized with the lysosome marker LAMP-1 (lysosomal-associated membrane protein 1) in endothelial cells, and inhibition of lysosome activity with chloroquine reversed the effect of NO. Likewise, ILK colocalized with the early endosome marker EEA1 (early endosome antigen 1). ILK endocytosis proceeded via dynamin because a specific inhibitor of dynamin (Dyngo 4a) was able to reverse ILK endocytosis and its lysosome degradation. Endocytosis regulates ILK signaling in vascular remodeling where there is an overload of inducible NO, and thus its inhibition may represent a novel target to fight atherosclerotic disease. © 2017 American Heart Association, Inc.

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

    Higashi, Yukihito


    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

  5. Enterosalivary nitrate metabolism and the microbiome: Intersection of microbial metabolism, nitric oxide and diet in cardiac and pulmonary vascular health. (United States)

    Koch, Carl D; Gladwin, Mark T; Freeman, Bruce A; Lundberg, Jon O; Weitzberg, Eddie; Morris, Alison


    Recent insights into the bioactivation and signaling actions of inorganic, dietary nitrate and nitrite now suggest a critical role for the microbiome in the development of cardiac and pulmonary vascular diseases. Once thought to be the inert, end-products of endothelial-derived nitric oxide (NO) heme-oxidation, nitrate and nitrite are now considered major sources of exogenous NO that exhibit enhanced vasoactive signaling activity under conditions of hypoxia and stress. The bioavailability of nitrate and nitrite depend on the enzymatic reduction of nitrate to nitrite by a unique set of bacterial nitrate reductase enzymes possessed by specific bacterial populations in the mammalian mouth and gut. The pathogenesis of pulmonary hypertension (PH), obesity, hypertension and CVD are linked to defects in NO signaling, suggesting a role for commensal oral bacteria to shape the development of PH through the formation of nitrite, NO and other bioactive nitrogen oxides. Oral supplementation with inorganic nitrate or nitrate-containing foods exert pleiotropic, beneficial vascular effects in the setting of inflammation, endothelial dysfunction, ischemia-reperfusion injury and in pre-clinical models of PH, while traditional high-nitrate dietary patterns are associated with beneficial outcomes in hypertension, obesity and CVD. These observations highlight the potential of the microbiome in the development of novel nitrate- and nitrite-based therapeutics for PH, CVD and their risk factors. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Phenotype commitment in vascular smooth muscle cells derived from coronary atherosclerotic plaques: differential gene expression of endothelial Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    ML Rossi


    Full Text Available Unstable angina and myocardial infarction are the clinical manifestations of the abrupt thrombotic occlusion of an epicardial coronary artery as a result of spontaneous atherosclerotic plaque rupture or fissuring, and the exposure of highly thrombogenic material to blood. It has been demonstrated that the proliferation of vascular smooth muscle cells (VSMCs and impaired bioavailabilty of nitric oxide (NO are among the most important mechanisms involved in the progression of atherosclerosis. It has also been suggested that a NO imbalance in coronary arteries may be involved in myocardial ischemia as a result of vasomotor dysfunction triggering plaque rupture and the thrombotic response. We used 5’ nuclease assays (TaqMan™ PCRs to study gene expression in coronary plaques collected by means of therapeutic directional coronary atherectomy from 15 patients with stable angina (SA and 15 with acute coronary syndromes (ACS without ST elevation. Total RNA was extracted from the 30 plaques and the cDNA was amplified in order to determine endothelial nitric oxide synthase (eNOS gene expression. Analysis of the results showed that the expression of eNOS was significantly higher (p<0.001 in the plaques from the ACS patients. Furthermore, isolated VSMCs from ACS and SA plaques confirmed the above pattern even after 25 plating passages. In situ RT-PCR was also carried out to co-localize the eNOS messengers and the VSMC phenotype.

  7. Genetic Deletion of ACE2 Induces Vascular Dysfunction in C57BL/6 Mice: Role of Nitric Oxide Imbalance and Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Luiza A Rabelo

    Full Text Available Accumulating evidence indicates that angiotensin-converting enzyme 2 (ACE2 plays a critical role in cardiovascular homeostasis, and its altered expression is associated with major cardiac and vascular disorders. The aim of this study was to evaluate the regulation of vascular function and assess the vascular redox balance in ACE2-deficient (ACE2-/y animals. Experiments were performed in 20-22 week-old C57BL/6 and ACE2-/y male mice. Evaluation of endothelium-dependent and -independent relaxation revealed an impairment of in vitro and in vivo vascular function in ACE2-/y mice. Drastic reduction in eNOS expression at both protein and mRNA levels, and a decrease in •NO concentrations were observed in aortas of ACE2-/y mice in comparison to controls. Consistently, these mice presented a lower plasma and urine nitrite concentration, confirming reduced •NO availability in ACE2-deficient animals. Lipid peroxidation was significantly increased and superoxide dismutase activity was decreased in aorta homogenates of ACE2-/y mice, indicating impaired antioxidant capacity. Taken together, our data indicate, that ACE2 regulates vascular function by modulating nitric oxide release and oxidative stress. In conclusion, we elucidate mechanisms by which ACE2 is involved in the maintenance of vascular homeostasis. Furthermore, these findings provide insights into the role of the renin-angiotensin system in both vascular and systemic redox balance.

  8. Nitric oxide: an overview. (United States)

    Rodeberg, D A; Chaet, M S; Bass, R C; Arkovitz, M S; Garcia, V F


    Nitric oxide (NO), a paracrine-acting gas enzymatically synthesized from L-arginine, is a unique biologic mediator that has been implicated in a myriad of physiologic and pathophysiologic states. It is an important regulator of vascular tone and may be the mediator of the hemodynamic changes involved in sepsis and cirrhosis. In addition, there is increasing evidence that NO is involved in coagulation, immune function, inhibitory innervation of the gastrointestinal tract, protection of gastrointestinal mucosa, and the hepatotoxicity of cirrhosis. It has already been speculated that NO may represent a point of control or intervention in a number of disease states. The purpose of this paper is to provide the surgeon with a broad overview of the scientific and clinical aspects of this important molecule.

  9. ORIGINAL ARTICLE Relationship between endothelial nitric oxide ...

    African Journals Online (AJOL)


    Introduction: Endothelial nitric oxide synthase (eNOS), the enzyme in charge of nitric oxide production, plays a crucial role in vascular biology. However, the impact of single nucleotide polymorphisms (SNPs) affecting the gene encoding for eNOS (eNOS) on coronary artery diseases remains under debate and no data were ...

  10. Inducible nitric oxide synthase in renal transplantation

    NARCIS (Netherlands)

    Joles, JA; Vos, IH; Grone, HJ; Rabelink, TJ

    The importance of the endothelial isoform of nitric oxide synthase (eNOS) has been well established. Endothelium-derived nitric oxide has been shown to be essential for vascular homeostasis and modulation of eNOS has thus become a target in prevention of cardiovascular disease. The role of the

  11. Relationship between endothelial nitric oxide synthase gene ...

    African Journals Online (AJOL)

    Introduction: Endothelial nitric oxide synthase (eNOS), the enzyme in charge of nitric oxide production, plays a crucial role in vascular biology. However, the impact of single nucleotide polymorphisms (SNPs) affecting the gene encoding for eNOS (eNOS) on coronary artery diseases remains under debate and no data were ...

  12. Protective vascular effects of quercitrin in acute TNBS-colitis in rats: the role of nitric oxide. (United States)

    Romero, Miguel; Vera, Beatriz; Galisteo, Milagros; Toral, Marta; Gálvez, Julio; Perez-Vizcaino, Francisco; Duarte, Juan


    Quercitrin (quercetin 3-rhamnoside) is a bioflavonoid with anti-inflammatory activity in experimental colitis. Several studies have suggested that vascular injury might be a primary process in Crohn's disease, but there is no information about the function of the mesenteric bed in the experimental models of colitis. The aims of this study were to analyse whether the reactivity to vasoconstrictor agents is altered in the mesenteric vascular bed from animals with colitis induced by administration of trinitrobenzenesulfonic acid (TNBS) in the early stages of this pathology, and to determine the effects of quercitrin on such vascular alterations. Contraction of mesenteric beds produced by vasoconstrictor agents such as noradrenaline and KCl is reduced in rats in the early stages of experimental TNBS-induced colitis. This alteration was partially reverted by non-selective nitric oxide synthase (NOS) inhibition with N-nitro-l-arginine methylester, and enhanced by non-selective cyclooxygenase (COX) inhibition with indomethacin. However, the endothelium-dependent relaxant responses to acetylcholine were not significantly altered. iNOS, COX-2, NOX-1, tumor necrosis factor α (TNFα) and interleukin 1β (IL1β) expressions were higher in the mesenteric arteries from TNBS-treated rats, without changes in both eNOS expression and eNOS-Ser1177 phosphorylation. The in vivo pre-treatment with 5 mg kg-1 of the flavonoid quercitrin reverts both the early hyporesponse of mesenteric arteries to noradrenaline and the up-regulation of iNOS, COX2, NOX1, TNFα and IL1β in colitic rats. In conclusion, quercitrin improves the impaired mesenteric vascular reactivity in the acute phase of this colitis model, at least in part by reducing NO overproduction from iNOS.

  13. Endothelial Nitric Oxide Synthase-Induced Hypertrophy and Vascular Dysfunction Contribute to the Left Ventricular Dysfunction in Caveolin-1-/- Mice. (United States)

    Ebner, Annette; Kuerbis, Nadine; Brandt, Aljoscha; Zatschler, Birgit; Weinert, Sönke; Poitz, David M; Ebner, Bernd; Augstein, Antje; Wunderlich, Carsten; El-Armouche, Ali; Strasser, Ruth H


    Caveolin-1 (Cav1)-/- mice display impaired development of left ventricular pressure and increased left ventricular wall thickness but no dilated ventricle; these are typical findings in patients with heart failure with preserved ejection fraction (HfpEF). Aiming to clarify if dysfunctional endothelial nitric oxide synthase (eNOS) influences cardiomyocyte contractility, cardiac conduction system, or afterload/vascular resistance, we studied Cav1-/-/eNOS-/- mice. Cardiac function was assessed in vivo by pressure-volume-catheterization of the left ventricle, echocardiography and electrocardiography. In addition, isolated tissue experiments were performed to evaluate cardiomyocyte contractility (atria) and vessel morphology and function (aorta). Histology, immunoblotting and quantitative polymerase chain reaction were applied to characterise radical formation and oxidative stress in the heart. Cardiac hypertrophy was completely reversed in Cav1-/-/eNOS-/- mice. The impaired pump function in Cav1-/- mice was significantly improved in Cav1-/-/eNOS-/- mice, but no complete alignment with eNOS-/- controls was achieved, indicating an additional eNOS-independent mechanism contributing to HFpEF in Cav1-/- mice. It is unlikely that frequently occurring arrhythmias contributed to HFpEF in Cav1-/- mice. In contrast, numerous eNOS-dependent and eNOS-independent vascular abnomalities could explain the cardiac phenotypes of Cav1-/- mice. Synergistic effects between eNOS-related cardiac hypertrophy and vascular hypercontractility appear to underlie the left ventricular dysfunction in Cav1-/-mice. These findings provide insights relevant to the poorly understood pathophysiology of HFpEF. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  14. Role of Nitric Oxide Isoforms in Vascular and Alveolar Development and Lung Injury in Vascular Endothelial Growth Factor Overexpressing Neonatal Mice Lungs.

    Directory of Open Access Journals (Sweden)

    Mansoor A Syed

    Full Text Available The role of vascular endothelial growth factor (VEGF-induced 3 different nitric oxide synthase (NOS isoforms in lung development and injury in the newborn (NB lung are not known. We hypothesized that VEGF-induced specific NOS pathways are critical regulators of lung development and injury.We studied NB wild type (WT, lung epithelial cell-targeted VEGF165 doxycycline-inducible overexpressing transgenic (VEGFTG, VEGFTG treated with a NOS1 inhibitor (L-NIO, VEGFTG x NOS2-/- and VEGFTG x NOS3+/- mice in room air (RA for 7 postnatal (PN days. Lung morphometry (chord length, vascular markers (Ang1, Ang2, Notch2, vWF, CD31 and VE-cadherin, cell proliferation (Ki67, vascular permeability, injury and oxidative stress markers (hemosiderin, nitrotyrosine and 8-OHdG were evaluated.VEGF overexpression in RA led to increased chord length and vascular markers at PN7, which were significantly decreased to control values in VEGFTG x NOS2-/- and VEGFTG x NOS3+/- lungs. However, we found no noticeable effect on chord length and vascular markers in the VEGFTG / NOS1 inhibited group. In the NB VEGFTG mouse model, we found VEGF-induced vascular permeability in the NB murine lung was partially dependent on NOS2 and NOS3-signaling pathways. In addition, the inhibition of NOS2 and NOS3 resulted in a significant decrease in VEGF-induced hemosiderin, nitrotyrosine- and 8-OHdG positive cells at PN7. NOS1 inhibition had no significant effect.Our data showed that the complete absence of NOS2 and partial deficiency of NOS3 confers protection against VEGF-induced pathologic lung vascular and alveolar developmental changes, as well as injury markers. Inhibition of NOS1 does not have any modulating role on VEGF-induced changes in the NB lung. Overall, our data suggests that there is a significant differential regulation in the NOS-mediated effects of VEGF overexpression in the developing mouse lung.

  15. Effects of Chinese yellow wine on nitric oxide synthase and intercellular adhesion molecule-1 expressions in rat vascular endothelial cells. (United States)

    Zhao, Fei; Ji, Zheng; Chi, Jufang; Tang, Weiliang; Zhai, Xiaoya; Meng, Liping; Guo, Hangyuan


    The objective of this study was to determine similarities in the effect of yellow wine as compared to statin and the possibility that yellow wine inhibits tumour necrosis factor-α (TNF-α)-induced nitric oxide (NO) synthesis, endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and intercellular adhesion molecule-1 (ICAM-1) in cultured rat vascular endothelial cells (VECs). We isolated VECs, and cultivated and purified Sprague Dawley (SD) rat thoracic aortas in vitro. We selected the optimal wine concentration using clonogenic and MTT assays to measure cell survival. Next, we divided the cells into 9 groups: (1) control, (2) TNF-α, (3) TNF-α + rosuvastatin (10 μmol/L), (4) TNF-α + ethanol 0.5%, (5) TNF-α + yellow wine 0.5%, (6) TNF-α + ethanol 1.0%, (7) TNF-α + yellow wine 1.0%, (8) TNF-α + ethanol 1.5%, and (9) TNF-α + yellow wine 1.5% and they were given the corresponding treatment for 24 h. We determined NO production with nitrate reductase. We then measured eNOS activity, and detected eNOS, iNOS, and ICAM-1 protein levels by Western blotting. Compared with the TNF-α group, NO production, eNOS activity, and eNOS protein expression in the rosuvastatin, and yellow wine 1.0%, and 1.5% groups were significantly increased. Protein expression of iNOS and ICAM-1 in the rosuvastatin, yellow wine 1.0%, and 1.5% groups were significantly decreased. Compared with the rosuvastatin group, eNOS, iNOS, and ICAM-1 protein expression in the yellow wine (0.5% -1.5%) groups were significantly different. Treatment with yellow wine increased NO production, eNOS activity, and eNOS protein expression, which decreases iNOS and ICAM-1 protein expression. We conclude that yellow wine may have similar beneficial effects as rosuvastatin on the cardiovascular system. These effects may be attributed to their anti-atherosclerotic actions.

  16. Carbon monoxide does not contribute to vascular tonus improvement in exercise-trained rats with chronic nitric oxide synthase inhibition. (United States)

    Ülker, Seher Nasırcılar; Koçer, Günnur; Şentürk, Ümit Kemal


    Carbon monoxide (CO), an end product of heme oxygenase (HO) that is involved in the regulation of vascular tonus, may show a compensatory effect in nitric oxide (NO) deficiency. This study aimed to assess the effect of the HO/CO system on the vascular tone in exercise-trained rats with hypertension induced by chronic NO synthase (NOS) inhibition. Hypertension was induced by N-nitro-l-arginine methyl ester (25 mg/kg/day in drinking water), and exercise training comprised swimming 1 h/day, 5 days/week, for 6 weeks. Systolic blood pressure (BP) was measured weekly using a tail-cuff method. The effects of hypertension and/or exercise-training on the constriction and relaxation responses of the thoracic aorta and resistance arteries of the mesenteric and gastrocnemius vascular beds were evaluated. NOS inhibition produced a gradually developed hypertension, and the magnitude of the increase in BP was significantly attenuated by exercise training. Although phenylephrine (Phe)-induced contraction responses of aorta incubated with an HO-1 inhibitor were reduced in hypertensive animals, there was no difference in the hypertensive-exercise group. However, thoracic aortas in the hypertensive-exercise group exhibited significantly more relaxation in response to a CO donor. There was no change in Phe-induced contraction with or without HO inhibition CO donor relaxation responses in both resistance arteries. These results suggest that the HO/CO system does not contribute to diminishing BP by exercise training in a NOS inhibition-induced hypertension model. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Leptin Inhibits the Proliferation of Vascular Smooth Muscle Cells Induced by Angiotensin II through Nitric Oxide-Dependent Mechanisms

    Directory of Open Access Journals (Sweden)

    Amaia Rodríguez


    Full Text Available Objective. This study was designed to investigate whether leptin modifies angiotensin (Ang II-induced proliferation of aortic vascular smooth muscle cells (VSMCs from 10-week-old male Wistar and spontaneously hypertensive rats (SHR, and the possible role of nitric oxide (NO. Methods. NO and NO synthase (NOS activity were assessed by the Griess and 3H-arginine/citrulline conversion assays, respectively. Inducible NOS (iNOS and NADPH oxidase subutnit Nox2 expression was determined by Western-blot. The proliferative responses to Ang II were evaluated through enzymatic methods. Results. Leptin inhibited the Ang II-induced proliferative response of VSMCs from control rats. This inhibitory effect of leptin was abolished by NOS inhibitor, NMMA, and iNOS selective inhibitor, L-NIL, and was not observed in leptin receptor-deficient fa/fa rats. SHR showed increased serum leptin concentrations and lipid peroxidation. Despite a similar leptin-induced iNOS up-regulation, VSMCs from SHR showed an impaired NOS activity and NO production induced by leptin, and an increased basal Nox2 expression. The inhibitory effect of leptin on Ang II-induced VSMC proliferation was attenuated. Conclusion. Leptin blocks the proliferative response to Ang II through NO-dependent mechanisms. The attenuation of this inhibitory effect of leptin in spontaneous hypertension appears to be due to a reduced NO bioavailability in VSMCs.

  18. Sex differences in pulmonary vascular control: focus on the nitric oxide pathway. (United States)

    de Wijs-Meijler, Daphne P M; Danser, A H Jan; Reiss, Irwin K M; Duncker, Dirk J; Merkus, Daphne


    Although the incidence of pulmonary hypertension is higher in females, the severity and prognosis of pulmonary vascular disease in both neonates and adults have been shown to be worse in male subjects. Studies of sex differences in pulmonary hypertension have mainly focused on the role of sex hormones. However, the contribution of sex differences in terms of vascular signaling pathways regulating pulmonary vascular function remains incompletely understood. Consequently, we investigated pulmonary vascular function of male and female swine in vivo, both at rest and during exercise, and in isolated small pulmonary arteries in vitro, with a particular focus on the NO-cGMP-PDE5 pathway. Pulmonary hemodynamics at rest and during exercise were virtually identical in male and female swine. Moreover, NO synthase inhibition resulted in a similar degree of pulmonary vasoconstriction in male and female swine. However, NO synthase inhibition blunted bradykinin-induced vasodilation in pulmonary small arteries to a greater extent in male than in female swine. PDE5 inhibition resulted in a similar degree of vasodilation in male and female swine at rest, while during exercise there was a trend towards a larger effect in male swine. In small pulmonary arteries, PDE5 inhibition failed to augment bradykinin-induced vasodilation in either sex. Finally, in the presence of NO synthase inhibition, the pulmonary vasodilator effect of PDE5 inhibition was significantly larger in female swine both in vivo and in vitro. In conclusion, the present study demonstrated significant sex differences in the regulation of pulmonary vascular tone, which may contribute to understanding sex differences in incidence, treatment response, and prognosis of pulmonary vascular disease. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  19. Helicobacter pylori-induced inhibition of vascular endothelial cell functions: a role for VacA-dependent nitric oxide reduction. (United States)

    Tobin, Nicholas P; Henehan, Gary T; Murphy, Ronan P; Atherton, John C; Guinan, Anthony F; Kerrigan, Steven W; Cox, Dermot; Cahill, Paul A; Cummins, Philip M


    Epidemiological and clinical studies provide compelling support for a causal relationship between Helicobacter pylori infection and endothelial dysfunction, leading to vascular diseases. However, clear biochemical evidence for this association is limited. In the present study, we have conducted a comprehensive investigation of endothelial injury in bovine aortic endothelial cells (BAECs) induced by H. pylori-conditioned medium (HPCM) prepared from H. pylori 60190 [vacuolating cytotoxin A (Vac(+))]. BAECs were treated with either unconditioned media, HPCM (0-25% vol/vol), or Escherichia coli-conditioned media for 24 h, and cell functions were monitored. Vac(+) HPCM significantly decreased BAEC proliferation, tube formation, and migration (by up to 44%, 65%, and 28%, respectively). Posttreatment, we also observed sporadic zonnula occludens-1 immunolocalization along the cell-cell border, and increased BAEC permeability to FD40 Dextran, indicating barrier reduction. These effects were blocked by 5-nitro-2-(3-phenylpropylamino)benzoic acid (VacA inhibitor) and were not observed with conditioned media prepared from either VacA-deleted H. pylori or E. coli. The cellular mechanism mediating these events was also considered. Vac(+) HPCM (but not Vac(-)) reduced nitric oxide (NO) by >50%, whereas S-nitroso-N-acetylpenicillamine, an NO donor, recovered all Vac(+) HPCM-dependent effects on cell functions. We further demonstrated that laminar shear stress, an endothelial NO synthase/NO stimulus in vivo, could also recover the Vac(+) HPCM-induced decreases in BAEC functions. This study shows, for the first time, a significant proatherogenic effect of H. pylori-secreted factors on a range of vascular endothelial dysfunction markers. Specifically, the VacA-dependent reduction in endothelial NO is indicated in these events. The atheroprotective impact of laminar shear stress in this context is also evident.

  20. Sex differences in pulmonary vascular control: focus on the nitric oxide pathway

    NARCIS (Netherlands)

    D. de Wijs-Meijler (Daphne); A.H.J. Danser (Jan); I.K.M. Reiss (Irwin); D.J.G.M. Duncker (Dirk); D. Merkus (Daphne)


    textabstractAlthough the incidence of pulmonary hypertension is higher in females, the severity and prognosis of pulmonary vascular disease in both neonates and adults have been shown to be worse in male subjects. Studies of sex differences in pulmonary hypertension have mainly focused on the role

  1. Chemerin reduces vascular nitric oxide/cGMP signalling in rat aorta: a link to vascular dysfunction in obesity? (United States)

    Neves, Karla Bianca; Lobato, Núbia S; Lopes, Rhéure Alves Moreira; Filgueira, Fernando P; Zanotto, Camila Ziliotto; Oliveira, Ana Maria; Tostes, Rita C


    The adipokine chemerin has been implicated in cardiovascular complications associated with obesity and the metabolic syndrome. Chemerin has direct effects on the vasculature, augmenting vascular responses to contractile stimuli. As NO/cGMP signalling plays a role in vascular dysfunction associated with obesity and the metabolic syndrome, we hypothesized that chemerin induces vascular dysfunction by decreasing NO/cGMP signalling. Aortic rings from male Wistar rats (10-12 weeks of age) were incubated with chemerin (0.5 or 5 ng/ml for 1 h) or vehicle and isometric tension was recorded. Vasorelaxation in response to ACh (acetylcholine), SNP (sodium nitroprusside) and BAY 412272 [an sGC (soluble guanylate cyclase) stimulator] were decreased in chemerin-treated vessels. The NOS (NO synthase) cofactor BH4 (tetrahydrobiopterin), an O2- (superoxide anion) scavenger (tiron) and a SOD (superoxide dismutase) mimetic (tempol) abolished the effects of chemerin on ACh-induced vasodilation. eNOS (endothelial NOS) phosphorylation, determined by Western blotting, was increased in chemerin-treated vessels; however, the enzyme was mainly in the monomeric form, with decreased eNOS dimer/monomer ratio. Chemerin decreased the mRNA levels of the rate-limiting enzyme for BH4 biosynthesis GTP cyclohydrolase I. Chemerin-incubated vessels displayed decreased NO production, along with increased ROS (reactive oxygen species) generation. These effects were abrogated by BH4, tempol and L-NAME (NG-nitro-L-arginine methyl ester). sGC protein expression and cGMP levels were decreased in chemerin-incubated vessels. These results demonstrate that chemerin reduces NO production, enhances NO breakdown and also decreases NO-dependent cGMP signalling, thereby reducing vascular relaxation. Potential mechanisms mediating the effects of chemerin in the vasculature include eNOS uncoupling, increased O2- generation and reduced GC activity.

  2. Effect of nitric oxide scavengers, carboxy-PTIO on endotoxin ...

    African Journals Online (AJOL)

    Research evidence shows that sepsis-associated vascular relaxation is mediated by nitric oxide. Nitric oxide formation is stimulated by endotoxin, cytokines such as Tumor necrosis factor, and Interleukines. The stimulation is due to the activation of an inducible nitric oxide synthase, which transforms an amino acid ...

  3. Effect of magnesium supplementation on blood pressure and vascular reactivity in nitric oxide synthase inhibition-induced hypertension model. (United States)

    Basralı, Filiz; Koçer, Günnur; Ülker Karadamar, Pınar; Nasırcılar Ülker, Seher; Satı, Leyla; Özen, Nur; Özyurt, Dilek; Şentürk, Ümit Kemal


    The aim of this study was to assess the effect of oral magnesium supplementation (Mg-supp) on blood pressure (BP) and possible mechanism in nitric oxide synthase (NOS) inhibition-induced hypertension model. Hypertension and/or Mg-supp were created by N-nitro-l-arginine methyl ester (25 mg/kg/day by drinking water) and magnesium-oxide (0.8% by diet) for 6 weeks. Systolic BP was measured weekly by tail-cuff method. The effects of hypertension and/or Mg-supp in thoracic aorta and third branch of mesenteric artery constriction and relaxation responses were evaluated. NOS-inhibition produced a gradually developing hypertension and the magnitude of the BP was significantly attenuated after five weeks of Mg-supp. The increased phenylephrine-induced contractile and decreased acetylcholine (ACh)-induced dilation responses were found in both artery segments of hypertensive groups. Mg-supp was restored ACh-relaxation response in both arterial segments and also Phe-constriction response in thoracic aorta but not in mesenteric arteries. The contributions of NO, prostaglandins and K(+) channels to the dilator response of ACh were similar in the aorta of all the groups. The contribution of the NO to the ACh-mediated relaxation response of mesenteric arteries was suppressed in hypertensive rats, whereas this was corrected by Mg-supp. The flow-mediated dilation response of mesenteric arteries in hypertensive rats failed and could not be corrected by Mg-supp. Whereas, vascular eNOS protein and magnesium levels were not changed and plasma nitrite levels were reduced in hypertensive rats. The results of this study showed that Mg-supp lowered the arterial BP in NOS-inhibition induced hypertension model by restoring the agonist-induced relaxation response of the arteries.

  4. Vascular protective actions of a nitric oxide aspirin analog in both in vitro and in vivo models of diabetes mellitus. (United States)

    Pieper, Galen M; Siebeneich, Wolfgang; Olds, Cara L; Felix, Christopher C; Del Soldato, Piero


    Defective endothelium-dependent relaxation is observed in experimental and human diabetes mellitus. The nature of this defect is not fully understood but may involve decreased nitric oxide (NO) bioactivity due to enhanced production of reactive oxygen species (ROS). In this paper, we examine the benefits and actions of a novel NO-donating, antioxidant called 2-acetoxybenzoic acid 2-(2-nitrooxymethyl) phenyl ester, and denoted as NCX4016, on NO-mediated endothelium-dependent relaxation in normal arteries exposed to acute elevations in glucose or in arteries derived from chronic diabetic animals. Intrinsic free radical scavenging by NO-NSAIDs in solution were evaluated using electron paramagnetic resonance (EPR) spectroscopy and spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). In acute studies, normal rat aortas were exposed in tissue culture for 18 h to 5.5 mM or 40 mM in the presence or absence of NCX4016, a NO-donating NSAID unrelated to aspirin (NCX2216) or aspirin. Vascular reactivity of thoracic aortic rings to endothelium-dependent relaxation to acetylcholine in vitro was determined. For chronic hyperglycemia, diabetes was induced in rats by intravenous injection with streptozotocin. Vascular reactivity of thoracic aortic rings to endothelium-dependent relaxation to acetylcholine in vitro was determined after 8 wks in untreated animals or animals chronically-treated with NCX4016. Antioxidant efficacy in vivo was determined by measurement of plasma isoprostanes and by nuclear binding activity of NF-kappaB in nuclear fractions of aortae. Incubation with NCX4016 and NCX2216 produced a concentration-dependent inhibition of DMPO-OH formation indicating scavenging of hydroxyl radicals (HO(*)). In contrast, little efficacy to scavenge superoxide anion radicals was noted. Acute incubation of normal arteries with elevated glucose concentration caused inhibition of normal relaxation to acetylcholine. This impairment was prevented by co-incubation with NCX4106

  5. Nitric oxide synthase (NOS) in the trigeminal vascular system and other brain structures related to pain in rats

    DEFF Research Database (Denmark)

    Ramachandran, Roshni; Ploug, Kenneth Beri; Hay-Schmidt, Anders


    Nitric oxide (NO) is considered to be a key mediator in the pathophysiology of migraine but the localisation of NO synthesizing enzymes (NOS) throughout the pain pathways involved in migraine has not yet been fully investigated. We have used quantitative real-time PCR and Western blotting...

  6. beta-very low density lipoprotein enhances inducible nitric oxide synthase expression in cytokine-stimulated vascular smooth muscle cells. (United States)

    Takahashi, Masafumi; Takahashi, Sadao; Shimpo, Masahisa; Naito, Akitaka; Ogata, Yukiyo; Kobayashi, Eiji; Ikeda, Uichi; Shimada, Kazuyuki


    beta-very low-density lipoprotein (beta-VLDL), a collective term for VLDL and chylomicron remnants, has recently shown to potently promote the development of atherosclerosis. However, the effects of beta-VLDL on the accumulation of nitric oxide (NO) and the expression of inducible NO synthase (iNOS) in vascular smooth muscle cells (VSMC) have not been determined. In this study, we measured the accumulation of nitrite, stable metabolite of NO and examined the expression of iNOS protein and mRNA using Western blotting and RT-PCR, respectively, in VSMC. NF-kappaB activation in VSMC was examined by gel retardation assay. Incubation of cell cultures with interleukin-1beta (IL-1beta) for 24 h caused a significant increase in nitrite accumulation. Although beta-VLDL alone did not increase nitrite accumulation in unstimulated VSMC, beta-VLDL significantly enhanced nitrite accumulation in IL-1beta-stimulated VSMC in a time- and dose-dependent manner. beta-VLDL-induced nitrite accumulation in IL-1beta-stimulated VSMC was accompanied by an increase in iNOS protein and mRNA expression. In addition, IL-1beta induced NF-kappaB activation in VSMC, an effect that was increased by the addition of beta-VLDL. Use of specific tyrosine kinase inhibitor herbimycin A, genistein, or PP2 (Src family kinase inhibitor) indicated that tyrosine kinases are required for IL-1beta-stimulated and beta-VLDL-enhanced nitrite accumulation, while specific inhibition of ERK1/2 or p38-MAP kinase had no effects. Our results suggest that beta-VLDL enhances iNOS expression and nitrite accumulation in IL-1beta-stimulated VSMC through tyrosine kinase(s)-dependent mechanisms.

  7. Nitric oxide and hypoxia signaling. (United States)

    Jeffrey Man, H S; Tsui, Albert K Y; Marsden, Philip A


    Nitric oxide (NO) production is catalyzed by three distinct enzymes, namely, neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS). The production of NO by vascular endothelium relies mainly on eNOS. Curiously, iNOS and nNOS also are relevant for vascular NO production in certain settings. By relaxing vascular smooth muscle, the classical view is that NO participates in O2 homeostasis by increasing local blood flow and O2 delivery. It is now appreciated that NO has an even more fundamental role in cellular oxygen sensing at the cellular and physiological level. A key component of cellular oxygen sensing is the hypoxia-inducible factor (HIF) that activates a transcriptional program to promote cellular survival under conditions of inadequate oxygen supply. Important new insights demonstrate that HIF protein is stabilized by two parallel pathways: (1) a decrease in the O2-dependent prolyl hydroxylation of HIF and (2) NO-dependent S-nitrosylation of HIF pathway components including HIF-α. The need for these two complementary pathways to HIF activation arises because decreased oxygen delivery can occur not only by decreased ambient oxygen but also by decreased blood oxygen-carrying capacity, as with anemia. In turn, NO production is tightly linked to O2 homeostasis. O2 is a key substrate for the generation of NO and impacts the enzymatic activity and expression of the enzymes that catalyze the production of NO, the nitric oxide synthases. These relationships manifest in a variety of clinical settings ranging from the unique situation of humans living in hypoxic environments at high altitudes to the common scenario of anemia and the use of therapeutics that can bind or release NO. © 2014 Elsevier Inc. All rights reserved.

  8. Spironolactone Prevents Endothelial Nitric Oxide Synthase Uncoupling and Vascular Dysfunction Induced by β-Adrenergic Overstimulation: Role of Perivascular Adipose Tissue. (United States)

    Victorio, Jamaira A; Clerici, Stefano P; Palacios, Roberto; Alonso, María J; Vassallo, Dalton V; Jaffe, Iris Z; Rossoni, Luciana V; Davel, Ana P


    Sustained stimulation of β-adrenoceptors (β-ARs) and activation of renin-angiotensin-aldosterone system are common features of cardiovascular diseases with rising sympathetic activation, including essential hypertension, myocardial infarction, and heart failure. In this study, we investigated the role of AT1 receptor and mineralocorticoid receptor (MR) in the vascular alterations caused by β-AR overstimulation. β-AR overstimulation with associated cardiac hypertrophy and increased vasoconstrictor response to phenylephrine in aorta were modeled in rats by 7-day isoproterenol treatment. The increased vasoconstrictor response to phenylephrine in this model was blunted by the MR antagonist spironolactone, but not by the AT1 receptor antagonist losartan, despite the blunting of cardiac hypertrophy with both drugs. Spironolactone, but not losartan, restored NO bioavailability in association with lower endothelial nitric oxide synthase-derived superoxide production, increased endothelial nitric oxide synthase dimerization, and aortic HSP90 upregulation. MR genomic and nongenomic functions were activated in aortas from isoproterenol-treated rats. Isoproterenol did not modify plasma levels of MR ligands aldosterone and corticosterone but rather increased perivascular adipose tissue-derived corticosterone in association with increased expression of 11β-hydroxysteroid dehydrogenase type 1. The anticontractile effect of aortic perivascular adipose tissue was impaired by β-AR overstimulation and restored by MR blockade. These results suggest that activation of vascular MR signaling contributes to the vascular dysfunction induced by β-AR overstimulation associated with endothelial nitric oxide synthase uncoupling. These findings reveal an additional explanation for the protective effects of MR antagonists in cardiovascular disorders with sympathetic activation. © 2016 The Authors.

  9. Inhaled nitric oxide in chronic obstructive lung disease

    Energy Technology Data Exchange (ETDEWEB)

    Tiihonen, J.; Hakola, P.; Paanila, J.; Turtiainen (Univ. of Kuopio (Finland). Dept. of Forensic Psychiatry)


    During an investigation of the effect of nitric oxide on the pulmonary circulation the authors had the opportunity to give nitric oxide to a patient with longstanding obstructive airway disease, with successful results. A 72-year-old man with chronic obstructive pulmonary disease was referred to the institution for assessment of pulmonary vascular reactivity to acetylcholine and nitric oxide. Acetylcholine was infused into the main pulmonary artery followed 15 min later by an inhalation of 80 parts per million (ppm) nitric oxide. Heart rate and systemic arterial and pulmonary arterial pressures were continuously monitored. Throughout the study the inspired oxygen concentration was kept constant at 98%. Nitrogen dioxide and nitric oxide concentrations were monitored while nitric oxide was delivered. The infusion of acetylcholine resulted in a small increase in pulmonary artery pressure and pulmonary vascular resistance. Nitric oxide produced a substantial fall in pulmonary artery pressure and pulmonary vascular resistance with a concomitant increase in systemic arterial oxygen tension. These results suggest that endothelium-dependent relaxation of the pulmonary vasculature was impaired in the patient and that exogenous nitric oxide was an effective pulmonary vasodilator. In-vitro investigation of explanted airways disease suggests not only that endothelium-dependent pulmonary artery relaxation is impaired but also that the dysfunction is related to pre-existing hypoxemia and hypercapnia. Nitric oxide inhibits proliferation of cultured vascular smooth muscle cells and might alter the pulmonary vascular remodeling characteristic of patients with chronic obstructive airways disease.

  10. Vascular hyporeactivity to angiotensin II induced by Escherichia coli endotoxin is reversed by Nω-Nitro-L-Arginine, an inhibitor of nitric oxide synthase

    Directory of Open Access Journals (Sweden)



    Full Text Available

    Septic shock or sepsis is reported to be one of the major causes of death when followed by systemic infectious trauma in humans and other mammals. Its development leads to a large drop in blood pressure and a reduction in vascular responsiveness to physiological vasoconstrictors which, if not contained, can lead to death. It is proposed that this vascular response is due to the action of bacterial cell wall products released into the bloodstream by the vascular endothelium and is considered a normal response of the body`s defenses against infection. A reduction in vascular reactivity to epinephrine and norepinephrine is observed under these conditions. In the present study in rats, the aim was to assess whether those effects of hypotension and hyporeactivity are also related to another endogenous vasoconstrictor, angiotensin II (AII. We evaluated the variation in the power of this vasoconstrictor over the mean arterial pressure in anesthetized rats, before and after the establishment of hypotension by Escherichia coli endotoxin (Etx. Our results show that in this model of septic shock, there is a reduction in vascular reactivity to AII and this reduction can be reversed by the inhibitor of nitric oxide synthase, Nω-Nitro-L-Arginine (NωNLA. Our results also suggest that other endogenous factors (not yet fully known are involved in the protection of rats against septic shock, in addition to the L-arginine NO pathway. Keywords: vascular hyporeactivity; NO; rat; angiotensin II; NωNLA Escherichia coli endotoxin.

  11. Methylxanthines and calcium-mobilizing agents inhibit the expression of cytokine-inducible nitric oxide synthase and vascular cell adhesion molecule-1 in murine microvascular endothelial cells. (United States)

    Bereta, M; Bereta, J; Georgoff, I; Coffman, F D; Cohen, S; Cohen, M C


    In response to exposure to the inflammatory cytokines tumor necrosis factor-alpha (TNF) and interferon-gamma (IFN-gamma), murine brain microvascular endothelial cells (MME) synthesize the cell surface molecule, vascular cell adhesion molecule-1 (VCAM-1), and the intracellular enzyme, inducible nitric oxide synthase (iNOS). However, iNOS synthesis requires the presence of both TNF and IFN-gamma, while VCAM-1 can be induced by either cytokine alone. We examined the induction of VCAM-1 and iNOS under a variety of conditions to better define the regulation of TNF and IFN-gamma signal transduction pathways in MME. We utilized the analysis of steady-state levels of iNOS mRNA as well as the measurement of MME-released NO-EDRF (nitric oxide as an endothelium-derived relaxing factor) activity and accumulation of nitrite in the culture medium to define iNOS expression and activity. VCAM-1 expression was determined by flow cytometric analysis. Our data indicate that low density lipoproteins inhibited cytokine-induced iNOS activity by affecting the steady-state levels of iNOS mRNA. Methylxanthines (caffeine and theophylline) as well as several calcium-mobilizing agents inhibited the expression/activity of both iNOS and VCAM-1 in MME. The effectiveness of these agents was dependent upon the degree of disruption in cell calcium homeostasis during cytokine treatment. Cells which had been pretreated with calcium-modulating drugs and then washed and allowed to return to normal calcium homeostasis showed little to no effect from these agents. In addition, our results suggest that NO produced by iNOS acts as a metabolic switch during inflammation by inhibiting oxidative phosphorylation and forcing vascular endothelial cells to temporarily utilize anaerobic energy metabolism.

  12. Hydrogen Sulfide Stimulates Ischemic Vascular Remodeling Through Nitric Oxide Synthase and Nitrite Reduction Activity Regulating Hypoxia‐Inducible Factor‐1α and Vascular Endothelial Growth Factor–Dependent Angiogenesis (United States)

    Bir, Shyamal C.; Kolluru, Gopi K.; McCarthy, Paul; Shen, Xinggui; Pardue, Sibile; Pattillo, Christopher B.; Kevil, Christopher G.


    Background Hydrogen sulfide (H2S) therapy is recognized as a modulator of vascular function during tissue ischemia with the notion of potential interactions of nitric oxide (NO) metabolism. However, little is known about specific biochemical mechanisms or the importance of H2S activation of NO metabolism during ischemic tissue vascular remodeling. The goal of this study was to determine the effect of H2S on NO metabolism during chronic tissue ischemia and subsequent effects on ischemic vascular remodeling responses. Methods and Results The unilateral, permanent femoral artery ligation model of hind‐limb ischemia was performed in C57BL/6J wild‐type and endothelial NO synthase–knockout mice to evaluate exogenous H2S effects on NO bioavailability and ischemic revascularization. We found that H2S selectively restored chronic ischemic tissue function and viability by enhancing NO production involving both endothelial NO synthase and nitrite reduction mechanisms. Importantly, H2S increased ischemic tissue xanthine oxidase activity, hind‐limb blood flow, and angiogenesis, which were blunted by the xanthine oxidase inhibitor febuxostat. H2S treatment increased ischemic tissue and endothelial cell hypoxia‐inducible factor‐1α expression and activity and vascular endothelial growth factor protein expression and function in a NO‐dependent manner that was required for ischemic vascular remodeling. Conclusions These data demonstrate that H2S differentially regulates NO metabolism during chronic tissue ischemia, highlighting novel biochemical pathways to increase NO bioavailability for ischemic vascular remodeling. PMID:23316304

  13. Nitric oxide. A novel signal transduction mechanism for transcellular communication. (United States)

    Ignarro, L J


    Nitric oxide first captured the interest of biologists when this inorganic molecule was found to activate cytosolic guanylate cyclase and stimulate cyclic guanosine monophosphate (GMP) formation in mammalian cells. Further studies led to the finding that nitric oxide causes vascular smooth muscle relaxation and inhibition of platelet aggregation by mechanisms involving cyclic GMP and that several clinically used nitrovasodilators owe their biological actions to nitric oxide. Nitric oxide possesses physicochemical and pharmacological properties that make it an ideal candidate for a short-term regulator or modulator of vascular smooth muscle tone and platelet function. Nitric oxide is synthesized by various mammalian tissues including vascular endothelium, macrophages, neutrophils, hepatic Kupffer cells, adrenal tissue, cerebellum, and other tissues. Nitric oxide is synthesized from endogenous L-arginine by a nitric oxide synthase system that possesses different cofactor requirements in different cell types. The nitric oxide formed diffuses out of its cells of origin and into nearby target cells, where it binds to the heme group of cytosolic guanylate cyclase and thereby causes enzyme activation. This interaction represents a novel and widespread signal transduction mechanism that links extracellular stimuli to the biosynthesis of cyclic GMP in nearby target cells. The small molecular size and lipophilic nature of nitric oxide enable communication with nearby cells containing cytosolic guanylate cyclase. The extent of transcellular communication is limited by the short half-life of nitric oxide, thereby ensuring a localized response. Labile nitric oxide-generating molecules such as S-nitrosothiols may be involved as precursors or effectors. Further research will provide a deeper understanding of the biology of nitric oxide and the nature of associated pathophysiological states.

  14. Vascular endothelial growth factor inhibitor-induced hypertension: from pathophysiology to prevention and treatment based on long-acting nitric oxide donors. (United States)

    Kruzliak, Peter; Novák, Jan; Novák, Miroslav


    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.

  15. Catalysis by nitric oxide synthase. (United States)

    Marletta, M A; Hurshman, A R; Rusche, K M


    The enzyme nitric oxide synthase catalyzes the oxidation of the amino acid L-arginine to L-citrulline and nitric oxide in an NADPH-dependent reaction. Nitric oxide plays a critical role in signal transduction pathways in the cardiovascular and nervous systems and is a key component of the cytostatic/cytotoxic function of the immune system. Characterization of nitric oxide synthase substrates and cofactors has outlined the broad details of the overall reaction and suggested possibilities for chemical steps in the reaction; however, the molecular details of the reaction mechanism are still poorly understood. Recent evidence suggests a role for the reduced bound pterin in the first step of the reaction--the hydroxylation of L-arginine.

  16. Adiponectin attenuates angiotensin II-induced vascular smooth muscle cell remodeling through nitric oxide and the RhoA/ROCK pathway.

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    Wared eNour-Eldine


    Full Text Available INTRODUCTION: Adiponectin (APN, an adipocytokine, exerts protective effects on cardiac remodeling, while angiotensin II (Ang II induces hypertension and vascular remodeling. The potential protective role of APN on the vasculature during hypertension has not been fully elucidated yet. Here, we evaluate the molecular mechanisms of the protective role of APN in the physiological response of the vascular wall to Ang II.METHODS AND RESULTS: Rat aortic tissues were used to investigate the effect of APN on Ang II-induced vascular remodeling and hypertrophy. We investigated whether nitric oxide (NO, the RhoA/ROCK pathway, actin cytoskeleton remodeling, and reactive oxygen species (ROS mediate the anti-hypertrophic effect of APN. Ang II-induced protein synthesis was attenuated by pre-treatment with APN, NO donor (SNAP, or cGMP. The hypertrophic response to Ang II was associated with a significant increase in RhoA activation and vascular force production, which were prevented by APN and SNAP. NO was also associated with inhibition of Ang II-induced phosphorylation of cofilin. In addition, immunohistochemistry revealed that 24 hr Ang II treatment increased the F- to G-actin ratio, an effect that was inhibited by SNAP. Ang II-induced ROS formation and upregulation of p22phox mRNA expression were inhibited by APN and NO. Both compounds failed to inhibit Nox1 and p47phox expression. CONCLUSIONS: Our results suggest that the anti-hypertrophic effects of APN are due, in part, to NO-dependent inhibition of the RhoA/ROCK pathway and ROS formation.

  17. Regulation of Ca(2+)-activated K+ channels in pulmonary vascular smooth muscle cells: role of nitric oxide. (United States)

    Peng, W; Hoidal, J R; Farrukh, I S


    Nitric oxide (NO.) is believed to mediate nitrovasodilators and acetylcholine-induced vasodilatation via increasing intracellular guanosine 3',5'-cyclic monophosphate (cGMP) levels. The cellular mechanisms involved in No.-mediated pulmonary vasodilatation are complex and include membrane hyperpolarization. Using the patch-clamp technique in cell-attached and inside-out configurations, we examined the effect of NO. gas, 3-morpholinosydnomimine hydrochloride (SIN-1), and perfusate from ACh-stimulated human pulmonary arterial endothelial cells, or endothelium-derived relaxing factors (EDRF), on the Ca(2+)-dependent K+ (KCa) channels in isolated cultured human pulmonary arterial smooth muscle cells (HPSMC). NO., SIN-1, and EDRF caused similar increases in KCa channel activity. Inhibiting cGMP generation with methylene blue or inhibiting the effect(s) of cGMP with the cGMP antagonist 8-bromoguanosine 3',5'-cyclic monophosphorothioate Rp isomer Rp-cGMPS prevented the NO.- and SIN-1-mediated activation of KCa channels, respectively. Treating the human pulmonary arterial endothelial cells with methylene blue blocked the EDRF-mediated activation of KCa channels in HPSMC. The cGMP analogue 8-bromo-cGMP increased KCa channel activity in intact cells and in excised inside-out HPSMC membrane patches. In the presence of cGMP and ATP, the alpha-isozyme of the cGMP-dependent protein kinase (I alpha-cGMP-PK) significantly increased KCa channel activity, and the channel activation was further increased on addition of the protein phosphatase inhibitors okadaic acid and calyculin A. Furthermore, the cGMP-mediated KCa channel activation was reduced by the cyclic nucleotide-dependent protein kinase inhibitor N-[2-methylamino)ethyl]-5-isoquinlinesulfonamide (H-8). Thus, in HPSMC, the mechanism of NO.- and native EDRF-induced KCa channel activation appears to be mediated via cGMP-I alpha-cGMP-PK phosphorylation of KCa channels.

  18. Nitric Oxide Modulators: An Emerging Class of Medicinal Agents (United States)

    Deshpande, S. R.; Satyanarayana, K.; Rao, M. N. A.; Pai, K. V.


    Nitric oxide, a unique messenger in biological system, is ubiquitously present virtually in all tissues revealing its versatile nature of being involved in diverse physiological functions such as vascular tone, inhibition of platelet aggregation, cell adhesion, neurotransmission and enzyme and immune regulation. The tremendous advancements made in the past few decades in this area suggests that the nitric oxide modulation either by its exogenous release through nitric oxide donors or inhibition of its synthesis by nitric oxide synthase inhibitors in physiological milieu may provide newer clinical strategies for the treatment of some diseases. In this review, an attempt is made to document and understand the biological chemistry of different classes of nitric oxide modulators that would prove to be a fruitful area in the years to come. PMID:23798773

  19. Plasma Vascular Endothelial Growth Factor Concentration and Alveolar Nitric Oxide as Potential Predictors of Disease Progression and Mortality in Idiopathic Pulmonary Fibrosis

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    Jalpa Kotecha


    Full Text Available Background: Declining lung function signifies disease progression in idiopathic pulmonary fibrosis (IPF. Vascular endothelial growth factor (VEGF concentration is associated with declining lung function in 6 and 12-month studies. Alveolar nitric oxide concentration (CANO is increased in patients with IPF, however its significance is unclear. This study investigated whether baseline plasma VEGF concentration and CANO are associated with disease progression or mortality in IPF. Methods: 27 IPF patients were studied (maximum follow-up 65 months. Baseline plasma VEGF concentration, CANO and pulmonary function tests (PFTs were measured. PFTs were performed the preceding year and subsequent PFTs and data regarding mortality were collected. Disease progression was defined as one of: death, relative decrease of ≥10% in baseline forced vital capacity (FVC % predicted, or relative decrease of ≥15% in baseline single breath diffusion capacity of carbon monoxide (TLCO-SB % predicted. Results: Plasma VEGF concentration was not associated with progression-free survival or mortality. There was a trend towards shorter time to disease progression and death with higher CANO. CANO was significantly higher in patients with previous declining versus stable lung function. Conclusion: The role of VEGF in IPF remains uncertain. It may be of value to further investigate CANO in IPF.

  20. A cystine-knot miniprotein from tomato fruit inhibits endothelial cell migration and angiogenesis by affecting vascular endothelial growth factor receptor (VEGFR) activation and nitric oxide production. (United States)

    Treggiari, Davide; Zoccatelli, Gianni; Molesini, Barbara; Degan, Maurizio; Rotino, Giuseppe Leonardo; Sala, Tea; Cavallini, Chiara; MacRae, Calum A; Minuz, Pietro; Pandolfini, Tiziana


    Cystine-knot miniproteins are bioactive molecules with a broad range of potential therapeutic applications. Recently, it was demonstrated that two tomato cystine-knot miniproteins (TCMPs) exhibit in vitro antiangiogenic activity on human umbilical vein cells. The aim of the present study was to investigate the effects of a fruit-specific cystine-knot miniprotein of tomato on in vitro endothelial cell migration and in vivo angiogenesis using a zebrafish model. The cystine-knot protein purified from tomato fruits using gel filtration LC and RP-HPLC inhibited cell migration when tested at 200 nM using the wound healing assay, and reduced nitric oxide formation probed by 4-amino-5-methylamino-27-difluorofluoscescin diacetate. RT-PCR and Western blot analyses demonstrated that vascular endothelium growth factor A dependent signaling was the target of TCMP bioactivity. Angiogenesis was inhibited in vivo in zebrafish embryos treated with 500 nM TCMP. Our results demonstrate that cystine-knot miniproteins present in mature tomato fruits are endowed with antiangiogenic activity in vitro and in vivo. These molecules may confer beneficial effects to tomato dietary intake, along with lycopene and other antioxidants. Further investigation is warranted to explore the potential of these compounds as model scaffolds for the development of new drugs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Effect of inhibitors of nitric oxide release and action on vascular tone in isolated lungs of pig, sheep, dog and man. (United States)

    Cremona, G; Wood, A M; Hall, L W; Bower, E A; Higenbottam, T


    1. The actions of inhibitors of the release or action of nitric oxide (NO) on pulmonary vascular resistance (PVR) were investigated in lungs isolated from pig, sheep, dog and man. 2. In pig, sheep and human lungs perfused with Krebs-dextran solution, both N omega-nitro-L-arginine methyl ester (L-NAME; 10(-5) M) and Methylene Blue (10(-4) M) increased basal PVR. This increase was reversed by sodium nitroprusside (10(-5) M). In pig lungs N omega-monomethyl-L-arginine (10(-4) M) increased PVR by 154%. This increase was partially reversed by L-arginine (10(-3) M). L-NAME had no effect in dog lungs. 3. Pulmonary artery pressure-flow (PPA/Q) relationships were studied over a wide range of flows. In pigs, sheep and human lungs perfused with Krebs-dextran solution, L-NAME increased the PPA/Q slope. This increase was reversed by sodium nitroprusside. In dog lungs L-NAME had no effect. 4. In blood-perfused lungs, the respective responses to L-NAME were similar to those observed with saline. Acute hypoxia in pig and dog lungs increased intercept pressure. Addition of L-NAME during hypoxia increased the PPA/Q slope in both species. 5. In the human, there was no difference in the absolute increase of PVR or PPA/Q slope elicited by L-NAME between hypertensive and control lungs. 6. We conclude that NO is continuously released in the pulmonary vascular bed of pig, sheep and humans under normoxic conditions. In dog lungs inhibition of NO synthesis increases PVR only under hypoxic conditions. In human lungs with pulmonary hypertension, NO is still released under basal conditions.

  2. Exercise and possible molecular mechanisms of protection from vascular disease and diabetes: the central role of ROS and nitric oxide. (United States)

    Newsholme, Philip; Homem De Bittencourt, Paulo I; O' Hagan, Ciara; De Vito, Giuseppe; Murphy, Colin; Krause, Mauricio S


    It is now widely accepted that hypertension and endothelial dysfunction are associated with an insulin-resistant state and thus with the development of T2DM (Type 2 diabetes mellitus). Insulin signalling is impaired in target cells and tissues, indicating that common molecular signals are involved. The free radical NO* regulates cell metabolism, insulin signalling and secretion, vascular tone, neurotransmission and immune system function. NO* synthesis is essential for vasodilation, the maintenance of blood pressure and glucose uptake and, thus, if levels of NO* are decreased, insulin resistance and hypertension will result. Decreased blood levels of insulin, increased AngII (angiotensin II), hyperhomocysteinaemia, increased ADMA (asymmetric omega-NG,NG-dimethylarginine) and low plasma L-arginine are all conditions likely to decrease NO* production and which are associated with diabetes and cardiovascular disease. We suggest in the present article that the widely reported beneficial effects of exercise in the improvement of metabolic and cardiovascular health are mediated by enhancing the flux of muscle- and kidney-derived amino acids to pancreatic and vascular endothelial cells aiding the intracellular production of NO*, therefore resulting in normalization of insulin secretion, vascular tone and insulin sensitivity. Exercise may also have an impact on AngII and ADMA signalling and the production of pro- and anti-inflammatory cytokines in muscle, so reducing the progression and development of vascular disease and diabetes. NO* synthesis will be increased during exercise in the vascular endothelial cells so promoting blood flow. We suggest that exercise may promote improvements in health due to positive metabolic and cytokine-mediated effects.

  3. Atorvastatin restores arsenic-induced vascular dysfunction in rats: Modulation of nitric oxide signaling and inflammatory mediators

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    Kesavan, Manickam; Sarath, Thengumpallil Sasindran; Kannan, Kandasamy; Suresh, Subramaniyam; Gupta, Priyanka; Vijayakaran, Karunakaran; Sankar, Palanisamy; Kurade, Nitin Pandurang; Mishra, Santosh Kumar; Sarkar, Souvendra Nath, E-mail:


    We evaluated whether atorvastatin, an extensively prescribed statin for reducing the risks of cardiovascular diseases, can reduce the risk of arsenic-induced vascular dysfunction and inflammation in rats and whether the modulation could be linked to improvement in vascular NO signaling. Rats were exposed to sodium arsenite (100 ppm) through drinking water for 90 consecutive days. Atorvastatin (10 mg/kg bw, orally) was administered once daily during the last 30 days of arsenic exposure. On the 91{sup st} day, blood was collected for measuring serum C-reactive protein. Thoracic aorta was isolated for assessing reactivity to phenylephrine, sodium nitroprusside and acetylcholine; evaluating eNOS and iNOS mRNA expression and measuring NO production, while abdominal aorta was used for ELISA of cytokines, chemokine and vascular cell adhesion molecules. Histopathology was done in aortic arches. Arsenic did not alter phenylephrine-elicited contraction. Atorvastatin inhibited E{sub max} of phenylephrine, but it augmented the contractile response in aortic rings from arsenic-exposed animals. Sodium nitroprusside-induced relaxation was not altered with any treatment. However, arsenic reduced acetylcholine-induced relaxation and affected aortic eNOS at the levels of mRNA expression, protein concentration, phosphorylation and NO production. Further, it increased aortic iNOS mRNA expression, iNOS-derived NO synthesis, production of pro-inflammatory mediators (IL-1β, IL-6, MCP-1, VCAM, sICAM) and serum C-reactive protein and aortic vasculopathic lesions. Atorvastatin attenuated these arsenic-mediated functional, biochemical and structural alterations. Results show that atorvastatin has the potential to ameliorate arsenic-induced vascular dysfunction and inflammation by restoring endothelial function with improvement in NO signaling and attenuating production of pro-inflammatory mediators and cell adhesion molecules. - Highlights: • We evaluated if atorvastatin reduce arsenic

  4. Nitric oxide in the rat vestibular system. (United States)

    Harper, A; Blythe, W R; Zdanski, C J; Prazma, J; Pillsbury, H C


    Nitric oxide is known to function as a neurotransmitter in the central nervous system. It is also known to be involved in the central nervous system excitatory amino acid neurotransmission cascade. Activation of excitatory amino acid receptors causes an influx of calcium, which activates nitric oxide synthase. The resulting increase in intracellular nitric oxide activates soluble guanylate cyclase, leading to a rise in cyclic guanosine monophosphate. The excitatory amino acids glutamate and aspartate are found in the vestibular system and have been postulated to function as vestibular system neurotransmitters. Although nitric oxide has been investigated as a neurotransmitter in other tissues, no published studies have examined the role of nitric oxide in the vestibular system. Neuronal NADPH-diaphorase has been characterized as a nitric oxide synthase. This enzyme catalyzes the conversion of L-arginine to L-citrulline, producing nitric oxide during the reaction. We used a histochemical stain characterized by Hope et al. (Proc Natl Acad Sci 1991;88:2811) as specific for neuronal nitric oxide synthase to localize the enzyme in the rat vestibular system. An immunocytochemical stain was used to examine rat inner ear tissue for the presence of the enzyme's end product, L-citrulline, thereby demonstrating nitric oxide synthase activity. Staining of vestibular ganglion sections showed nitric oxide synthase presence and activity in ganglion cells and nerve fibers. These results indicate the presence of active nitric oxide synthase in these tissues and suggest modulation of vestibular neurotransmission by nitric oxide.

  5. Relaxation of rabbit corpus cavernosum smooth muscle and aortic vascular endothelium induced by new nitric oxide donor substances of the nitrosyl-ruthenium complex

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    Joao B. G. Cerqueira


    Full Text Available INTRODUCTION: Endothelial dysfunction characterized by endogenous nitric oxide (NO deficiency made 56% of patients affected with erectile dysfunction decline treatment with PDE-5 inhibitors. New forms of treatment are currently being developed for this group of patients. MATERIALS AND METHODS: The study compared the effect of sodium nitroprusside (SNP and two substances of the nitrosyl-ruthenium complex, cis-[Ru(bpy2(SO3(NO]PF-6-9 ("FONO1” and trans-[Ru(NH34(caffeine(NO]C13 ("LLNO1” on relaxation of rabbit corpus cavernosum smooth muscle and aortic vascular endothelium. The samples were immersed in isolated baths and precontracted with 0.1 µM phenylephrine (PE and the corresponding relaxation concentration/response curves were plotted. In order to investigate the relaxation mechanisms involved, 100 µM ODQ (a soluble guanylate cyclase-specific inhibitor, 3 µM or 10 µM oxyhemoglobin (an extracellular NO scavenger or 1 mM L-cysteine (a nitrosyl anion-specific scavenger was added to the samples. RESULTS: All the NO donors tested produced a significant level of relaxation in the vascular endothelium. In corpus cavernosum samples, FONO1 produced no significant effect, but LLNO1 and SNP induced dose-dependent relaxation with comparable potency (pEC50 = 6.14 ± 0.08 and 6.4 ± 0.14, respectively and maximum effect (Emax = 82% vs. 100%, respectively. All NO donors were found to activate soluble guanylate cyclase, since the addition of the corresponding inhibitor (100 µM ODQ completely neutralized the relaxation effect observed. The addition of oxyhemoglobin reduced the relaxation effect, but did not inhibit it completely. In aortic vascular endothelium 3 µM oxyhemoglobin decreased the relaxation effect by 26% on the average, while 10 µM oxyhemoglobin reduced it by over 52%. The addition of 100 µM L-cysteine produced no significant inhibiting effect. CONCLUSIONS: These results suggest that LLNO1 and FONO1 are potent vasodilators. LLNO1 was

  6. The Relationship between Estrogen and Nitric Oxide in the Prevention of Cardiac and Vascular Anomalies in the Developing Zebrafish (Danio Rerio

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    Benjamin G. Sykes


    Full Text Available It has been known that both estrogen (E2 and nitric oxide (NO are critical for proper cardiovascular system (CVS function. It has also been demonstrated that E2 acts as an upstream effector in the nitric oxide (NO pathway. Results from this study indicate that the use of a nitric oxide synthase (NOS inhibitor (NOSI which targets specifically neuronal NOS (nNOS or NOS1, proadifen hydrochloride, caused a significant depression of fish heart rates (HR accompanied by increased arrhythmic behavior. However, none of these phenotypes were evident with either the inhibition of endothelial NOS (eNOS or inducible NOS (iNOS isoforms. These cardiac arrhythmias could also be mimicked by inhibition of E2 synthesis with the aromatase inhibitor (AI, 4-OH-A, in a manner similar to that of nNOSI. In both scenarios, by using an NO donor (DETA-NO in either NO + nNOSI or E2 + AI co-treatments, fish could be significantly rescued from decreased HR and increased arrhythmias. However, the addition of an NOS inhibitor (L-NAME to the E2 + AI co-treatment fish prevented the rescue of low heart rates and arrhythmias, which strongly implicates the NO pathway as a downstream E2 targeted molecule for the maintenance of healthy cardiomyocyte contractile conditions in the developing zebrafish. Cardiac arrhythmias could be mimicked by the S-nitrosylation pathway inhibitor DTT (1,4-dithiothreitol but not by ODQ (1H-[1–3]oxadiazolo[4,3-a]quinoxalin-1-one, the inhibitor of the NO receptor molecule sGC in the cGMP-dependent pathway. In both the nNOSI and AI-induced arrhythmic conditions, 100% of the fish expressed the phenotype, but could be rapidly rescued with maximum survival by a washout with dantrolene, a ryanodine Ca2+ channel receptor blocker, compared to the time it took for rescue using a control salt solution. In addition, of the three NOS isoforms, eNOS was the one most implicated in the maintenance of an intact developing fish vascular system. In conclusion, results

  7. Evidence for generation of a large amount of nitric oxide-like vascular smooth muscle relaxant by cholesterol-rich neutrophils. (United States)

    Mehta, J L; Lawson, D L; Nicolini, F A; Cain, D A; Mehta, P; Schreier, H


    To determine the effect of cholesterol incorporation on the ability of neutrophils to generate superoxide radicals and nitric oxide-like vasorelaxant material, isolated human neutrophils were incubated with cholesterol-rich liposomes, which increased total cholesterol content by 141% and esterified cholesterol content by 523%. Cholesterol loading resulted in 5 to 7 fold increase in cytosolic calcium in resting as well as in PMA or f-MLP-stimulated cells, but a marked (P less than 0.01) reduction in both PMA- and f-MLP-stimulated superoxide radical generation by these cells. Nitric oxide-like activity measured as relaxation of rat aortic rings was more pronounced (P less than 0.02) in cholesterol-rich than in cholesterol-poor cells. The greater relaxation of aortic rings in response to cholesterol-rich neutrophils was observed in rings with or without intact endothelium, and was potentiated by superoxide dismutase and inhibited by oxyhemoglobin as well as L-NMMA, thus suggesting that the vasorelaxant material was nitric oxide. The greater generation of nitric oxide by cholesterol-rich neutrophils occurs perhaps in response to increased cytosolic calcium.

  8. Nitric oxide attenuates overexpression of Giα proteins in vascular smooth muscle cells from SHR: Role of ROS and ROS-mediated signaling.

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    Oli Sarkar

    Full Text Available Vascular smooth muscle cells (VSMC from spontaneously hypertensive rats (SHR exhibit decreased levels of nitric oxide (NO that may be responsible for the overexpression of Giα proteins that has been shown as a contributing factor for the pathogenesis of hypertension in SHR. The present study was undertaken to investigate if increasing the intracellular levels of NO by NO donor S-Nitroso-N-acetyl-DL-penicillamine (SNAP could attenuate the enhanced expression of Giα proteins in VSMC from SHR and explore the underlying mechanisms responsible for this response. The expression of Giα proteins and phosphorylation of ERK1/2, growth factor receptors and c-Src was determined by Western blotting using specific antibodies. Treatment of VSMC from SHR with SNAP for 24 hrs decreased the enhanced expression of Giα-2 and Giα-3 proteins and hyperproliferation that was not reversed by 1H (1, 2, 4 oxadiazole (4, 3-a quinoxalin-1-one (ODQ, an inhibitor of soluble guanylyl cyclase, however, PD98059, a MEK inhibitor restored the SNAP-induced decreased expression of Giα proteins towards control levels. In addition, the increased production of superoxide anion, NAD(PH oxidase activity, overexpression of AT1 receptor, Nox4, p22phox and p47phox proteins, enhanced levels of TBARS and protein carbonyl, increased phosphorylation of PDGF-R, EGF-R, c-Src and ERK1/2 in VSMC from SHR were all decreased to control levels by SNAP treatment. These results suggest that NO decreased the enhanced expression of Giα-2/3 proteins and hyperproliferation of VSMC from SHR by cGMP-independent mechanism and involves ROS and ROS-mediated transactivation of EGF-R/PDGF-R and MAP kinase signaling pathways.

  9. Hypoxia-inducible factor-1α, vascular endothelial growth factor, inducible nitric oxide synthase, and endothelin-1 expression correlates with angiogenesis in congenital heart disease

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    Hsin-Ling Yin


    Full Text Available In Taiwan, the average prevalence of congenital heart disease (CHD is 13.08/1000 live births. Most children with CHD die before the age of 5 years; therefore, identifying treatment methods to extend the life of CHD patients is an important issue in clinical practice. The objective of this study is to evaluate the roles of hypoxia-inducible factor-1α (HIF-1α, vascular endothelial growth factor (VEGF, inducible nitric oxide synthase (iNOS, endothelin-1 (ET-1, and CD34 in CHD autopsy cases in comparison with autopsy cases without CHD. The study included 19 autopsy cases, which were divided into the following four groups: acyanotic CHD (n = 11, cyanotic CHD (n = 3, CHD associated with chromosomal abnormalities (n = 3, and complex CHD (n = 2. Heart specimens obtained from 10 autopsy cases without CHD were included as controls. Our results indicated that high percentages of HIF-1α (100%, VEGF (89.5%, iNOS (78.9%, and ET-1 (84.2% expressions were observed in CHD autopsy cases and this was found to be significant. HIF-1α induced by hypoxia could play a potential role in relating downstream gene expressions in CHD patients. Upregulation of VEGF by HIF-1α could play an important role in triggering angiogenesis to protect myocardial cell survival in a hypoxic microenvironment. Therefore, HIF-1α could be a significant prognosis marker in CHD and be a prospective candidate in the development of target therapy in cardiovascular diseases.

  10. Tobacco Xenobiotics Release Nitric Oxide

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    Lam EWN


    Full Text Available Abstract Many xenobiotic compounds exert their actions through the release of free radicals and related oxidants 12, bringing about unwanted biological effects 3. Indeed, oxidative events may play a significant role in tobacco toxicity from cigarette smoke. Here, we demonstrate the direct in vitro release of the free radical nitric oxide (•NO from extracts and components of smokeless tobacco, including nicotine, nitrosonornicotine (NNN and 4-(methyl-N-nitrosamino-1-(3-pyridyl-1-butanone (NNK in phosphate buffered saline and human saliva using electron spin resonance and chemiluminescence detection. Our findings suggest that tobacco xenobiotics represent as yet unrecognized sources of •NO in the body.

  11. Hemorrhagic Shock-Induced Vascular Hyporeactivity in the Rat: Relationship to Gene Expression of Nitric Oxide Synthase, Endothelin-1, and Select Cytokines in Corresponding Organs (United States)


    Parvathaneni, L. S., Bourlier, V., Sauter, C., Laubach, V. E., and Cobb, J. P. iNOS gene expression modu- lates microvascular responsiveness in endotoxin...Burtrum, D., and Silerstein, F. S. Cerebral hypoxia-ischemia stimulates cytokine gene expression in peri- natal rats. Stroke 26: 1093, 1995. 22...Mattson, D. L., and Wu, F. Nitric oxide synthase activity and isoforms in rat renal vasculature. Hypertension 35: 337, 2000. 23. Thiemermann, C., Szabó, C

  12. Vascular endothelial growth factor-induced nitric oxide- and PGI2-dependent relaxation in human internal mammary arteries: a comparative study with KDR and Flt-1 selective mutants. (United States)

    Wei, Wei; Jin, Hongkui; Chen, Zhi-Wu; Zioncheck, Thomas F; Yim, Anthony P C; He, Guo-Wei


    The role of the vascular endothelial growth factors (VEGF) receptors (KDR and Flt-1) and their characteristics in VEGF-induced vasodilation in human vessels is unclear. This study investigated the in vitro vasorelaxant effects of KDR-selective (KDR-SM) and Flt-1-selective mutants (Flt-1-SM) in the human internal mammary artery (IMA). IMA segments (n = 183) taken from 48 patients were studied in organ baths. The cumulative concentration (-12 to -8 log10M)-relaxation curves were established for VEGF, KDR-SM, Flt-1-SM, and placenta growth factor (PlGF) in the absence or presence of indomethacin (INDO, 7 microM), N-nitro-L-arginine (L-NNA, 300 microM), L-NNA + oxyhemoglobin (HbO, 20 microM), or INDO + L-NNA + HbO. The VEGF-induced relaxation was abolished in endothelium-denuded IMA. In the endothelium-intact vessel rings, VEGF (63.2 +/- 3.9%) induced significantly more (P < 0.001) relaxation than Flt-1-SM (28.5 +/- 4.3%, 95% CI 18.1-51.3%), and PlGF (26.0 +/- 4.7%, 95% CI 17.6-56.8%). The maximal relaxation induced by KDR-SM (53.0 +/- 4.0%) was only slightly less than that by VEGF (P = 0.075) but significantly more than that by Flt-1-SM (P = 0.001, 95% CI 7.8-41.1%). Pretreatment of INDO or L-NNA + HbO significantly (P < 0.001) inhibited the relaxation by VEGF (21.2 +/- 3.9% or 23.3 +/- 4.3%) and KDR-SM (9.8 +/- 8.2% or 10.1 +/- 17.8%). INDO + L-NNA + HbO completely inhibited the relaxation by VEGF, KDR-SM, or Flt-1-SM. KDR may be the dominant receptor in mediating the VEGF-mediated relaxation, which is regulated by both PGI2 and nitric oxide but probably not by endothelium-derived hyperpolarizing factor, in the human IMA. This study gives insight into the characteristics of the VEGF-mediated vasodilation and provides a scientific basis for potential clinical application of VEGF/KDR-SM in ischemic heart disease.

  13. Expression of p53, inducible nitric oxide synthase and vascular endothelial growth factor in gastric precancerous and cancerous lesions: correlation with clinical features

    Directory of Open Access Journals (Sweden)

    Jiao Lian


    Full Text Available Abstract Background The growth and metastasis of tumors depend on the development of an adequate blood supply via angiogenesis. Recent studies indicate that the inducible nitric oxide synthase (iNOS, vascular endothelial growth factor (VEGF and the tumor suppressor p53 are fundamental play-markers of the angiogenic process. Overexpression of iNOS and VEGF has been shown to induce angiogenesis in tumors. P53 suppresses angiogenesis by down-regulating VEGF and iNOS. The correlation of expression of p53, VEGF and iNOS and clinical features in gastric carcinogenesis, however, has not been well characterized. Methods The expression of p53, iNOS and VEGF in gastric precancerous and cancerous lesions and its relation with the clinical features was determined with immunohistochemistry (avidin-biotin-peroxidase complex method on 55 randomly selected GC patients and 60 symptom-free subjects from the mass survey in the high-incidence area for GC in Henan, northern China. Results The positive immunostainig rates for p53, iNOS and VEGF in gastric carcinomas were 51%, 44% and 51%, respectively, and correlated well with TNM stages, but did not show significant difference among the groups with different degrees of gastric wall invasion depth by GC. A positive immunostaining reaction for the iNOS protein was significantly correlated with lymph node metastasis (p = 0.019; Spearman correlation coefficient. P53 protein accumulation was higher in the poorly-differentiated gastric carcinoma than in well-differentiated one. In gastric biopsies, no positive immunosatining was observed for p53, iNOS and VEGF in the histologically normal tissue and chronic superficial gastritis (CSG. However, p53, iNOS and VEGF positive immunostaining was observed in the tissues with different severities of lesions of chronic atrophic gastritis (CAG, intestinal metaplasia (IM and dysplasia (DYS, and the positive rates increased with the lesion progression from CAG to IM to DYS. A high

  14. Evaluation of Fractioned Nitric Oxide in Chronic Cough Patients ...

    African Journals Online (AJOL)

    Introduction: Cough exceeding 3-8 weeks was defined as chronic cough in various guides. Asthma is the most common cause of chronic-specific cough. Causes other than asthma include prolonged bacterial bronchitis and upper airway cough syndrome (UACS). Nitric oxide (NO) causes vascular smooth muscle relaxation, ...

  15. Nitric oxide and carbon monoxide diffusing capacity of the lung

    NARCIS (Netherlands)

    Lee, I. van der


    The single breath diffusion capacity of the lung for carbon monoxide (DLCO) is measure for gas uptake by the lung, and consists of a membrane and a vascular component. Nitric oxide (NO) binds 400 times faster to hemoglobin than carbon monoxide, thus the uptake of NO by the blood is very large.

  16. Resveratrol and Endothelial Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Ning Xia


    Full Text Available Nitric oxide (NO derived from the endothelial NO synthase (eNOS has antihypertensive, antithrombotic, anti-atherosclerotic and antiobesogenic properties. Resveratrol is a polyphenol phytoalexin with multiple cardiovascular and metabolic effects. Part of the beneficial effects of resveratrol are mediated by eNOS. Resveratrol stimulates NO production from eNOS by a number of mechanisms, including upregulation of eNOS expression, stimulation of eNOS enzymatic activity and reversal of eNOS uncoupling. In addition, by reducing oxidative stress, resveratrol prevents oxidative NO inactivation by superoxide thereby enhancing NO bioavailability. Molecular pathways underlying these effects of resveratrol involve SIRT1, AMPK, Nrf2 and estrogen receptors.

  17. Immunobiology of Nitric Oxide and Regulation of Inducible Nitric Oxide Synthase. (United States)

    Lee, Martin; Rey, Kevin; Besler, Katrina; Wang, Christine; Choy, Jonathan

    Nitric oxide (NO) is a bioactive gas that has multiple roles in innate and adaptive immune responses. In macrophages, nitric oxide is produced by inducible nitric oxide synthase upon microbial and cytokine stimulation. It is needed for host defense against pathogens and for immune regulation. This review will summarize the role of NO and iNOS in inflammatory and immune responses and will discuss the regulatory mechanisms that control inducible nitric oxide synthase expression and activity.

  18. Liver cirrhosis and nitric oxide

    Directory of Open Access Journals (Sweden)

    Yusuf Ergun


    Full Text Available Liver cirrhosis is a clinical condition which appears due to various etiologies and basically contains diffuse fibrozis and nodularity. Portal hypertension frequently accompanies this condition and constitutes the complications with negative effects concerning patients mortality and morbidity. For this reason, understanding the pathophysiologies of cirrhosis and portal hypertension is essential for the supplementation of new treatment options. In this review, the role of nitric oxide in the pathophysiologies of fibrosis, cirrhosis and portal hypertension has been discussed. [Archives Medical Review Journal 2009; 18(2.000: 91-131

  19. Role of nitric oxide in cerebrovascular reactivity to NMDA and hypercapnia during prenatal development in sheep


    Harris, Andrew P.; Ohata, Hiroto; Koehler, Raymond C.


    Cerebral vasodilatory responses evoked by activation of NMDA receptors and by hypercapnia are important factors in the integrated vascular response to perinatal cerebral ischemia. Cerebral vasodilation to NMDA is mediated by nitric oxide in adult and newborn animals, whereas vasodilation to hypercapnia is thought to become modulated by nitric oxide, at least in swine, after the newborn period. The developmental role of nitric oxide in the cerebral blood flow response to NMDA and hypercapnia w...

  20. Cervical nitric oxide release in women postterm. (United States)

    Väisänen-Tommiska, Mervi; Nuutila, Mika; Ylikorkala, Olavi


    Nitric oxide may be a factor in cervical ripening. We compared the nitric oxide metabolite levels in cervical fluid in women going beyond term and in women delivering spontaneously at term. We studied a total of 208 women with singleton pregnancies: 108 women who went beyond term (294 days or longer), and 100 women who went spontaneously into labor at term. Cervical fluid samples, collected well before the initiation of labor, were assessed for nitric oxide metabolites using an assay with a detection limit of 3.8 micromol/L. Women going beyond term had detectable levels of nitric oxide metabolites in their cervical fluid (60%) less often (P =.001) than women delivering at term (87%). The nitric oxide metabolite concentration in cervical fluid in women going beyond term (median 23.5 micromol/L; 95% confidence interval less than 3.8, 31.8) was 4.5 times lower (P postterm labor were included in the comparison. Both nulliparous (median less than 3.8 micromol/L) and parous (median 31.3 micromol/L) women going beyond term had lower (P postterm group, women with cervical fluid nitric oxide metabolite concentrations at or below the median failed more often (P <.001) to progress in labor and had longer (P =.02) duration of labor than those with cervical fluid nitric oxide metabolite concentrations above the median. Reduced cervical nitric oxide release may contribute to prolonged pregnancy. II-2

  1. Low-level expression and limited role for the inducible isoform of nitric oxide synthase in the vascular hyporeactivity and mortality associated with cecal ligation and puncture in the rat. (United States)

    Vromen, A; Arkovitz, M S; Zingarelli, B; Salzman, A L; Garcia, V F; Szabó, C


    Expression of the inducible isoform of nitric oxide synthase (iNOS) contributes to the hypotension and vascular hyporeactivity in various models of shock induced by bacterial lipopolysaccharide (LPS). However, the role of iNOS in response to shock caused by live bacteria is more controversial. In the present study, we investigated the role of iNOS in a rat model of cecal ligation and puncture (CLP). CLP resulted in increased plasma nitrite/nitrate levels (up to 59 microM at 24 h) and increased pulmonary iNOS activity (up to 71 fmoles/mg/min at 12 h) and caused a significant vascular hyporeactivity at 18 h. The degree of NO production and iNOS induction was approximately 30% of that observed several hours after administration of LPS in the same species, and the degree of vascular hyporeactivity was less than that observed after LPS injection. Selective inhibition of iNOS with mercaptoethylguanidine (MEG) reduced plasma nitrite/nitrate levels, but did not prevent the development of vascular hyporeactivity, and did not improve survival in this model of CLP. Thus, CLP-induced sepsis causes low-level induction of iNOS, but factors other than iNOS are the crucial determinants of the vascular failure and mortality in this model.

  2. Nitric oxide, S-nitrosation, and endothelial permeability. (United States)

    Durán, Walter N; Beuve, Annie V; Sánchez, Fabiola A


    S-Nitrosation is rapidly emerging as a regulatory mechanism in vascular biology, with particular importance in the onset of hyperpermeability induced by pro-inflammatory agents. This review focuses on the role of endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) in regulating S-Nitrosation of adherens junction proteins. We discuss evidence for translocation of eNOS, via caveolae, to the cytosol and analyze the significance of eNOS location for S-Nitrosation and onset of endothelial hyperpermeability to macromolecules. © 2013 International Union of Biochemistry and Molecular Biology.

  3. Hydroxocobalamins as biologically compatible donors of nitric oxide implicated in the acceleration of wound healing. (United States)

    Bauer, J A


    In the late 1970s, research was unfolding that implicated nitric oxide involvement in the process of vasodilation. By 1986, research culminated in the identification of nitric oxide as the endothelium-derived relaxing factor responsible for the maintenance of vascular tone, thus implicating nitric oxide as a potential wound-healing agent. Biomedical researchers involved in wound-healing research quickly embraced the utility of developing a polymeric donor of nitric oxide which would enhance the wound-healing process. Several synthetic nitric oxide donors have been developed, dubbed 'NONOates', which have achieved great success in delivering nitric oxide to wounds. However, the impact on wound healing has been ambiguous and deemed antagonistic to the immune system in some cases. The propensity for the immune system to reject 'non-self' is a major factor in evaluating the usefulness of synthetic polymeric nitric oxide donors. The necessity of natural-product nitric oxide donors is apparent when examining the complications which are possible in a synthetic delivery system. Given the affinity nitric oxide has for transition metals, and the biological availability of transition-metal-centered products in vivo, it seems logical to pursue a transition-metal nitric oxide donor which is biologically friendly. Vitamin B12a (hydroxocobalamin), a natural product, offers an ideal environment to serve as a donor of nitric oxide.

  4. Nitric oxide signaling in hypoxia. (United States)

    Ho, J J David; Man, H S Jeffrey; Marsden, Philip A


    Endothelial-derived nitric oxide (NO) is classically viewed as a regulator of vasomotor tone. NO plays an important role in regulating O(2) delivery through paracrine control of vasomotor tone locally and cardiovascular and respiratory responses centrally. Very soon after the cloning and functional characterization of the endothelial nitric oxide synthase (eNOS), studies on the interaction between O(2) and NO made the paradoxical finding that hypoxia led to decreases in eNOS expression and function. Why would decreases in O(2) content in tissues elicit a loss of a potent endothelial-derived vasodilator? We now know that restricting our view of NO as a regulator of vasomotor tone or blood pressure limited deeper levels of mechanistic insight. Exciting new studies indicate that functional interactions between NO and O(2) exhibit profound complexity and are relevant to diseases states, especially those associated with hypoxia in tissues. NOS isoforms catalytically require O(2). Hypoxia regulates steady-state expression of the mRNA and protein abundance of the NOS enzymes. Animals genetically deficient in NOS isoforms have perturbations in their ability to adapt to changes in O(2) supply or demand. Most interestingly, the intracellular pathways for O(2) sensing that evolved to ensure an appropriate balance of O(2) delivery and utilization intersect with NO signaling networks. Recent studies demonstrate that hypoxia-inducible factor (HIF) stabilization and transcriptional activity is achieved through two parallel pathways: (1) a decrease in O(2)-dependent prolyl hydroxylation of HIF and (2) S-nitrosylation of HIF pathway components. Recent findings support a role for S-nitrosothiols as hypoxia-mimetics in certain biological and/or disease settings, such as living at high altitude, exposure to small molecules that can bind NO, or anemia.

  5. Nitric oxide and chronic colitis

    Directory of Open Access Journals (Sweden)

    Matthew B Grisham


    Full Text Available Nitric oxide (NO is thought to play an important role in modulating the inflammatory response by virtue of its ability to affect bloodflow, leukocyte function and cell viability. The objective of this study was to assess the role that NO may play in mediating the mucosal injury and inflammation in a model of chronic granulomatous colitis using two pharmacologically different inhibitors of nitric oxide synthase (NOS. Chronic granulomatous colitis with liver and spleen inflammation was induced in female Lewis rats via the subserosal (intramural injection of peptidoglycan/polysaccharide (PG/PS derived from group A streptococci. Chronic NOS inhibition by oral administration of NG-nitro-L-arginine methyl ester (L-NAME (15 µmol/kg/day or amino-guanidine (AG (15 µmol/ kg/day was found to attenuate the PG/PS-induced increases in macroscopic colonic inflammation scores and colonic myeloperoxidase activity. Only AG -- not L-NAME – attenuated the PG/PS-induced increases in colon dry weight. Both L-NAME and AG significantly attenuated the PG/PS-induced increases in spleen weight whereas neither was effective at significantly attenuating the PG/PS-induced increases in liver weight. Although both L-NAME and AG inhibited NO production in vivo, as measured by decreases in plasma nitrite and nitrate levels, only AG produced significantly lower values (38±3 versus 83±8 µM, respectively, P<0.05. Finally, L-NAME, but not AG, administration significantly increased mean arterial pressure from 83 mmHg in colitic animals to 105 mmHg in the PG/PS+ L-NAME-treated animals (P<0.05. It is concluded that NO may play an important role in mediating some of the pathophysiology associated with this model of chronic granulomatous colitis.

  6. (SNP) of endothelial nitric oxide synthase gene and serum level of ...

    African Journals Online (AJOL)

    T-786C single-nucleotide polymorphism (SNP) of endothelial nitric oxide synthase gene and serum level of vascular endothelial relaxant factor (VERF) in non-diabetic patients with coronary artery disease.

  7. Nitric oxide in marine photosynthetic organisms. (United States)

    Kumar, Amit; Castellano, Immacolata; Patti, Francesco Paolo; Palumbo, Anna; Buia, Maria Cristina


    Nitric oxide is a versatile and powerful signaling molecule in plants. However, most of our understanding stems from studies on terrestrial plants and very little is known about marine autotrophs. This review summarizes current knowledge about the source of nitric oxide synthesis in marine photosynthetic organisms and its role in various physiological processes under normal and stress conditions. The interactions of nitric oxide with other stress signals and cross talk among secondary messengers are also highlighted. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Nitric oxide and cardiovascular risk factors

    Directory of Open Access Journals (Sweden)

    Livio Dai Cas


    Full Text Available The endothelium is a dynamic organ with many properties that takes part in the regulation of the principal mechanisms of vascular physiology. Its principal functions include the control of blood-tissue exchange and permeability, the vascular tonus, and the modulation of inflammatory or coagulatory mechanisms. Many vasoactive molecules, produced by the endothelium, are involved in the control of these functions. The most important is nitric oxide (NO, a gaseous molecule electrically neutral with an odd number of electrons that gives the molecule chemically reactive radical properties. Already known in the twentieth century, NO, sometimes considered as a dangerous molecule, recently valued as an important endogenous vasodilator factor. Recently, it was discovered that it is involved in several physiological mechanisms of endothelial protection (Tab. I. In 1992, Science elected it as “molecule of the year”; 6 yrs later three American researchers (Louis Ignarro, Robert Furchgott and Fried Murad obtained a Nobel Prize for Medicine and Physiology “for their discoveries about NO as signal in the cardiovascular system”.

  9. The Glu298Asp single nucleotide polymorphism in the endothelial nitric oxide synthase gene differentially affects the vascular response to acute consumption of fruit and vegetable puree based drinks. (United States)

    George, Trevor W; Waroonphan, Saran; Niwat, Chutamat; Gordon, Michael H; Lovegrove, Julie A


    Diets low in fruits and vegetables (FV) are responsible for 2.7 million deaths from cardiovascular diseases (CVD) and certain cancers annually. Many FV and their juices contain flavonoids, some of which increase endothelial nitric oxide synthase (eNOS) activity. A single nucleotide polymorphism in the eNOS gene, where thymine (T) replaces guanine (G) at position 894 predicting substitution of glutamate for aspartate at codon 298 (Glu298Asp), has been associated with increased CVD risk due to effects on nitric oxide synthesis and subsequently vascular reactivity. Individuals can be homozygous for guanine (GG), thymine (TT) or heterozygous (GT). We investigated the effects of acute ingestion of a FV-puree-based-drink (FVPD) on vasodilation and antioxidant status in subjects retrospectively genotyped for this polymorphism. Healthy volunteers (n = 24; 11 GG, 11 GT, 2 TT) aged 30-70 were recruited to a randomized, controlled, crossover, acute study. We showed that acute consumption of 400 mL FVPD differentially affected individuals depending on their genotype. There was a significant genotype interaction for endothelium-dependent vasodilation measured by laser Doppler imaging with iontophoresis (P puree-based drink. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Nitric oxide synthases: structure, function and inhibition

    National Research Council Canada - National Science Library

    Alderton, W K; Cooper, C E; Knowles, R G


    This review concentrates on advances in nitric oxide synthase (NOS) structure, function and inhibition made in the last seven years, during which time substantial advances have been made in our understanding of this enzyme family...

  11. Nitric oxide donors for treating preterm labour. (United States)

    Duckitt, Kirsten; Thornton, Steve; O'Donovan, Oliver P; Dowswell, Therese


    A number of tocolytics have been advocated for the treatment of threatened preterm labour in order to delay birth. The rationale is that a delay in birth may be associated with improved neonatal morbidity or mortality. Nitric oxide donors, such as nitroglycerin, have been used to relax the uterus. This review addresses their efficacy, adverse effects and influence on neonatal outcome. To determine whether nitric oxide donors administered in threatened preterm labour are associated with a delay in birth, adverse effects or improved neonatal outcome. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 December 2013). Randomised controlled trials of nitric oxide donors administered for tocolysis. Two review authors independently assessed trial quality and extracted data. Twelve trials, including a total of 1227 women at risk of preterm labour, contributed data to this updated review. The methodological quality of trials was mixed; trials comparing nitric oxide donors with other types of tocolytics were not blinded and this may have had an impact on findings.Three studies compared nitric oxide donors (glyceryl trinitrate (GTN)) with placebo. There was no significant evidence that nitric oxide donors prolonged pregnancy beyond 48 hours (average risk ratio (RR) 1.19, 95% confidence interval (CI) 0.74 to 1.90, two studies, 186 women), and although for most adverse effects there was no significant difference between groups, women in the active treatment group in one study were at higher risk of experiencing a headache. For infant outcomes there was no significant evidence that nitric oxide donors reduced the risk of neonatal death or serious morbidity (stillbirth RR 0.36, 95% CI 0.01 to 8.59, one study, 153 infants; neonatal death RR 0.43, 95% CI 0.06 to 2.89, two studies, 186 infants). One study, using a composite outcome, reported a reduced risk of serious adverse outcomes for infants in the GTN group which approached statistical significance (RR

  12. Nitric oxide in cancer metastasis. (United States)

    Cheng, Huiwen; Wang, Lei; Mollica, Molly; Re, Anthony T; Wu, Shiyong; Zuo, Li


    Cancer metastasis is the spread and growth of tumor cells from the original neoplasm to further organs. This review analyzes the role of nitric oxide (NO), a signaling molecule, in the regulation of cancer formation, progression, and metastasis. The action of NO on cancer relies on multiple factors including cell type, metastasis stage, and organs involved. Various chemotherapy drugs cause cells to release NO, which in turn induces cytotoxic death of breast, liver, and skin tumors. However, NO has also been clinically connected to a poor cancer prognosis because of its role in angiogenesis and intravasation. This supports the claim that NO can be characterized as both pro-metastatic and anti-metastatic, depending on specific factors. The inhibition of cell proliferation and anti-apoptosis pathways by NO donors has been proposed as a novel therapy to various cancers. Studies suggest that NO-releasing non-steroidal anti-inflammatory drugs act on cancer cells in several ways that may make them ideal for cancer therapy. This review summarizes the biological significance of NO in each step of cancer metastasis, its controversial effects for cancer progression, and its therapeutic potential. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Nitric Oxide for preterm infants

    Directory of Open Access Journals (Sweden)

    Manuel Sánchez Luna


    Full Text Available Inhaled nitric oxide (iNO is a selective pulmonary vasodilator that has demonstrated its efficacy when used to treat severe hypoxemic respiratory failure associated to pulmonary hypertension in term or near term newborns since 1992. Premature newborn infants are not included in the approved indication of iNO use, but in some circumstances, when pulmonary hypertension is associated to severe respiratory failure iNO has been demonstrated as an effective therapy to improve respiratory failure. Also iNO demonstrated in animal studies its potential use to treat or prevent BPD, but clinical trials have failed to demonstrate any beneficial effect of this drug when used as routine or rescue therapy, and probably only in a selected group of preterm infants, used soon after delivery and not severely ill it could have a role if any. The neuro-protective effect found in some experimental studies and clinical reports gives a new attractive potential indication of iNO use in this population, but current data of follow-up multicenter randomized controlled trials do not support this effect. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  14. Processes regulating nitric oxide emissions from soils

    DEFF Research Database (Denmark)

    Pilegaard, Kim


    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...

  15. The Effect of Aerobic Training and Arbotin on Cardiac Nitric Oxide, Tumor Necrosis Factor alpha, and Vascular Endothelial Growth Factor in Male Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Rahemeh Jahangiri Jahangiri


    Full Text Available Background and Objectives: Diabetes is one of the most important metabolic diseases, which its incidence rate has increased in recent years. In this disease, the insulin function is impaired, leading to several complications. Physical exercise and medicinal plants are considered as a way to control diabetes along with nutrition and medicine. The present study was conducted with the purpose of determining the effect of aerobic training and use of arbutin on cardiac nitric oxide, tumor necrosis factor-α and vessel endothelial growth factor in male diabetic rats. Methods: In this experimental study, 42 male adult Wistar rats (age, 8 weeks; weight, 190-220g, were randomly divided into 6 groups of 7 each (control, arbutin, diabetic, diabetic+training, diabetic+arbutin, and diabetic+training+arbutin. Training programs included 5 days of swimming per week for 6 weeks. Sampling from the heart was performed 72 hours after the last training session and arbutin consumption to analyze NO, TNF-α and VEGF. Data were analyzed using one-way ANOVA at the significance level p≤0.05. Results: Aerobic training along with use of arbutin led to increased levels of NO and VEGF and decreased level of TNF-α in cardiac tissue of diabetic rats (p<0.001. Conclusion: The results indicated that a period of regular aerobic training and use of arbutin can be considered as an appropriate non-medicinal method to control diabetes mellitus type 2 through decrease in inflammatory factors.

  16. The Effects of Beta-Glucan Rich Oat Bread on Serum Nitric Oxide and Vascular Endothelial Function in Patients with Hypercholesterolemia

    Directory of Open Access Journals (Sweden)

    Faezeh Tabesh


    Full Text Available Introduction. Oats are high in soluble fibers and effective in reducing the risk of cardiovascular diseases (CVD. We assessed the effects of beta-glucan from oat bran on serum nitric oxide (NO endothelial function in patients with hypercholesterolemia. Method. Sixty hypercholesterolemic patients were randomly divided to receive an experimental bread rich in beta-glucan from oat bran (intervention or bread rich in wheat fiber (control for four weeks. All subjects had the same diet for two-week baseline period and hypocaloric diet for four weeks of intervention. Serum NO concentration and flow-mediated dilation (FMD were determined before and after the experiment. Results. Mean age of the participants was 51.1 ± 9.3 years and 65% (n=39 were female. After intervention, serum NO concentration increased by 50.2 ± 19.8 μmol/lit in the intervention group (P=0.017, but no change was observed in the control group (17.5 ± 27.5 μmol/lit; P=0.530. No change of FMD was observed in the intervention (0.48 ± 0.78%; P=0.546 or in the control group (0.59 ± 0.92%; P=0.533. Conclusion. Consumption of oat bread for four weeks increases serum NO concentration but has no effect on FMD. Further studies are warranted in this regard.

  17. New nitric oxide donors based on ruthenium complexes

    Directory of Open Access Journals (Sweden)

    C.N. Lunardi


    Full Text Available Nitric oxide (NO donors produce NO-related activity when applied to biological systems. Among its diverse functions, NO has been implicated in vascular smooth muscle relaxation. Despite the great importance of NO in biological systems, its pharmacological and physiological studies have been limited due to its high reactivity and short half-life. In this review we will focus on our recent investigations of nitrosyl ruthenium complexes as NO-delivery agents and their effects on vascular smooth muscle cell relaxation. The high affinity of ruthenium for NO is a marked feature of its chemistry. The main signaling pathway responsible for the vascular relaxation induced by NO involves the activation of soluble guanylyl-cyclase, with subsequent accumulation of cGMP and activation of cGMP-dependent protein kinase. This in turn can activate several proteins such as K+ channels as well as induce vasodilatation by a decrease in cytosolic Ca2+. Oxidative stress and associated oxidative damage are mediators of vascular damage in several cardiovascular diseases, including hypertension. The increased production of the superoxide anion (O2- by the vascular wall has been observed in different animal models of hypertension. Vascular relaxation to the endogenous NO-related response or to NO released from NO deliverers is impaired in vessels from renal hypertensive (2K-1C rats. A growing amount of evidence supports the possibility that increased NO inactivation by excess O2- may account for the decreased NO bioavailability and vascular dysfunction in hypertension.

  18. Inducible nitric oxide synthase is responsible for nitric oxide release from murine pituicytes

    DEFF Research Database (Denmark)

    Kjeldsen, T H; Rivier, C; Lee, S


    This study investigated whether pituicytes were able to produce and release nitric oxide (NO), and which type of nitric oxide synthase (NOS) would be responsible for this phenomenon. Lipopolysaccharide (LPS) 1 micro g/ml was used as inflammatory mediator. Because pituicytes are known to secrete...

  19. Nitric oxide production and nitric oxide synthase expression in acute human renal allograft rejection

    NARCIS (Netherlands)

    Albrecht, EWJA; van Goor, H; Tiebosch, ATMG; Moshage, H; Tegzess, Adam; Stegeman, CA


    Background Nitric oxide (NO) is produced by nitric oxide synthases (NOS), which are either constitutively expressed in the kidney or inducible, in resident and infiltrating cells during inflammation and allograft rejection. NO is rapidly degraded to the stable end products nitrite and nitrate, which

  20. Inhaled nitric oxide improves lung allograft function after prolonged storage. (United States)

    Okabayashi, K; Triantafillou, A N; Yamashita, M; Aoe, M; DeMeester, S R; Cooper, J D; Patterson, G A


    Morbidity caused by early allograft dysfunction, manifested by a progressive increase in pulmonary vascular resistance and a decrease in oxygenation, remains a serious problem in lung transplantation. Inhalation of nitric oxide, an essential homeostatic molecule, has been shown to have beneficial effects on a variety of acute lung injuries. The purpose of the present study was to investigate the effect of inhaled nitric oxide on posttransplant function of canine left lung allografts. Fourteen dogs underwent left lung allotransplantation. Donors received systemic heparin and prostaglandin E1 followed by pulmonary artery flush with modified Euro-Collins solution. Donor left lungs were stored for 18 hours at 1 degree C and subsequently implanted. Immediately after reperfusion, the contralateral right main pulmonary artery and bronchus were ligated. The chest was closed and recipients turned to the supine position for the 6-hour assessment period. Hemodynamic and arterial and venous blood gas analyses were made at 15-minute intervals at an inspired oxygen fraction of 1.0 and 5 cm of water positive end-expiratory pressure. Animals were killed at the end of the assessment. Allograft myeloperoxidase activity assays and wet/dry weight ratios were done. In group I (n = 5), nitric oxide gas was administered continuously at concentrations of 60 to 70 ppm before reperfusion and throughout the 6-hour assessment period. In group II (n = 5), nitric oxide administration was initiated at the same concentration after reperfusion injury had developed. Group III animals (n = 4) received no nitric oxide. Significant improvement in gas exchange was apparent in group I. At the end of the 6-hour assessment period, mean arterial oxygen tension was 253.8 +/- 44.7 mm Hg and 114.9 +/- 25.5 mm Hg in groups I and III, respectively (p < 0.05). Group II animals had no improvement in oxygenation with nitric oxide. Systemic hemodynamics were unaffected by nitric oxide. However, an immediate


    Directory of Open Access Journals (Sweden)

    Cintia Rabelo e Paiva CARIA


    Full Text Available Context Intestinal inflammation can induce a local reduction in oxygen levels that triggers an adaptive response centered on the expression of hypoxia-inducible factors (HIFs. Nitric oxide, a well-described inflammatory mediator, may interfere with hypoxia signaling. Objectives We aimed to evaluate the role of nitric oxide in hypoxia signaling during colonic inflammation. Methods Colitis was induced by single (acute or repeated (reactivated colitis trinitrobenzenosulfonic acid administration in rats. In addition, one group of rats with reactivated colitis was also treated with Nw-Nitro-L-arginine methyl ester hydrochloride to block nitric oxide synthase. Colitis was assessed by macroscopic score and myeloperoxidase activity in the colon samples. Hypoxia was determined using the oxygen-dependent probe, pimonidazole. The expression of HIF-1α and HIF-induced factors (vascular endothelial growth factor - VEGF and apelin was assessed using Western blotting. Results The single or repeated administration of trinitrobenzenosulfonic acid to rats induced colitis which was characterized by a high macroscopic score and myeloperoxidase activity. Hypoxia was observed with both protocols. During acute colitis, HIF-1α expression was not increased, but VEGF and apelin were increased. HIF-1α expression was inhibited during reactivated colitis, and VEGF and apelin were not increased. Nw-Nitro-L-arginine methyl ester hydrochloride blockade during reactivated colitis restored HIF-1α, VEGF and apelin expression. Conclusions Nitric oxide could interfere with hypoxia signaling during reactivated colitis inflammation modifying the expression of proteins regulated by HIF-1α.

  2. Nitric oxide interferes with hypoxia signaling during colonic inflammation. (United States)

    Caria, Cintia Rabelo e Paiva; Moscato, Camila Henrique; Tomé, Renata Bortolin Guerra; Pedrazzoli, José; Ribeiro, Marcelo Lima; Gambero, Alessandra


    Intestinal inflammation can induce a local reduction in oxygen levels that triggers an adaptive response centered on the expression of hypoxia-inducible factors (HIFs). Nitric oxide, a well-described inflammatory mediator, may interfere with hypoxia signaling. We aimed to evaluate the role of nitric oxide in hypoxia signaling during colonic inflammation. Colitis was induced by single (acute) or repeated (reactivated colitis) trinitrobenzenosulfonic acid administration in rats. In addition, one group of rats with reactivated colitis was also treated with Nw-Nitro-L-arginine methyl ester hydrochloride to block nitric oxide synthase. Colitis was assessed by macroscopic score and myeloperoxidase activity in the colon samples. Hypoxia was determined using the oxygen-dependent probe, pimonidazole. The expression of HIF-1α and HIF-induced factors (vascular endothelial growth factor - VEGF and apelin) was assessed using Western blotting. The single or repeated administration of trinitrobenzenosulfonic acid to rats induced colitis which was characterized by a high macroscopic score and myeloperoxidase activity. Hypoxia was observed with both protocols. During acute colitis, HIF-1α expression was not increased, but VEGF and apelin were increased. HIF-1α expression was inhibited during reactivated colitis, and VEGF and apelin were not increased. Nw-Nitro-L-arginine methyl ester hydrochloride blockade during reactivated colitis restored HIF-1α, VEGF and apelin expression. Nitric oxide could interfere with hypoxia signaling during reactivated colitis inflammation modifying the expression of proteins regulated by HIF-1α.

  3. Nitric oxide synthases: regulation and function (United States)

    Förstermann, Ulrich; Sessa, William C.


    Nitric oxide (NO), the smallest signalling molecule known, is produced by three isoforms of NO synthase (NOS; EC They all utilize l-arginine and molecular oxygen as substrates and require the cofactors reduced nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and (6R-)5,6,7,8-tetrahydrobiopterin (BH4). All NOS bind calmodulin and contain haem. Neuronal NOS (nNOS, NOS I) is constitutively expressed in central and peripheral neurons and some other cell types. Its functions include synaptic plasticity in the central nervous system (CNS), central regulation of blood pressure, smooth muscle relaxation, and vasodilatation via peripheral nitrergic nerves. Nitrergic nerves are of particular importance in the relaxation of corpus cavernosum and penile erection. Phosphodiesterase 5 inhibitors (sildenafil, vardenafil, and tadalafil) require at least a residual nNOS activity for their action. Inducible NOS (NOS II) can be expressed in many cell types in response to lipopolysaccharide, cytokines, or other agents. Inducible NOS generates large amounts of NO that have cytostatic effects on parasitic target cells. Inducible NOS contributes to the pathophysiology of inflammatory diseases and septic shock. Endothelial NOS (eNOS, NOS III) is mostly expressed in endothelial cells. It keeps blood vessels dilated, controls blood pressure, and has numerous other vasoprotective and anti-atherosclerotic effects. Many cardiovascular risk factors lead to oxidative stress, eNOS uncoupling, and endothelial dysfunction in the vasculature. Pharmacologically, vascular oxidative stress can be reduced and eNOS functionality restored with renin- and angiotensin-converting enzyme-inhibitors, with angiotensin receptor blockers, and with statins. PMID:21890489

  4. Oxidative stress and vascular inflammation in aging. (United States)

    El Assar, Mariam; Angulo, Javier; Rodríguez-Mañas, Leocadio


    Vascular aging, a determinant factor for cardiovascular disease and health status in the elderly, is now viewed as a modifiable risk factor. Impaired endothelial vasodilation is a early hallmark of arterial aging that precedes the clinical manifestations of vascular dysfunction, the first step to cardiovascular disease and influencing vascular outcomes in the elderly. Accordingly, the preservation of endothelial function is thought to be an essential determinant of healthy aging. With special attention on the effects of aging on the endothelial function, this review is focused on the two main mechanisms of aging-related endothelial dysfunction: oxidative stress and inflammation. Aging vasculature generates an excess of the reactive oxygen species (ROS), superoxide and hydrogen peroxide, that compromise the vasodilatory activity of nitric oxide (NO) and facilitate the formation of the deleterious radical, peroxynitrite. Main sources of ROS are mitochondrial respiratory chain and NADPH oxidases, although NOS uncoupling could also account for ROS generation. In addition, reduced antioxidant response mediated by erythroid-2-related factor-2 (Nrf2) and downregulation of mitochondrial manganese superoxide dismutase (SOD2) contributes to the establishment of chronic oxidative stress in aged vessels. This is accompanied by a chronic low-grade inflammatory phenotype that participates in defective endothelial vasodilation. The redox-sensitive transcription factor, nuclear factor-κB (NF-κB), is upregulated in vascular cells from old subjects and drives a proinflammatory shift that feedbacks oxidative stress. This chronic NF-κB activation is contributed by increased angiotensin-II signaling and downregulated sirtuins and precludes adequate cellular response to acute ROS generation. Interventions targeted to recover endogenous antioxidant capacity and cellular stress response rather than exogenous antioxidants could reverse oxidative stress-inflammation vicious cycle in

  5. Concentrations of endothelial nitric oxide synthase, angiotensin-converting enzyme, vascular endothelial growth factor and placental growth factor in maternal blood and maternal metabolic status in pregnancy complicated by hypertensive disorders. (United States)

    Zawiejska, A; Wender-Ozegowska, E; Iciek, R; Brazert, J


    Hypertensive disorders of pregnancy (HDPs) are associated with altered maternal metabolism, impaired perinatal outcome and increased risk for remote maternal complications. The aim of our study was to analyse associations between circulating levels of angiogenic factors and markers of oxidative stress and metabolic status in women with HDP. Forty-six women in singleton pregnancies complicated by HDP and 30 healthy controls were enrolled in a prospective observational study. Serum concentrations of endothelial nitric oxide synthase (eNOS), angiotensin-converting enzyme, vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) were measured in the third trimester and correlated with maternal anthropometrics and metabolic status. We found significantly lower eNOS levels in patients with severe hypertension vs controls, a strong association between eNOS and PlGF in the study group, a significant association between maternal prepregnancy body mass index (BMI) and VEGF levels and an inverse correlation between VEGF and PlGF. Maternal prepregnancy BMI was the only independent predictor for VEGF concentrations. We noted reduced levels of PlGF and eNOS and increased VEGF levels in women with severe hypertension/preeclampsia. First, different forms of HDP are associated with different alteration patterns in concentrations of angiogenic factors and markers of oxidative stress. Second, maternal prepregnancy BMI, but not body weight, is a significant predictor for VEGF levels in late pregnancy.

  6. Nitric oxide blunts the endothelin-mediated pulmonary vasoconstriction in exercising swine.

    NARCIS (Netherlands)

    B. Houweling (Birgit); D. Merkus (Daphne); M.M. Dekker (Marjolein); D.J.G.M. Duncker (Dirk)


    textabstractWe have previously shown that vasodilators and vasoconstrictors that are produced by the vascular endothelium, including nitric oxide (NO), prostanoids and endothelin (ET), contribute to the regulation of systemic and pulmonary vascular tone in swine, in particular during treadmill

  7. Nitric oxide: considerations for the treatment of ischemic stroke (United States)

    Terpolilli, Nicole A; Moskowitz, Michael A; Plesnila, Nikolaus


    Some 40 years ago it was recognized by Furchgott and colleagues that the endothelium releases a vasodilator, endothelium-derived relaxing factor (EDRF). Later on, several groups identified EDRF to be a gas, nitric oxide (NO). Since then, NO was identified as one of the most versatile and unique molecules in animal and human biology. Nitric oxide mediates a plethora of physiological functions, for example, maintenance of vascular tone and inflammation. Apart from these physiological functions, NO is also involved in the pathophysiology of various disorders, specifically those in which regulation of blood flow and inflammation has a key role. The aim of the current review is to summarize the role of NO in cerebral ischemia, the most common cause of stroke. PMID:22333622

  8. Nitrate tolerance impairs nitric oxide-mediated vasodilation in vivo

    DEFF Research Database (Denmark)

    Laursen, Jørn Bech; Boesgaard, Søren; Poulsen, Henrik E.


    Nitrates, Nitrate tolerence, Nitric oxide, acetylcholine, N-acetylcholine, N-acetylcysteine, L-NAME, Rat, Anesthetized......Nitrates, Nitrate tolerence, Nitric oxide, acetylcholine, N-acetylcholine, N-acetylcysteine, L-NAME, Rat, Anesthetized...

  9. Endothelial nitric oxide synthase gene polymorphisms associated ...

    African Journals Online (AJOL)



    May 24, 2010 ... NOS3 gene polymorphisms and clinical parameters in patients with periodontal disease. Genomic DNA was obtained from the ... Key words: Periodontal diseases, nitric oxide synthases gene, DNA, PCR. INTRODUCTION ... various diseases' pathogenesis because of its dual role. *Corresponding author.

  10. Endothelial nitric oxide synthase gene polymorphisms associated ...

    African Journals Online (AJOL)

    Endothelial nitric oxide synthase (NOS3) is involved in key steps of immune response. Genetic factors predispose individuals to periodontal disease. This study's aim was to explore the association between NOS3 gene polymorphisms and clinical parameters in patients with periodontal disease. Genomic DNA was obtained ...

  11. Nitric oxide formation from nitrite in zebrafish

    DEFF Research Database (Denmark)

    Jensen, Frank Bo


    Nitrite is a potential nitric oxide (NO) donor and may have important biological functions at low concentrations. The present study tests the hypothesis that nitrite accumulation across the gills in fish will cause a massive NO production from nitrite. Zebrafish were exposed to three different...

  12. Compartmentalized nitric oxide signaling in the resistance vasculature. (United States)

    Mutchler, Stephanie M; Straub, Adam C


    Nitric oxide (NO) was first described as a bioactive molecule through its ability to stimulate soluble guanylate cyclase, but the revelation that NO was the endothelium derived relaxation factor drove the field to its modern state. The wealth of research conducted over the past 30 years has provided us with a picture of how diverse NO signaling can be within the vascular wall, going beyond simple vasodilation to include such roles as signaling through protein S-nitrosation. This expanded view of NO's actions requires highly regulated and compartmentalized production. Importantly, resistance arteries house multiple proteins involved in the production and transduction of NO allowing for efficient movement of the molecule to regulate vascular tone and reactivity. In this review, we focus on the many mechanisms regulating NO production and signaling action in the vascular wall, with a focus on the control of endothelial nitric oxide synthase (eNOS), the enzyme responsible for synthesizing most of the NO within these confines. We also explore how cross talk between the endothelium and smooth muscle in the microcirculation can modulate NO signaling, illustrating that this one small molecule has the capability to produce a plethora of responses. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Nitric Oxide Manipulation: A Therapeutic Target for Peripheral Arterial Disease?

    Directory of Open Access Journals (Sweden)

    Gareth Williams


    Full Text Available Peripheral Arterial Disease (PAD is a cause of significant morbidity and mortality in the Western world. Risk factor modification and endovascular and surgical revascularisation are the main treatment options at present. However, a significant number of patients still require major amputation. There is evidence that nitric oxide (NO and its endogenous inhibitor asymmetric dimethylarginine (ADMA play significant roles in the pathophysiology of PAD. This paper reviews experimental work implicating the ADMA-DDAH-NO pathway in PAD, focussing on both the vascular dysfunction and effects within the ischaemic muscle, and examines the potential of manipulating this pathway as a novel adjunct therapy in PAD.

  14. Differential modulation of nitric oxide synthases in aging: therapeutic opportunities

    Directory of Open Access Journals (Sweden)

    Stêfany Bruno De Assis Cau


    Full Text Available Vascular aging is the term that describes the structural and functional disturbances of the vasculature with advancing aging. The molecular mechanisms of aging-associated endothelial dysfunction are complex, but reduced nitric oxide (NO bioavailability and altered vascular expression and activity of NO synthase (NOS enzymes have been implicated as major players. Impaired vascular relaxation in aging has been attributed to reduced endothelial NOS (eNOS-derived NO, while increased inducible NOS (iNOS expression seems to account for nitrosative stress and disrupted vascular homeostasis. Although eNOS is considered the main source of NO in the vascular endothelium, neuronal NOS (nNOS also contributes to endothelial cells-derived NO, a mechanism that is reduced in aging. Pharmacological modulation of NO generation and expression/activity of NOS isoforms may represent a therapeutic alternative to prevent the progression of cardiovascular diseases. Accordingly, this review will focus on drugs that modulate NO bioavailability, such as nitrite anions and NO-releasing non-steroidal anti-inflammatory drugs, hormones (dehydroepiandrosterone and estrogen, statins, resveratrol and folic acid, since they may be useful to treat/to prevent aging-associated vascular dysfunction. The impact of these therapies on life quality in elderly and longevity will be discussed.

  15. Nitric oxide turnover in permeable river sediment

    DEFF Research Database (Denmark)

    Schreiber, Frank; Stief, Peter; Kuypers, Marcel M M


    We measured nitric oxide (NO) microprofiles in relation to oxygen (O2) and all major dissolved N-species (ammonium, nitrate, nitrite, and nitrous oxide [N2O]) in a permeable, freshwater sediment (River Weser, Germany). NO reaches peak concentrations of 0.13 μmol L-1 in the oxic zone and is consumed...... in the oxic-anoxic transition zone. Apparently, NO is produced by ammonia oxidizers under oxic conditions and consumed by denitrification under microoxic conditions. Experimental percolation of sediment cores with aerated surface water resulted in an initial rate of NO production that was 12 times higher than...

  16. Protective effect of nitric oxide against arsenic-induced oxidative ...

    African Journals Online (AJOL)

    Nitric oxide (NO) is a key molecule involved in many physiology processes. The effects of NO on alleviating arsenic-induced oxidative damage in tall fescue leaves were investigated. Arsenic (25 M) treatment induced significantly accumulation of reactive oxygen species (ROS) and led to serious lipid peroxidation in tall ...

  17. Role of inhaled nitric oxide in ischaemia-reperfusion injury in the perfused rabbit lung. (United States)

    Ishibe, Y; Liu, R; Ueda, M; Mori, K; Miura, N


    We have tested if inhaled nitric oxide (NO) is beneficial in ischaemia-reperfusion (IR) lung injury using an isolated perfused rabbit lung model. Ischaemia for 60 min was followed by reperfusion and ventilation with nitric oxide 40 ppm (n = 6) or without nitric oxide ventilation (n = 6) for 60 min. In the control group (n = 6), the lungs were perfused continuously for 120 min. Permeability coefficient (Kfc) and vascular resistance (PVR) were measured serially for 60 min after reperfusion. We also determined the left lung W/D ratio and measured nitric oxide metabolites (NOx) and cGMP concentrations in bronchoalveolar lavage (BAL) fluid from the right lung. IR increased Kfc, PVR and W/D followed by decreased cGMP. Ventilation with nitric oxide restored these changes by preventing the decrease in cGMP. Differences in NOx concentrations in BAL fluid between the control and IR groups were not statistically significant. Our results indicate that IR impaired pulmonary vascular function and resulted in microvascular constriction and leakage. Ventilation with nitric oxide from the beginning of the reperfusion period improved pulmonary dysfunction such as vasoconstriction and capillary leak by restoring cGMP concentrations.

  18. Endothelial nitric oxide synthase in the microcirculation. (United States)

    Shu, Xiaohong; Keller, T C Stevenson; Begandt, Daniela; Butcher, Joshua T; Biwer, Lauren; Keller, Alexander S; Columbus, Linda; Isakson, Brant E


    Endothelial nitric oxide synthase (eNOS, NOS3) is responsible for producing nitric oxide (NO)--a key molecule that can directly (or indirectly) act as a vasodilator and anti-inflammatory mediator. In this review, we examine the structural effects of regulation of the eNOS enzyme, including post-translational modifications and subcellular localization. After production, NO diffuses to surrounding cells with a variety of effects. We focus on the physiological role of NO and NO-derived molecules, including microvascular effects on vessel tone and immune response. Regulation of eNOS and NO action is complicated; we address endogenous and exogenous mechanisms of NO regulation with a discussion of pharmacological agents used in clinical and laboratory settings and a proposed role for eNOS in circulating red blood cells.

  19. Therapeutic strategies to address neuronal nitric oxide synthase deficiency and the loss of nitric oxide bioavailability in Duchenne Muscular Dystrophy. (United States)

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


    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.

  20. Role of nitric oxide in cancer biology. (United States)

    Moochhala, S; Rajnakova, A


    The role of nitric oxide (NO) in tumorigenesis is multifactorial. NO can participate in the complicated process of carcinogenesis by mediating DNA damage in early phases of tumorigenesis, as well as support tumor progression through the induction of angiogenesis and suppression of the immune response. This paper addresses the effects of NO on transcriptional regulation following DNA damage and cyclooxygenase expression in the multistep process of tumorigenesis.

  1. Nitric oxide transport in normal human thoracic aorta: effects of hemodynamics and nitric oxide scavengers.

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    Full Text Available Despite the crucial role of nitric oxide (NO in the homeostasis of the vasculature, little quantitative information exists concerning NO transport and distribution in medium and large-sized arteries where atherosclerosis and aneurysm occur and hemodynamics is complex. We hypothesized that local hemodynamics in arteries may govern NO transport and affect the distribution of NO in the arteries, hence playing an important role in the localization of vascular diseases. To substantiate this hypothesis, we presented a lumen/wall model of the human aorta based on its MRI images to simulate the production, transport and consumption of NO in the arterial lumen and within the aortic wall. The results demonstrated that the distribution of NO in the aorta was quite uneven with remarkably reduced NO bioavailability in regions of disturbed flow, and local hemodynamics could affect NO distribution mainly via flow dependent NO production rate of endothelium. In addition, erythrocytes in the blood could moderately modulate NO concentration in the aorta, especially at the endothelial surface. However, the reaction of NO within the wall could only slightly affect NO concentration on the luminal surface, but strongly reduce NO concentration within the aortic wall. A strong positive correlation was revealed between wall shear stress and NO concentration, which was affected by local hemodynamics and NO reaction rate. In conclusion, the distribution of NO in the aorta may be determined by local hemodynamics and modulated differently by NO scavengers in the lumen and within the wall.

  2. Blastomyces dermatitidis Yeast Cells Inhibit Nitric Oxide Production by Alveolar Macrophage Inducible Nitric Oxide Synthase ▿ (United States)

    Rocco, Nicole M.; Carmen, John C.; Klein, Bruce S.


    The ability of pathogens to evade host antimicrobial mechanisms is crucial to their virulence. The dimorphic fungal pathogen Blastomyces dermatitidis can infect immunocompetent patients, producing a primary pulmonary infection that can later disseminate to other organs. B. dermatitidis possesses a remarkable ability to resist killing by alveolar macrophages. To date, no mechanism to explain this resistance has been described. Here, we focus on macrophage production of the toxic molecule nitric oxide as a potential target of subversion by B. dermatitidis yeast cells. We report that B. dermatitidis yeast cells reduce nitric oxide levels in the supernatants of activated alveolar macrophages. This reduction is not due to detoxification of nitric oxide, but rather to suppression of macrophage nitric oxide production. We show that B. dermatitidis yeast cells do not block upregulation of macrophage inducible nitric oxide synthase (iNOS) expression or limit iNOS access to its arginine substrate. Instead, B. dermatitidis yeast cells appear to inhibit iNOS enzymatic activity. Further investigation into the genetic basis of this potential virulence mechanism could lead to the identification of novel antifungal drug targets. PMID:21444664

  3. In-vivo effects of Glu298Asp endothelial nitric oxide synthase polymorphism. (United States)

    Sofowora, G; Dishy, V; Xie, H G; Imamura, H; Nishimi, Y; Morales, C R; Morrow, J D; Kim, R B; Stein, C M; Wood, A J


    Endothelial nitric oxide synthase catalyses the formation of the vasodilator nitric oxide, a major regulator of vascular tone. The Asp298 polymorphism of the nitric oxide synthase gene is associated with altered function and expression of the enzyme in vitro and myocardial infarction and coronary artery spasm in vivo. We examined the effect of the Glu298Asp polymorphism on: (1) local vascular responses to phenylephrine, acetylcholine, glyceryl trinitrate and prostaglandin E1 in the dorsal hand vein; (2) changes in forearm blood flow during mental stress, a measure of nitric oxide-mediated effect on resistance vessels; (3) excretion of urinary nitrite/nitrate as a measure of total body nitric oxide production; and (4) F2-isoprostane metabolite, a measure of oxidative stress, in healthy Glu298 (n = 12) and Asp298 (n = 13) homozygotes. There were no significant differences in acetylcholine dose responses (P = 0.29) in Glu298 and Asp298 homozygotes. Responses to glyceryl trinitrate, prostaglandin E1 and the alpha-adrenergic agonist phenylephrine did not differ by genotype. Forearm blood flow was similar at rest and increased significantly (from 7.5 ml/min/100 ml to 12.2 ml/min/100 ml; P = 0.003), but similarly (P = 0.2), during mental stress in both genotypes. Asp298 homozygotes excreted significantly less nitrate/nitrite than Glu298 homozygotes (nitrate + nitrite/creatinine ratio 0.05 +/- 0.01 vs. 0.09 +/- 0.01, respectively; P < 0.005). Urinary F2-isoprostane metabolite excretion did not differ (Glu298, 2.04 +/- 0.25 ng/mg creatinine; Asp298, 1.85 +/- 0.37 ng/mg creatinine; P = 0.7). We conclude that in healthy volunteers the Glu298Asp polymorphism affects endogenous nitric oxide production without affecting nitric oxide-mediated vascular responses. This polymorphism may only have clinical significance in the presence of endothelial dysfunction.

  4. Biological nitric oxide signalling: chemistry and terminology. (United States)

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


    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. © 2013 The British Pharmacological Society.

  5. Biological nitric oxide signalling: chemistry and terminology (United States)

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


    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

  6. Hypoxia tolerance, nitric oxide, and nitrite

    DEFF Research Database (Denmark)

    Fago, Angela; Jensen, Frank Bo


    survival resides in concerted physiological responses, including strong metabolic depression, protection against oxidative damage and – in air breathing animals - redistribution of blood flow. Each of these responses is known to be tightly regulated by nitric oxide (NO) and during hypoxia by its metabolite...... of NO and nitrite signaling in the adaptive response to hypoxia in vertebrate animals.......Among vertebrates able to tolerate periods of oxygen deprivation, the painted and red-eared slider turtles (Chrysemys picta and Trachemys scripta) and the crucian carp (Carassius carassius) are the most extreme and can survive even months of total lack of oxygen during winter. The key to hypoxia...

  7. Nitric oxide donors for the treatment of prostate cancer


    Nortcliffe, Andrew


    Chapter One provides a general introduction into the biology and chemistry of nitric oxide, with particular focus on the role of nitric oxide in cardiovascular disease, cancer and hypoxia. It also details the types of organic functional groups used as nitric oxide donors, with detailed discussion of nitrate esters, furoxans and sydnonimines. Chapter Two discusses prostate cancer. It provides an overview into the development of prostate cancer, prostate cancer staging, and treatment. The ke...

  8. Role of nitric oxide in hyporeactivity to noradrenaline of isolated aortic rings in portal hypertensive rats

    NARCIS (Netherlands)

    Michielsen, P. P.; Boeckxstaens, G. E.; Sys, S. U.; Herman, A. G.; Pelckmans, P. A.


    To test the hypothesis that induction of nitric oxide synthase causes systemic vascular hyporesponsiveness to vasopressors in portal hypertension, we performed in vitro experiments on isolated thoracic aortic rings from partial portal vein ligated or sham operated rats at 3 weeks postoperatively.

  9. Is flow-mediated dilation nitric oxide mediated?: A meta-analysis.

    NARCIS (Netherlands)

    Green, D.J.; Dawson, E.A.; Groenewoud, H.M.; Jones, H.; Thijssen, D.H.J.


    Flow-mediated dilation (FMD) is a noninvasive index of endothelial function and vascular health in humans. Studies examining the role of nitric oxide (NO) are not conclusive. In this article, we quantified the contribution of NO in FMD of conduit arteries and explored the effect of the protocol (ie,

  10. Role of reduced glutathione, nitric oxide and some trace elements in ...

    African Journals Online (AJOL)

    Role of reduced glutathione, nitric oxide and some trace elements in Alzheimer's disease and vascular dementia. Adel M Assiri, Kholoud S Ramadan, Mohamed H Mahfouz. Abstract. No Abstract. The Egyptian Journal of Biochemistry and Molecular Biology Vol. 24(1) 2006: 55-71. Full Text: EMAIL FULL TEXT EMAIL FULL ...

  11. Measuring nasal nitric oxide in allergic rhinitis patients. (United States)

    Nesic, V S; Djordjevic, V Z; Tomic-Spiric, V; Dudvarski, Z R; Soldatovic, I A; Arsovic, N A


    This study aimed to compare two sampling methods for nasal nitric oxide in healthy individuals and allergic rhinitis patients, and to examine the within-subject reliability of nasal nitric oxide measurement. The study included 23 allergic rhinitis patients without concomitant asthma and 10 healthy individuals. For all participants, nitric oxide levels were measured non-invasively from the lungs through the mouth (i.e. the oral fractional exhaled nitric oxide) and the nose. Nasal nitric oxide was measured by two different methods: (1) nasal aspiration via one nostril during breath holding and (2) single-breath quiet exhalation against resistance through a tight facemask (i.e. the nasal fractional exhaled nitric oxide). Compared with healthy participants, allergic rhinitis patients had significantly higher average oral and nasal nitric oxide levels. All methods of nitric oxide measurement had excellent reliability. Nasal nitric oxide measurement is a useful and reliable clinical tool for diagnosing allergic rhinitis in patients without asthma in an out-patient setting.

  12. Nitric oxide: an antiparasitic molecule of invertebrates. (United States)

    Rivero, Ana


    Since Furchgott, Ignarro and Murad won the Nobel prize in 1998 for their work on the role of nitric oxide (NO) as a signaling molecule, many reports have shown the seemingly limitless range of body functions controlled by this compound. In vertebrates, the role of NO as a defense against infection caused by viruses, bacteria, and protozoan and metazoan parasites has been known for several years. New evidence, however, shows that NO is also important in defending invertebrates against parasites. This discovery is a breakthrough in the understanding of how the invertebrate immune system works, and it has implications for the emerging field of invertebrate ecological immunology.

  13. Changes in the level of cytosolic calcium, nitric oxide and nitric oxide ...

    Indian Academy of Sciences (India)

    Variceal bleeding due to abnormal platelet function is a well-known complication of cirrhosis. Nitric oxide-related stress has been implicated in the pathogenesis of liver cirrhosis. In the present investigation, we evaluated the level of platelet aggregation and concomitant changes in the level of platelet cytosolic calcium ...

  14. Óxido nítrico: revisão Nitric oxide: review

    Directory of Open Access Journals (Sweden)

    Nereide Freire Cerqueira


    Full Text Available O óxido nítrico é um mediador gasoso responsável por uma variedade de fenômenos fisiológicos. A l-arginina é a precursora da síntese do óxido nítrico, na presença de óxido nítrico-sintase. Este artigo revê as funções das óxido nítrico-sintases e como o óxido nítrico atua na permeabilidade vascular e na síndrome de isquemia e reperfusão, assim como possíveis métodos para sua mensuração.Nitric oxide is a gaseous mediator responsible for a variety of physiologic effects. The l-arginine is the precursor of the synthesis of nitric oxide in presence of nitric oxide synthase. This article reviews the functions of nitric oxide synthases, the action of nitric oxide on vascular permeability and ischemia-reperfusion injury, as well as possible methods for determination of NO.

  15. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    Directory of Open Access Journals (Sweden)

    Nevzat Selim Gokay


    Full Text Available The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg, inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg, or nitric oxide precursor L-arginine (200 mg/kg. After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P=0.044 positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

  16. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage. (United States)

    Gokay, Nevzat Selim; Yilmaz, Ibrahim; Komur, Baran; Demiroz, Ahu Senem; Gokce, Alper; Dervisoglu, Sergülen; Gokay, Banu Vural


    The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg), inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg), or nitric oxide precursor L-arginine (200 mg/kg). After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P = 0.044) positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

  17. Nitric oxide rescues thalidomide mediated teratogenicity (United States)

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


    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

  18. Melatonin and its precursors scavenge nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

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


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

  19. The correlation between total antioxidant capacity and nitric oxide ...

    African Journals Online (AJOL)

    Semen samples from 45 infertile men and 70 normozospermic men were examined for DNA damage, nitric oxide concentration and TAC. DNA damage was measured by comet assay and nitric oxide concentration was evaluated by Griess assay. TAC was measured in seminal plasma based on the generation of peroxyl ...

  20. Nitric oxide inhalation in infants with respiratory distress syndrome. (United States)

    Skimming, J W; Bender, K A; Hutchison, A A; Drummond, W H


    This study was designed to test the hypothesis that nitric oxide inhalation increases systemic arterial blood oxygen tension of prematurely delivered infants with respiratory distress syndrome. Nitric oxide was administered to 23 preterm infants with a diagnosis of respiratory distress syndrome. The infants were randomly assigned to receive either 5 or 20 ppm of nitric oxide and were studied between 24 and 168 hours after delivery. The treatment period for each infant lasted 15 minutes and was preceded by and followed by a 15-minute control period. We evaluated all outcome variables by using two-way repeated measures analysis of variance; p values less than 0.01 were considered significant. Nitric oxide inhalation caused significant increases in the following: arterial blood oxygen tension, directly measured arterial oxyhemoglobin saturation, and transcutaneously measured arterial oxyhemoglobin saturation. No differences between the effects of the two nitric oxide concentrations were detected, nor were residual effects detected 15 minutes after either dose of nitric oxide was discontinued. Inhalation of both 5 and 20 ppm nitric oxide causes concentration-independent increases in the blood oxygen tensions of preterm infants with respiratory distress syndrome. We speculate that nitric oxide inhalation may be a useful adjunctive therapy for these patients.

  1. Effects of inhaled nitric oxide on oxygenation and haemodynamic ...

    African Journals Online (AJOL)

    always mandatory for such procedures, it improves access to the operative field and expedites the surgery. The most is the endothelial dependent vasorelaxing factor nitric oxide. (NO). in theory inhaled nitric oxide (iNO) could increase oxygenation by selectively decreasing pulmonary resistance and increasing blood flow to ...

  2. Propolis Ameliorates Tumor Nerosis Factor-α, Nitric Oxide levels ...

    African Journals Online (AJOL)

    Background: Increased nitric oxide (NO), neuronal inflammation and apoptosis have been proposed to be involved in excitotoxicity plays a part in many neurodegenerative diseases. To understand the neuro-protective effects of propolis, activities of Nitric oxide synthase (NOS) and caspase-3 along with NO and tumor ...

  3. Catalytic abatement of nitrous oxide from nitric and production

    NARCIS (Netherlands)

    Oonk, J.


    Nitric acid production is identified as a main source of nitrous oxide. Options for emission reduction however are not available. TNO and Hydro Agri studied the technological and economic feasibility of catalytic decomposition of nitrous oxide in nitric acid tail-gases. Although in literature

  4. Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 ...

    African Journals Online (AJOL)

    Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 and Lipid Peroxidation by Methanol Extract of Pericarpium Zanthoxyli. ... Production of iNOS induced by LPS was significantly (p < 0.05) inhibited by the extract, suggesting that the extract inhibits nitric oxide (NO) production by suppressing iNOS expression.

  5. Influence of nitric oxide on histamine and carbachol – induced ...

    African Journals Online (AJOL)

    The study aimed to determine the influence of nitric oxide (NO) on the action of histamine and carbachol on acid secretion in the common African toad – Bufo regularis. Gastric acidity was determined by titration method. The acid secretion was determined when nitric oxide was absent following administration of NO synthase ...

  6. Evaluation of nitric oxide as a novel diagnostic marker for ...

    African Journals Online (AJOL)

    45%. Nitrite/Nitrate is a stable end product of nitric oxide increase in patients with HCC. Aim: It was to evaluate nitric oxide as a novel diagnostic marker for hepatocellular carcinoma. Methods: Eighty patients and 15 normal individuals enrolled in the study: Group (1) 15 normal individuals. Group (2) 30 patients with chronic ...

  7. Effect of nitric oxide scavengers, carboxy-PTIO on endotoxin ...

    African Journals Online (AJOL)

    values of the cardiovascular parameters considered in this study. This indicates that carboxy-PTIO is an efficient nitric oxide scavenger chemical of trapping nitric oxide immediately after its synthesis. Therefore, based on the current result, carboxy-PTIO can be used as one possible treatment agent against septic shock.

  8. Adrenoceptor-activated nitric oxide synthesis in salivary acinar cells

    DEFF Research Database (Denmark)

    Looms, Dagnia; Dissing, Steen; Tritsaris, Katerina


    We investigated the cellular regulation of nitric oxide synthase (NOS) activity in isolated acinar cells from rat parotid and human labial salivary glands, using the newly developed fluorescent nitric oxide (NO) indicator, DAF-2. We found that sympathetic stimulation with norepinephrine (NE) caused...

  9. Endothelial nitric oxide synthase gene haplotypes and diabetic nephropathy among Asian Indians

    DEFF Research Database (Denmark)

    Ahluwalia, Tarun Veer Singh; Ahuja, Monica; Rai, Taranjit Singh


    Endothelial dysfunction plays a key role in the pathogenesis of diabetic vascular disease, including diabetic nephropathy. Endothelial-derived nitric oxide synthase (eNOS) gene polymorphisms affect eNOS activity and are associated with endothelial dysfunction. We evaluated the association...... of the constitutive endothelial nitric oxide synthase gene (eNOS) polymorphisms with type 2 diabetic nephropathy. We genotyped three polymorphisms of eNOS (Two SNPs: -786T > C, 894G > T and one 27-bp repeat polymorphism in Intron 4 (27VNTR)) in type 2 diabetic nephropathy patients (cases: n = 195) and type 2 diabetic...

  10. Anti-obesogenic role of endothelial nitric oxide synthase (United States)

    Sansbury, Brian E.; Hill, Bradford G.


    The prevalence of obesity has increased remarkably in the past four decades. Because obesity can promote the development of type 2 diabetes and cardiovascular disease, understanding the mechanisms that engender weight gain and discovering safe anti-obesity therapies are of critical importance. In particular, the gaseous signaling molecule, nitric oxide (NO), appears to be a central factor regulating adiposity and systemic metabolism. Obese and diabetic states are characterized by a deficit in bioavailable NO, with such decreases commonly attributed to downregulation of endothelial NO synthase (eNOS), loss of eNOS activity, or quenching of NO by its reaction with oxygen radicals. Gain-of-function studies, in which vascular-derived NO has been increased pharmacologically or genetically, reveal remarkable actions of NO on body composition and systemic metabolism. This review addresses the metabolic actions of eNOS and the potential therapeutic utility of harnessing its anti-obesogenic effects. PMID:25189393

  11. [Nitric oxide participation during amoebic liver abscess development]. (United States)

    Ramirez-Emiliano, Joel; Flores-Villavicencio, Lerida Liss; Segovia, Jose; Arias-Negrete, Sergio


    Nitric oxide participates in both physiological and pathophysiological functions, and it plays an important role in the mammalian immune system in killing or inhibiting the growth of many pathogens, including parasites, viruses and bacteria. Entamoeba histolytica is a protozoan parasite that causes amoebiasis, which is characterized by intestinal damage and amoebic liver abscess development. The development of amoebic liver abscess in hamsters is similar to that in humans, whereas mice are resistant to amoebic liver abscess development due to an increase in nitric oxide production. Unlike in mice, amoebic liver abscess development in hamsters is due to an excess in nitric oxide production or possibly to a greater susceptibility of the hamster to damage caused by nitric oxide. Therefore, it could be important to elucidate if, in humans, an excess in nitric oxide production favors amoebic liver abscess development.

  12. Vascular aging: chronic oxidative stress and impairment of redox signaling-consequences for vascular homeostasis and disease. (United States)

    Bachschmid, Markus M; Schildknecht, Stefan; Matsui, Reiko; Zee, Rebecca; Haeussler, Dagmar; Cohen, Richard A; Pimental, David; Loo, Bernd van der


    Characteristic morphological and molecular alterations such as vessel wall thickening and reduction of nitric oxide occur in the aging vasculature leading to the gradual loss of vascular homeostasis. Consequently, the risk of developing acute and chronic cardiovascular diseases increases with age. Current research of the underlying molecular mechanisms of endothelial function demonstrates a duality of reactive oxygen and nitrogen species in contributing to vascular homeostasis or leading to detrimental effects when formed in excess. Furthermore, changes in function and redox status of vascular smooth muscle cells contribute to age-related vascular remodeling. The age-dependent increase in free radical formation causes deterioration of the nitric oxide signaling cascade, alters and activates prostaglandin metabolism, and promotes novel oxidative posttranslational protein modifications that interfere with vascular and cell signaling pathways. As a result, vascular dysfunction manifests. Compensatory mechanisms are initially activated to cope with age-induced oxidative stress, but become futile, which results in irreversible oxidative modifications of biological macromolecules. These findings support the 'free radical theory of aging' but also show that reactive oxygen and nitrogen species are essential signaling molecules, regulating vascular homeostasis.

  13. Nitric oxide and mitochondria in metabolic syndrome (United States)

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


    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

  14. [Effect of nitric oxide in vestibular compensation]. (United States)

    Jiang, Zi-dong; Zhang, Lian-shan


    To study the effect of nitric oxide (NO) in vestibular compensation after unilateral vestibular deafferentation. Eighteen animals were divided into two groups, 6 of group a as control, 12 of group b received gentamicin intratympanic injection in the left ear. Half of the animals were killed respectively after 5 days and 10 days. Vestibular endorgan and brainstem tissue sections were subjected to NADPH-d reactive test of NOS for histochemical examination. In group a, NOS-like reactivity in both sides of vestibular endorgan and nucli. In group b during 5 days, NOS-like reactivity in right side of vestibular endorgan and nucli, those of the left side were negative. During 10 days, NOS-like reactivity only in the right side of vestibular endorgan. Changes of NOS expression in the contralateral vestibular nucli might have played a role in vestibular compensation.

  15. The role of nitric oxide in reproduction

    Directory of Open Access Journals (Sweden)

    McCann S.M.


    Full Text Available Nitric oxide (NO plays a crucial role in reproduction at every level in the organism. In the brain, it activates the release of luteinizing hormone-releasing hormone (LHRH. The axons of the LHRH neurons project to the mating centers in the brain stem and by afferent pathways evoke the lordosis reflex in female rats. In males, there is activation of NOergic terminals that release NO in the corpora cavernosa penis to induce erection by generation of cyclic guanosine monophosphate (cGMP. NO also activates the release of LHRH which reaches the pituitary and activates the release of gonadotropins by activating neural NO synthase (nNOS in the pituitary gland. In the gonad, NO plays an important role in inducing ovulation and in causing luteolysis, whereas in the reproductive tract, it relaxes uterine muscle via cGMP and constricts it via prostaglandins (PG.

  16. Nitric oxide in liver fibrosis: The role of inducible nitric oxide synthase. (United States)

    Iwakiri, Yasuko


    The inducible form of nitric oxide synthase (iNOS) is expressed in hepatic cells in pathological conditions. Its induction is involved in the development of liver fibrosis, and thus iNOS could be a therapeutic target for liver fibrosis. This review summarizes the role of iNOS in liver fibrosis, focusing on 1) iNOS biology, 2) iNOS-expressing liver cells, 3) iNOS-related therapeutic strategies, and 4) future directions.

  17. Trace elements and nitric oxide function. (United States)

    Marletta, Michael A; Spiering, Michelle M


    Nitric oxide (NO) has emerged over the last 15 y as a mammalian metabolic intermediate that is involved in the regulation of critical physiological functions such as blood vessel homeostasis, neuronal transmission and host response to infection. NO is synthesized by the enzyme nitric oxide synthase, which converts the amino acid L-arginine to citrulline and NO. NO functions in biological systems in two very important ways. First, it has been found to be a messenger by which cells communicate with one another (signal transduction), and second, it plays a critical role in the host response to infection. In this second function, it appears that the toxic properties of NO have been harnessed by the immune system to kill or at least slow the growth of invading organisms. The nonspecific chemical reactivity with key cellular targets is responsible for this action. In signaling, NO directly activates the enzyme soluble guanylate cyclase (sGC). Once activated, sGC converts GTP to cGMP and pyrophosphate. The cGMP formed is responsible for the well-documented actions of NO such as blood vessel dilation. With the initial discovery of NO signaling, several important questions emerged that centered largely on the issue of how a signaling system functions when the signaling agent is chemically reactive (short lived), highly diffusible and toxic. Critical, especially in signaling, are the control of NO biosynthesis and interaction with the biological receptors at a concentration that will not harm the host. Why did Nature choose NO for the roles it has? That question engenders only speculation. How does NO work (i.e., what does NO do, and how does it do it without harm yet with specificity)? Answers to these questions can now be offered as the molecular level details emerge to form an interesting picture.

  18. Estrogen increases the severity of anaphylaxis in female mice through enhanced endothelial nitric oxide synthase expression and nitric oxide production. (United States)

    Hox, Valerie; Desai, Avanti; Bandara, Geethani; Gilfillan, Alasdair M; Metcalfe, Dean D; Olivera, Ana


    Clinical observations suggest that anaphylaxis is more common in adult women compared with adult men, although the mechanistic basis for this sex bias is not well understood. We sought to document sex-dependent differences in a mouse model of anaphylaxis and explore the role of female sex hormones and the mechanisms responsible. Passive systemic anaphylaxis was induced in female and male mice by using histamine, as well as IgE or IgG receptor aggregation. Anaphylaxis was assessed by monitoring body temperature, release of mast cell mediators and/or hematocrit, and lung weight as a measure of vascular permeability. A combination of ovariectomy, estrogen receptor antagonism, and estrogen administration techniques were used to establish estrogen involvement. Anaphylactic responses were more pronounced in female than male mice. The enhanced severity of anaphylaxis in female mice was eliminated after pretreatment with an estrogen receptor antagonist or ovariectomy but restored after administration of estradiol in ovariectomized mice, demonstrating that the sex-specific differences are due to the female steroid estradiol. Estrogen did not affect mast cell responsiveness or anaphylaxis onset. Instead, it increased tissue expression of endothelial nitric oxide synthase (eNOS). Blockage of NOS activity with the inhibitor L-NG-nitroarginine methyl ester or genetic eNOS deficiency abolished the sex-related differences. Our study defines a contribution of estrogen through its regulation of eNOS expression and nitric oxide production to vascular hyperpermeability and intensified anaphylactic responses in female mice, providing additional mechanistic insights into risk factors and possible implications for clinical management in the further exploration of human anaphylaxis. Published by Elsevier Inc.

  19. Increased cortical nitric oxide release after phencyclidine administration. (United States)

    Pålsson, Erik; Finnerty, Niall; Fejgin, Kim; Klamer, Daniel; Wass, Caroline; Svensson, Lennart; Lowry, John


    Phencyclidine exerts psychotomimetic effects in humans and is used as a pharmacological animal model for schizophrenia. We, and others, have demonstrated that phencyclidine induces cognitive deficits in rats that are associated with schizophrenia. These cognitive deficits can be normalized by inhibition of nitric oxide synthase. The development of selective microelectrochemical nitric oxide sensors may provide direct evidence for the involvement of nitric oxide in these effects. The aim of the present study was to use LIVE (long term in vivo electrochemistry) to investigate the effect of phencyclidine, alone or in combination with the nitric oxide synthase inhibitor L-NAME, on nitric oxide levels in the medial prefrontal cortex of freely moving rats. Phencyclidine (2 mg kg(-1)) produced an increase in cortical nitric oxide levels and this increase was ameliorated by L-NAME (10 mg kg(-1)). Tentatively, the results from the present study provide a biochemical rationale for the involvement of nitric oxide in the phencyclidine model of schizophrenia. (c) 2009 Wiley-Liss, Inc.

  20. Nitric oxide in the psychobiology of mental disorders

    Directory of Open Access Journals (Sweden)

    Altan Eşsizoğlu


    Full Text Available Nitric oxide is in a gaseous form and is widespread in the human body. It functions by acting as a secondary messenger in the modulatory activities of neuronal functions of the central nervous system. Nitric oxide is the first identified neurotransmitter of the nontraditional neurotransmitter family.Studies conducted on experimental animals demonstrate that nitric oxide has a neuromodulatory efficacy on the secretions of other neurotransmitters and that it has an effect on learning and memory functions, and on various neuronal mechanisms. Many studies have been conducted to investigate the location of nitric oxide in the central nervous system, its effect on anxiety and depression, its relationship with other neurotransmitters, and also about its role on neurotoxicity. There are clinical studies concerning the level of nitrate, a product of nitric oxide metabolism, and also experimental studies concerning its rewarding effect of alcohol and substance use, in patients with depression and schizophrenia. However, limited studies have been conducted to investigate its relationship with stress, which is an important factor in the etiology of psychiatric disorders. These studies demonstrate that nitric oxide is closely related with stress physiology.Nitric oxide is a neuromodulator, which is frequently being mentioned about nowadays in psychiatry. Clinical and experimental studies play an important role in the psychobiology of psychiatric disorders.

  1. Prognostic value of nitric oxide in pediatric septic shock


    Ari L. Runtunuwu; Jeanette I. Ch. Manoppo; Dasril Daud; Irawan Yusuf; Idham Jaya Ganda


    Background Nitric oxide (NO) play a key role in the pathogenesis of septic shock. Nitrit oxide metabolite is reported as a good predictor for shock although its role as mortality predictor in sepsis still controversial. Objective To assess the serum nitric oxide (NO) levels and outcomes in pediatric patients with septic shock. Methods We conducted a prospective cohort study from January 2013 to April 2014 in Pediatric Intensive Care Unit (PICU) Prof. Dr. R. D. Kandou Hospital, Manad...

  2. Monoclonal L-citrulline immunostaining reveals nitric oxide-producing vestibular neurons (United States)

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


    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.

  3. [Role of nitric oxide and other endothelium-derived factors]. (United States)

    Stankevicius, Edgaras; Kevelaitis, Egidijus; Vainorius, Enrikas; Simonsen, Ulf


    The endothelial cell layer displays the features of a distributed organ and has a variety of biological functions such as keeping the balance between coagulation and fibrinolysis, expression of adhesion molecules for cells in the immune system, metabolism of noradrenaline and 5-hydroxytryptamine, and conversion of angiotensin I and bradykinin. The endothelium also regulates the underlying smooth muscle layer and vascular tone by release of endothelium-derived relaxing factors such as nitric oxide (NO), prostaglandins, and endothelium-derived hyperpolarizing factor (EDHF) as well as vasoconstricting factors such as endothelin, superoxide (O(2)(-)), and thromboxane. We have reviewed the nature, mechanisms of action, and role of these factors in regulation of vascular tone, with special emphasis on NO. By a process catalyzed by NO synthase, NO and citrulline is formed from the substrates molecular O(2) and L-arginine. The main receptor for NO is guanylyl cyclase leading to formation of smooth muscle cyclic guanosinmonophosphate and relaxation. EDHF is an endothelium-derived factor causing vasorelaxation of the underlying smooth muscle layer by hyperpolarization. The nature of EDHF is still unknown, but several candidates for EDHF have been proposed such as potassium ions, hydrogen peroxide, and epoxyeicosatrienoic acids. Prostaglandins such as prostacyclin and prostaglandin E2 binds to specific receptors followed by increases in cyclic adenosinmonophosphate and vasorelaxation, while contractile prostaglandins constrict vessels by activation of thromboxane and endoperoxidase receptors. Superoxide anions induce contraction of vascular smooth muscles cells by scavenging NO. Endothelin is a potent endothelium-derived contractile factor. The synthesis of endothelin-1 is induced by hypoxia, thrombin, interleukin-1, transforming growth factor-beta1, vasopressin, and catecholamines. Cardiovascular risk factors like age, hypertension, and hyperlipidemia are associated with

  4. Diabetes, oxidative stress, nitric oxide and mitochondria function. (United States)

    Friederich, Malou; Hansell, Peter; Palm, Fredrik


    The role of altered mitochondria function has recently emerged as an important mechanism for the development of diabetic complications. Altered mitochondria function has also been implicated in the ageing process, defective insulin secretion, hypertension, arteriosclerosis, ischemia-reperfusion injury and apoptosis. Normally, the mitochondria are associated with ATP production using primarily pyruvate as the substrate, but recent reports indicate that tissue specific preferences exist. Also, the mitochondria are a substantial source of superoxide production, preferentially during states of elevated intracellular glucose concentrations. The mitochondria function is regulated by several factors including nitric oxide, oxidative stress, mammalian target of rapamycin, ADP and P(i) availability, which result in a complex regulation of ATP production and oxygen consumption, but also superoxide generation. These factors seem to be tissue specific, which warrants a more diverse mechanistic model applying to that specific tissue or cell type. This review presents the basic functions of the mitochondria and focuses on the complex interplay between oxidative stress, nitric oxide and uncoupling proteins in regulating mitochondria function with special focus on diabetes-induced alterations occurring on the mitochondria level.

  5. Nitric Oxide Synthases in Heart Failure (United States)

    Carnicer, Ricardo; Crabtree, Mark J.; Sivakumaran, Vidhya


    Abstract Significance: The regulation of myocardial function by constitutive nitric oxide synthases (NOS) is important for the maintenance of myocardial Ca2+ homeostasis, relaxation and distensibility, and protection from arrhythmia and abnormal stress stimuli. However, sustained insults such as diabetes, hypertension, hemodynamic overload, and atrial fibrillation lead to dysfunctional NOS activity with superoxide produced instead of NO and worse pathophysiology. Recent Advances: Major strides in understanding the role of normal and abnormal constitutive NOS in the heart have revealed molecular targets by which NO modulates myocyte function and morphology, the role and nature of post-translational modifications of NOS, and factors controlling nitroso-redox balance. Localized and differential signaling from NOS1 (neuronal) versus NOS3 (endothelial) isoforms are being identified, as are methods to restore NOS function in heart disease. Critical Issues: Abnormal NOS signaling plays a key role in many cardiac disorders, while targeted modulation may potentially reverse this pathogenic source of oxidative stress. Future Directions: Improvements in the clinical translation of potent modulators of NOS function/dysfunction may ultimately provide a powerful new treatment for many hearts diseases that are fueled by nitroso-redox imbalance. Antioxid. Redox Signal. 18, 1078–1099. PMID:22871241

  6. The impact of tumor nitric oxide production on VEGFA expression and tumor growth in a zebrafish rat glioma xenograft model.

    Directory of Open Access Journals (Sweden)

    Nadhir Yousfi

    Full Text Available To investigate the effect of nitric oxide on tumor development, we established a rat tumor xenograft model in zebrafish embryos. The injected tumor cells formed masses in which nitric oxide production could be detected by the use of the cell-permeant DAF-FM-DA (diaminofluorophore 4-amino-5-methylamino-2'-7'-difluorofluorescein diacetate and DAR-4M-AM (diaminorhodamine-4M. This method revealed that nitric oxide production could be co-localized with the tumor xenograft in 46% of the embryos. In 85% of these embryos, tumors were vascularized and blood vessels were observed on day 4 post injection. Furthermore, we demonstrated by qRT-PCR that the transplanted glioma cells highly expressed Nos2, Vegfa and Cyclin D1 mRNA. In the xenografted embryos we also found increased zebrafish vegfa expression. Glioma and zebrafish derived Vegfa and tumor Cyclin D1 expression could be down regulated by the nitric oxide scavenger 2-(4-Carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide or CPTIO. We conclude that even if there is a heterogeneous nitric oxide production by the xenografted glioma cells that impacts Vegfa and Cyclin D1 expression levels, our results suggest that reduction of nitric oxide levels by nitric oxide scavenging could be an efficient approach to treat glioma.

  7. Immunohistochemical localization of endothelial nitric oxide synthase in endometrial tissue of women with unexplained infertility

    Directory of Open Access Journals (Sweden)

    Tohid Najafi


    Full Text Available Background: Nitric oxide (NO is a molecule that incorporates in many physiological processes of female reproductive system. Recent studies suggested the possible role of endothelial isoform of nitric oxide synthase (eNOS enzyme in female infertility. Objective: The aim of this study is to evaluate the expression of endothelial nitric oxide synthase in endometrial tissue of women with unexplained infertility. Materials and Methods: In this case-control study a total of 18 endometrial tissues obtained from 10 women with unexplained infertility and 8 normal and fertile women by endometrial biopsy, 6 to 10 days after LH surge. Specimens were fixed in 4% paraformaldhyde fixative and frozen sectioned for semi-quantitative immunohistochemical evaluation using monoclonal anti-human eNOS antibody. Hematoxilin and Eosin was used for Histological dating. Results: Localization of endothelial nitric oxide synthase was seen in glandular and luminal epithelium, vascular endothelium and stroma in both fertile women and women with unexplained infertility. Although there were differences in immunoreactivity of glandular epithelium (p=0.44, vascular endothelium (p=0.60 and stroma (p=0.63 but only over-expression of eNOS in luminal epithelium (p=0.045 of women with unexplained infertility compared to fertile women was statistically significant (p<0.05. Conclusion: This study suggests that changes in luminal expression of eNOS may influence receptivity of endometrium

  8. Significance of Nitric Oxide Level in Giardiasis. (United States)

    Zarebavani, Mitra; Dargahi, Delaram; Einollahi, Nahid; Dashti, Nasrin; Safari, Fatemeh; Rezaeian, Mostafa


    Giardiasis is one of the most prevalent intestinal protozoa infections in humans. Nowadays, nitric oxide (NO) is known to be involved in the immune system against Giardia intestinalis. Therefore, the aim of the present study was to evaluate the level of NO in individuals with giardiasis in comparison to normal subjects. This descriptive study was conducted among 49 Giadia positive and 39 age and gender matched healthy volunteers. Examination of stool samples was done by wet mount technique and formol-ether concentration method. Serum samples were obtained for laboratory examination. NO production was quantified by measuring nitrite, a stable end product of NO, using the Griess reaction based on ELISA method. By using the standard curve in Excel program, the concentration of NO2- in samples was obtained. Finally, all data were analyzed using SPSS version 17. Values obtained from NO assays were placed into 4 groups: ≤ 10 (decline), 10.01 - 15 (normal), 15.01 - 25 (increase), and more than 25 µM (sharp increase). The mean level of NO in patients with G. intestinalis was 32.19 ± 2.15 µM and in people without G. intestinalis was 17.1 ± 1.33 µM. Eight point two percent of patients with Giardiasis were in normal range, but 2%, 20.4%, and 69.4% were in decline, increase, and sharp increase ranges, respectively. In group 2 (without infection), 17.9% were in normal range, and 20.5%, 51.3%, and 10.3% were in decline, increase, and sharp increase ranges, respectively. There was a statistical difference in nitric oxide levels between positive and negative groups with a 95% confidence interval. (p-value = 0.001). In our study, the number of people who showed a sharp increase in NO levels was significantly higher in individuals with giardiasis as compared to the control group, and patients infected with giardiasis showed significant increase in NO levels. Therefore, we suggest that further studies are required to understand the exact function of NO in the immune system

  9. Estetrol modulates endothelial nitric oxide synthesis in human endothelial cells

    Directory of Open Access Journals (Sweden)

    Maria Magdalena eMontt-Guevara


    Full Text Available Estetrol (E4 is a natural human estrogen that is present at high concentrations during pregnancy. E4 has been reported to act as an endogenous estrogen receptor modulator, exerting estrogenic actions on the endometrium or the central nervous system but presenting antagonistic effects on the breast. Due to these characteristics, E4 is currently being developed for a number of clinical applications, including contraception and menopausal hormone therapy. Endothelial nitric oxide (NO is a key player for vascular function and disease during pregnancy and throughout ageing in women. Endothelial NO is an established target of estrogens that enhance its formation in human endothelial cells. We here addressed the effects of E4 on the activity and expression of the endothelial nitric oxide synthase (eNOS in cultured human umbilical vein endothelial cells (HUVEC. E4 stimulated the activation of eNOS and NO secretion in HUVEC. E4 was significantly less effective compared to E2 and a peculiar concentration-dependent effect was found, with higher amounts of E4 being less effective than lower concentrations. When E2 was combined with E4, an interesting pattern was noted. E4 antagonized NO synthesis induced by pregnancy-like E2 concentrations. However, E4 did not impede the modest induction of NO synthesis associated with postmenopausal-like E2 levels. These results support the hypothesis that E4 may be a regulator of NO synthesis in endothelial cells and raise questions on its peculiar signaling in this context. Our results may be useful to interpret the role of E4 during human pregnancy and possibly to help develop this interesting steroid for clinical use.

  10. The correlation between total antioxidant capacity and nitric oxide ...

    African Journals Online (AJOL)



    citrulline by a family of isoenzymes known as the nitric oxide synthase (NOS) and involved in diverse physiological and pathophysiological processes in various organs, including the human male and female reproductive tracts ...

  11. Adhesion Development and the Expression of Endothelial Nitric Oxide Synthase

    Directory of Open Access Journals (Sweden)

    David M. Svinarich


    Full Text Available Objective: This study was conducted to determine whether nitric oxide (NO, a potent vasodilator and inhibitor of thrombus formation, is involved in the formation and maintenance of adhesions.

  12. Inhibition of Nitric Oxide and Prostaglandin E 2 Expression by ...

    African Journals Online (AJOL)

    Inhibition of Nitric Oxide and Prostaglandin E 2 Expression by Methanol Extract of Polyopes affinis in Lipopolysaccharide-stimulated BV2 Microglial Cells through Suppression of Akt-dependent NF-kB Activity and MAPK Pathway.

  13. Nitric oxide inhibits glycogen synthesis in isolated rat hepatocytes

    NARCIS (Netherlands)

    Sprangers, F.; Sauerwein, H. P.; Romijn, J. A.; van Woerkom, G. M.; Meijer, A. J.


    There is increasing evidence for the existence of intrahepatic regulation of glucose metabolism by Kupffer cell products. Nitric oxide (NO) is known to inhibit gluconeogenic flux through pyruvate carboxylase and phosphoenolpyruvate carboxykinase. However, NO may also influence glucose metabolism at

  14. Hemoglobin: A Nitric-Oxide Dioxygenase

    Directory of Open Access Journals (Sweden)

    Paul R. Gardner


    Full Text Available Members of the hemoglobin superfamily efficiently catalyze nitric-oxide dioxygenation, and when paired with native electron donors, function as NO dioxygenases (NODs. Indeed, the NOD function has emerged as a more common and ancient function than the well-known role in O2 transport-storage. Novel hemoglobins possessing a NOD function continue to be discovered in diverse life forms. Unique hemoglobin structures evolved, in part, for catalysis with different electron donors. The mechanism of NOD catalysis by representative single domain hemoglobins and multidomain flavohemoglobin occurs through a multistep mechanism involving O2 migration to the heme pocket, O2 binding-reduction, NO migration, radical-radical coupling, O-atom rearrangement, nitrate release, and heme iron re-reduction. Unraveling the physiological functions of multiple NODs with varying expression in organisms and the complexity of NO as both a poison and signaling molecule remain grand challenges for the NO field. NOD knockout organisms and cells expressing recombinant NODs are helping to advance our understanding of NO actions in microbial infection, plant senescence, cancer, mitochondrial function, iron metabolism, and tissue O2 homeostasis. NOD inhibitors are being pursued for therapeutic applications as antibiotics and antitumor agents. Transgenic NOD-expressing plants, fish, algae, and microbes are being developed for agriculture, aquaculture, and industry.

  15. Nitric oxide negatively regulates mammalian adult neurogenesis (United States)

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


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

  16. Tapentadol and nitric oxide synthase systems. (United States)

    Bujalska-Zadrożny, Magdalena; Wolińska, Renata; Gąsińska, Emilia; Nagraba, Łukasz


    Tapentadol, a new analgesic drug with a dual mechanism of action (μ-opioid receptor agonism and norepinephrine reuptake inhibition), is indicated for the treatment of moderate to severe acute and chronic pain. In this paper, the possible additional involvement of the nitric oxide synthase (NOS) system in the antinociceptive activity of tapentadol was investigated using an unspecific inhibitor of NOS, L-NOArg, a relatively specific inhibitor of neuronal NOS, 7-NI, a relatively selective inhibitor of inducible NOS, L-NIL, and a potent inhibitor of endothelial NOS, L-NIO. Tapentadol (1-10 mg/kg, intraperitoneal) increased the threshold for mechanical (Randall-Selitto test) and thermal (tail-flick test) nociceptive stimuli in a dose-dependent manner. All four NOS inhibitors, administered intraperitoneally in the dose range 0.1-10 mg/kg, potentiated the analgesic action of tapentadol at a low dose of 2 mg/kg in both models of pain. We conclude that NOS systems participate in tapentadol analgesia.

  17. Structures of human constitutive nitric oxide synthases. (United States)

    Li, Huiying; Jamal, Joumana; Plaza, Carla; Pineda, Stephanie Hai; Chreifi, Georges; Jing, Qing; Cinelli, Maris A; Silverman, Richard B; Poulos, Thomas L


    Mammals produce three isoforms of nitric oxide synthase (NOS): neuronal NOS (nNOS), inducible NOS (iNOS) and endothelial NOS (eNOS). The overproduction of NO by nNOS is associated with a number of neurodegenerative disorders; therefore, a desirable therapeutic goal is the design of drugs that target nNOS but not the other isoforms. Crystallography, coupled with computational approaches and medicinal chemistry, has played a critical role in developing highly selective nNOS inhibitors that exhibit exceptional neuroprotective properties. For historic reasons, crystallography has focused on rat nNOS and bovine eNOS because these were available in high quality; thus, their structures have been used in structure-activity-relationship studies. Although these constitutive NOSs share more than 90% sequence identity across mammalian species for each NOS isoform, inhibitor-binding studies revealed that subtle differences near the heme active site in the same NOS isoform across species still impact enzyme-inhibitor interactions. Therefore, structures of the human constitutive NOSs are indispensible. Here, the first structure of human neuronal NOS at 2.03 Å resolution is reported and a different crystal form of human endothelial NOS is reported at 1.73 Å resolution.

  18. Nitric oxide in legume-rhizobium symbiosis. (United States)

    Meilhoc, Eliane; Boscari, Alexandre; Bruand, Claude; Puppo, Alain; Brouquisse, Renaud


    Nitric oxide (NO) is a gaseous signaling molecule with a broad spectrum of regulatory functions in plant growth and development. NO has been found to be involved in various pathogenic or symbiotic plant-microbe interactions. During the last decade, increasing evidence of the occurrence of NO during legume-rhizobium symbioses has been reported, from early steps of plant-bacteria interaction, to the nitrogen-fixing step in mature nodules. This review focuses on recent advances on NO production and function in nitrogen-fixing symbiosis. First, the potential plant and bacterial sources of NO, including NO synthase-like, nitrate reductase or electron transfer chains of both partners, are presented. Then responses of plant and bacterial cells to the presence of NO are presented in the context of the N(2)-fixing symbiosis. Finally, the roles of NO as either a regulatory signal of development, or a toxic compound with inhibitory effects on nitrogen fixation, or an intermediate involved in energy metabolism, during symbiosis establishment and nodule functioning are discussed. Copyright © 2011. Published by Elsevier Ireland Ltd.

  19. Involvement of nitric oxide in learning & memory processes


    Paul, Vanaja; Ekambaram, Perumal


    Nitric oxide (NO), synthesized from the amino acid, L-arginine by nitric oxide synthase (NOS) has received attention as a neurotransmitter in the brain. NO has been found to induce cognitive behaviour in experimental animals. In order to show evidence for the involvement of NO in learning and memory processes, the reports indicating the effects of its precursor, donors, and inhibitors of its synthesis in mammals, birds, fishes and invertebrates have been reviewed. Further, learning and memory...



    CARIA,Cintia Rabelo e Paiva; MOSCATO,Camila Henrique; TOMÉ,Renata Bortolin Guerra; PEDRAZZOLI Jr,José; RIBEIRO,Marcelo Lima; GAMBERO,Alessandra


    Context Intestinal inflammation can induce a local reduction in oxygen levels that triggers an adaptive response centered on the expression of hypoxia-inducible factors (HIFs). Nitric oxide, a well-described inflammatory mediator, may interfere with hypoxia signaling. Objectives We aimed to evaluate the role of nitric oxide in hypoxia signaling during colonic inflammation. Methods Colitis was induced by single (acute) or repeated (reactivated colitis) trinitrobenzenosulfonic acid administ...

  1. Detection of Nitric Oxide by Electron Paramagnetic Resonance Spectroscopy


    Hogg, Neil


    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.

  2. Detecting and Understanding the Roles of Nitric Oxide in Biology


    Tonzetich, Zachary J.; McQuade, Lindsey E.; Lippard, Stephen J.


    We are pursuing a dual strategy for investigating the chemistry of nitric oxide as a biological signaling agent. In one approach, metal-based fluorescent sensors for the detection of NO in living cells are evaluated, and a sensor based on a copper fluorescein complex has proved to be a valuable lead compound. Sensors of this class permit identification of NO from both inducible and constitutive forms of nitric oxide synthase and facilitate investigation of different NO functions in response t...

  3. Nitric oxide in adaptation to altitude (United States)

    Laskowski, Daniel; Erzurum, Serpil C.


    This review summarizes published information on levels of nitric oxide gas (NO) in the lungs and NO-derived liquid phase molecules in the acclimatization of visitors newly arrived at altitudes of 2500m or more and adaptation of populations whose ancestors arrived thousands of years ago. Studies of acutely exposed visitors to high altitude focus on the first 24–48 hours with just a few extending to days or weeks. Among healthy visitors, NO levels in the lung, plasma and/or red blood cells fell within three hours, but then returned toward baseline or slightly higher by 48 hours, and increased above baseline by 5 days. Among visitors ill with high-altitude pulmonary edema at the time of the study or in the past, NO levels were lower than their healthy counterparts. As for highland populations, Tibetans had NO levels in the lung, plasma and red blood cells that were at least double and in some cases orders of magnitude greater than other populations regardless of altitude. Red blood cell associated nitrogen oxides were more than two hundred times higher. Other highland populations had generally higher levels although not to the degree showed by Tibetans. Overall, responses of those acclimatized and those presumed to be adapted are in the same direction although the Tibetans have much larger responses. Missing are long-term data on lowlanders at altitude showing how similar they become to the Tibetan phenotype. Also missing are data on Tibetans at low altitude to see the extent to which their phenotype is a response to the immediate environment or expressed constitutively. The mechanisms causing the visitors’ and the Tibetans’ high levels of NO and NO-derived molecules at altitude remain unknown. Limited data suggest processes including hypoxic upregulation of NO synthase gene expression, hemoglobin-NO reactions and genetic variation. Gains in understanding will require integrating appropriate methods and measurement techniques with indicators of adaptive function

  4. Post-Translational Modification of Constitutive Nitric Oxide Synthase in the Penis


    Musicki, Biljana; Ross, Ashley E.; Champion, Hunter C.; Burnett, Arthur L.; Bivalacqua, Trinity J.


    Erectile dysfunction (ED) is a common men's health problem characterized by the consistent inability to sustain an erection sufficient for sexual intercourse. Basic science research on erectile physiology has been devoted to investigating the pathogenesis of ED and has led to the conclusion that ED is predominately a disease of vascular origin and/or neurogenic dysfunction. The constitutive forms of nitric oxide synthase [NOS; endothelial NOS (eNOS) and neuronal NOS (nNOS)] are important enzy...

  5. [Potential protective role of nitric oxide and Hsp70 linked to functional foods in the atherosclerosis]. (United States)

    Camargo, Alejandra B; Manucha, Walter

    Atherosclerosis, one of the main pathologic entities considered epidemic and a worldwide public health problem, is currently under constant review as regards its basic determining mechanisms and therapeutic possibilities. In this regard, all patients afflicted with the disease exhibit mitochondrial dysfunction, oxidative stress and inflammation. Interestingly, nitric oxide - a known vasoactive messenger gas - has been closely related to the inflammatory, oxidative and mitochondrial dysfunctional process that characterizes atherosclerosis. In addition, it has recently been demonstrated that alterations in the bioavailability of nitric oxide would induce the expression of heat shock proteins. This agrees with the use of functional foods as a strategy to prevent both vascular aging and the development of atherosclerosis. Finally, a greater knowledge regarding the mechanisms implied in the development of atherosclerosis will enable proposing new and possible hygiene, health and therapeutic interventions. Copyright © 2016 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Vasomotor control in mice overexpressing human endothelial nitric oxide synthase. (United States)

    van Deel, Elza D; Merkus, Daphne; van Haperen, Rien; de Waard, Monique C; de Crom, Rini; Duncker, Dirk J


    Nitric oxide (NO) plays a key role in regulating vascular tone. Mice overexpressing endothelial NO synthase [eNOS-transgenic (Tg)] have a 20% lower systemic vascular resistance (SVR) than wild-type (WT) mice. However, because eNOS enzyme activity is 10 times higher in tissue homogenates from eNOS-Tg mice, this in vivo effect is relatively small. We hypothesized that the effect of eNOS overexpression is attenuated by alterations in NO signaling and/or altered contribution of other vasoregulatory pathways. In isoflurane-anesthetized open-chest mice, eNOS inhibition produced a significantly greater increase in SVR in eNOS-Tg mice compared with WT mice, consistent with increased NO synthesis. Vasodilation to sodium nitroprusside (SNP) was reduced, whereas the vasodilator responses to phosphodiesterase-5 blockade and 8-bromo-cGMP (8-Br-cGMP) were maintained in eNOS-Tg compared with WT mice, indicating blunted responsiveness of guanylyl cyclase to NO, which was supported by reduced guanylyl cyclase activity. There was no evidence of eNOS uncoupling, because scavenging of reactive oxygen species (ROS) produced even less vasodilation in eNOS-Tg mice, whereas after eNOS inhibition the vasodilator response to ROS scavenging was similar in WT and eNOS-Tg mice. Interestingly, inhibition of other modulators of vascular tone [including cyclooxygenase, cytochrome P-450 2C9, endothelin, adenosine, and Ca-activated K(+) channels] did not significantly affect SVR in either eNOS-Tg or WT mice, whereas the marked vasoconstrictor responses to ATP-sensitive K(+) and voltage-dependent K(+) channel blockade were similar in WT and eNOS-Tg mice. In conclusion, the vasodilator effects of eNOS overexpression are attenuated by a blunted NO responsiveness, likely at the level of guanylyl cyclase, without evidence of eNOS uncoupling or adaptations in other vasoregulatory pathways.

  7. Nitric oxide and reactive oxygen species in the nucleus revisited. (United States)

    Provost, Chantale; Choufani, Faten; Avedanian, Levon; Bkaily, Ghassan; Gobeil, Fernand; Jacques, Danielle


    Recent work from our group showed that the nuclear envelope membranes contain several G protein-coupled receptors, including prostaglandin E2 (EP3R) and endothelin-1 (ET-1) receptors. Activation of EP3R increased endothelial nitric oxide synthase (eNOS) RNA expression in nuclei. eNOS and inducible NOS (iNOS) are reported to also be present at the nuclear level. Furthermore, reactive oxygen species (ROS) were also localized at the nuclear level. In this review, we show that stimulation with NO donor sodium nitroprusside results in an increase of intranuclear calcium that was dependent on guanylate cyclase activation, but independent of MAPK. This increase in nuclear calcium correlated with an increase in nuclear transcription of iNOS. H2O2 and ET-1 increase both cytosolic and nuclear ROS in human endocardial endothelial cells and in human aortic vascular smooth muscle cells. This increase in ROS levels by H2O2 and ET-1 was reversed by the antioxidant glutathione. In addition, our results strongly suggest that cytosolic signalization is not only transmitted to the nucleus but is also generated by the nucleus. Furthermore, we demonstrate that oxidative stress can be sensed by the nucleus. These results highly suggest that ROS formation is also generated directly by the nucleus and that free radicals may contribute to ET-1 regulation of nuclear Ca2+ homeostasis.

  8. Direct measurements of nitric oxide release in relation to expression of endothelial nitric oxide synthase in isolated porcine mitral valves

    DEFF Research Database (Denmark)

    Moesgaard, Sophia Gry; Olsen, Lisbeth Høier; Aasted, Bent


    The aim of this study was to measure the direct release of nitric oxide (NO) from the porcine mitral valve using a NO microelectrode. Furthermore, the expression and localization of endothelial nitric oxide synthase (eNOS) in the mitral valve was studied using immunohistochemistry, Western blotti...... techniques for investigations into the role of local NO release in mitral valve diseases.......The aim of this study was to measure the direct release of nitric oxide (NO) from the porcine mitral valve using a NO microelectrode. Furthermore, the expression and localization of endothelial nitric oxide synthase (eNOS) in the mitral valve was studied using immunohistochemistry, Western blotting...... and RT-PCR. Results show that bradykinin increases NO release from mitral valves (¿Bradykinin: 33.71 ± 10.41 nM NO, P

  9. Nitric oxide synthase localized in a subpopulation of vestibular efferents with NADPH diaphorase histochemistry and nitric oxide synthase immunohistochemistry. (United States)

    Lysakowski, A; Singer, M


    Efferent innervation of the vestibular labyrinth is known to be cholinergic. More recent studies have also demonstrated the presence of the neuropeptide calcitonin gene-related peptide in this system. Nitric oxide is one of a new class of neurotransmitters, the gaseous transmitters. It acts as a second messenger and neurotransmitter in diverse physiological systems. We decided to investigate the anatomical distribution of the synthetic enzyme for nitric oxide, nitric oxide synthase (NOS), to clarify the role of nitric oxide in the vestibular periphery. NADPH diaphorase histochemical and NOS I immunohistochemical studies were done in the adult chinchilla and rat vestibular brainstem; diaphorase histochemistry was done in the chinchilla periphery. Retrograde tracing studies to verify the presence of NOS in brainstem efferent neurons were performed in young chinchillas. Our light microscopic results show that NOS I, as defined mainly by the presence of NADPH diaphorase, is present in a subpopulation of both brainstem efferent neurons and peripheral vestibular efferent boutons. Our ultrastructural results confirm these findings in the periphery. NADPH diaphorase is also present in a subpopulation of type I hair cells, suggesting that nitric oxide might be produced in and act locally upon these cells and other elements in the sensory epithelium. A hypothesis about how nitric oxide is produced in the vestibular periphery and how it may interact with other elements in the vestibular sensory apparatus is presented in the discussion. Copyright 2000 Wiley-Liss, Inc.

  10. Mitochondrial dysfunction associated with nitric oxide pathways in glutamate neurotoxicity. (United States)

    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.

  11. Salicylates, nitric oxide, malaria, and Reye's syndrome. (United States)

    Clark, I; Whitten, R; Molyneux, M; Taylor, T


    Reye's syndrome virtually disappeared from much of the world after the use of salicylate in febrile children was successfully discouraged. This severe sepsis-like disease was thought to be caused by a hypersensitivity to salicylates in children with mild viral infections, although no mechanism consistent with this proposal was ever established. Salicylate toxicity in African children has been noted to have many clinical features in common with severe falciparum malaria, including acidosis, altered consciousness, convulsions, and hypoglycaemia. Salicylates are widely available in various formulations in many African countries, and are commonly used for initial treatment of the symptoms that malaria shares with other diseases. There is now experimental evidence that salicylate increases and prolongs the activity of key elements along the signalling pathway through which interferon gamma generates inducible nitric oxide synthase (iNOS), and we have shown that iNOS is strongly expressed in fatal malaria and other acute fevers in African children. We further propose that, in areas where salicyaltes are still used to treat the symptoms of febrile illnesses in children, this mechanism could exacerbate potentially serious infectious diseases, including falciparum malaria. In contrast, the absence of salicylate use in children in some Pacific islands could contribute to the milder outcome of falciparum malaria than is observed in Africa. Widespread expression of iNOS has also been seen in the tissues of a patient with fatal clinically defined Reye's syndrome. This finding suggests that Reye's syndrome can be mediated through salicylate enhancement of iNOS expression, the initial trigger in this instance usually being a viral infection.

  12. Endothelial nitric oxide synthase polymorphism G298T in ...

    Indian Academy of Sciences (India)

    Supplementary data: Endothelial nitric oxide synthase polymorphism G298T in association with oxidative DNA damage in coronary atherosclerosis. Rajesh G. Kumar, Mrudula K. Spurthi, Kishore G. Kumar, Sanjib K. Sahu and Surekha H. Rani. J. Genet. 91, 349–352. Table 1. The demographic and clinical data of the CHD ...

  13. Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 ...

    African Journals Online (AJOL)


    Purpose: To explore the antioxidant properties of the methanol extract of Pericarpium Zanthoxyli and its effect on inducible nitric oxide synthase (iNOS), cycleooxygenase-2 (COX-2) and lipopolysaccharides (LPS)-induced cell damage in macrophage cells. Methods: Anti-oxidant activities were tested by measuring free ...

  14. Nitric oxide in health and disease of the respiratory system

    NARCIS (Netherlands)

    Ricciardolo, Fabio L. M.; Sterk, Peter J.; Gaston, Benjamin; Folkerts, Gert


    During the past decade a plethora of studies have unravelled the multiple roles of nitric oxide (NO) in airway physiology and pathophysiology. In the respiratory tract, NO is produced by a wide variety of cell types and is generated via oxidation of l-arginine that is catalyzed by the enzyme NO

  15. The correlation between total antioxidant capacity and nitric oxide ...

    African Journals Online (AJOL)



    Aug 30, 2010 ... Sperm DNA quality is important in male fertility. Oxidative stress increases sperm DNA damages. Antioxidants decrease production of free radicals and scavenge them. Nitric oxide (NO) is a free radical which is produced by most cells and has a dual role on cells. Low concentrations of NO is essential in.

  16. The role of nitrite in nitric oxide homeostasis

    DEFF Research Database (Denmark)

    Jensen, Frank Bo


    Nitrite is endogenously produced as an oxidative metabolite of nitric oxide, but it also functions as a NO donor that can be activated by a number of cellular proteins under hypoxic conditions. This article discusses the physiological role of nitrite and nitrite-derived NO in blood flow regulatio...

  17. A nitric oxide donor (nitroglycerin) triggers genuine migraine attacks

    DEFF Research Database (Denmark)

    Thomsen, L L; Kruuse, C; Iversen, Helle Klingenberg


    Supersensitivity to induction of headache and arterial dilatation by a donor of nitric oxide (nitroglycerin) has recently been demonstrated in migraine sufferers. The aims of the present study were to examine whether the nitric oxide donor nitroglycerin may induce a typical migraine attack, to ex.......03). The time pattern of headache and estimated middle cerebral artery dilatation corresponded well. The study therefore demonstrates that activation of the nitric oxide cGMP pathway may cause typical migraine attacks.......Supersensitivity to induction of headache and arterial dilatation by a donor of nitric oxide (nitroglycerin) has recently been demonstrated in migraine sufferers. The aims of the present study were to examine whether the nitric oxide donor nitroglycerin may induce a typical migraine attack......, to exclude placebo-related effects and to describe the relation between middle cerebral artery dilatation and provoked migraine. Nitroglycerin (0.5 μg/kg/min for 20 min) or placebo was infused into 12 migraine patients in a double-blind cross-over trial. Blood velocity in the middle cerebral artery...

  18. Exogenous nitric oxide inhibits shedding of ADAM17 substrates. (United States)

    Bzowska, Monika; Stalińska, Krystyna; Mezyk-Kopeć, Renata; Wawro, Karolina; Duda, Katarzyna; Das, Sudipta; Bereta, Joanna


    Both ADAM17, the secretase responsible for the shedding of ectodomains of numerous membrane proteins including TNF and its receptors, as well as nitric oxide synthesized by inducible nitric oxide synthase play regulatory roles in inflammation and tumor progression. We analyzed the effect of endogenous and exogenous nitric oxide on the expression and activity of ADAM17 in murine endothelial cells and a monocyte/macrophage cell line. We found that endogenous nitric oxide influenced neither ADAM17 mRNA level nor the shedding of two ADAM17 substrates, TNF and TNFR1. Exogenous NO significantly diminished the release of TNF and TNFR1 without affecting the ADAM17 transcript level. Our data seem contrary to a previous report that showed the activation of ADAM17 by nitric oxide (Zhang et al., 2000, J Biol Chem 275: 15839-15844). We discuss potential mechanisms of NO-mediated inhibition of ectodomain shedding and possible reasons of discrepancy between our results and the previous report.

  19. Nitric Oxide in Astrocyte-Neuron Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nianzhen [Iowa State Univ., Ames, IA (United States)


    Astrocytes, a subtype of glial cell, have recently been shown to exhibit Ca2+ elevations in response to neurotransmitters. A Ca2+ elevation can propagate to adjacent astrocytes as a Ca2+ wave, which allows an astrocyte to communicate with its neighbors. Additionally, glutamate can be released from astrocytes via a Ca2+-dependent mechanism, thus modulating neuronal activity and synaptic transmission. In this dissertation, the author investigated the roles of another endogenous signal, nitric oxide (NO), in astrocyte-neuron signaling. First the author tested if NO is generated during astrocytic Ca2+ signaling by imaging NO in purified murine cortical astrocyte cultures. Physiological concentrations of a natural messenger, ATP, caused a Ca2+-dependent NO production. To test the roles of NO in astrocytic Ca2+ signaling, the author applied NO to astrocyte cultures via addition of a NO donor, S-nitrosol-N-acetylpenicillamine (SNAP). NO induced an influx of external Ca2+, possibly through store-operated Ca2+ channels. The NO-induced Ca2+ signaling is cGMP-independent since 8-Br-cGMP, an agonistic analog of cGMP, did not induce a detectable Ca2+ change. The consequence of this NO-induced Ca2+ influx was assessed by simultaneously monitoring of cytosolic and internal store Ca2+ using fluorescent Ca2+ indicators x-rhod-1 and mag-fluo-4. Blockage of NO signaling with the NO scavenger PTIO significantly reduced the refilling percentage of internal stores following ATP-induced Ca2+ release, suggesting that NO modulates internal store refilling. Furthermore, locally photo-release of NO to a single astrocyte led to a Ca2+ elevation in the stimulated astrocyte and a subsequent Ca2+ wave to neighbors. Finally, the author tested the role of NO inglutamate-mediated astrocyte-neuron signaling by

  20. Pyocyanin inhibits both nitric oxide-dependent and -independent relaxation in porcine coronary arteries. (United States)

    Hempenstall, Allison; Grant, Gary D; Anoopkumar-Dukie, Shailendra; Johnson, Peter J


    The effects of the Pseudomonas aeruginosa virulence factor pyocyanin (PCN) on the contractile function of porcine coronary arteries was investigated in vitro. Artery rings (5 mm) were suspended in organ baths containing Krebs' solution for the measurement of isometric tension. The effect of PCN on resting and precontracted coronary arteries was initially investigated with various agents. Arteries were precontracted with prostaglandin (PG) F2α or potassium chloride and endothelium-dependent relaxations were induced by various agents in the presence of PCN. Pyocyanin (0.1-10 μmol/L) evoked small-amplitude, dose-dependent contractions in resting porcine coronary arteries. In addition, PCN amplified the contractile response to PGF2α , but did not alter responses to carbachol. Pyocyanin (0.1-10 μmol/L) significantly inhibited endothelium-dependent relaxations evoked by neurokinin A. Pyocyanin also inhibited relaxations evoked by diethylamine nitric oxide (a nitric oxide donor), forskolin (an adenylate cyclase activator), dibuytyryl-cAMP (a cAMP analogue), 8-bromo-cGMP (a cGMP analogue) and P1075 (a KATP channel activator), but not isoprenaline (β-adrenoceceptor agonist). These results indicate that physiological concentrations of PCN interfere with multiple intracellular processes involved in vascular smooth muscle relaxation, in particular pathways downstream of nitric oxide release. Thus, PCN may alter normal vascular function in patients infected with P. aeruginosa. © 2014 Wiley Publishing Asia Pty Ltd.

  1. Targeting Bacterial Nitric Oxide Synthase with Aminoquinoline-Based Inhibitors. (United States)

    Holden, Jeffrey K; Lewis, Matthew C; Cinelli, Maris A; Abdullatif, Ziad; Pensa, Anthony V; Silverman, Richard B; Poulos, Thomas L


    Nitric oxide is produced in Gram-positive pathogens Bacillus anthracis and Staphylococcus aureus by the bacterial isoform of nitric oxide synthase (NOS). Inhibition of bacterial nitric oxide synthase (bNOS) has been identified as a promising antibacterial strategy for targeting methicillin-resistant S. aureus [Holden, J. K., et al. (2015) Chem. Biol. 22, 785-779]. One class of NOS inhibitors that demonstrates antimicrobial efficacy utilizes an aminoquinoline scaffold. Here we report on a variety of aminoquinolines that target the bacterial NOS active site, in part, by binding to a hydrophobic patch that is unique to bNOS. Through mutagenesis and crystallographic studies, our findings demonstrate that aminoquinolines are an excellent scaffold for further aiding in the development of bNOS specific inhibitors.

  2. Pain modulation by nitric oxide in the spinal cord.

    Directory of Open Access Journals (Sweden)

    Marco Aurelio M Freire


    Full Text Available Nitric oxide (NO is a versatile messenger molecule first associated with endothelial relaxing effects. In the central nervous system (CNS, NO synthesis is primarily triggered by activation of N-methyl-D-aspartate (NMDA receptors and has a Janus face, with both beneficial and harmful properties, depending on concentration and the identity of its synthetic enzyme isoform. There are three isoforms of the NO synthesizing enzyme nitric oxide synthase (NOS: neuronal (nNOS, endothelial (eNOS, and inducible nitric oxide synthase (iNOS, each one involved with specific events in the brain. In CNS, nNOS is involved with modulation of synaptic transmission through long-term potentiation in several regions, including nociceptive circuits in the spinal cord. Here, we review the role played by NO on central pain sensitization.

  3. Detecting and understanding the roles of nitric oxide in biology. (United States)

    Tonzetich, Zachary J; McQuade, Lindsey E; Lippard, Stephen J


    We are pursuing a dual strategy for investigating the chemistry of nitric oxide as a biological signaling agent. In one approach, metal-based fluorescent sensors for the detection of NO in living cells are evaluated, and a sensor based on a copper fluorescein complex has proved to be a valuable lead compound. Sensors of this class permit identification of NO from both inducible and constitutive forms of nitric oxide synthase and facilitate investigation of different NO functions in response to external stimuli. In the other approach, we employ synthetic model complexes of iron-sulfur clusters to probe their reactivity toward nitric oxide as biomimics of the active sites of iron-sulfur proteins. Our studies reveal that NO disassembles the Fe-S clusters to form dinitrosyl iron complexes.

  4. Nitric oxide and changes of iron metabolism in exercise. (United States)

    Qian, Zhong Ming


    Accumulated data imply that exercise itself might not lead to a true iron deficiency or 'sport anaemia' in a healthy athlete who has adequate iron intake. The higher prevalence of iron deficiency anaemia in younger female athletes might be not due to exercise itself, but probably results from dietary choices, inadequate iron intake and menstruation. These factors can also induce iron deficiency or anaemia in the general population. However, exercise does affect iron metabolism, leading to low or sub-optimal iron status. The underlying mechanism is unknown. In this review, recent advances in the study of the effect of exercise on iron metabolism and nitric oxide, and the relationship between nitric oxide and iron status in exercise are discussed. A hypothesis that increased production of nitric oxide might contribute to sub-optimal iron status in exercise is proposed.

  5. Topological control of nitric oxide secretion by tantalum oxide nanodot arrays. (United States)

    Dhawan, Udesh; Lee, Chia Hui; Huang, Chun-Chung; Chu, Ying Hao; Huang, Guewha S; Lin, Yan-Ren; Chen, Wen-Liang


    Nitric oxide (NO) plays a very important role in the cardiovascular system as a major secondary messenger in signaling pathway. Its concentration regulates most of the important physiological indexes including the systemic blood pressure, blood flow, regional vascular tone and other cardiac functions. The effect of nanotopography on the NO secretion in cardiomyocytes has not been elucidated before. In this study, we report how the nanotopography can modulate the secretion profile of NO and attempt to elucidate the genetic pathways responsible for the same by using Tantalum Oxide nanodot arrays ranging from 10 to 200 nm. A series of nanodot arrays were fabricated with dot diameter ranging from 10 to 200 nm. Temporal NO release of cardiomyocytes was quantified when grown on different surfaces. Quantitative RT-PCR and Western blot were performed to verify the genetic pathways of NO release. After hours 24 of cell seeding, NO release was slowly enhanced by the increase of dot diameter from 10 nm up to 50 nm, mildly enhanced to a medium level at 100 nm, and increase rapidly to a high level at 200 nm. The temporal enhancement of NO release dropped dramatically on day 3. On day 5, a topology-dependent profile was established that maximized at 50 nm and dropped to control level at 200 nm. The NO releasing profile was closely associated with the expression patterns of genes associated with Endothelial nitric oxide synthase (eNOS) pathway [GPCR, PI3K, Akt, Bad, Bcl-2, NFκB(p65), eNOS], but less associated with Inducible nitric oxide synthase (iNOS) pathway (TNF-α, ILK, Akt, IκBα, NFκB, iNOS). Western blotting of Akt, eNOS, iNOS, and NFκB further validated that eNOS pathway was modulated by nanotopology. Based on the findings of the present study, 50, 100 nm can serve as the suitable nanotopography patterns for cardiac implant surface design. These two nanodot arrays promote NO secretion and can also promote the vascular smooth muscle relaxation. The results of this

  6. Nitric oxide donors for the treatment of preterm labour. (United States)

    Duckitt, K; Thornton, S


    A number of tocolytics have been advocated for the treatment of threatened preterm labour in order to delay delivery. The rationale is that a delay in delivery may be associated with improved neonatal morbidity or mortality. Nitric oxide donors, such as nitroglycerin, have been used to relax the uterus. This review addresses their efficacy, side effects and influence on neonatal outcome. To determine whether nitric oxide donors administered in threatened preterm labour are associated with a delay in delivery, adverse side effects or improved neonatal outcome. A comprehensive search of the Cochrane Pregnancy and Childbirth Group trials register (March 2002) and the Cochrane Controlled Trials Register (The Cochrane Library, Issue 1, 2002) was undertaken. Randomised controlled trials of nitric oxide donors administered for tocolysis. Trial quality assessment and data extraction were done independently by two reviewers. Five randomised controlled trials (466 women) were included. Nitroglycerine was the NO donor used in all these trials. Nitric oxide donors did not delay delivery nor improve neonatal outcome when compared with placebo, no treatment or alternative tocolytics such as ritodrine, albuterol and magnesium sulphate. There was, however, a reduction in number of deliveries less than 37 weeks when compared with alternative tocolytics but the numbers of deliveries before 32 and 34 weeks were not influenced. Side effects (other than headache) were reduced in women who received nitric oxide donors rather than other tocolytics. However, women were significantly more likely to experience headache when NO donors had been used. There is currently insufficient evidence to support the routine administration of nitric oxide donors in the treatment of threatened preterm labour.

  7. Post-Translational Modification of Constitutive Nitric Oxide Synthase in the Penis (United States)

    Musicki, Biljana; Ross, Ashley E.; Champion, Hunter C.; Burnett, Arthur L.; Bivalacqua, Trinity J.


    Erectile dysfunction (ED) is a common men's health problem characterized by the consistent inability to sustain an erection sufficient for sexual intercourse. Basic science research on erectile physiology has been devoted to investigating the pathogenesis of ED and has led to the conclusion that ED is predominately a disease of vascular origin and/or neurogenic dysfunction. The constitutive forms of nitric oxide synthase [NOS; endothelial NOS (eNOS) and neuronal NOS (nNOS)] are important enzymes involved in the production of nitric oxide (NO) and thus regulate penile vascular homeostasis. Given the impact of endothelial- and neuronal-derived NO in penile vascular biology, a great deal of research over the past decade has focused on the role of NO synthesis from the endothelium and nitrergic nerve terminal in normal erectile physiology as well as in disease states. Loss of the functional integrity of the endothelium and subsequent endothelial dysfunction plays an integral role in the occurrence of ED. Therefore, molecular mechanisms involved in dysregulation of these NOS isoforms in the development of ED are essential to discovering the pathogenesis of ED in various disease states. This communication reviews the role of eNOS and nNOS in erectile physiology and discusses the alterations in eNOS and nNOS via post-translation modification in various vascular diseases of the penis. PMID:19342700

  8. [Localization of nitric oxide synthase in the chicken vestibular system]. (United States)

    Nie, Guohui; Wang, Jibao


    To locate nitric oxide synthase (NOS) in the chicken vestibular system. The frozen section were processed for NADPH-d histochemistry in a solution containing NADPH and nitroblue tetnazolium (NBT) to demonstrate NOS positive reactivity. NOS positive staining, black-blue in color, was seen at the nerve ending, nerve fibers of the utricul and saculla and ampiculium. Ganglion cells had different activity. The shape of the cells seems to be round or oral. Collectively, data indicate the presence of active NOS in these tissue and suggest modulation of vestibular neurotransmission by nitric oxide.

  9. Involvement of nitric oxide in aminoglycoside vestibulotoxicity in guinea pigs. (United States)

    Nakagawa, T; Yamane, H; Takayama, M; Sunami, K; Nakai, Y


    Involvement of nitric oxide (NO) has been reported in physiological and pathological conditions in the inner ear. Recently, the presence of nitric oxide synthase (NOS) was demonstrated in the vestibular epithelium. In this study we used nicotinamide adenine dinucleotide phosphate-diapholase staining to monitor NOS activity during degeneration of guinea pig vestibular epithelia affected by streptomycin. Increased NOS activity was observed in affected epithelia in a dose- and time-dependent manner and a NOS inhibitor could protect hair cells from apoptosis. Additionally, cycloheximide significantly reduced NOS activity and the occurrence of apoptosis. These findings suggest that NO is involved in the degenerative process of vestibular epithelia caused by aminoglycosides.

  10. Nitric oxide availability in deeply hypoxic crucian carp

    DEFF Research Database (Denmark)

    Hansen, Marie Niemann; Gerber, Lucie; Jensen, Frank Bo


    nitric oxide synthase-2 gene variant. The data support that ambient nitrite is taken up across the gills to be distributed via the blood to tissues, particularly the heart, where it assists in cytoprotection and other functions. Cardiac nitrite was not elevated in acutely exposed fish, revealing......Recent research suggest that anoxia-tolerant fish transfer extracellular nitrite into the tissues, where it is used for nitric oxide (NO) generation, iron-nitrosylation and S-nitrosation of proteins as part of the cytoprotective response towards prolonged oxygen lack and subsequent re...

  11. Recent Advances on Nitric Oxide in the Upper Airways. (United States)

    Maniscalco, Mauro; Bianco, Andrea; Mazzarella, Gennaro; Motta, Andrea


    Exhaled nitric oxide (NO) originates from the upper airways, and takes action, to varying extents, in regulation, protection and defense, as well as in noxious processes. Nitric oxide retains important functions in a wide range of physiological and pathophysiological processes of the human body, including vaso-regulation, antimicrobial activity, neurotransmission and respiration. This review article reports the ongoing investigations regarding the source, biology and relevance of NO within upper respiratory tract. In addition, we discuss the role of NO, originating from nasal and paranasal sinuses, in inflammatory disorders such as allergic rhinitis, sinusitis, primary ciliary dyskinesia, and cystic fibrosis.

  12. Nitric oxide availability in deeply hypoxic crucian carp

    DEFF Research Database (Denmark)

    Hansen, Marie Niemann; Gerber, Lucie; Jensen, Frank Bo


    Recent research suggest that anoxia-tolerant fish transfer extracellular nitrite into the tissues, where it is used for nitric oxide (NO) generation, iron-nitrosylation and S-nitrosation of proteins as part of the cytoprotective response towards prolonged oxygen lack and subsequent re...... nitric oxide synthase-2 gene variant. The data support that ambient nitrite is taken up across the gills to be distributed via the blood to tissues, particularly the heart, where it assists in cytoprotection and other functions. Cardiac nitrite was not elevated in acutely exposed fish, revealing...

  13. Featured Article: Differential regulation of endothelial nitric oxide synthase phosphorylation by protease-activated receptors in adult human endothelial cells. (United States)

    Tillery, Lakeisha C; Epperson, Tenille A; Eguchi, Satoru; Motley, Evangeline D


    , suggesting protease-activated receptor coupling to Gq and G12/13, respectively. These data suggest a vascular bed specific differential coupling of protease-activated receptors to the signaling pathways that regulate endothelial nitric oxide synthase and nitric oxide production that may be responsible for endothelial dysfunction associated with cardiovascular disease. © 2016 by the Society for Experimental Biology and Medicine.

  14. Interleukin 1 beta induces diabetes and fever in normal rats by nitric oxide via induction of different nitric oxide synthases

    DEFF Research Database (Denmark)

    Reimers, J I; Bjerre, U; Mandrup-Poulsen, T


    Substantial in vitro evidence suggests that nitric oxide may be a major mediator of interleukin 1 (IL-1) induced pancreatic beta-cell inhibition and destruction in the initial events leading to insulin-dependent diabetes mellitus. Using NG-nitro-L-arginine methyl ester, an inhibitor of both......, glucagon, corticosterone and leukocyte- and differential-counts in normal rats injected once daily for 5 days with interleukin 1 beta (IL-1 beta) (0.8 microgram/rat = 4.0 micrograms/kg). Inhibition of both the constitutive and the inducible forms of nitric oxide synthase prevented IL-1 beta-induced fever...

  15. Modulation of Fibrosis in Systemic Sclerosis by Nitric Oxide and Antioxidants

    Directory of Open Access Journals (Sweden)

    Audrey Dooley


    Full Text Available Systemic sclerosis (scleroderma: SSc is a multisystem, connective tissue disease of unknown aetiology characterized by vascular dysfunction, autoimmunity, and enhanced fibroblast activity resulting in fibrosis of the skin, heart, and lungs, and ultimately internal organ failure, and death. One of the most important and early modulators of disease activity is thought to be oxidative stress. Evidence suggests that the free radical nitric oxide (NO, a key mediator of oxidative stress, can profoundly influence the early microvasculopathy, and possibly the ensuing fibrogenic response. Animal models and human studies have also identified dietary antioxidants, such as epigallocatechin-3-gallate (EGCG, to function as a protective system against oxidative stress and fibrosis. Hence, targeting EGCG may prove a possible candidate for therapeutic treatment aimed at reducing both oxidant stress and the fibrotic effects associated with SSc.

  16. Inhibition of influenza virus replication by nitric oxide

    NARCIS (Netherlands)

    G.F. Rimmelzwaan (Guus); M.M.J.W. Baars (Marianne); P. de Lijster; R.A.M. Fouchier (Ron); A.D.M.E. Osterhaus (Albert)


    textabstractNitric oxide (NO) has been shown to contribute to the pathogenesis of influenza virus-induced pneumonia in mouse models. Here we show that replication of influenza A and B viruses in Mabin Darby canine kidney cells is severely impaired by the NO donor,

  17. Expression of Inducible Nitric Oxide Synthase in the Epithelial ...

    African Journals Online (AJOL)

    Conclusion: iNOS was over expressed in OKCs when compared with DC and RC suggesting that iNOS may contribute to the aggressive behavior of OKC. This is yet another evidence to support that OKC is the neoplasm. Keywords: Dentigerous cyst, Immunohistochemistry, Inducible nitric oxide synthase, Odontogenic ...

  18. Arginine, citrulline and nitric oxide metabolism in sepsis (United States)

    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...

  19. [Effect of nitric oxide on viscosity of nerve cell membranes]. (United States)

    Ul'ianova, N A; Maksimov, G V; Churin, A A; Rubin, A B


    The influence of nitric oxide on the microviscosity of nerve cell membranes was investigated by resonance Raman (RR) spectroscopy. Changes in membrane viscosity were estimated from the resonance Raman-spectra of carotenoids localized in the axon plasmatic membrane and membranes of subcellular vesicles (cytosomes). For the nerve fibre, the extracellular addition of nitric oxide donor, sodium nitroprusside (0.5 mM), caused an increase in the 1526 cm(-1) band relative half-width and the modification of 1160 cm-1 band structure. Moreover, sodium nitroprusside led to an increase in the I1526/I1160 ratio by 13% in 25 min and a decrease in this ratio by 10% in 50 min. In the case of cytosomes, sodium nitroprusside (0.5 mM) resulted in the reduction of the I1526/I1160 ratio by 8% in 25 and 50 min. It was shown that the neuron rhythmic activity correlated with the I1526/I1160 ratio and cytosome membrane microviscosity. We suppose that nitric oxide causes a conformational transition of carotenoids in the axon plasmatic membrane and the membranes of cytosomes. This process can be due to nitric oxide-induced changes of the membrane microviscosity or potential.

  20. The levels of nitric oxide in megaloblastic anemia

    Directory of Open Access Journals (Sweden)

    Emin Kaya


    Full Text Available Objective: The purpose of this study was to investigate the relationship between nitric oxide degradation products (nitrate and nitrite levels and megaloblastic anemia which is treated with cyalocobalamin. Materials and Methods: A total of 30 patients with megaloblastic anemia (16 Male, 14 Female were included in the study. Cyanocobalamin was administered (1.000 µg/day intramuscularly until the reticulocyte crisis occurred to the normal range. The control group consisted of 30 healthy subjects (15 Male, 15 Female. Nitric oxide levels were measured before treatment and compared with the values obtained during peak reticulocyte count. Results: Plasma direct nitrite, total nitrite and nitrate levels were 24,86±3,87, 60.56±7,01 and 36,02±5,24 in before treatment versus 15,48±3,05, 38,92±6,44 and 22,77±6,04 μmol/dl in after treatment, respectively. Plasma direct nitrite, total nitrite and nitrate levels were significantly lower in after treatment compared with the before treatment (p<0.001. Conclusion: Nitric oxide levels are seen to increase in megaloblastic anemia. This study suggested that abnormalities in the nitric oxide levels in megaloblastic anemia are restored by vitamin B12 replacement therapy.

  1. Ginsenoside Rb1 Reduces Nitric Oxide Production via Inhibition of ...

    African Journals Online (AJOL)

    potential mechanisms of ginseng activity in OA treatment of TCM. Keywords: Ginsenoside Rb1, Nitric oxide, Nuclear factor-κB, Chondrocytes, Osteoarthritis. Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus,. International Pharmaceutical Abstract, Chemical Abstracts, ...

  2. Role of Endothelial Nitric Oxide Synthase Gene Polymorphisms ...

    African Journals Online (AJOL)

    Background: Previous studies indicated an association between endothelial nitric oxide synthase (eNOS) activity and maintenance of pregnancy, but it is rather controversial whether polymorphisms of the gene encoding for eNOS are associated with recurrent spontaneous abortions (RSAs). Aim: The aim was to investigate ...

  3. Serum Iron and Nitric Oxide Production in Trypanosoma brucei ...

    African Journals Online (AJOL)

    Infected rats, treated and untreated, were sacrificed daily for the serum iron levels and nitric oxide synthase activities. For haematological parameters, infected and uninfected but treated rats were sacrificed on days 7 and 12 along with untreated rats. Results showed that tetracycline brought about a significant reduction in ...

  4. Analysis of genetic variation of inducible nitric oxide synthase and ...

    African Journals Online (AJOL)



    Feb 21, 2011 ... The genetic diversity of 100 Malaysian native chickens was investigated using polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) for two candidate genes: inducible nitric oxide synthase (INOS) and natural resistance-associated macrophage protein 1 (NRAMP1). The two genes.

  5. Nitric oxide inhibitory activity of Strychnos spinosa (loganiaceae ...

    African Journals Online (AJOL)

    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 solventsolvent ...

  6. Ginsenoside Rb1 Reduces Nitric Oxide Production via Inhibition of ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect and the potential mechanisms of ginsenoside Rb1 on nitric oxide (NO) production in chondrocytes. Methods: SW1353 chondrosarcoma cells were stimulated with interleukin-1β (IL-1β) in the presence of 20, 40, 80 μM ginsenoside Rb1. NO concentration was assessed by the Griess reaction ...

  7. Nitric oxide radical scavenging potential of some Elburz medicinal ...

    African Journals Online (AJOL)

    Some plants scavenge nitric oxide (NO) with high affinity. For this purpose, forty extracts from 26 medicinal plants, growing extensively in Elburz mountains, were evaluated for their NO scavenging activity. Total phenolic and flavonoid contents of these extracts were also measured by Folin Ciocalteu and AlCl3 colorimetric ...

  8. Nitric oxide production by rat bronchoalveolar macrophages or ...

    Indian Academy of Sciences (India)


    contributions of AMs and PMNs to the amounts of NO produced by BAL cells following intratracheal (IT) instillation of ... [Huffman L J, Prugh D J, Millecchia L, Schuller K C, Cantrell S and Porter D W 2003 Nitric oxide production by rat bronchoalveolar macrophages or ..... dase blocking with methanol and H2O2. Slides were ...

  9. 21 CFR 862.3080 - Breath nitric oxide test system. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 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...

  10. Cross sections for electron collisions with nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Itikawa, Yukikazu, E-mail: [Institute of Space and Astronautical Science, Sagamihara 252-5210 (Japan)


    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.

  11. Inhibition of Nitric Oxide and Prostaglandin E2 Expression by ...

    African Journals Online (AJOL)


    Purpose: To determine whether the methanol extract of Polyopes affinis (MEPA) down-regulates the expression of pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Methods: The production of nitric oxide (NO) and prostaglandin E2 (PGE2) was measured by the Griess reagents and ...

  12. Serum Iron and Nitric Oxide Production in Trypanosoma brucei ...

    African Journals Online (AJOL)


    dependent enzyme that plays a central role in cell division and proliferation6. Another importance of this therapy, which is of interest in this study, is the modulation of the activity of nitric oxide synthase- a cytokine inducible enzyme which catalyses the formation of ..... lifespan of the rats, unlike when tetracycline alone was ...

  13. Restoration Of Glutamine Synthetase Activity, Nitric Oxide Levels ...

    African Journals Online (AJOL)

    Background: Propolis has been proposed to be protective on neurodegenerative disorders. To understand the neuroprotective effects of honeybee propolis, glutamine synthetase (GS) activity, nitric oxide (NO), thiobarbituric acid reactive substances (TBARS) and total antioxidant status (TAS) were studied in different brain ...

  14. Methodological aspects of exhaled nitric oxide measurements in infants.

    NARCIS (Netherlands)

    Gabriele, C.; Wiel, E.C. van der; Nieuwhof, E.M.; Moll, H.A.; Merkus, P.J.F.M.; Jongste, J.C. de


    Guidelines for the measurement of fractional exhaled nitric oxide (FE(NO)) recommend refraining from lung function tests (LFT) and certain foods and beverages before performing FE(NO) measurements, as they may lead to transiently altered FE(NO) levels. Little is known of such factors in infants. The

  15. Nitrite and Nitric Oxide Metabolism in Peripheral Artery Disease


    Allen, Jason D; Giordano, Tony; Kevil, Christopher G.


    Peripheral Artery Disease (PAD) represents a burgeoning form of cardiovascular disease associated with significant clinical morbidity and increased 5 year cardiovascular disease mortality. It is characterized by impaired blood flow to the lower extremities, claudication pain and severe exercise intolerance. Pathophysiological factors contributing to PAD include atherosclerosis, endothelial cell dysfunction, and defective nitric oxide metabolite physiology and biochemistry that collectively le...

  16. On EPR detection of nitric oxide in vivo

    NARCIS (Netherlands)

    van Faassen, E.E.H.|info:eu-repo/dai/nl/071100938


    Nitric oxide (NO ) is a peculiar radical: Ground state is not paramagnetic (g = 0 since orbital and spin magnetic moments cancel); low reactivity with other molecules except superoxide (O2 ); thermodynamically unstable; dimerizes to N2O2; difficult to detect in-vivo.

  17. Variation of nitric oxide levels in imported Plasmodium falciparum ...

    African Journals Online (AJOL)

    Nitric oxide (NO) has been recognized during the past two decades as one of the most versatile players in the immune system. Even though the molecular mechanisms responsible by the naturally acquired immunity against malaria are still to be clarified, the production of NO seems to play an important role as a marker for ...

  18. Alleviating effect of exogenous nitric oxide in cucumber seedling ...

    African Journals Online (AJOL)

    The study indicated that exogenous NO at 1.0 mmoll-1 SNP enhanced chilling stress tolerance. In comparison with cvZND 461, cvZND407 had higher tolerance ability to chilling stress. Key words: Antioxidative enzymes, chilling stress, cucumber, nitric oxide (NO) osmotic adjustment; reactive oxygen species (ROS).

  19. Endothelial nitric oxide synthase gene Glu298Asp polymorphism ...

    African Journals Online (AJOL)

    Preeclampsia (PE) is the most serious complication of pregnancy that causes maternal and fetal morbidity and mortality. Although the exact pathophysiology of PE is unknown, a large number of studies have shown that abnormalities in nitric oxide (NO) synthesis may contribute to the development of this disorder. There are ...

  20. Insecticidal, brine shrimp cytotoxicity, antifungal and nitric oxide free ...

    African Journals Online (AJOL)

    The crude methanolic extract and various fractions derived from the aerial parts of Myrsine africana were screened in vitro for possible insecticidal, antifungal, brine shrimp lethality and nitric oxide free radical scavenging activities. Low insecticidal activity (20 %) was shown by chloroform (CHCl3) and aqueous fractions ...

  1. Endothelial nitric oxide synthase polymorphism G298T in ...

    Indian Academy of Sciences (India) Keywords. coronary artery disease; endothelial nitric oxide synthase; myocardial infarction; reactive oxygen species. Author Affiliations. Rajesh G. Kumar1 Mrudula K. Spurthi1 Kishore G. Kumar1 Sanjib K. Sahu2 Surekha H. Rani1. Department of Genetics, Osmania ...

  2. Oxidative stress, nitric oxide and prostaglandin E2 levels in the gastrointestinal tract of aging rats. (United States)

    Mármol, Frederic; Sánchez, Juan; López, Diego; Martínez, Nuria; Mitjavila, Maria Teresa; Puig-Parellada, Pere


    To evaluate the presence of oxidative stress and alterations in the levels of two cytoprotective agents, prostaglandin E2 and nitric oxide, in the gastrointestinal tract of aging rats. The production of superoxide anion, lipid peroxides, levels of superoxide dismutase and catalase, and production of prostaglandin E2 and nitric oxide in the stomach and duodenum of rats were determined at 1.5, 3, 12, 18 and 24 months of age. Oxidative stress was present in the stomach of the old rats (24 months), whereas prostaglandin E2 and nitric oxide production remained stable at 18 and 24 months. In the duodenum, no oxidative stress was observed at 24 months, but at 18 months, an increase in superoxide anion levels was detected. Prostaglandin E2 remained constant in the aged rats but nitric oxide decreased significantly at 24 months. The absence of macroscopic gastric injury throughout the gastrointestinal tract indicates that the oxidative stress in the stomach and the significant decrease of nitric oxide in the duodenum in the old rats are not sufficient to disrupt the mucosal defence network. The results support the notion that the disruption of the mucosal network is essentially regulated by the cytoprotective agents prostaglandin E2 and nitric oxide, and that injury appears only when both substances are concurrently reduced.

  3. Nitric oxide and the autonomic regulation of cardiac excitability. The G.L. Brown Prize Lecture. (United States)

    Paterson, D


    Cardiac sympathetic imbalance and arrhythmia; Nitric oxide-cGMP pathway and the cholinergic modulation of cardiac excitability; Nitric oxide-cGMP pathway and the sympathetic modulation of cardiac excitability; Functional significance of nitric oxide in the autonomic regulation of cardiac excitability; Summary; References. Experimental Physiology (2001) 86.1, 1-12.

  4. Review Article: The Role of Nitric Oxide Synthase in Post-Operative ...

    African Journals Online (AJOL)

    Nitric Oxide (NO) is produced by nitric oxide synthase (NOS) isoenzymes. Inducible nitric oxide synthase (iNOS) is not a normal cellular constitute. It is expressed by cytokines and non-cytokines e.g. fasting, trauma, intravenous glucose, and lipid infusion, which are encountered in surgical operations. Review of current ...

  5. Isoxazole derivatives as new nitric oxide elicitors in plants

    Directory of Open Access Journals (Sweden)

    Anca Oancea


    Full Text Available Several 3,5-disubstituted isoxazoles were obtained in good yields by regiospecific 1,3-dipolar cycloaddition reactions between aromatic nitrile oxides, generated in situ from the corresponding hydroxyimidoyl chlorides, with non-symmetrical activated alkynes in the presence of catalytic amounts of copper(I iodide. Effects of 3,5-disubstituted isoxazoles on nitric oxide and reactive oxygen species generation in Arabidopsis tissues was studied using specific diaminofluoresceine dyes as fluorescence indicators.

  6. Significance of nitric oxide synthases: Lessons from triple nitric oxide synthases null mice

    Directory of Open Access Journals (Sweden)

    Masato Tsutsui


    Full Text Available Nitric oxide (NO is synthesized by three distinct NO synthases (neuronal, inducible, and endothelial NOSs, all of which are expressed in almost all tissues and organs in humans. The regulatory roles of NOSs in vivo have been investigated in pharmacological studies with non-selective NOS inhibitors. However, the specificity of the inhibitors continues to be an issue of debate, and the authentic significance of NOSs is still poorly understood. To address this issue, we generated mice in which all three NOS genes are completely disrupted. The triple NOSs null mice exhibited cardiovascular abnormalities, including hypertension, arteriosclerosis, myocardial infarction, cardiac hypertrophy, diastolic heart failure, and reduced EDHF responses, with a shorter survival. The triple NOSs null mice also displayed metabolic abnormalities, including metabolic syndrome and high-fat diet-induced severe dyslipidemia. Furthermore, the triple NOSs null mice showed renal abnormalities (nephrogenic diabetes insipidus and pathological renal remodeling, lung abnormalities (accelerated pulmonary fibrosis, and bone abnormalities (increased bone mineral density and bone turnover. These results provide evidence that NOSs play pivotal roles in the pathogenesis of a wide variety of disorders. This review summarizes the latest knowledge on the significance of NOSs in vivo, based on lessons learned from experiments with our triple mutant model.

  7. Amino acids as modulators of endothelium-derived nitric oxide. (United States)

    Kakoki, Masao; Kim, Hyung-Suk; Edgell, Cora-Jean S; Maeda, Nobuyo; Smithies, Oliver; Mattson, David L


    To examine the mechanisms whereby amino acids modulate nitric oxide (NO) production and blood flow in the renal vasculature, chemiluminescence techniques were used to quantify NO in the renal venous effluent of the isolated, perfused rat kidney as different amino acids were added to the perfusate. The addition of 10(-4) or 10(-3) M cationic amino acids (l-ornithine, l-lysine, or l-homoarginine) or neutral amino acids (l-glutamine, l-leucine, or l-serine) to the perfusate decreased NO and increased renal vascular resistance. Perfusion with anionic amino acids (l-glutamate or l-aspartate) had no effect on either parameter. The effects of the cationic and neutral amino acids were reversed with 10(-3) M l-arginine and prevented by deendothelialization or NO synthase inhibition. The effects of the neutral amino acids but not the cationic amino acids were dependent on extracellular sodium. Cationic and neutral amino acids also decreased calcimycin-induced NO, as assessed by DAF-FM-T fluorescence, in cultured EA.hy926 endothelial cells. Inhibition of system y(+) or y(+)L by siRNA for the cationic amino acid transporter 1 or the CD98/4F2 heavy chain diminished the NO-depleting effects of these amino acids. Finally, transport studies in cultured cells demonstrated that cationic or neutral amino acids in the extracellular space stimulate efflux of l-arginine out of the cell. Thus the present experiments demonstrate that cationic and neutral amino acids can modulate NO production in endothelial cells by altering cellular l-arginine transport through y(+) and y(+)L transport mechanisms.

  8. Nitric oxide signalling and neuronal nitric oxide synthase in the heart under stress (United States)

    Zhang, Yin Hua


    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. PMID:28649367

  9. Endothelial nitric oxide synthase is not essential for nitric oxide production by osteoblasts subjected to fluid shear stress in vitro

    NARCIS (Netherlands)

    Bakker, A.D.; Huesa, C.; Hughes, A.; Aspden, R.M.; van 't Hof, R.J.; Klein-Nulend, J.; Helfrich, M.H.


    Endothelial nitric oxide synthase (eNOS) has long been held responsible for NO production by mechanically stimulated osteoblasts, but this has recently been disputed. We investigated whether one of the three known NOS isoforms is essential for NO production by mechanically stimulated osteoblasts in

  10. Relevance of nitric oxide to the response of tumors to photodynamic therapy (United States)

    Korbelik, Mladen; Shibuya, Hiroshi; Cecic, Ivana


    Oxidative stress is the term used for a sudden and intense exposure of living tissue to reactive oxygen radicals. Tumor tissue response to oxidative stress, invoked in the action of photodynamic therapy (PDT) and some other modalities for cancer treatment, at the level of vascular endothelium has important therapeutic implications. Nitric oxide (NO), a transient radical species which is an important bioregulatory molecule involved in a diverse array of physiological events, has important functions in the regulation of progression of cancerous growth. Response to cancer therapies associated with the induction of oxidative stress was suggested to be amenable to NO mediation. Events involved in antitumor effects of PDT that can be markedly affected by changes in NO availability are listed. The correlation between endogenous NO production in tumors and the response of these lesions to PDT is discussed. Results of treatments aimed at modulating NO levels in PDT treated tumors are reviewed and evaluated.

  11. Nitric Oxide Bioavailability in Obstructive Sleep Apnea: Interplay of Asymmetric Dimethylarginine and Free Radicals

    Directory of Open Access Journals (Sweden)

    Mohammad Badran


    Full Text Available Obstructive sleep apnea (OSA occurs in 2% of middle-aged women and 4% of middle-aged men and is considered an independent risk factor for cerebrovascular and cardiovascular diseases. Nitric oxide (NO is an important endothelium derived vasodilating substance that plays a critical role in maintaining vascular homeostasis. Low levels of NO are associated with impaired endothelial function. Asymmetric dimethylarginine (ADMA, an analogue of L-arginine, is a naturally occurring product of metabolism found in the human circulation. Elevated levels of ADMA inhibit NO synthesis while oxidative stress decreases its bioavailability, so impairing endothelial function and promoting atherosclerosis. Several clinical trials report increased oxidative stress and ADMA levels in patients with OSA. This review discusses the role of oxidative stress and increased ADMA levels in cardiovascular disease resulting from OSA.

  12. Molecular cloning and characterization of the constitutive bovine aortic endothelial cell nitric oxide synthase.


    Nishida, K; Harrison, D.G.; Navas, J P; Fisher, A.A.; Dockery, S P; Uematsu, M; Nerem, R M; Alexander, R W; Murphy, T. J.


    The constitutive endothelial cell nitric oxide synthase (NOS) importantly regulates vascular homeostasis. To gain understanding of this enzyme, a pEF BOS cDNA library of 5 x 10(5) clones was prepared from bovine aortic endothelial cells (BAEC) and screened with a 2.8-kb cDNA BamHI fragment of rat brain NOS. Clone pBOS13 was found to express NO synthase activity when transfected into COS-7 cells. Sequence analysis revealed sequences compatible with binding domains for calcium/calmodulin, flavi...

  13. Endothelial nitric oxide gene polymorphisms, nitric oxide production and coronary artery disease risk in a South Indian population. (United States)

    Angeline, T; Isabel, W; Tsongalis, Gregory J


    Nitric oxide (NO) synthesized by vascular endothelial cells, is a vasodilator agent produced from endothelial NO synthase (eNOS). It has been reported that decreased bioavailability of NO plays an important role in the development and progression of atherosclerosis. Electrocardiographically proven 100 patients with acute myocardial infarction and 100 age and sex matched healthy individuals with normal coronary arteries were included for the study. The genotypes of a 27-bp insertion/deletion in intron 4 (eNOS 4b/4a) and G894T polymorphism in exon 7, were determined by PCR analysis based on the banding pattern on gel electrophoresis. The genotype frequencies were calculated following the Hardy-Weinberg law. Serum NO level was also estimated by the Griess method. NO levels in AMI patients were higher than those of the healthy subjects (median [interquartile range], (14.36[12.42-15.78]) μM compared with 11.28[10.32-11.89]) μM; p<0.001; Mann-Whitney rank sum test, U=285. Mutant "T" allele frequency of the eNOS-G894T polymorphism was found to be comparatively higher (0.29) in AMI patients than among the controls (0.17). The calculated Odds ratio showed that the occurrence of mutant allele "T" was 1.6 fold as frequent in cases than controls [OR=1.6 (95%CI 0.898 to 2.833)]. To conclude, in the present study, (i) NO levels were found to be increased in patients than in controls, (ii) the homozygous mutant (TT) genotype confers genetic susceptibility to coronary artery disease (iii) both the eNOS 4a/b and G894T polymorphisms were not associated with serum NO levels in a South Indian Tamil population. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. Inhaled nitric oxide decreases pulmonary endothelial nitric oxide synthase expression and activity in normal newborn rat lungs

    Directory of Open Access Journals (Sweden)

    Thông Hua-Huy


    Full Text Available Inhaled nitric oxide (iNO is commonly used in the treatment of very ill pre-term newborns. Previous studies showed that exogenous NO could affect endothelial NO synthase (eNOS activity and expression in vascular endothelial cell cultures or adult rat models, but this has never been fully described in newborn rat lungs. We therefore aimed to assess the effects of iNO on eNOS expression and activity in newborn rats. Rat pups, post-natal day (P 0 to P7, and their dams were placed in a chamber containing NO at 5 ppm (iNO-5 ppm group or 20 ppm (iNO-20 ppm group, or in room air (control group. Rat pups were sacrificed at P7 and P14 for evaluation of lung eNOS expression and activity. At P7, eNOS protein expression in total lung lysates, in bronchial and arterial sections, was significantly decreased in the iNO-20 ppm versus control group. At P14, eNOS expression was comparable among all three groups. The amounts of eNOS mRNA significantly differed at P7 between the iNO-20 ppm and control groups. NOS activity decreased in the iNO-20 ppm group at P7 and returned to normal levels at P14. There was an imbalance between superoxide dismutase and NOS activities in the iNO-20 ppm group at P7. Inhalation of NO at 20 ppm early after birth decreases eNOS gene transcription, protein expression and enzyme activity. This decrease might account for the rebound phenomenon observed in patients treated with iNO.

  15. Human blood platelets lack nitric oxide synthase activity. (United States)

    Böhmer, Anke; Gambaryan, Stepan; Tsikas, Dimitrios


    Reports on expression and functionality of nitric oxide synthase (NOS) activity in human blood platelets and erythrocytes are contradictory. We used a specific gas chromatography-mass spectrometry (GC-MS) method to detect NOS activity in human platelets. The method measures simultaneously [(15)N]nitrite and [(15)N]nitrate formed from oxidized (15)N-labeled nitric oxide ((15)NO) upon its NOS-catalyzed formation from the substrate l-[guanidino-(15)N2]-arginine. Using this GC-MS assay, we did not detect functional NOS in non-stimulated platelets and in intact platelets activated by various agonists (adenosine diphosphate, collagen, thrombin, or von Willebrand factor) or lysed platelets. l-[guanidino-nitro]-Arginine-inhibitable NOS activity was measured after addition of recombinant human endothelial NOS to lysed platelets. Previous and recent studies from our group challenge expression and functionality of NOS in human platelets and erythrocytes.

  16. Nitric oxide in prepubertal rat ovary contribution of the ganglionic nitric oxide synthase system via superior ovarian nerve. (United States)

    Casais, Marilina; Delgado, Silvia Marcela; Vallcaneras, Sandra; Sosa, Zulema; Rastrilla, Ana María


    Both peripheral innervation and nitric oxide (NO) participate in ovarian steroidogenesis. Considering the existence of the nitric oxide/ nitric oxide synthase system in the peripheral neural system and in the ovary, the aim of this work was to analyze if the liberation of NO in the ovarian compartment of prepubertal rats is of ovarian and/or ganglionic origin. The analysis is carried out from a physiological point of view using the experimental coeliac ganglion--Superior Ovarian Nerve--ovary model with and without ganglionic cholinergic stimulus Acetylcholine (Ach) 10(-6) M. Non selective and selective inhibitors of the synthase nitric oxide enzyme were added to the ovarian and ganglionic compartment, and the liberation of nitrites (soluble metabolite of the nitric oxide) in the ovarian incubation liquid was measured. We found that the non-selective inhibitor L-nitro-arginina methyl ester (L-NAME) in the ovarian compartment decreased the liberation of nitrites, and that Aminoguanidine (AG) in two concentrations in a non-dose dependent form provoked the same effect. The addition of Ach in ganglion magnified the effect of the inhibitors of the NOS enzyme. The most relevant results after the addition of inhibitors in ganglion were obtained with AG 400 and 800 microM. The inhibition was made evident with and without the joint action of Ach in ganglion. These data suggest that the greatest production of NO in the ovarian compartment comes from the ovary, mainly the iNOS isoform, though the coeliac ganglion also contributes through the superior ovarian nerve but with less quantity.

  17. Detection of nitric oxide in exhaled air using cavity enhanced absorption spectroscopy (United States)

    Medrzycki, R.; Wojtas, J.; Rutecka, B.; Bielecki, Z.


    The article describes an application one of the most sensitive optoelectronic method - Cavity Enhanced Absorption Spectroscopy in investigation of nitric oxide in exhaled breath. Measurement of nitric oxide concentration in exhaled breath is a quantitative, non-invasive, simple, and safe method of respiratory inflammation and asthma diagnosis. For detection of nitric oxide by developed optoelectronic sensor the vibronic molecular transitions were used. The wavelength ranges of these transitions are situated in the infrared spectral region. A setup consists of the optoelectronic nitric oxide sensor integrated with sampling and sample conditioning unit. The constructed detection system provides to measure nitric oxide in a sample of 0-97% relative humidity.

  18. Nitric Oxide and Reactive Oxygen Species in the Pathogenesis of Preeclampsia

    Directory of Open Access Journals (Sweden)

    Keiichi Matsubara


    Full Text Available Preeclampsia (PE is characterized by disturbed extravillous trophoblast migration toward uterine spiral arteries leading to increased uteroplacental vascular resistance and by vascular dysfunction resulting in reduced systemic vasodilatory properties. Its pathogenesis is mediated by an altered bioavailability of nitric oxide (NO and tissue damage caused by increased levels of reactive oxygen species (ROS. Furthermore, superoxide (O2− rapidly inactivates NO and forms peroxynitrite (ONOO−. It is known that ONOO− accumulates in the placental tissues and injures the placental function in PE. In addition, ROS could stimulate platelet adhesion and aggregation leading to intravascular coagulopathy. ROS-induced coagulopathy causes placental infarction and impairs the uteroplacental blood flow in PE. The disorders could lead to the reduction of oxygen and nutrients required for normal fetal development resulting in fetal growth restriction. On the other hand, several antioxidants scavenge ROS and protect tissues against oxidative damage. Placental antioxidants including catalase, superoxide dismutase (SOD, and glutathione peroxidase (GPx protect the vasculature from ROS and maintain the vascular function. However, placental ischemia in PE decreases the antioxidant activity resulting in further elevated oxidative stress, which leads to the appearance of the pathological conditions of PE including hypertension and proteinuria. Oxidative stress is defined as an imbalance between ROS and antioxidant activity. This review provides new insights about roles of oxidative stress in the pathophysiology of PE.

  19. Treatment Of Sunitinib-Induced Hypertension In Solid Tumors By Nitric Oxid Donors

    Directory of Open Access Journals (Sweden)

    Luís A. Leon


    Hypertension (HT is one of the most common adverse effects of angiogenesis inhibitors. Hypertension 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 hypertension. Although the exact mechanism by TKIs induce hypertension 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.

  20. What is next in nitric oxide research? From cardiovascular system to cancer biology. (United States)

    Bian, Ka; Murad, Ferid


    The broad role of nitric oxide (NO) and cyclic GMP in biochemistry and biology as important messenger molecules is evident from the numerous publications in this research field. NO and cGMP have been known as components of the key signaling pathway in regulating numerous processes such as vascular dilation, blood pressure, neurotransmission, cardiovascular function, and renal function. In spite of almost 150,000 publications with nitric oxide and cyclic GMP, there are few publications regarding the effects of these messenger molecules on gene regulation, cell differentiation and cell proliferation. Our research data with embryonic stem cells and several cancer cell lines suggest that nitric oxide, its receptor soluble guanylyl cyclase (sGC) and sGC's product cyclic GMP can regulate the processes of proliferation and differentiation. Furthermore, we have found that undifferentiated stem cells and some malignant tumors such as human glioma have decreased levels of sGC and translocation of the sGCβ1 subunit to the nucleus. We propose that sGC and cyclic GMP function as tumor suppressors. An understanding of the mechanisms of the translocation of the sGCβ1 subunit into the nucleus and the possible regulation of gene expression of NO and/or cyclic CMP could lead to novel and innovative approaches to cancer therapy and stem cell proliferation and differentiation. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Placental Vesicles Carry Active Endothelial Nitric Oxide Synthase and Their Activity is Reduced in Preeclampsia. (United States)

    Motta-Mejia, Carolina; Kandzija, Neva; Zhang, Wei; Mhlomi, Vuyane; Cerdeira, Ana Sofia; Burdujan, Alexandra; Tannetta, Dionne; Dragovic, Rebecca; Sargent, Ian L; Redman, Christopher W; Kishore, Uday; Vatish, Manu


    Preeclampsia, a multisystem hypertensive disorder of pregnancy, is associated with increased systemic vascular resistance. Placentae from patients with preeclampsia have reduced levels of endothelial nitric oxide synthase (eNOS) and, thus, less nitric oxide (NO). Syncytiotrophoblast extracellular vesicles (STBEV), comprising microvesicles (STBMV) and exosomes, carry signals from the syncytiotrophoblast to the mother. We hypothesized that STBEV-bound eNOS (STBEV-eNOS), capable of producing NO, are released into the maternal circulation. Dual-lobe ex vivo placental perfusion and differential centrifugation was used to isolate STBEV from preeclampsia (n=8) and normal pregnancies (NP; n=11). Plasma samples of gestational age-matched preeclampsia and NP (n=6) were used to isolate circulating STBMV. STBEV expressed placental alkaline phosphatase, confirming placental origin. STBEV coexpressed eNOS, but not inducible nitric oxide synthase, confirmed using Western blot, flow cytometry, and immunodepletion. STBEV-eNOS produced NO, which was significantly inhibited by N   G -nitro-l-arginine methyl ester (eNOS inhibitor; P preeclampsia-perfused placentae had lower levels of STBEV-eNOS (STBMV; P preeclampsia women had lower STBEV-eNOS expression compared with that from NP women ( P preeclampsia placentae, as well as in plasma. The lower STBEV-eNOS NO production seen in preeclampsia may contribute to the decreased NO bioavailability in this disease. © 2017 The Authors.

  2. Smoking and gingivitis: focus on inducible nitric oxide synthase, nitric oxide and basic fibroblast growth factor. (United States)

    Özdemir, B; Özmeric, N; Elgün, S; Barış, E


    Periodontal disease pathogenesis has been associated with smoking. Gingivitis is a mild and reversible form of periodontal disease and it tends to progress to periodontitis only in susceptible individuals. In the present study, we aimed to examine the impact of smoking on host responses in gingivitis and to evaluate and compare the inducible nitric oxide synthase (iNOS) activity in gingival tissue and NO and basic fibroblast growth factor (bFGF) levels in the gingival crevicular fluid of patients with gingivitis and healthy individuals. Forty-one participants were assigned to the gingivitis-smoker (n = 13), gingivitis (n = 13), healthy-smoker (n = 7) and healthy groups (n = 8). Clinical indices were recorded; gingival biopsy and gingival crevicular fluid samples were obtained from papillary regions. iNOS expression was evaluated by immunohistochemical staining. The immunoreactive cells were semiquantitatively assessed. For the quantitative determination of nitrite and nitrate in gingival crevicular fluid, the NO assay kit was used. The amount of bFGF in gingival crevicular fluid was determined by enzyme-linked immunosorbent assay. The gingivitis-smoker group demonstrated a stronger iNOS expression than the non-smoker gingivitis group. iNOS expression intensity was lower in the non-smoker healthy group compared to that in healthy-smokers. No significant gingival crevicular fluid NO and bFGF level changes were observed between groups. Among patients with gingivitis, a positive correlation was detected between gingival crevicular fluid NO and bFGF levels (r = 0.806, p = 0.001). Our data suggest that smoking has significant effects on iNOS expression but not on gingival crevicular fluid NO or bFGF levels in healthy and patients with gingivitis. However, our results suggest that bFGF might be involved in the regulation of NO production via iNOS. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Hypergravity upregulates renal inducible nitric oxide synthase expression and nitric oxide production. (United States)

    Yoon, Gun; Oh, Choong Sik; Kim, Hyun-Soo


    Exposure to hypergravity severely decreases renal blood flow, potentially causing renal dysfunction. Nitric oxide (NO), which is endogenously synthesized by inducible NO synthase (iNOS), plays an important role in the regulation of renal function. The purpose of this study was to examine the effect of hypergravity exposure on the production of NO in kidneys. To determine whether hypergravity induces renal hypoxia and alters renal iNOS expression and NO production, mice were exposed to short-term hypergravity at +3Gz for 1 h. The time course of iNOS mRNA expression, hypoxia-inducible factor (HIF)-1α expression, and NO production was examined. Renal HIF-1α levels were significantly elevated immediately after centrifugation, and this increase was sustained for 3 h post-exposure. iNOS mRNA levels were also significantly increased immediately after exposure and were maintained during the reoxygenation period. Immunohistochemical staining for iNOS revealed that the cortical tubular epithelium exhibited moderate to strong cytoplasmic iNOS immunoreactivity immediately after hypergravity exposure and during the reoxygenation period. The time course of NO production was similar to that of iNOS expression. Our results suggest that both hypoxia and reoxygenation might be involved in the upregulation of HIF-1α in the kidneys of mice exposed to hypergravity. Significant increases in renocortical iNOS expression immediately after centrifugation and during the reoxygenation period suggest that iNOS expression induced by hypergravity exposure might play a protective role against hypoxia/reoxygenation injury in the renal cortex. Further investigations are necessary to clarify the role of iNOS and NO in kidneys exposed to hypergravity.

  4. Antenatal insults modify newborn olfactory function by nitric oxide produced from neuronal nitric oxide synthase. (United States)

    Drobyshevsky, Alexander; Yu, Lei; Yang, Yirong; Khalid, Syed; Luo, Kehuan; Jiang, Rugang; Ji, Haitao; Derrick, Matthew; Kay, Leslie; Silverman, Richard B; Tan, Sidhartha


    Newborn feeding, maternal, bonding, growth and wellbeing depend upon intact odor recognition in the early postnatal period. Antenatal stress may affect postnatal odor recognition. We investigated the exact role of a neurotransmitter, nitric oxide (NO), in newborn olfactory function. We hypothesized that olfactory neuron activity depended on NO generated by neuronal NO synthase (NOS). Utilizing in vivo functional manganese enhanced MRI (MEMRI) in a rabbit model of cerebral palsy we had shown previously that in utero hypoxia-ischemia (H-I) at E22 (70% gestation) resulted in impaired postnatal response to odorants and poor feeding. With the same antenatal insult, we manipulated NO levels in the olfactory neuron in postnatal day 1 (P1) kits by administration of intranasal NO donors or a highly selective nNOS inhibitor. Olfactory function was quantitatively measured by the response to amyl acetate stimulation by MEMRI. The relevance of nNOS to normal olfactory development was confirmed by the increase of nNOS gene expression from fetal ages to P1 in olfactory epithelium and bulbs. In control kits, nNOS inhibition decreased NO production in the olfactory system and increased MEMRI slope enhancement. In H-I kits the MEMRI slope did not increase, implicating modification of endogenous NO-mediated olfactory function by the antenatal insult. NO donors as a source of exogenous NO did not significantly change function in either group. In conclusion, olfactory epithelium nNOS in newborn rabbits probably modulates olfactory signal transduction. Antenatal H-I injury remote from delivery may affect early functional development of the olfactory system by decreasing NO-dependent signal transduction. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Surface modification of PLGA nanoparticles to deliver nitric oxide to inhibit Escherichia coli growth

    Energy Technology Data Exchange (ETDEWEB)

    Reger, Nina A. [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); Meng, Wilson S. [Division of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282 (United States); Gawalt, Ellen S., E-mail: [Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282 (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219 (United States)


    Highlights: • Thin film functionalized PLGA nanoparticles were modified to release nitric oxide from an s-nitrosothiol donor. • The nitric oxide modified nanoparticles were bacteriostatic against Escherichia coli. • The nitric oxide modified nanoparticles increased the effectiveness of tetracycline against Escherichia coli. • The modified nitric oxide nanoparticles did not exhibit cytotoxic effects against fibroblasts. - Abstract: Polymer nanoparticles consisting of poly (DL-lactic-co-glycolic acid) were surface functionalized to deliver nitric oxide. These biodegradable and biocompatible nanoparticles were modified with an S-nitrosothiol molecule, S-nitrosocysteamine, as the nitric oxide delivery molecule. S-nitrosocysteamine was covalently immobilized on the nanoparticle surface using small organic molecule linkers and carbodiimide coupling. Nanoparticle size, zeta potential, and morphology were determined using dynamic light scattering and scanning electron microscopy, respectively. Subsequent attachment of the S-nitrosothiol resulted in a nitric oxide release of 37.1 ± 1.1 nmol per milligram of nanoparticles under physiological conditions. This low concentration of nitric oxide reduced Escherichia coli culture growth by 31.8%, indicating that the nitric oxide donor was effective at releasing nitric oxide even after attachment to the nanoparticle surface. Combining the nitric oxide modified nanoparticles with tetracycline, a commonly prescribed antibiotic for E. coli infections, increased the effectiveness of the antibiotic by 87.8%, which allows for lower doses of antibiotics to be used in order to achieve the same effect. The functionalized nanoparticles were not cytotoxic to mouse fibroblasts.

  6. Do tobacco stimulate the production of nitric oxide by up regulation of inducible nitric oxide synthesis in cancer: Immunohistochemical determination of inducible nitric oxide synthesis in oral squamous cell carcinoma - A comparative study in tobacco habituers and non-habituers

    Directory of Open Access Journals (Sweden)

    B Karthik


    Conclusions: The results of the present study indicate the enhanced expression in OSCC of tobacco habituers when compared to OSCC of tobacco non-habituers indicating the effect of tobacco on nitric oxide. Carcinogenic chemical compounds in Tobacco induce nitric oxide production by iNOS, by its tumor-promoting effects which may enhance the process of carcinogenesis.

  7. Exhaled nitric oxide in children after accidental exposure to chlorine gas. (United States)

    Grasemann, Hartmut; Tschiedel, Eva; Groch, Manuela; Klepper, Jörg; Ratjen, Felix


    Chronic exposure to chlorine gas has been shown to cause occupational asthma. Acute inhalation of chlorine is known to cause airway inflammation and induce airway nitric oxide formation. Exhaled nitric oxide may therefore be a marker of airway damage after chlorine gas exposure. After accidental chlorine gas exposure in a swimming pool, exhaled nitric oxide and pulmonary function were repeatedly measured in 18 children over a 1-mo period. Symptomatic children with impaired pulmonary function had higher nitric oxide levels on the day after the exposure compared to day 8 and day 28. Differences in exhaled nitric oxide were more pronounced at a higher exhalation flow compared to lower flow, suggesting peripheral rather than central airway damage. This was in accordance with the observed changes in pulmonary function. No changes in exhaled nitric oxide were seen in asymptomatic children. These data suggest that acute chlorine gas exposure results in a mild increase of exhaled nitric oxide in symptomatic children.

  8. Refractory Oxide Coatings on Titanium for Nitric Acid Applications (United States)

    Ravi Shankar, A.; Kamachi Mudali, U.


    Tantalum and Niobium have good corrosion resistance in nitric acid as well as in molten chloride salt medium encountered in spent fuel nuclear reprocessing plants. Commercially, pure Ti (Cp-Ti) exhibits good corrosion resistance in nitric acid medium; however, in vapor condensates of nitric acid, significant corrosion was observed. In the present study, a thermochemical diffusion method was pursued to coat Ta2O5, Nb2O5, and Ta2O5 + Nb2O5 on Ti to improve the corrosion resistance and enhance the life of critical components in reprocessing plants. The coated samples were characterized by XRD, SEM, EDX, profilometry, micro-scratch test, and ASTM A262 Practice-C test in 65 pct boiling nitric acid. The SEM micrograph of the coated samples showed that uniform dense coating containing Ta2O5 and/or Nb2O5 was formed. XRD patterns indicated the formation of TiO2, Ta2O5/Nb2O5, and mixed oxide/solid solution phase on coated Ti samples. ASTM A262 Practice-C test revealed reproducible outstanding corrosion resistance of Ta2O5-coated sample in comparison to Nb2O5- and Ta2O5 + Nb2O5-coated sample. The hardness of the Ta2O5-coated Cp-Ti sample was found to be twice that of uncoated Cp-Ti. The SEM and XRD results confirmed the presence of protective oxide layer (Ta2O5, rutile TiO2, and mixed phase) on coated sample which improved the corrosion resistance remarkably in boiling liquid phase of nitric acid compared to uncoated Cp-Ti and Ti-5Ta-1.8Nb alloy. Three phase corrosion test conducted on Ta2O5-coated samples in boiling 11.5 M nitric acid showed poor corrosion resistance in vapor and condensate phases of nitric acid due to poor adhesion of the coating. The adhesive strength of the coated samples needs to be optimized in order to improve the corrosion resistance in vapor and condensate phases of nitric acid.

  9. Atomic Layer Deposition of Tin Oxide with Nitric Oxide as an Oxidant Gas


    Heo, Jaeyeong; Gordon, Roy Gerald; Kim, Sang Bok


    Atomic layer deposition (ALD) of tin oxide \\((SnO_2)\\) thin films was achieved using a cyclic amide of Sn(II) (1,3-bis(1,1-dimethylethyl)-4,5-dimethyl-(4R,5R)-1,3,2-diazastannolidin-2-ylidene) as a tin precursor and nitric oxide (NO) as an oxidant gas. Film properties as a function of growth temperature from \\(130-250^{\\circ}C\\) were studied. Highly conducting \\(SnO_2\\) films were obtained at \\(200-250^{\\circ}C\\) with the growth per cycle of \\(~1.4 \\mathring{A}\\)/cycle, while insulating films...

  10. Regulation and control of nitric oxide (NO) in macrophages

    DEFF Research Database (Denmark)

    Kovacevic, Zaklina; Sahni, Sumit; Lok, K.H.


    We recently demonstrated that a novel storage and transport mechanism for nitric oxide (NO) mediated by glutathione-S-transferase P1 (GSTP1) and multidrug resistance protein 1 (MRP1/ABCC1), protects M1-macrophage (M1-MØ) models from large quantities of endogenous NO. This system stores and transp......We recently demonstrated that a novel storage and transport mechanism for nitric oxide (NO) mediated by glutathione-S-transferase P1 (GSTP1) and multidrug resistance protein 1 (MRP1/ABCC1), protects M1-macrophage (M1-MØ) models from large quantities of endogenous NO. This system stores...... be responsible for delivering cytotoxic NO as DNICs via MRP1 from M1-MØs, to tumor cell targets....


    Directory of Open Access Journals (Sweden)

    I. V. Panova


    Full Text Available The important part in the group of biological compounds, participating in the regulation of the functions of the gastro-intestinal tract, is assigned to endothelial factors because of their impact on the majority of physiological and pathophysiological processes of the digestive system. The article provides information about physiological role of nitric oxide and endothelin-1 and presents a review of scientific data on the participation of nitric oxide and endothelin-1 in the pathogenesis of many digestive system diseases, emphasizing chronic inflammatory disorders of the upper gastrointestinal tract. The authors accentuate the importance of endothelium endocrine function research in children with esophagogastroduodenal disorders at the beginning of puberty, which is the critical period of ontogenesis.

  12. Nitric oxide-induced signalling in rat lacrimal acinar cells

    DEFF Research Database (Denmark)

    Looms, Dagnia Karen; Tritsaris, K.; Dissing, S.


    The aim of the present study was to investigate the physiological role of nitric oxide (NO) in mediating secretory processes in rat lacrimal acinar cells. In addition, we wanted to determine whether the acinar cells possess endogenous nitric oxide synthase (NOS) activity by measuring NO productio...... using the fluorescent NO indicator 4,5-diaminofluorescein (DAF-2). We initiated investigations by adding NO from an external source by means of the NO-donor, S-nitroso-N-acetyl-penicillamine (SNAP). Cellular concentrations of cyclic guanosine 5'-phosphate (cGMP) ([cGMP]) were measured...... by radioimmunoassay (RIA), and we found that SNAP induced a fast increase in the [cGMP], amounting to 350% of the [cGMP] in resting cells. Moreover, addition of SNAP and elevating [cGMP] in fura-2 loaded lacrimal acinar cells, resulted in a cGMP-dependent protein kinase-mediated release of Ca2+ from intracellular...

  13. Arginine and Nitric Oxide Pathways in Obesity-Associated Asthma

    Directory of Open Access Journals (Sweden)

    Fernando Holguin


    Full Text Available Obesity is a comorbidity that adversely affects asthma severity and control by mechanisms that are not fully understood. This review will discuss evidence supporting a role for nitric oxide (NO as a potential mechanistic link between obesity and late-onset asthma (>12 years. Several studies have shown that there is an inverse association between increasing body mass index (BMI and reduced exhaled NO. Newer evidence suggests that a potential explanation for this paradoxical relationship is related to nitric oxide synthase (NOS uncoupling, which occurs due to an imbalance between L-arginine (NOS substrate and its endogenous inhibitor, asymmetric di-methyl arginine (ADMA. The review will propose a theoretical framework to understand the relevance of this pathway and how it may differ between early and late-onset obese asthmatics. Finally, the paper will discuss potential new therapeutic approaches, based on these paradigms, for improving the respiratory health of obese subjects with asthma.

  14. Nitric Oxide Scavenging by Hemoglobin in Health, Disease, and Therapeutics (United States)

    Kim-Shapiro, Daniel


    Nitric oxide (NO) is the endothelium-derived relaxing factor (EDRF). It is made in endothelial cells lining blood vessels and diffuses to smooth muscle cells where it leads to muscle relaxation, vessel dilatation, and increased blood flow and also plays a large role in controlling platelet aggregation and inflammation. Hemoglobin (Hb), the oxygen carrying molecule in the blood, reacts at nearly diffusion limited rates with nitric oxide to (in some reactions) form nitrate ands thereby destroy NO activity. The presence of such large amounts of such a potent NO scavenger in the blood challenges the idea that NO is indeed the EDRF. Encapsulation in red blood cells in healthy individuals limits NO scavenging by Hb. Biophysical experiments will be described exploring and evaluating these mechanisms. Other studies will be described discussing how red cells break open (lyse) in pathological situations and the cell-free Hb reduces NO bioavailability. Finally, methods to restore NO bioavailability through therapeutics will be discussed.

  15. Nitric Oxide: A Physiologic Mediator of Penile Erection (United States)

    Burnett, Arthur L.; Lowenstein, Charles J.; Bredt, David S.; Chang, Thomas S. K.; Snyder, Solomon H.


    Nitric oxide (NO) is a cytotoxic agent of macrophages, a messenger molecule of neurons, and a vasodilator produced by endothelial cells. NO synthase, the synthetic enzyme for NO, was localized to rat penile neurons innervating the corpora cavernosa and to neuronal plexuses in the adventitial layer of penile arteries. Small doses of NO synthase inhibitors abolished electrophysiologically induced penile erections. These results establish NO as a physiologic mediator of erectile function.

  16. Nitric oxide synthase expression and enzymatic activity in multiple sclerosis

    DEFF Research Database (Denmark)

    Broholm, H; Andersen, B; Wanscher, B


    We used post-mortem magnetic resonance imaging (MRI) guidance to obtain paired biopsies from the brains of four patients with clinical definite multiple sclerosis (MS). Samples were analyzed for the immunoreactivity (IR) of the three nitric oxide (NO) synthase isoforms [inducible, neuronal...... and sex showed no such changes. Our data support the hypothesis that NO is a pathogenic factor in MS, and that NOS IR is strongly expressed in brain regions appearing normal by MRI...

  17. Tuning the nitric oxide release from CPO-27 MOFs. (United States)

    Cattaneo, Damiano; Warrender, Stewart J; Duncan, Morven J; Kelsall, Christopher J; Doherty, Mary K; Whitfield, Phillip D; Megson, Ian L; Morris, Russell E


    Nitric oxide (NO) storage and release measurements have been recorded for Ni-doped CPO-27 (Mg) and CPO-27 (Zn), and the biological effect of the released NO was assessed in porcine coronary artery relaxation tests. The results indicate that the doping strategy leads to increased levels of NO storage and delivery compared to the parent materials and that the NO dosage and biological response can be tuned via this approach to suit the requirements of particular applications.

  18. Mechanisms of vasodilatation in pregnancy: studies of the role of prostaglandins and nitric-oxide in changes of vascular reactivity in the in situ blood perfused mesentery of pregnant rats.


    Chu, Z. M.; Beilin, L. J.


    1. To examine the possible mechanisms of the vasodilatation and blunted pressor responses in late pregnancy, we have studied vascular reactivity of the in situ blood perfused mesenteric resistance vessels of 18-20 day pregnant Wistar-Kyoto rats (WKY). 2. Intra-arterial mean blood pressure (MBP) was lower in pregnant rats than in nonpregnant controls. There was no significant difference in basal mesenteric perfusion pressure (BPP) between groups. 3. Vascular reactivity to electrical stimulatio...

  19. Exercise promotes collateral artery growth mediated by monocytic nitric oxide. (United States)

    Schirmer, Stephan H; Millenaar, Dominic N; Werner, Christian; Schuh, Lisa; Degen, Achim; Bettink, Stephanie I; Lipp, Peter; van Rooijen, Nico; Meyer, Tim; Böhm, Michael; Laufs, Ulrich


    Collateral artery growth (arteriogenesis) is an important adaptive response to hampered arterial perfusion. It is unknown whether preventive physical exercise before limb ischemia can improve arteriogenesis and modulate mononuclear cell function. This study aimed at investigating the effects of endurance exercise before arterial occlusion on MNC function and collateral artery growth. After 3 weeks of voluntary treadmill exercise, ligation of the right femoral artery was performed in mice. Hindlimb perfusion immediately after surgery did not differ from sedentary mice. However, previous exercise improved perfusion restoration ≤7 days after femoral artery ligation, also when exercise was stopped at ligation. This was accompanied by an accumulation of peri-collateral macrophages and increased expression of endothelial nitric oxide synthase and inducible nitric oxide synthase (iNOS) in hindlimb collateral and in MNC of blood and spleen. Systemic monocyte and macrophage depletion by liposomal clodronate but not splenectomy attenuated exercise-induced perfusion restoration, collateral artery growth, peri-collateral macrophage accumulation, and upregulation of iNOS. iNOS-deficient mice did not show exercise-induced perfusion restoration. Transplantation of bone marrow-derived MNC from iNOS-deficient mice into wild-type animals inhibited exercise-induced collateral artery growth. In contrast to sedentary controls, thrice weekly aerobic exercise training for 6 months in humans increased peripheral blood MNC iNOS expression. Circulating mononuclear cell-derived inducible nitric oxide is an important mediator of exercise-induced collateral artery growth. © 2015 American Heart Association, Inc.

  20. Nitric oxide: a pro-inflammatory mediator in lung disease?

    Directory of Open Access Journals (Sweden)

    Eiserich Jason P


    Full Text Available Abstract Inflammatory diseases of the respiratory tract are commonly associated with elevated production of nitric oxide (NO• and increased indices of NO• -dependent oxidative stress. Although NO• is known to have anti-microbial, anti-inflammatory and anti-oxidant properties, various lines of evidence support the contribution of NO• to lung injury in several disease models. On the basis of biochemical evidence, it is often presumed that such NO• -dependent oxidations are due to the formation of the oxidant peroxynitrite, although alternative mechanisms involving the phagocyte-derived heme proteins myeloperoxidase and eosinophil peroxidase might be operative during conditions of inflammation. Because of the overwhelming literature on NO• generation and activities in the respiratory tract, it would be beyond the scope of this commentary to review this area comprehensively. Instead, it focuses on recent evidence and concepts of the presumed contribution of NO• to inflammatory diseases of the lung.

  1. Nitric-oxide synthase trafficking inducer is a pleiotropic regulator of endothelial cell function and signaling. (United States)

    Chakraborty, Shreeta; Ain, Rupasri


    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. © 2017 by The American Society for

  2. Contribution of intravascular versus interstitial purines and nitric oxide in the regulation of exercise hyperaemia in humans

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Nyberg, Michael Permin; Mortensen, Stefan Peter


    Abstract The regulation of blood flow to skeletal muscle involves a complex interaction between several locally formed vasodilators that are produced both in the skeletal muscle interstitium and intravascularly. The gas nitric oxide (NO) and the purines ATP and adenosine, are potent vasodilators...... of intravascular versus interstitial vasodilators is not known but evidence suggests that both compartments are important. In cardiovascular disease, a reduced capacity to form adenosine in the muscle interstitium may be a contributing factor in increased peripheral vascular resistance....

  3. MRI assessment of coronary microvascular endothelial nitric oxide synthase function using myocardial T1 mapping. (United States)

    Cui, Sophia X; Epstein, Frederick H


    Endothelial nitric oxide synthase (eNOS) plays a central role in regulating vascular tone, blood flow, and microvascular permeability. Endothelial dysfunction, including eNOS dysfunction, is an early biomarker of vascular disease. This study aimed to show that myocardial T1 mapping during nitric oxide synthase (NOS) inhibition could assess coronary microvascular eNOS function. Wild-type mice, eNOS-/- mice, and wild-type mice fed a high-fat diet underwent T1 mapping at baseline and for 20 min after injection of NG -nitro-L-arginine methyl ester (LNAME), a NOS inhibitor. First-pass perfusion MRI was performed in wild-type mice at baseline and 5 min after LNAME injection. T1 mapping detected an increase in myocardial T1 5 min after an injection of 4 mg/kg LNAME compared with baseline in control mice (T1  = 1515 ± 30 ms with LNAME versus T1  = 1402 ± 30 ms at baseline, P coronary microvascular eNOS dysfunction in high-fat-diet mice. T1 mapping during NOS inhibition may be useful in preclinical studies aiming to investigate mechanisms underlying and therapies for coronary microvascular eNOS dysfunction. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  4. Nitric oxide synthases in infants and children with pulmonary hypertension and congenital heart disease

    Directory of Open Access Journals (Sweden)

    McPhaden Allan R


    Full Text Available Abstract Rationale Nitric oxide is an important regulator of vascular tone in the pulmonary circulation. Surgical correction of congenital heart disease limits pulmonary hypertension to a brief period. Objectives The study has measured expression of endothelial (eNOS, inducible (iNOS, and neuronal nitric oxide synthase (nNOS in the lungs from biopsies of infants with pulmonary hypertension secondary to cardiac abnormalities (n = 26, compared to a control group who did not have pulmonary or cardiac disease (n = 8. Methods eNOS, iNOS and nNOS were identified by immunohistochemistry and quantified in specific cell types. Measurements and main results Significant increases of eNOS and iNOS staining were found in pulmonary vascular endothelial cells of patients with congenital heart disease compared to control infants. These changes were confined to endothelial cells and not present in other cell types. Patients who strongly expressed eNOS also had strong expression of iNOS. Conclusion Upregulation of eNOS and iNOS occurs at an early stage of pulmonary hypertension, and may be a compensatory mechanism limiting the rise in pulmonary artery pressure.

  5. Inhibition of nitric oxide synthesis for four days induces vascular abnormalities and myocardial infarct areas but not significant arterial hypertension Inibição da síntese do óxido nítrico durante quatro dias induz anormalidades vasculares e áreas de infarto miocárdico, porém, não induz hipertensão arterial significativa

    Directory of Open Access Journals (Sweden)

    Ricardo Xavier-Vidal


    Full Text Available BACKGROUND: Nitric oxide is an endothelium vasorelaxing factor and at least in some cases is the main cause of arterial hypertension, which is one of the most important risk factors of cardiovascular diseases. In Brazil, cardiovascular diseases are the first cause of mortality, representing about 30% of the total deaths. The L-NAME (Nω-nitro-arginine-methyl-ester blocks the nitric oxide synthesis necessary to maintain the normal arterial pressure. OBJECTIVE: To study lesions in myocardium due to the inhibition of nitric oxide synthesis during four days (via L-NAME oral administration, concentration: 75 mgs versus 100 mL-1. METHODS: Fourteen normotensive young adults Wistar rats were submitted, during four days, to L-NAME. Six rats were utilized as the Control Group. At day 4 of the experiment, the animals were anesthetized, weighed, and their thoraxes were opened, and the cardiotomy was performed. The hearts were weighed, fixed, and processed using routine methods, and they were sectioned in 3 µm and stained. RESULTS: Abnormalities were observed in the wall of arterial vessels of any dimension, as vascular damage with increasing wall thickness related mainly to proliferation of arterial smooth muscle cell in submitted animals. Proliferation of cells in the intimal layer and its thickening were also observed in small arterial vessels (arteriole. Infarct areas were present. CONCLUSIONS: The present data suggested that inhibition of nitric oxide synthesis for four days induces vascular abnormalities and myocardial infarct areas, but not arterial hypertension.CONTEXTO: O óxido nítrico é um fator de relaxamento vascular e, pelo menos em certos casos, é a principal causa de hipertensão arterial no ser humano. A hipertensão arterial é um importante fator de risco de doenças cardiovasculares. No Brasil, as doenças cardiovasculares são a primeira causa de mortalidade, representando cerca de 30% do total de óbitos. O L-NAME (N

  6. Impaired endothelial nitric oxide bioavailability: a common link between aging, hypertension, and atherogenesis?

    LENUS (Irish Health Repository)

    Walsh, Thomas


    Endothelial-derived nitric oxide (NO) is responsible for maintaining continuous vasodilator tone and for regulating local perfusion and systemic blood pressure. It also has significant antiproliferative effects on vascular smooth muscle and platelet anti-aggregatory effects. Impaired endothelial-dependent (NO mediated) vasorelaxation is observed in most animal and human models of healthy aging. It also occurs in age-associated conditions such as atherosclerosis and hypertension. Such "endotheliopathy" increases vascular risk in older adults. Studies have indicated that pharmacotherapeutic intervention with angiotensin-converting enzyme inhibitors and 3-hydroxy-3-methyl-glutaryl coenzyme-A reductase inhibitors may improve NO-mediated vasomotor function. This review, evaluates the association between impaired endothelial NO bioavailability, accelerated vascular aging, and the age-associated conditions hypertension and atherogenesis. This is important, because pharmacotherapy aimed at improving endothelial NO bioavailability could modify age-related vascular disease and transform age into a potentially modifiable vascular risk factor, at least in a subpopulation of older adults.

  7. L-citrulline immunostaining identifies nitric oxide production sites within neurons (United States)

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


    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.

  8. Nitric oxide effect on colonocyte metabolism: co-action of sulfides and peroxide. (United States)

    Roediger, W E; Babidge, W J


    Luminal levels of nitric oxide/nitrite are high in colitis. Whether nitric oxide is injurious or protective to human colonocytes is unknown and the role of nitric oxide in the genesis of colitis unclear. The aims were to establish whether nitric oxide was injurious to oxidation of substrates (n-butyrate and D-glucose) in isolated human and rat colonocytes both alone and in the presence of hydrogen sulfide and hydrogen peroxide, agents implicated in cell damage of colitis. Nitric oxide generation from S-nitrosoglutathione was measured by nitrite appearance. Colonocytes were isolated and incubated with [1-14C] butyrate or [6-14C] glucose and 2.6 microM nitric oxide, 1.5 mM sodium hydrogen sulfide or 2.5 mM hydrogen peroxide. Acyl-CoA esters were measured by high performance liquid chromatography, 14CO2 radiochemically and lactate/ketones by enzymic methods. Results indicate that nitric oxide very significantly (p Peroxide and sulfide with nitric oxide resulted in significant reduction (p oxidation to CO2. Sulfide significantly stimulated release of nitric oxide from S-nitrosoglutathione. The principal conclusion is that nitric oxide diminishes CoA metabolism in colonocytes. CoA depletion has been observed in chronic human colitis for which a biochemical explanation has been lacking. For acute injurious action in human colonocytes nitric oxide requires co-action of peroxide and sulfide to impair oxidation of substrates in cells. From current observations treatment of colitis should aim to reduce simultaneously nitric oxide, peroxide and sulfide generation in the colon.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wenzhen; Yang, Bingwu; Fu, Huiling; Ma, Long; Liu, Tingting; Chai, Rongfei; Zheng, Zhaodi [Shandong Provincial Key Laboratory of Animal Resistant Biology, School of Life Sciences, Shandong Normal University, Jinan 250014 (China); Zhang, Qunye, E-mail: [Key Laboratory of Cardiovascular Remodeling and Function Research Chinese Ministry of Education and Ministry of Public Health, Qilu Hospital, Shandong University, Jinan, Shandong (China); Li, Guorong, E-mail: [Shandong Provincial Key Laboratory of Animal Resistant Biology, School of Life Sciences, Shandong Normal University, Jinan 250014 (China)


    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-induced 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.

  10. How the Location of Superoxide Generation Influences the β-Cell Response to Nitric Oxide* (United States)

    Broniowska, Katarzyna A.; Oleson, Bryndon J.; McGraw, Jennifer; Naatz, Aaron; Mathews, Clayton E.; Corbett, John A.


    Cytokines impair the function and decrease the viability of insulin-producing β-cells by a pathway that requires the expression of inducible nitric oxide synthase (iNOS) and generation of high levels of nitric oxide. In addition to nitric oxide, excessive formation of reactive oxygen species, such as superoxide and hydrogen peroxide, has been shown to cause β-cell damage. Although the reaction of nitric oxide with superoxide results in the formation of peroxynitrite, we have shown that β-cells do not have the capacity to produce this powerful oxidant in response to cytokines. When β-cells are forced to generate peroxynitrite using nitric oxide donors and superoxide-generating redox cycling agents, superoxide scavenges nitric oxide and prevents the inhibitory and destructive actions of nitric oxide on mitochondrial oxidative metabolism and β-cell viability. In this study, we show that the β-cell response to nitric oxide is regulated by the location of superoxide generation. Nitric oxide freely diffuses through cell membranes, and it reacts with superoxide produced within cells and in the extracellular space, generating peroxynitrite. However, only when it is produced within cells does superoxide attenuate nitric oxide-induced mitochondrial dysfunction, gene expression, and toxicity. These findings suggest that the location of radical generation and the site of radical reactions are key determinants in the functional response of β-cells to reactive oxygen species and reactive nitrogen species. Although nitric oxide is freely diffusible, its biological function can be controlled by the local generation of superoxide, such that when this reaction occurs within β-cells, superoxide protects β-cells by scavenging nitric oxide. PMID:25648890

  11. Dynamics of Nitric Oxide and Nitrous Oxide Emission during Nitrogen Conversion Processes

    NARCIS (Netherlands)

    Kampschreur, M.J.


    Nitric oxide (NO) and nitrous oxide (N2O) emissions can be a serious threat to the environment. Rising levels of N2O in the atmosphere contribute to global warming and destruction of the ozone layer. This thesis describes an investigation on the emission of NO and N2O during nitrogen conversion

  12. Increased brain nitric oxide levels following ethanol administration. (United States)

    Finnerty, Niall; O'Riordan, Saidhbhe L; Klamer, Daniel; Lowry, John; Pålsson, Erik


    Nitric oxide is a ubiquitous messenger molecule, which at elevated concentrations has been implicated in the pathogenesis of several neurological disorders. Its role in oxidative stress, attributed in particular to the formation of peroxynitrite, proceeds through its high affinity for the superoxide radical. Alcoholism has recently been associated with the induction of oxidative stress, which is generally defined as a shift in equilibrium between pro-oxidant and anti-oxidant species in the direction of the former. Furthermore, its primary metabolite acetaldehyde, has been extensively associated with oxidative damage related toxic effects following alcohol ingestion. The principal objective of this study was the application of long term in vivo electrochemistry (LIVE) to investigate the effect of ethanol (0.125, 0.5 and 2.0 g kg(-1)) and acetaldehyde (12.5, 50 and 200 mg kg(-1)) on NO levels in the nucleus accumbens of freely moving rats. Systemic administrations of ethanol and acetaldehyde resulted in a dose-dependent increases in NO levels, albeit with very differing time courses. Subsequent to this the effect on accumbal NO levels, of subjecting the animal to different drug combinations, was also elucidated. The nitric oxide synthase inhibitor L-NAME (20 mg kg(-1)) and acetaldehyde sequestering agent D-penicillamine (50 mg kg(-1)) both attenuated the increase in NO levels following ethanol (1 g kg(-1)) administration. Conversely, the alcohol dehydrogenase inhibitor 4-methylpyrazole (25 mg kg(-1)) and catalase inhibitor sodium azide (10 mg kg(-1)) potentiated the increase in NO levels following ethanol administration. Finally, dual inhibition of aldehyde dehydrogenase and catalase by cyanamide (25 mg kg(-1)) caused an attenuation of ethanol effects on NO levels. Taken together these data highlight a robust increase in brain NO levels following systemic alcohol administration which is dependent on NO synthase activity and may involve both alcohol- and acetaldehyde

  13. Inflammatory monocytes determine endothelial nitric-oxide synthase uncoupling and nitro-oxidative stress induced by angiotensin II. (United States)

    Kossmann, Sabine; Hu, Hanhan; Steven, Sebastian; Schönfelder, Tanja; Fraccarollo, Daniela; Mikhed, Yuliya; Brähler, Melanie; Knorr, Maike; Brandt, Moritz; Karbach, Susanne H; Becker, Christian; Oelze, Matthias; Bauersachs, Johann; Widder, Julian; Münzel, Thomas; Daiber, Andreas; Wenzel, Philip


    Endothelial nitric-oxide synthase (eNOS) uncoupling and increased inducible NOS (iNOS) activity amplify vascular oxidative stress. The role of inflammatory myelomonocytic cells as mediators of these processes and their impact on tetrahydrobiopterin availability and function have not yet been defined. Angiotensin II (ATII, 1 mg/kg/day for 7 days) increased Ly6C(high) and CD11b(+)/iNOS(high) leukocytes and up-regulated levels of eNOS glutathionylation in aortas of C57BL/6 mice. Vascular iNOS-dependent NO formation was increased, whereas eNOS-dependent NO formation was decreased in aortas of ATII-infused mice as assessed by electron paramagnetic resonance (EPR) spectroscopy. Diphtheria toxin-mediated ablation of lysozyme M-positive (LysM(+)) monocytes in ATII-infused LysM(iDTR) transgenic mice prevented eNOS glutathionylation and eNOS-derived N(ω)-nitro-L-arginine methyl ester-sensitive superoxide formation in the endothelial layer. ATII increased vascular guanosine triphosphate cyclohydrolase I expression and biopterin synthesis in parallel, which was reduced in monocyte-depleted LysM(iDTR) mice. Vascular tetrahydrobiopterin was increased by ATII infusion but was even higher in monocyte-depleted ATII-infused mice, which was paralleled by a strong up-regulation of dihydrofolate reductase expression. EPR spectroscopy revealed that both vascular iNOS- and eNOS-dependent NO formation were normalized in ATII-infused mice following monocyte depletion. Additionally, deletion as well as pharmacologic inhibition of iNOS prevented ATII-induced endothelial dysfunction. In summary, ATII induces an inflammatory cell-dependent increase of iNOS, guanosine triphosphate cyclohydrolase I, tetrahydrobiopterin, NO formation, and nitro-oxidative stress as well as eNOS uncoupling in the vessel wall, which can be prevented by ablation of LysM(+) monocytes. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Spectrophotometric activity microassay for pure and recombinant cytochrome P450-type nitric oxide reductase

    CSIR Research Space (South Africa)

    Garny, S


    Full Text Available Nitric oxide reductase (NOR) of the P450 oxidoreductase family accepts electrons directly from its cofactor, NADH, to reduce two nitric oxide (NO) molecules to one nitrous oxide molecule and water. The enzyme plays a key role in removal of radical...

  15. Endothelial Nitric Oxide Synthase Phosphorylation at Threonine 495 and Mitochondrial Reactive Oxygen Species Formation in Response to a High H2O2 Concentration

    DEFF Research Database (Denmark)

    Guterbaum, Thomas Jeremy; Braunstein, Thomas Hartig; Fossum, A


    Hydrogen peroxide (H₂O₂) is produced in vessels during ischemia/reperfusion and during inflammation, both leading to vascular dysfunction. We investigated cellular pathways involved in endothelial nitric oxide synthase (eNOS) phosphorylation at Threonine 495 (Thr(495)) in human umbilical vein...

  16. Nitric oxide synthase inhibitors: a review of patents from 2011 to the present. (United States)

    Yang, Yanyan; Yu, Tao; Lian, Yu-Ji; Ma, Rujun; Yang, Sungjae; Cho, Jae Youl


    Nitric oxide synthases (NOSs) are a family of enzymes that play an essential role in synthesizing nitric oxide (NO) by oxidizing l-arginine. As previously reported, NO is a significant mediator in cellular signaling pathways. It serves as a crucial regulator in insulin secretion, vascular tone, peristalsis, angiogenesis, neural development and inflammation. Due to its important role, the inhibition of these vital enzymes provides, as tools, the opportunity to gain an insight into potential therapeutic applications targeting NOSs. This paper reviews the patent literature between 2011 and mid-2014 that specified inhibitors of NOS family members as the significant targets. Google and Baidu search engines were used to find relevant patents and clinical information using NOSs or NOS inhibitor as search terms. Considerable recent progress has been made in the development of NOS inhibitors with pharmacodynamic and pharmacokinetic properties, and such development is likely to continue. The patented compounds attenuated mostly embodying evidence from in vitro and in vivo trials that demonstrate good potential for future clinical human trials and industrial applications. Furthermore, new techniques such as X-ray ligand crystallographic study and structure-activity relationship were popularly utilized, which give new insights for developing novel, safe, efficient and selective NOS inhibitors.

  17. Nitric Oxide Suppresses β-Cell Apoptosis by Inhibiting the DNA Damage Response (United States)

    Oleson, Bryndon J.; Broniowska, Katarzyna A.; Naatz, Aaron; Hogg, Neil; Tarakanova, Vera L.


    Nitric oxide, produced in pancreatic β cells in response to proinflammatory cytokines, plays a dual role in the regulation of β-cell fate. While nitric oxide induces cellular damage and impairs β-cell function, it also promotes β-cell survival through activation of protective pathways that promote β-cell recovery. In this study, we identify a novel mechanism in which nitric oxide prevents β-cell apoptosis by attenuating the DNA damage response (DDR). Nitric oxide suppresses activation of the DDR (as measured by γH2AX formation and the phosphorylation of KAP1 and p53) in response to multiple genotoxic agents, including camptothecin, H2O2, and nitric oxide itself, despite the presence of DNA damage. While camptothecin and H2O2 both induce DDR activation, nitric oxide suppresses only camptothecin-induced apoptosis and not H2O2-induced necrosis. The ability of nitric oxide to suppress the DDR appears to be selective for pancreatic β cells, as nitric oxide fails to inhibit DDR signaling in macrophages, hepatocytes, and fibroblasts, three additional cell types examined. While originally described as the damaging agent responsible for cytokine-induced β-cell death, these studies identify a novel role for nitric oxide as a protective molecule that promotes β-cell survival by suppressing DDR signaling and attenuating DNA damage-induced apoptosis. PMID:27185882

  18. Imaging the nanomolar range of nitric oxide with an amplifier-coupled fluorescent indicator in living cells (United States)

    Sato, Moritoshi; Hida, Naoki; Umezawa, Yoshio


    Nitric oxide (NO) is a small uncharged free radical that is involved in diverse physiological and pathophysiological mechanisms. NO is generated by three isoforms of NO synthase, endothelial, neuronal, and inducible ones. When generated in vascular endothelial cells, NO plays a key role in vascular tone regulation, in particular. Here, we describe an amplifier-coupled fluorescent indicator for NO to visualize physiological nanomolar dynamics of NO in living cells (detection limit of 0.1 nM). This genetically encoded high-sensitive indicator revealed that 1 nM of NO, which is enough to relax blood vessels, is generated in vascular endothelial cells even in the absence of shear stress. The nanomolar range of basal endothelial NO thus revealed appears to be fundamental to vascular homeostasis. fluorescence resonance energy transfer | genetic encoding

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

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)


    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 that 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.

  20. Arginase expression modulates nitric oxide production in Leishmania (Leishmania) amazonensis. (United States)

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


    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.

  1. Nitric Oxide is Protective Against Mercury Induced Depression

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    Arezo Nahavandi


    Full Text Available A B S T R A C T Introduction: Mercury is the second most metal pollutant in the world and has the potential to induce many pathologic conditions, especially in nervous system, such as depression. Here we tried to find out if nitric oxide has any possible role in the pathophysiology of depression induced by this metal. Although the role of nitric oxide has been shown in mood control, here we use specific doses of nitric oxide inducer and/or inhibitors which had no effect on normal rats. Methods: 120 male wistar rats weighting 200-250 gram were divided into two main groups: control and methyl mercury(MM treated. Each main group was divided into four different sub-goups: Saline, L-Arginine, L-Name or 7-nitroindazole (7-NI respectively. The duration of taking MM or saline was daily for 15 days for both. After the 15th injection a forced swimming test was done. This test shows behavioral immobility (BI or latency of attempt to escape (LAE, as a depression indicator. Results: Our study showed that low dose L-arginine is protective against MM induced depression as it could turn behavioral immobility (BI to normal levels in groups taking MM plus L-Arginine, while in group taking just MM, BI was much longer showing the intensity of depression. L-Name and 7-NI did aggravated depression in MM groups but not control ones, on the other hand just in the case of 7-NI the result was significant. Discussion: Our results showed 1 MM could induce depression in rat 2 L-Arginine could improve depression to normal situation in MM group, while in control group has no effec 3 7-NI, a selective nNOS inhibitor can aggravate mental depression in intoxicated rats. These results showed the important role of nNOS in protection against MM induced depression.

  2. The role of nitric oxide in low level light therapy (United States)

    Hamblin, Michael R.


    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?

  3. Elucidating nitric oxide synthase domain interactions by molecular dynamics. (United States)

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


    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.

  4. Cancer Cell Metabolism and the Modulating Effects of Nitric Oxide (United States)

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


    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

  5. Structure-function studies on nitric oxide synthases. (United States)

    Li, Huiying; Poulos, Thomas L


    Nitric oxide synthase (NOS) catalyzes the oxidation of one l-arginine guanidinium N atom to nitric oxide (NO). NOS consists of a heme domain linked to a flavin mononucleotide (FMN)/flavin adenine dinucleotide (FAD) reductase that shuttles electrons from nicotinamide adenine dinucleotide phosphate (NADPH) to the heme. This review summarizes various aspects of NOS structure and function derived from crystal structures coupled with a wealth of biochemical and biophysical data. This includes the binding of diatomic ligands, especially the product, NO, whose binding to the heme iron blocks enzyme activity. An unusual feature of NOS catalysis is the strict requirement for the essential cofactor, tetrahydrobiopterin (H4B). It now is generally agreed that H4B serves as an electron donor to the heme-oxy complex. The reason NOS may have recruited H4B as an electron transfer cofactor is to provide rapid coupled proton/electron transfer required for O2 activation. NOS is a highly regulated enzyme which is controlled by calmodulin (CaM) at the level of electron transfer within the FMN/FAD reductase and between the reductase and heme domains. Recent crystal structures provide a basis for developing models on the structural underpinnings of NOS regulation. In addition to the complex and fascinating functional and regulatory features of NOS, NOS is an important therapeutic target. Crystal structures have revealed the structural basis of isoform-selective inhibition by a group of dipeptide inhibitors which opens the way for structure-based inhibitor design.

  6. Low Nitric Oxide Synthases (NOS) in Eyes with Age-related Macular Degeneration (AMD) (United States)

    Bhutto, Imran A.; Baba, Takayuki; Merges, Carol; McLeod, D. Scott; Lutty, Gerard A.


    Nitric oxide (NO) production by vascular endothelium is important in regulation of blood flow. Reduced production of NO can adversely affect blood flow and other vascular functions. We investigated the expression of three nitric oxide synthase (NOS) isoforms in retina and choroid of aged human eyes and eyes with AMD. Alkaline phosphatase immunohistochemistry was performed using antibodies against inducible (iNOS), neuronal (nNOS), and endothelial (eNOS) NOSs on cryopreserved sections from aged control donor eyes (n= 13) and eyes with AMD (n= 22). CD34 antibody was used as an endothelial cell (EC) marker. Three independent masked observers scored the intensity of the immunohistochemical reaction product. Mean scores from the aged control and AMD eyes were statistically compared. In aged control retinas, nNOS was in ganglion cells (RGCs) and neurons of both nuclear layers. In choroid, perivascular nerve fibers and retinal pigment epithelial (RPE) cells were nNOS+. eNOS and iNOS were confined to the retinal and choroidal vascular ECs. Some cells presumably melanocytes or dendritic cells in choroid were also eNOS+. In AMD eyes, nNOS was significantly lower in RGCs, neurons, retinal vessels and RPE (p≤0.05) compared to the aged control eyes. iNOS and eNOS showed no significant differences between aged control and AMD eyes except that there was significantly less eNOS in choroidal arteries (p=0.006) and choroidal cells (p=0.03) of AMD eyes. Although NO was not measured directly, these findings suggest that there is less NO produced in AMD eyes. The decrease in retinal nNOS in AMD eyes is probably related to neuronal degeneration. The decrease in nNOS and eNOS in AMD choroid could be associated with vasoconstriction and hemodynamic changes. PMID:19836390

  7. The nitric oxide production in the moss Physcomitrella patens is mediated by nitrate reductase.

    Directory of Open Access Journals (Sweden)

    Rigoberto Medina-Andrés

    Full Text Available During the last 20 years multiple roles of the nitric oxide gas (•NO have been uncovered in plant growth, development and many physiological processes. In seed plants the enzymatic synthesis of •NO is mediated by a nitric oxide synthase (NOS-like activity performed by a still unknown enzyme(s and nitrate reductase (NR. In green algae the •NO production has been linked only to NR activity, although a NOS gene was reported for Ostreococcus tauri and O. lucimarinus, no other Viridiplantae species has such gene. As there is no information about •NO synthesis neither for non-vascular plants nor for non-seed vascular plants, the interesting question regarding the evolution of the enzymatic •NO production systems during land plant natural history remains open. To address this issue the endogenous •NO production by protonema was demonstrated using Electron Paramagnetic Resonance (EPR. The •NO signal was almost eliminated in plants treated with sodium tungstate, which also reduced the NR activity, demonstrating that in P. patens NR activity is the main source for •NO production. The analysis with confocal laser scanning microscopy (CLSM confirmed endogenous NO production and showed that •NO signal is accumulated in the cytoplasm of protonema cells. The results presented here show for the first time the •NO production in a non-vascular plant and demonstrate that the NR-dependent enzymatic synthesis of •NO is common for embryophytes and green algae.

  8. Localization of nitric oxide synthase in the adult rat brain. (United States)

    Rodrigo, J; Springall, D R; Uttenthal, O; Bentura, M L; Abadia-Molina, F; Riveros-Moreno, V; Martínez-Murillo, R; Polak, J M; Moncada, S


    The distribution of the immunoreactivity to nitric oxide synthase has been examined from rostral to caudal areas of the rat central nervous system using light microscopy. Endogenous nitric oxide synthase was located using a specific polyclonal antiserum, produced against affinity purified nitric oxide synthase from whole rat brain, following the avidin-biotin peroxidase procedure. Immunoreactive cell bodies and processes showed a widespread distribution in the brain. In the telencephalon, immunoreactive structures were distributed in all areas of the cerebral cortex, the ventral endopiriform nucleus and claustrum, the main and accessory olfactory bulb, the anterior and posterior olfactory nuclei, the precommisural hippocampus, the taenia tecta, the nucleus accumbens, the stria terminalis, the caudate putamen, the olfactory tubercle and islands of Calleja, septum, globus pallidus and substantia innominata, hippocampus and amygdala. In the diencephalon, the immunoreactivity was largely found in both the hypothalamus and thalamus. In the hypothalamus, immunoreactive cell bodies were characteristically located in the perivascular-neurosecretory systems and mamillary bodies. In addition, immunoreactive nerve fibres were detected in the median eminence of the infundibular stem. The mesencephalon showed nitric oxide synthase immunoreactivity in the ventral tegmental area, the interpeduncular nucleus, the rostral linear nucleus of the raphe and the dorsal raphe nucleus. Immunoreactive structures were also found in the nuclei of the central grey, the peripeduncular nucleus and substantia nigra pars lateralis, the geniculate nucleus and in the superior and inferior colliculi. The pons displayed immunoreactive structures principally in the pedunculopontine and laterodorsal tegmental nuclei, the ventral tegmental nucleus, the reticulotegmental pontine nucleus, the parabrachial nucleus and locus coeruleus. In the medulla oblongata, immunoreactive neurons and processes were

  9. Flavanols, the Kuna, Cocoa Consumption, and Nitric Oxide (United States)

    Hollenberg, Norman K.; Fisher, Naomi D.L.; McCullough, Marjorie L.


    The Kuna Indians who reside in an archipelago on the Caribbean Coast of Panama have very low blood pressure levels, live longer than other Panamanians, and have a reduced frequency of myocardial infarction, stroke, diabetes mellitus, and cancer -- at least on their death certificates. One outstanding feature of their diet includes a very high intake of flavanol-rich cocoa. Flavonoids in cocoa activate nitric oxide synthesis in healthy humans. The possibility that the high flavanol intake protects the Kuna against high blood pressure, ischemic heart disease, stroke, diabetes mellitus, and cancer is sufficiently intriguing and sufficiently important that large, randomized controlled clinical trials should be pursued. PMID:20409950

  10. Can nitric oxide induce migraine in normal individuals?

    DEFF Research Database (Denmark)

    Olesen, Jes; Ashina, Messoud


    migraine expression. The question is whether any person may express a migraine attack given a sufficiently strong stimulus or provocation. Here, we reviewed and discussed the ability of nitric oxide to induce migraine-like attacks in normal individuals. CONCLUSION: Experimental data show that normal...... individuals may develop a migraine-like attack and that the human data point to different ways of further developing existing animal and human models.......INTRODUCTION: For many years, scientists have debated the possibility that an individual "migraine threshold" determines the likelihood with which individuals may express migraine attacks. DISCUSSION: Recent discoveries provided evidence for both genetic and environmental influences on individual...

  11. Nitric oxide and reactive oxygen species in plant biotic interactions. (United States)

    Scheler, Claudia; Durner, Jörg; Astier, Jeremy


    Nitric oxide (NO) and reactive oxygen species (ROS) are important signaling molecules in plants. Recent progress has been made in defining their role during plant biotic interactions. Over the last decade, their function in disease resistance has been highlighted and focused a lot of investigations. Moreover, NO and ROS have recently emerged as important players of defense responses after herbivore attacks. Besides their role in plant adaptive response development, NO and ROS have been demonstrated to be involved in symbiotic interactions between plants and microorganisms. Here we review recent data concerning these three sides of NO and ROS functions in plant biotic interactions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Localization of nitric oxide synthase in human skeletal muscle

    DEFF Research Database (Denmark)

    Frandsen, Ulrik; Lopez-Figueroa, M.; Hellsten, Ylva


    The present study investigated the cellular localization of the neuronal type I and endothelial type III nitric oxide synthase in human skeletal muscle. Type I NO synthase immunoreactivity was found in the sarcolemma and the cytoplasm of all muscle fibres. Stronger immunoreactivity was expressed...... I NO synthase immunoreactivity and NADPH diaphorase activity. Type III NO synthase immunoreactivity was observed both in the endothelium of larger vessels and of microvessels. The results establish that human skeletal muscle expresses two different constitutive isoforms of NO synthase in different...... endothelium is consistent with a role for NO in the control of blood flow in human skeletal muscle....

  13. Direct and controllable nitric oxide delivery into biological media and living cells by a pin-to-hole spark discharge (PHD) plasma

    Energy Technology Data Exchange (ETDEWEB)

    Dobrynin, D; Friedman, G [Electrical and Computer Engineering Department, College of Engineering, Drexel University, Philadelphia, PA (United States); Arjunan, K; Clyne, A Morss [School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA (United States); Fridman, A, E-mail: [Department of Mechanical Engineering and Mechanics, College of Engineering, Drexel University, Philadelphia, PA (United States)


    Nitric oxide has great potential for improving wound healing through both inflammatory and vascularization processes. Nitric oxide can be produced in high concentrations by atmospheric pressure thermal plasmas. We measured the physical characteristics and nitric oxide production of a pin-to-hole spark discharge (PHD) plasma, as well as plasma-produced nitric oxide delivery into liquid and endothelial cells. The plasma temperature was calculated as 9030 {+-} 320 K by the Boltzmann method, which was adequate to produce nitric oxide, although the average gas temperature was near room temperature. The plasma produced significant UV radiation and hydrogen peroxide, but these were prevented from reaching the cells by adding a straight or curved tube extension to the plasma device. Plasma-produced nitric oxide in gas reached 2000 ppm and rapidly diffused into liquid and cells. Cells remained viable following plasma treatment and showed a linear increase in cGMP concentration with plasma treatment, indicating an intracellular functional response to PHD plasma NO. These data suggest that this plasma may provide a novel method for delivering NO locally and directly for enhanced wound healing.

  14. Hypo- and hyperglycemia impair endothelial cell actin alignment and nitric oxide synthase activation in response to shear stress.

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    Steven Frank Kemeny

    Full Text Available Uncontrolled blood glucose in people with diabetes correlates with endothelial cell dysfunction, which contributes to accelerated atherosclerosis and subsequent myocardial infarction, stroke, and peripheral vascular disease. In vitro, both low and high glucose induce endothelial cell dysfunction; however the effect of altered glucose on endothelial cell fluid flow response has not been studied. This is critical to understanding diabetic cardiovascular disease, since endothelial cell cytoskeletal alignment and nitric oxide release in response to shear stress from flowing blood are atheroprotective. In this study, porcine aortic endothelial cells were cultured in 1, 5.55, and 33 mM D-glucose medium (low, normal, and high glucose and exposed to 20 dynes/cm(2 shear stress for up to 24 hours in a parallel plate flow chamber. Actin alignment and endothelial nitric oxide synthase phosphorylation increased with shear stress for cells in normal glucose, but not cells in low and high glucose. Both low and high glucose elevated protein kinase C (PKC levels; however PKC blockade only restored actin alignment in high glucose cells. Cells in low glucose instead released vascular endothelial growth factor (VEGF, which translocated β-catenin away from the cell membrane and disabled the mechanosensory complex. Blocking VEGF in low glucose restored cell actin alignment in response to shear stress. These data suggest that low and high glucose alter endothelial cell alignment and nitric oxide production in response to shear stress through different mechanisms.

  15. Modulation of Vascular ACE by Oxidative Stress in Young Syrian Cardiomyopathic Hamsters: Therapeutic Implications

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    Nildris Cruz


    Full Text Available Increased vascular angiotensin-converting enzyme (ACE activity and oxidative stress are present in young Syrian cardiomyopathic hamsters (SCH before the clinical manifestation of heart failure (HF. The developmental time-course of these alterations and their potential interactions, however, are still unknown. We evaluated mRNA and protein levels of ACE, endothelial nitric oxide synthase (eNOS, and inducible nitric oxide synthase (iNOS in the vasculature of SCH from one to four months of age. Total RNA and proteins were quantified with real-time reverse transcriptase-polymerase chain reaction (RT-PCR and Western blot, respectively. The role of nitric oxide (NO on vascular ACE activity was also assessed. ACE mRNA and protein levels were up-regulated in SCH at two months of age compared with controls (CT (p < 0.05. At this two-month stage, eNOS protein levels were lower in SCH (87% than in CT (100% (p < 0.05, although iNOS protein levels increased significantly (482% compared to CT (100%; p < 0.05. In addition, ACE mRNA expression and activity were modulated by NO at two months of age. Thus, the combination of low eNOS and high iNOS protein levels may underlie vascular renin-angiotensin system (RAS over-activation. Altogether, these factors may contribute to the development of endothelial dysfunction and vascular hyper-reactivity in the early stages of heart failure, and eventually trigger cardiac deterioration in this animal model of HF.

  16. Nasal nitric oxide is dependent on sinus obstruction in allergic rhinitis. (United States)

    Suojalehto, Hille; Vehmas, Tapio; Lindström, Irmeli; Kennedy, David W; Kilpeläinen, Maritta; Plosila, Tuomas; Savukoski, Sauli; Sipilä, Jukka; Varpula, Matti; Wolff, Henrik; Alenius, Harri; Toskala, Elina


    The aim of this study was to evaluate the associations between nasal nitric oxide and nasal symptoms, sinus opacification, and markers of allergic inflammation in allergic and in nonallergic rhinitis while taking into account the effect of sinus obstruction. We studied 175 young adult subjects divided into three groups: 1) allergic rhinitis, 2) nonallergic rhinitis, and 3) controls. We measured nasal nitric oxide using the breath-holding method and exhaled nitric oxide and scored semiquantitatively nasal computed tomography scans for opacification and obstruction. We also assessed the visual analogue scores of nasal symptoms, eosinophil count, and interleukin-13 mRNA levels in nasal biopsies. The level of nasal nitric oxide correlated with exhaled nitric oxide (r = 0.377, P allergic rhinitis, nasal nitric oxide was elevated when compared to the controls, and an inverse correlation existed between the nasal nitric oxide level and sinus ostial obstruction (r = -0.272, P = .013). In nonallergic rhinitis, the level of nasal nitric oxide was similar to that of the controls. In allergic rhinitis, nasal nitric oxide correlated positively with the opacification score (r = 0.250, P = .033) and the nasal eosinophil count (r = 0.293, P = .030) of patients without a marked sinus ostial obstruction. Sinus ostial obstruction lowers the level of nasal nitric oxide and reduces its value as an indicator of allergic mucosal inflammation. A high nasal nitric oxide level may be a useful marker of eosinophilic inflammation in the nasal cavity and indicate the absence of marked sinus ostial obstruction. 3b. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  17. Nitric Oxide-Mediated Posttranslational Modifications: Impacts at the Synapse

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    Sophie A. Bradley


    Full Text Available Nitric oxide (NO is an important gasotransmitter molecule that is involved in numerous physiological processes throughout the nervous system. In addition to its involvement in physiological plasticity processes (long-term potentiation, LTP; long-term depression, LTD which can include NMDAR-mediated calcium-dependent activation of neuronal nitric oxide synthase (nNOS, new insights into physiological and pathological consequences of nitrergic signalling have recently emerged. In addition to the canonical cGMP-mediated signalling, NO is also implicated in numerous pathways involving posttranslational modifications. In this review we discuss the multiple effects of S-nitrosylation and 3-nitrotyrosination on proteins with potential modulation of function but limit the analyses to signalling involved in synaptic transmission and vesicular release. Here, crucial proteins which mediate synaptic transmission can undergo posttranslational modifications with either pre- or postsynaptic origin. During normal brain function, both pathways serve as important cellular signalling cascades that modulate a diverse array of physiological processes, including synaptic plasticity, transcriptional activity, and neuronal survival. In contrast, evidence suggests that aging and disease can induce nitrosative stress via excessive NO production. Consequently, uncontrolled S-nitrosylation/3-nitrotyrosination can occur and represent pathological features that contribute to the onset and progression of various neurodegenerative diseases, including Parkinson’s, Alzheimer’s, and Huntington’s.

  18. Hyperbaric oxygen upregulates cochlear constitutive nitric oxide synthase

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    Kao Ming-Ching


    Full Text Available Abstract Background Hyperbaric oxygen therapy (HBOT is a known adjuvant for treating ischemia-related inner ear diseases. Controversies still exist in the role of HBOT in cochlear diseases. Few studies to date have investigated the cellular changes that occur in inner ears after HBOT. Nitric oxide, which is synthesized by nitric oxide synthase (NOS, is an important signaling molecule in cochlear physiology and pathology. Here we investigated the effects of hyperbaric oxygen on eardrum morphology, cochlear function and expression of NOS isoforms in cochlear substructures after repetitive HBOT in guinea pigs. Results Minor changes in the eardrum were observed after repetitive HBOT, which did not result in a significant hearing threshold shift by tone burst auditory brainstem responses. A differential effect of HBOT on the expression of NOS isoforms was identified. Upregulation of constitutive NOS (nNOS and eNOS was found in the substructures of the cochlea after HBOT, but inducible NOS was not found in normal or HBOT animals, as shown by immunohistochemistry. There was no obvious DNA fragmentation present in this HBOT animal model. Conclusions The present evidence indicates that the customary HBOT protocol may increase constitutive NOS expression but such upregulation did not cause cell death in the treated cochlea. The cochlear morphology and auditory function are consequently not changed through the protocol.

  19. Nitric Oxide Signaling in Hypergravity-Induced Neuronal Plasticity (United States)

    Holstein, Gay R.


    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.

  20. Cytokinins can act as suppressors of nitric oxide in Arabidopsis. (United States)

    Liu, Wei-Zhong; Kong, Dong-Dong; Gu, Xue-Xin; Gao, Hong-Bo; Wang, Jin-Zheng; Xia, Min; Gao, Qian; Tian, Li-Li; Xu, Zhang-Hong; Bao, Fang; Hu, Yong; Ye, Neng-Sheng; Pei, Zhen-Ming; He, Yi-Kun


    Maintaining nitric oxide (NO) homeostasis is essential for normal plant physiological processes. However, very little is known about the mechanisms of NO modulation in plants. Here, we report a unique mechanism for the catabolism of NO based on the reaction with the plant hormone cytokinin. We screened for NO-insensitive mutants in Arabidopsis and isolated two allelic lines, cnu1-1 and 1-2 (continuous NO-unstressed 1), that were identified as the previously reported altered meristem program 1 (amp1) and as having elevated levels of cytokinins. A double mutant of cnu1-2 and nitric oxide overexpression 1 (nox1) reduced the severity of the phenotypes ascribed to excess NO levels as did treating the nox1 line with trans-zeatin, the predominant form of cytokinin in Arabidopsis. We further showed that peroxinitrite, an active NO derivative, can react with zeatin in vitro, which together with the results in vivo suggests that cytokinins suppress the action of NO most likely through direct interaction between them, leading to the reduction of endogenous NO levels. These results provide insights into NO signaling and regulation of its bioactivity in plants.

  1. Environmental Effects on Fractional Exhaled Nitric Oxide in Allergic Children

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    Stefania La Grutta


    Full Text Available Fractional exhaled nitric oxide (FeNO is a non-invasive marker of airway inflammation in asthma and respiratory allergy. Environmental factors, especially indoor and outdoor air quality, may play an important role in triggering acute exacerbations of respiratory symptoms. The authors have reviewed the literature reporting effects of outdoor and indoor pollutants on FeNO in children. Although the findings are not consistent, urban and industrial pollution—mainly particles (PM2.5 and PM10, nitrogen dioxide (NO2, and sulfur dioxide (SO2—as well as formaldehyde and electric baseboard heating have been shown to increase FeNO, whilst ozone (O3 tends to decrease it. Among children exposed to Environmental Tobacco Smoke (ETS with a genetic polymorphisms in nitric oxide synthase genes (NOS, a higher nicotine exposure was associated with lower FeNO levels. Finally, although more studies are needed in order to better investigate the effect of gene and environment interactions which may affect the interpretation of FeNO values in the management of children with asthma, clinicians are recommended to consider environmental exposures when taking medical histories for asthma and respiratory allergy. Further research is also needed to assess the effects of remedial interventions aimed at reducing/abating environmental exposures in asthmatic/allergic patients.

  2. Nitric oxide heme interactions in nitrophorin from Cimex lectularius

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, R.; Auerbach, H., E-mail: [University of Kaiserslautern, Department of Physics (Germany); Berry, R. E.; Walker, F. A. [The University of Arizona, Department of Chemistry and Biochemistry (United States); Schünemann, V. [University of Kaiserslautern, Department of Physics (Germany)


    The nitrophorin from the bedbug Cimex lectularius (cNP) is a nitric oxide (NO) carrying protein. Like the nitrophorins (rNPs) from the kissing bug Rhodnius prolixus, cNP forms a stable heme Fe(III)-NO complex, where the NO can be stored reversibly for a long period of time. In both cases, the NPs are found in the salivary glands of blood-sucking bugs. The insects use the nitrophorins to transport the NO to the victim’s tissues, resulting in vasodilation and reduced blood coagulation. However, the structure of cNP is significantly different to those of the rNPs from Rhodnius prolixus. Furthermore, the cNP can bind a second NO molecule to the proximal heme cysteine when present at higher concentrations. High field Mössbauer spectroscopy on {sup 57}Fe enriched cNP complexed with NO shows reduction of the heme iron and formation of a ferrous nitric oxide (Fe(II)-NO) complex. Density functional theory calculations reproduce the experimental Mössbauer parameters and confirm this observation.

  3. Nitric oxide regulates the aggregation of stimulated human neutrophils. (United States)

    Forslund, T; Nilsson, H M; Sundqvist, T


    Neutrophil aggregation is mediated by both CD18 integrin and L-selectin. Nitric oxide attenuates the integrin-mediated adhesion of neutrophils to collagen and to endothelium and may therefore affect aggregation as well. FMLP-stimulated neutrophils exposed to l-arginine showed increased and prolonged aggregation, whereas cells pretreated with L-NAME did not differ from FMLP-stimulated controls. Nitric oxide is known to induce ADP ribosylation of G-actin, which inhibits polymerization. We detected equivalent levels of total F-actin in cells pretreated with l-arginine or L-NAME and non-pretreated controls. However, neutrophils pretreated with l-arginine and stimulated by CD18 integrin cross-linking exhibited a more limited increase in total F-actin, compared to control and L-NAME-pretreated cells. Thus at least two signaling pathways may be involved FMLP-stimulated aggregation, mediated by CD18 integrins. More specifically, it is plausible that FMLP-receptor signaling upregulates CD18 integrins and endogenous NO subsequently modulates CD18-mediated signaling to prolong aggregation, possibly through ADP-ribosylation of actin. Copyright 2000 Academic Press.

  4. Involvement of nitric oxide in lipopolysaccharide induced anorexia. (United States)

    Riediger, Thomas; Cordani, Caroline; Potes, Catarina Soares; Lutz, Thomas A


    Treatment with the bacterial endotoxin lipopolysaccharide (LPS) is a commonly used model to induce disease-related anorexia. Following LPS treatment inducible nitric oxide synthase (iNOS) is expressed in the hypothalamic arcuate nucleus (ARC), where nitric oxide (NO) inhibits orexigenic neurons. Intracellular STAT signaling is triggered by inflammatory stimuli and has been linked to the transcriptional regulation of iNOS. We evaluated whether pharmacological blockade of iNOS by the specific inhibitor 1400W attenuates LPS-induced anorexia. Furthermore, we hypothesized that the tolerance to the anorectic effect occurring after repeated LPS treatment is paralleled by a blunted STAT3 phosphorylation in the ARC. Rats treated with a subcutaneous injection of 1400W (10 mg/kg) showed an attenuated anorectic LPS response relative to control rats receiving only LPS (100 µg/kg; i.p.). Similarly, iNOS blockade attenuated LPS-induced adipsia, hyperthermia, inactivity and the concomitant drop in energy expenditure. While single LPS treatment increased STAT3 phosphorylation in the ARC, rats treated repeatedly with LPS showed no anorectic response and also no STAT3 phosphorylation in the ARC after the second and third LPS injections, respectively. Hence, pSTAT3 signaling in the ARC might be part of the intracellular cascades translating pro-inflammatory stimuli into suppression of food intake. The current findings substantiate a role of iNOS dependent NO formation in disease-related anorexia. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Exhaled nitric oxide in diagnosis and management of respiratory diseases

    Directory of Open Access Journals (Sweden)

    Abba Abdullah


    Full Text Available The analysis of biomarkers in exhaled breath constituents has recently become of great interest in the diagnosis, treatment and monitoring of many respiratory conditions. Of particular interest is the measurement of fractional exhaled nitric oxide (FENO in breath. Its measurement is noninvasive, easy and reproducible. The technique has recently been standardized by both American Thoracic Society and European Respiratory Society. The availability of cheap, portable and reliable equipment has made the assay possible in clinics by general physicians and, in the near future, at home by patients. The concentration of exhaled nitric oxide is markedly elevated in bronchial asthma and is positively related to the degree of esinophilic inflammation. Its measurement can be used in the diagnosis of bronchial asthma and titration of dose of steroids as well as to identify steroid responsive patients in chronic obstructive pulmonary disease. In primary ciliary dyskinesia, nasal NO is diagnostically low and of considerable value in diagnosis. Among lung transplant recipients, FENO can be of great value in the early detection of infection, bronchioloitis obliterans syndrome and rejection. This review discusses the biology, factors affecting measurement, and clinical application of FENO in the diagnosis and management of respiratory diseases.

  6. Estimation of nitric oxide as an inflammatory marker in periodontitis

    Directory of Open Access Journals (Sweden)

    Menaka K


    Full Text Available Nitric oxide (NO is not only important in host defense and homeostasis but it is also regarded as harmful and has been implicated in the pathogenesis of a wide variety of inflammatory and autoimmune diseases. The presence of NO in periodontal disease may reflect the participation of an additional mediator of bone resorption responsible for disease progression. The aim of this study was to assess the level of NO in serum in chronic periodontitis, and correlate these levels with the severity of periodontal disease. Sixty subjects participated in the study and were divided into two groups. NO levels were assayed by measuring the accumulation of stable oxidative metabolite, nitrite with Griess reaction. Results showed subjects with periodontitis had significantly high nitrite in serum than healthy subjects. NO production is increased in periodontal disease, this will enable us to understand its role in disease progression and selective inhibition of NO may be of therapeutic utility in limiting the progression of periodontitis.

  7. Nitric Oxide-Releasing Dendrimers as Antibacterial Agents (United States)

    Sun, Bin; Slomberg, Danielle L.; Chudasama, Shalini L.; Lu, Yuan


    The antibacterial activity of a series of nitric oxide (NO)-releasing poly(propylene imine) (PPI) dendrimers was evaluated against both Gram-positive and Gram-negative pathogenic bacteria, including methicillin-resistant Staphylococcus aureus. A direct comparison of the bactericidal efficacy between NO-releasing and control PPI dendrimers (i.e., non-NO-releasing) revealed both enhanced biocidal action of NO-releasing dendrimers and reduced toxicity against mammalian fibroblast cells. Antibacterial activity for the NO donor-functionalized PPI dendrimers was shown to be a function of both dendrimer size (molecular weight) and exterior functionality. In addition to minimal toxicity against fibroblasts, NO-releasing PPI dendrimers modified with styrene oxide exhibited the greatest biocidal activity (≥9.999% killing) against all bacterial strains tested. The N-diazeniumdiolate NO donor-functionalized PPI dendrimers presented in this study hold promise as effective NO-based therapeutics for combating bacterial infections. PMID:23013537

  8. Generation, translocation, and action of nitric oxide in living systems. (United States)

    Tennyson, Andrew G; Lippard, Stephen J


    Nitric oxide (NO) is a gaseous diatomic radical that is involved in a wide range of physiological and pathological functions in biology. Conceptually, the biochemistry of NO can be separated into three stages: generation (stage 1), translocation (stage 2), and action (stage 3). In stage 1 the oxygenase domain of NO synthase converts L-arginine to L-citrulline and NO (g). Owing to its short-lived nature, this molecule is converted into a different nitrogen oxide such as NO(2), an organonitrosyl such as a nitrosothiol, or a metal nitrosyl such as a heme-nitrosyl, for transportation in stage 2. Each of these derivatives features unique physical characteristics, chemical reactivity, and biological activity. Upon delivery in stage 3, NO exerts its physiological or pathological function by reaction with biomolecules containing redox-active metals or other residues. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Flow-dependent regulation of endothelial nitric oxide synthase: role of protein kinases (United States)

    Boo, Yong Chool; Jo, Hanjoong


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

  10. Effects of incretin agonists on endothelial nitric oxide synthase expression and nitric oxide synthesis in human coronary artery endothelial cells exposed to TNFα and glycated albumin. (United States)

    Garczorz, Wojciech; Francuz, Tomasz; Siemianowicz, Krzysztof; Kosowska, Agnieszka; Kłych, Agnieszka; Aghdam, Mohammad Reza F; Jagoda, Krystyna


    There have been a number of beneficial effects of incretin agonists on the cardiovascular system. Glycated albumin (GA) and tumor necrosis factor (TNFα) may lead to endothelial dysfunction. Due to reports of cardioprotective effects of incretin agonist, we wanted to determine if GLP-1 and exendin-4 can reverse diminished production of nitric oxide (NO) after treatment with TNFα and GA. The objective of our experiment was to study the interaction between incretin agonists and proinflammatory substances like TNFα and GA on production of NO in HCAEC. Human vascular endothelial cells from the coronary artery (HCAEC) were used. The mRNA expression and protein level of endothelial nitric oxide synthase (eNOS) and inducible (iNOS) were quantified. NO production was measured in cells using DAF-FM/DA and flow cytometry. TNFα (10 ng/mL) decreased eNOS: mRNA by 90% and protein level by 31%. TNFα also decreased NO by 33%. GA (500 μg/mL) neither affected eNOS expression nor the protein level, but inhibited nearly all formation of NO in endothelium. GLP-1 (100 nM) and exendin-4 (1 and 10nM) decreased the amount of NO compared to control. Incubation of HCAEC with TNFα and incretin agonists did not change or moderately reduce the amount of NO compared to TNFα alone. TNFα and GA decrease production of NO in HCAEC, presumably by inducing reactive oxygen species or eNOS uncoupling. Incretin agonists in tested concentrations in the presence of l-arginine were not able to reverse this effect and instead led to a further reduction in NO production. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  11. Study of nitric oxide catalytic oxidation on manganese oxides-loaded activated carbon at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    You, Fu-Tian [Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); University of Chinese Academy of Sciences, Beijing (China); Yu, Guang-Wei, E-mail: [Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Wang, Yin, E-mail: [Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Xing, Zhen-Jiao [Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Liu, Xue-Jiao; Li, Jie [Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); University of Chinese Academy of Sciences, Beijing (China)


    Highlights: • Loading manganese oxides on activated carbon effectively promotes NO oxidation. • NO adsorption-desorption on activated carbon is fundamental to NO oxidation. • A high Mn{sup 4+}/Mn{sup 3+} ratio contributes to NO oxidation by promoting lattice O transfer. - Abstract: Nitric oxide (NO) is an air pollutant that is difficult to remove at low concentration and low temperature. Manganese oxides (MnO{sub x})-loaded activated carbon (MLAC) was prepared by a co-precipitation method and studied as a new catalyst for NO oxidation at low temperature. Characterization of MLAC included X-ray diffraction (XRD), scanning electron microscopy (SEM), N{sub 2} adsorption/desorption and X-ray photoelectron spectroscopy (XPS). Activity tests demonstrated the influence of the amount of MnO{sub x} and the test conditions on the reaction. MLAC with 7.5 wt.% MnO{sub x} (MLAC003) exhibits the highest NO conversion (38.7%) at 1000 ppm NO, 20 vol.% O{sub 2}, room temperature and GHSV ca. 16000 h{sup −1}. The NO conversion of MLAC003 was elevated by 26% compared with that of activated carbon. The results of the MLAC003 activity test under different test conditions demonstrated that NO conversion is also influenced by inlet NO concentration, inlet O{sub 2} concentration, reaction temperature and GHSV. The NO adsorption-desorption process in micropores of activated carbon is fundamental to NO oxidation, which can be controlled by pore structure and reaction temperature. The activity elevation caused by MnO{sub x} loading is assumed to be related to Mn{sup 4+}/Mn{sup 3+} ratio. Finally, a mechanism of NO catalytic oxidation on MLAC based on NO adsorption-desorption and MnO{sub x} lattice O transfer is proposed.

  12. Role of nitric oxide in glucose-, fructose and galactose-induced ...

    African Journals Online (AJOL)

    Previous studies have shown that the infusion of glucose, fructose and galactose resulted in significant increases in intestinal glucose uptake (IGU) and the role of nitric oxide in these responses was not known. The present study was designed to investigate the role of nitric oxide in the observed increases in IGU.


    NARCIS (Netherlands)



    The effect of the chronic oral application of N-G-nitro-L-arginine methyl eater (L-NAME), a potent inhibitor of nitric oxide (NO) production, was studied on hypothalamic blood flow (HBF) and hypothalamic nitric oxide synthase (NOS) activity in rats. L-NAME was dissolved in the drinking water, in a

  14. Neuronal nitric oxide synthase-deficient mice have impaired Renin release but normal blood pressure

    DEFF Research Database (Denmark)

    Sällström, Johan; Carlström, Mattias; Jensen, Boye L


    BackgroundNitric oxide deficiency is involved in the development of hypertension, but the mechanisms are currently unclear. This study was conducted to further elucidate the role of neuronal nitric oxide synthase (nNOS) in blood pressure regulation and renin release in relation to different sodiu...

  15. Inhaled nitric oxide for prevention of bronchopulmonary dysplasia in premature babies (EUNO) : a randomised controlled trial

    NARCIS (Netherlands)

    Mercier, Jean-Christophe; Hummler, Helmut; Durrmeyer, Xavier; Sanchez-Luna, Manuel; Carnielli, Virgilio; Field, David; Greenough, Anne; Van Overmeire, Bart; Jonsson, Baldvin; Hallman, Mikko; Baldassarre, James


    Background In animal models, inhaled nitric oxide improved gas exchange and lung structural development, but its use in premature infants at risk of developing bronchopulmonary dysplasia remains controversial. We therefore tested the hypothesis that inhaled nitric oxide at a low concentration,

  16. Bone marrow-derived versus parenchymal sources of inducible nitric oxide synthase in experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Zehntner, Simone P; Bourbonniere, Lyne; Hassan-Zahraee, Mina


    The role of nitric oxide (NO) in central nervous system (CNS) inflammation is uncertain. Whereas experimental autoimmune encephalomyelitis (EAE) is exacerbated in mice deficient in inducible nitric oxide synthase (iNOS), inhibitor studies have suggested a pro-inflammatory role for NO. These discr...

  17. Association of extended nitric oxide parameters with bronchial hyperresponsiveness and bronchodilator response in children with asthma. (United States)

    Kim, Yoon Hee; Sol, In Suk; Yoon, Seo Hee; Kim, Min Jung; Kim, Kyung Won; Sohn, Myung Hyun; Kim, Kyu-Earn


    Theoretical non-linear modeling of exhaled nitric oxide has revealed extended flow-independent parameters that could explain where or how nitric oxide is produced in the lung and transferred to the airway gas stream. We aimed to evaluate the associations of bronchial hyperresponsiveness and bronchodilator response with extended flow-independent nitric oxide parameters. Nitric oxide (30, 50, 100, 200 ml s-1) was measured in 432 children with asthma on the same day with either a methacholine challenge test (n = 156) or spirometry with bronchodilator (n = 276; 96 previously diagnosed with asthma and treated with inhaled corticosteroid, 37 with acute exacerbation treated with systemic corticosteroid). We additionally included 107 healthy controls for evaluation of the suitability of the non-linear model of exhaled nitric oxide. In asthmatic children, the response-dose ratio of the methacholine challenge test was correlated positively with bronchial nitric oxide (JawNO) and airway tissue nitric oxide (CawNO) (r = 0.367 and r = 0.299, respectively; both p asthma but not those with acute exacerbation. Our findings suggest that bronchial hyperresponsiveness is associated with CawNO while factors other than airway tissue inflammation could affect bronchodilator response in children with mild asthma. Systemic corticosteroid use during asthma exacerbation could affect the association of bronchodilator response with extended nitric oxide parameters.

  18. Hyperbaric oxygen therapy may overcome nitric oxide blockage during cyanide intoxication

    DEFF Research Database (Denmark)

    Polzik, Peter; Hansen, Marco Bo; Olsen, Niels Vidiendal


    PURPOSE: To determine the effects of a blockade of nitric oxide (NO) synthesis on hyperbaric oxygen (HBO₂) therapy during cyanide (CN) intoxication. METHODS: 39 anesthetized female Sprague-Dawley rats were exposed to CN intoxication (5.4 mg/kg intra-arterially) with or without previous nitric oxide...

  19. Nitric oxide fumigation for control of bulb mites on flower bulbs and tubers (United States)

    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...

  20. Manipulation of nitric oxide in an animal model of acute liver injury ...

    African Journals Online (AJOL)

    Background: Nitric oxide may have a protective effect on the liver during endotoxemia and chronic inflammation. There is evidence that it maintains liver and intestinal tissue integrity during inflammatory processes. We evaluated the impact of altering nitric oxide release on acute liver injury, the associated gut injury and ...

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

    Zhu, Wenzhen; Yang, Bingwu; Fu, Huiling; Ma, Long; Liu, Tingting; Chai, Rongfei; Zheng, Zhaodi; Zhang, Qunye; Li, Guorong


    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-induced 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Study of nitric oxide catalytic oxidation on manganese oxides-loaded activated carbon at low temperature (United States)

    You, Fu-Tian; Yu, Guang-Wei; Wang, Yin; Xing, Zhen-Jiao; Liu, Xue-Jiao; Li, Jie


    Nitric oxide (NO) is an air pollutant that is difficult to remove at low concentration and low temperature. Manganese oxides (MnOx)-loaded activated carbon (MLAC) was prepared by a co-precipitation method and studied as a new catalyst for NO oxidation at low temperature. Characterization of MLAC included X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption/desorption and X-ray photoelectron spectroscopy (XPS). Activity tests demonstrated the influence of the amount of MnOx and the test conditions on the reaction. MLAC with 7.5 wt.% MnOx (MLAC003) exhibits the highest NO conversion (38.7%) at 1000 ppm NO, 20 vol.% O2, room temperature and GHSV ca. 16000 h-1. The NO conversion of MLAC003 was elevated by 26% compared with that of activated carbon. The results of the MLAC003 activity test under different test conditions demonstrated that NO conversion is also influenced by inlet NO concentration, inlet O2 concentration, reaction temperature and GHSV. The NO adsorption-desorption process in micropores of activated carbon is fundamental to NO oxidation, which can be controlled by pore structure and reaction temperature. The activity elevation caused by MnOx loading is assumed to be related to Mn4+/Mn3+ ratio. Finally, a mechanism of NO catalytic oxidation on MLAC based on NO adsorption-desorption and MnOx lattice O transfer is proposed.

  3. Hemodynamic effects of inhaled nitric oxide in women with mitral stenosis and pulmonary hypertension. (United States)

    Mahoney, P D; Loh, E; Blitz, L R; Herrmann, H C


    Mitral stenosis (MS) is associated with elevated left atrial pressure, increased pulmonary vascular resistance (PVR), and pulmonary hypertension (PH). The hemodynamic effects of inhaled nitric oxide (NO) in adults with MS are unknown. We sought to determine the acute hemodynamic effects of inhaled NO in adults with MS and PH. Eighteen consecutive women (mean age 58 +/- 15 years) with MS and PH underwent heart catheterization. Hemodynamic measurements were recorded at baseline, after NO inhalation at 80 ppm, and after percutaneous balloon valvuloplasty (n = 10). NO reduced pulmonary artery systolic pressure (62 +/- 14 mm Hg [baseline] vs 54 +/- 15 mm Hg [NO]; p Wood U [baseline] vs 2.2 +/- 1.4 Wood U [NO]; p tone is an important mechanism of elevated PVR in MS.

  4. Contribution of nonendothelial nitric oxide to altered rat uterine resistance artery serotonin reactivity during pregnancy. (United States)

    Mandalà, Maurizio; Gokina, Natalia; Osol, George


    The aims of this study were to evaluate the effects of pregnancy on the serotonin reactivity of the mesometrial arteries and to assess the relative contribution of endothelial and smooth muscle cells to the overall effect. Arteries were obtained from nonpregnant (n = 20) and late pregnant (n = 28) Sprague-Dawley rats and were cannulated in the chamber of an arteriograph. Changes in lumen diameter were measured by a video dimension analyzer. Statistical analysis used 2-way analysis of variance, followed by Bonferroni test. Intact vessels from late pregnant versus nonpregnant animals were significantly less sensitive to the constrictor effects of serotonin at concentrations Pregnancy significantly decreases uterine resistance artery sensitivity to serotonin. This difference in sensitivity is due to the enhanced production of nitric oxide by endothelial cells and, most likely, by vascular smooth muscle.

  5. The effect of magnesium sulfate on bleeding time and nitric oxide production in preeclamsia. (United States)

    Moslemizade, Narges; Rafiei, Alireza; Yazdani, Fereshteh; Hosseini-khah, Zahra; Yusefnezhad, Keyvan


    Preeclampsia is a disease regarding with altered vascular reactivity leading to hypertension of the mother and metabolic alterations in the fetus. This study aimed to assess nitric oxide and bleeding time following administration of magnesium sulfate to preeclamtic patients compared to normotensive pregnant women. A total of 112 subjects (56 preeclamtic patients and 56 normotensive pregnant controls) were enrolled in this case-control study. Cases and controls were matched for age, BMI, gestational age, parity and gravidity. Total concentration of nitrite and nitrate (NOx) was measured before and during magnesium sulfate (MgSO4) treatment using a modified Griess-based method. Systolic and diastolic blood pressures were significantly decreased during MgSO4 treatment in preeclamtic patients (p preeclamsia.

  6. Formation of nitric oxide under action of UV and visible light on S-nitrosocompounds (United States)

    Stepuro, Ivan I.; Adamchuk, Raisa I.; Anufrik, Slavomir S.; Stepuro, Vitali I.; Maskevich, Sergei A.


    It has been shown that NO is released under the exposure of the aqueous solutions of S-nitrosocompounds as well as blood plasma proteins and whole blood of healthy donors to UV and visible light. The NO release from degrading S- nitrosocompounds was monitored both spectrophotometrically (by nitrosohemoglobin formation) and using the quenching of pyrene fluorescence by nitric oxide. In addition to NO, thyil radicals which dismutate to disulfides, were formed under anaerobic conditions. In the presence of oxygen, peroxide compounds, cysteine acid derivatives and S-nitrocompounds are formed apart from disulfides, and NO is mainly converted to NO2-. It is suggested that NO releasing under the actin of UV and visible light from physiological depots induces vascular relaxation, which enhances the blood flow.

  7. Nitric oxide prevents alveolar senescence and emphysema in a mouse model.

    Directory of Open Access Journals (Sweden)

    Amanda E Boe

    Full Text Available Nω-nitro-L-arginine methyl ester (L-NAME treatment induces arteriosclerosis and vascular senescence. Here, we report that the systemic inhibition of nitric oxide (NO production by L-NAME causes pulmonary emphysema. L-NAME-treated lungs exhibited both the structural (alveolar tissue destruction and functional (increased compliance and reduced elastance characteristics of emphysema development. Furthermore, we found that L-NAME-induced emphysema could be attenuated through both genetic deficiency and pharmacological inhibition of plasminogen activator inhibitor-1 (PAI-1. Because PAI-1 is an important contributor to the development of senescence both in vitro and in vivo, we investigated whether L-NAME-induced senescence led to the observed emphysematous changes. We found that L-NAME treatment was associated with molecular and cellular evidence of premature senescence in mice, and that PAI-1 inhibition attenuated these increases. These findings indicate that NO serves to protect and defend lung tissue from physiological aging.

  8. Effect of nitric oxide synthase inhibition on the exchange of glucose and fatty acids in human skeletal muscle

    DEFF Research Database (Denmark)

    Heinonen, Ilkka; Saltin, Bengt; Kemppainen, Jukka


    The role of nitric oxide in controlling substrate metabolism in humans is incompletely understood.......The role of nitric oxide in controlling substrate metabolism in humans is incompletely understood....

  9. The Chemical Biology of Nitric Oxide. Implications in Cellular Signaling (United States)

    Thomas, Douglas D.; Ridnour, Lisa A.; Isenberg, Jeffrey S.; Flores-Santana, Wilmarie; Switzer, Christopher H.; Donzellie, Sonia; Hussain, Perwez; Vecoli, Cecilia; Paolocci, Nazareno; Ambs, Stefan; Colton, Carol; Harris, Curtis; Roberts, David D.; Wink, David A.


    Nitric oxide (NO) has earned the reputation of being a signaling mediator with many diverse and often opposing biological activities. The diversity in response to this simple diatomic molecule comes from the enormous variety of chemical reactions and biological properties associated with it. In the last few years, the importance of steady state NO concentrations have emerged as a key determinant of its biological function. Precise cellular responses are differentially regulated by specific NO concentration. We propose 5 basic distinct concentration levels of NO activity; cGMP mediated processes ([NO] 400 nM) and nitrosative stress (1 µM). In general, lower NO concentrations promote cell survival and proliferation, while higher levels favor cell cycle arrest, apoptosis, and senescence. Free radical interactions will also influence NO signaling. One of the consequences of reactive oxygen species (ROS) generation is to reduce NO concentrations. This antagonizes the signaling of nitric oxide and in some cases results in converting a cell cycle arrest profile to a cell survival one. The resulting reactive nitrogen species (RNS) that are generated from these reactions can also have biological effects and increase oxidative and nitrosative stress responses. A number of factors determine the formation of NO and its concentration, such as diffusion, consumption, and substrate availability which are referred to as Kinetic Determinants for Molecular Target Interactions. These are the chemical and biochemical parameters that shape cellular responses to NO. Herein we discuss signal transduction and the chemical biology of NO in terms of the direct and indirect reactions. PMID:18439435

  10. Nitric oxide modulation of the spontaneous firing of rat medial vestibular nuclear neurons. (United States)

    Kim, Hoo Won; Park, Jong-Seong; Jeong, Han-Seong; Jang, Myung Joo; Kim, Byeong-Chae; Kim, Myeong-Kyu; Cho, Ki-Hyun; Kim, Tae Sun; Park, Sung Wook


    Modulation of the spontaneous activity of rat medial vestibular nuclear neurons by nitric oxide was investigated using the whole-cell patch-clamp technique. The spike frequency was increased by sodium nitroprusside (SNP), a nitric oxide liberating agent, and it was also increased by another nitric oxide liberating agent, sodium-nitroso-N-acetylpenicillamine. L-Arginine, the substrate of nitric oxide synthase, increased the firing of the neurons. The increased SNP-induced firing was inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinozalin-1-one (ODQ), a specific inhibitor of guanylate cyclase. These results suggest that nitric oxide increases the neuronal excitability of the neurons by a cGMP-dependent mechanism.

  11. Nitric oxide modulates interleukin-2-induced proliferation in CTLL-2 cells

    Directory of Open Access Journals (Sweden)

    J. Padrón


    Full Text Available The role of the L-arginine–nitric oxide metabolic pathway was explored for interleukin-2-induced proliferation in the cytotoxic T lymphocyte clone CTLL-2. Specific inhibition of nitric oxide synthase significantly diminished, in a concentration-dependent manner, 3H-thymidine uptake of CTLL-2 cells in response to different concentrations of interleukin 2. Withdrawal of L-arginine from culture medium resulted as potent as the higher inhibition obtained when blocking nitric oxide synthase with L-arginine analogues. Furthermore, intermedial concentrations of Larginine and exogenous nitric oxide donors were found for achieving optimal IL2-induced proliferation of CTLL-2. These findings prompted us to suggest that intra- and/or inter-cellular nitric oxide signalling may contribute to the modulation of the IL2 mitogenic effect upon cytotoxic T lymphocytes.

  12. Acute Impact of Tobacco vs Electronic Cigarette Smoking on Oxidative Stress and Vascular Function. (United States)

    Carnevale, Roberto; Sciarretta, Sebastiano; Violi, Francesco; Nocella, Cristina; Loffredo, Lorenzo; Perri, Ludovica; Peruzzi, Mariangela; Marullo, Antonino G M; De Falco, Elena; Chimenti, Isotta; Valenti, Valentina; Biondi-Zoccai, Giuseppe; Frati, Giacomo


    The vascular safety of electronic cigarettes (e-Cigarettes) must still be clarified. We compared the impact of e-Cigarettes vs traditional tobacco cigarettes on oxidative stress and endothelial function in healthy smokers and nonsmoker adults. A crossover, single-blind study was performed in 40 healthy subjects (20 smokers and 20 nonsmokers, matched for age and sex). First, all subjects smoked traditional tobacco cigarettes. One week later, the same subjects smoked an e-Cigarette with the same nominal nicotine content. Blood samples were drawn just before and after smoking, and markers of oxidative stress, nitric oxide bioavailability, and vitamin E levels were measured. Flow-mediated dilation (FMD) was also measured. Smoking both e-Cigarettes and traditional cigarettes led to a significant increase in the levels of soluble NOX2-derived peptide and 8-iso-prostaglandin F2α and a significant decrease in nitric oxide bioavailability, vitamin E levels, and FMD. Generalized estimating equation analysis confirmed that all markers of oxidative stress and FMD were significantly affected by smoking and showed that the biologic effects of e-Cigarettes vstraditional cigarettes on vitamin E levels (P = .413) and FMD (P = .311) were not statistically different. However, e-Cigarettes seemed to have a lesser impact than traditional cigarettes on levels of soluble NOX2-derived peptide (P = .001), 8-iso-prostaglandin F2α (P = .046), and nitric oxide bioavailability (P = .001). Our study showed that both cigarettes have unfavorable effects on markers of oxidative stress and FMD after single use, although e-Cigarettes seemed to have a lesser impact. Future studies are warranted to clarify the chronic vascular effects of e-Cigarette smoking. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  13. Testosterone modulates platelet aggregation and endothelial cell growth through nitric oxide pathway. (United States)

    Campelo, Adrián E; Cutini, Pablo H; Massheimer, Virginia L


    The aim of the present study was to investigate the effect of testosterone on the modulation of cellular events associated with vascular homeostasis. In rat aortic strips, 5-20 min treatment with physiological concentrations of testosterone significantly increased nitric oxide (NO) production. The rapid action of the steroid was suppressed by the presence of an androgen receptor antagonist (flutamide). We obtained evidence that the enhancement in NO synthesis was dependent on the influx of calcium from extracellular medium, because in the presence of a calcium channel blocker (verapamil) the effect of testosterone was reduced. Using endothelial cell (EC) cultures, we demonstrated that androgen directly acts at the endothelial level. Chelerythrine or PD98059 compound completely suppressed the increase in NO production, suggesting that the mechanism of action of the steroid involves protein kinase C and mitogen-activated protein kinase pathways. It is known that endothelial NO released into the vascular lumen serves as an inhibitor of platelet activation and aggregation. We showed that testosterone inhibited platelet aggregation and this effect was dependent on endothelial NO synthesis. Indeed, the enhancement of NO production elicited by androgen was associated with EC growth. The steroid significantly increased DNA synthesis after 24 h of treatment, and this mitogenic action was blunted in the presence of NO synthase inhibitor N-nitro-l-arginine methyl ester. In summary, testosterone modulates vascular EC growth and platelet aggregation through its direct action on endothelial NO production.

  14. Plasma nitric oxide level is correlated with microvascular functions in the peripheral arterial disease. (United States)

    Akkoca, Muzaffer; Usanmaz, Suzan Emel; Koksoy, Cuneyt; Bengisun, Ugur; Demirel-Yilmaz, Emine


    At present there is no widely accepted biomarker for monitoring of vascular functions. The purpose of this prospective study was to investigate the association of some blood biomarkers with vascular reactivity in patients with peripheral arterial diseases (PAD). A prospective evaluation was made of 3 groups comprising a control group of healthy individuals, and patients with PAD caused by either atherosclerosis or Buerger's disease. Microvascular perfusion was examined using laser Doppler imaging of cutaneous erythrocyte flux after iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP). The correlation of microvascular reactivity with endothelium-related biomarkers was assessed. ACh-induced and SNP-induced vasodilations were significantly diminished in the PAD groups. The plasma nitric oxide (NO) levels of PAD patients were significantly higher than those of the control group, but asymmetric dimethylarginine, total antioxidant capacity and hydrogen sulphide levels were similar. Plasma NO level was negatively correlated with ACh and SNP-stimulated microvascular flow increase, whereas a positive correlation was detected with blood glucose and glycated hemoglobin (HbA1c) levels in all groups. These results indicate that a high plasma level of NO in PAD patients is associated with diminished endothelium-dependent and independent flow increase in the microvascular bed. An excessive amount of NO-induced nitrosative stress in an inflammatory condition that might be a reason for vascular dysfunction should be taken into consideration in the diagnostic and therapeutic approaches to PAD.

  15. Chlorine gas exposure causes systemic endothelial dysfunction by inhibiting endothelial nitric oxide synthase-dependent signaling. (United States)

    Honavar, Jaideep; Samal, Andrey A; Bradley, Kelley M; Brandon, Angela; Balanay, Joann; Squadrito, Giuseppe L; MohanKumar, Krishnan; Maheshwari, Akhil; Postlethwait, Edward M; Matalon, Sadis; Patel, Rakesh P


    Chlorine gas (Cl(2)) exposure during accidents or in the military setting results primarily in injury to the lungs. However, the potential for Cl(2) exposure to promote injury to the systemic vasculature leading to compromised vascular function has not been studied. We hypothesized that Cl(2) promotes extrapulmonary endothelial dysfunction characterized by a loss of endothelial nitric oxide synthase (eNOS)-derived signaling. Male Sprague Dawley rats were exposed to Cl(2) for 30 minutes, and eNOS-dependent vasodilation of aorta as a function of Cl(2) dose (0-400 ppm) and time after exposure (0-48 h) were determined. Exposure to Cl(2) (250-400 ppm) significantly inhibited eNOS-dependent vasodilation (stimulated by acetycholine) at 24 to 48 hours after exposure without affecting constriction responses to phenylephrine or vasodilation responses to an NO donor, suggesting decreased NO formation. Consistent with this hypothesis, eNOS protein expression was significantly decreased (∼ 60%) in aorta isolated from Cl(2)-exposed versus air-exposed rats. Moreover, inducible nitric oxide synthase (iNOS) mRNA was up-regulated in circulating leukocytes and aorta isolated 24 hours after Cl(2) exposure, suggesting stimulation of inflammation in the systemic vasculature. Despite decreased eNOS expression and activity, no changes in mean arterial blood pressure were observed. However, injection of 1400W, a selective inhibitor of iNOS, increased mean arterial blood pressure only in Cl(2)-exposed animals, suggesting that iNOS-derived NO compensates for decreased eNOS-derived NO. These results highlight the potential for Cl(2) exposure to promote postexposure systemic endothelial dysfunction via disruption of vascular NO homeostasis mechanisms.

  16. Chlorine Gas Exposure Causes Systemic Endothelial Dysfunction by Inhibiting Endothelial Nitric Oxide Synthase–Dependent Signaling (United States)

    Honavar, Jaideep; Samal, Andrey A.; Bradley, Kelley M.; Brandon, Angela; Balanay, Joann; Squadrito, Giuseppe L.; MohanKumar, Krishnan; Maheshwari, Akhil; Postlethwait, Edward M.; Matalon, Sadis; Patel, Rakesh P.


    Chlorine gas (Cl2) exposure during accidents or in the military setting results primarily in injury to the lungs. However, the potential for Cl2 exposure to promote injury to the systemic vasculature leading to compromised vascular function has not been studied. We hypothesized that Cl2 promotes extrapulmonary endothelial dysfunction characterized by a loss of endothelial nitric oxide synthase (eNOS)-derived signaling. Male Sprague Dawley rats were exposed to Cl2 for 30 minutes, and eNOS-dependent vasodilation of aorta as a function of Cl2 dose (0–400 ppm) and time after exposure (0–48 h) were determined. Exposure to Cl2 (250–400 ppm) significantly inhibited eNOS-dependent vasodilation (stimulated by acetycholine) at 24 to 48 hours after exposure without affecting constriction responses to phenylephrine or vasodilation responses to an NO donor, suggesting decreased NO formation. Consistent with this hypothesis, eNOS protein expression was significantly decreased (∼ 60%) in aorta isolated from Cl2–exposed versus air-exposed rats. Moreover, inducible nitric oxide synthase (iNOS) mRNA was up-regulated in circulating leukocytes and aorta isolated 24 hours after Cl2 exposure, suggesting stimulation of inflammation in the systemic vasculature. Despite decreased eNOS expression and activity, no changes in mean arterial blood pressure were observed. However, injection of 1400W, a selective inhibitor of iNOS, increased mean arterial blood pressure only in Cl2–exposed animals, suggesting that iNOS-derived NO compensates for decreased eNOS-derived NO. These results highlight the potential for Cl2 exposure to promote postexposure systemic endothelial dysfunction via disruption of vascular NO homeostasis mechanisms. PMID:21131444

  17. Nitric oxide blunts the endothelin-mediated pulmonary vasoconstriction in exercising swine (United States)

    Houweling, Birgit; Merkus, Daphne; Dekker, Marjolein MD; Duncker, Dirk J


    We have previously shown that vasodilators and vasoconstrictors that are produced by the vascular endothelium, including nitric oxide (NO), prostanoids and endothelin (ET), contribute to the regulation of systemic and pulmonary vascular tone in swine, in particular during treadmill exercise. Since NO and prostanoids can modulate the release of ET, and vice versa, we investigated the integrated endothelial control of pulmonary vascular resistance in exercising swine. Specifically, we tested the hypothesis that increased NO and prostanoid production during exercise limits the vasoconstrictor influence of ET, so that loss of these vasodilators results in exaggerated ET-mediated vasoconstriction during exercise. Fifteen instrumented swine were exercised on a treadmill at 0–5 km h−1 before and during ETA/ETB receptor blockade (tezosentan, 3 mg kg−1i.v.) in the presence and absence of inhibition of NO synthase (Nω-nitro-l-arginine, 20 mg kg−1i.v.) and/or cyclo-oxygenase (indometacin, 10 mg kg−1i.v.). In the systemic circulation, ET receptor blockade decreased vascular resistance at rest, which waned with increasing exercise intensity. Prior inhibition of either NO or prostanoid production augmented the vasodilator effect of ET receptor blockade, and these effects were additive. In contrast, in the pulmonary bed, ET receptor blockade had no effect under resting conditions, but decreased pulmonary vascular resistance during exercise. Prior inhibition of NO synthase enhanced the pulmonary vasodilator effect of ET receptor blockade, particularly during exercise, whereas inhibition of prostanoids had no effect, even after prior NO synthase inhibition. In conclusion, endogenous endothelin limits pulmonary vasodilatation in response to treadmill exercise. This vasoconstrictor influence is blunted by NO but not by prostanoids. PMID:16081484

  18. Involvement of Nitric Oxide in the Inhibition of Aortic Smooth Muscle Cell Proliferation by Calcium Dobesilate. (United States)

    Parés-Herbuté; Fliche; Monnier


    Vascular smooth muscle cell (SMC) proliferation is a key process in the pathogenesis of atherosclerosis. Numerous factors are involved in the regulation of SMC growth. Nitric oxide (NO) induces the inhibition of SMC proliferation whereas oxidized low-density lipoproteins (LDL) have a mitogenic effect. Calcium dobesilate (Doxium) is an angioprotective agent for treating vascular diseases. It has been shown to increase NO production and to have antioxidant properties but its mechanism of action is not yet fully understood. This study investigated the effect of calcium dobesilate on proliferation of rat aortic SMC in culture. Proliferation was evaluated by cell number and DNA synthesis. Orally administered calcium dobesilate (30, 100, or 200 mg/kg/day for 7 days) induced a dose-dependent decrease of proliferation of SMC in primary culture compared with controls. In vitro treatment with calcium dobesilate (0.05-5 mM) inhibited both DNA synthesis and proliferation in a time- and concentration-dependent manner. In both ex vivo and in vitro models, the inhibition was reversible upon removal of the drug. Calcium dobesilate also stimulated NO production and NO synthase activity. Inhibitors of NO synthesis attenuated the inhibitory effect of calcium dobesilate (300 µM) on DNA synthesis. In addition, calcium dobesilate (2.5-40 µM) induced a dose-dependent protection of cooper-induced LDL oxidation. These results showed that calcium dobesilate inhibits SMC proliferation, partly by a NO-dependent mechanism, and suggest that it could be effective in the treatment of pathological disorders associated with vascular SMC proliferation.

  19. Fabrication of nitric oxide-releasing polyurethane glucose sensor membranes (United States)

    Koh, Ahyeon; Riccio, Daniel A.; Sun, Bin; Carpenter, Alexis W.; Nichols, Scott P.; Schoenfisch, Mark H.


    Despite clear evidence that polymeric nitric oxide (NO) release coatings reduce the foreign body response (FBR) and may thus improve the analytical performance of in vivo continuous glucose monitoring devices when used as sensor membranes, the compatibility of the NO release chemistry with that required for enzymatic glucose sensing remains unclear. Herein, we describe the fabrication and characterization of NO-releasing polyurethane sensor membranes using NO donor-modified silica vehicles embedded within the polymer. In addition to demonstrating tunable NO release as a function of the NO donor silica scaffold and polymer compositions and concentrations, we describe the impact of the NO release vehicle and its release kinetics on glucose sensor performance. PMID:21795038

  20. Nitric oxide in marine invertebrates: a comparative perspective. (United States)

    Palumbo, Anna


    Since the discovery of the biological effects of nitric oxide (NO) more than two decades ago, NO has been identified as an important physiological modulator and a messenger molecule in mammals. Parallel to these studies, evidence that has accumulated in recent years has revealed that the NO signalling pathway is spread throughout the entire phylogenetic scale, being increasingly found in lower organisms, ranging from Chordata to Mollusca. The present review attempts to provide a survey of current knowledge of the genesis and possible roles of NO and the related signalling pathway in marine invertebrates, with special emphasis on Sepia, a choice dictated by the increasing appreciation of cephalopods as most valuable model systems for studies of NO biology and the present expectation for new exciting insights into as yet little explored segments of NO biology.

  1. Inducible nitric oxide synthase immunoreactivity in healthy rat pancreas. (United States)

    Keklikoglu, Nurullah


    Nitric oxide (NO) is produced by NO synthase (NOS) isoforms: neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). It is believed that, while nNOS and eNOS are effective in regulation of normal physiological processes, iNOS is expressed at an increasing rate especially in inflammatory process. The aim of this study was to determine the presence of iNOS immunoreactivity (iNOS-IR) and, to compare the iNOS-IR in islet of Langerhans cells (LC), acinar cells (AC), centroacinar cells (CC) and ductal cells (DC) by immunohistochemical (IHC) method in healthy rat pancreata. This study revealed the presence of iNOS-IR in all cell types except AC. Statistical analysis revealed a highly significant difference (preseach related to diabetes, it should not be disregarded that iNOS may be constitutively present in pancreatic islets.

  2. The role of nitric oxide in the object recognition memory. (United States)

    Pitsikas, Nikolaos


    The novel object recognition task (NORT) assesses recognition memory in animals. It is a non-rewarded paradigm that it is based on spontaneous exploratory behavior in rodents. This procedure is widely used for testing the effects of compounds on recognition memory. Recognition memory is a type of memory severely compromised in schizophrenic and Alzheimer's disease patients. Nitric oxide (NO) is sought to be an intra- and inter-cellular messenger in the central nervous system and its implication in learning and memory is well documented. Here I intended to critically review the role of NO-related compounds on different aspects of recognition memory. Current analysis shows that both NO donors and NO synthase (NOS) inhibitors are involved in object recognition memory and suggests that NO might be a promising target for cognition impairments. However, the potential neurotoxicity of NO would add a note of caution in this context. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Housing characteristics in relation to exhaled nitric oxide in China. (United States)

    Hou, Fan; Huang, Xiji; Liu, Chuanyao; Sun, Huizhen; Zhou, Ting; Song, Yuanchao; Rong, Yi; Zhu, Beibei; Chen, Wei; Wang, Jing; Wang, Jianshu; He, Meian; Miao, Xiaopin; Hoffmann, Barbara; Wu, Tangchun; Chen, Weihong; Yuan, Jing


    To investigate indoor factors affecting fractional exhaled nitric oxide (FeNO) in community residents. A total of 2404 adults (865 men, 1539 women, mean age 51.7 ± 13.3 years) were recruited to the study. Factors affecting FeNO were analyzed by multiple linear regression analysis. Participants without a kitchen exhaust fan/hood had higher FeNO (GM: 10.21%, 95% CI: 4.18%-16.59%). Participants engaged in home cooking who used only liquefied petroleum gas had higher FeNO (GM: 5.75%, 95% CI: 0.10%-11.73%) compared to those using natural gas for residential (home) cooking. Nonuse of a kitchen exhaust fan/hood and use of liquefied petroleum gas among persons engaged in home cooking were associated with higher FeNO levels.

  4. Ethylene, nitric oxide and haemoglobins in plant tolerance to flooding

    DEFF Research Database (Denmark)

    Mur, Luis A J; Gupta, Kapuganti J; Chakraborty, U


    As much as 12% of the world's soils may suffer excess water so that flooding is a major limiting factor on crop production in many areas. Plants attempt to deal with submergence by forming root aerenchyma to facilitate oxygen diffusion from the shoot to the root, initiating a hyponastic response......-tolerant species Rumex palustris and the model plant Arabidopsis thaliana have been extensively exploited to reveal some key molecular events. Our groups have recently demonstrated that nitric oxide (NO) triggers the biosynthesis of ethylene during stress and that NO plays key roles in PCD and the hyponastic....... This chapter will detail our understanding of the roles of ethylene, NO and haemoglobin in flooding stress....

  5. Regulation of Injury-Induced Neurogenesis by Nitric Oxide (United States)

    Carreira, Bruno P.; Carvalho, Caetana M.; Araújo, Inês M.


    The finding that neural stem cells (NSCs) are able to divide, migrate, and differentiate into several cellular types in the adult brain raised a new hope for restorative neurology. Nitric oxide (NO), a pleiotropic signaling molecule in the central nervous system (CNS), has been described to be able to modulate neurogenesis, acting as a pro- or antineurogenic agent. Some authors suggest that NO is a physiological inhibitor of neurogenesis, while others described NO to favor neurogenesis, particularly under inflammatory conditions. Thus, targeting the NO system may be a powerful strategy to control the formation of new neurons. However, the exact mechanisms by which NO regulates neural proliferation and differentiation are not yet completely clarified. In this paper we will discuss the potential interest of the modulation of the NO system for the treatment of neurodegenerative diseases or other pathological conditions that may affect the CNS. PMID:22997523

  6. Interaction of nitric oxide wth the (1010) face of ruthenium

    Energy Technology Data Exchange (ETDEWEB)

    Orent, T.W.


    The low-energy electron diffraction (LEED) technique was used to probe the atomic geometry of the surfaces that resulted from the steady-state interaction of nitric oxide with Ru(10 anti 10) as a function of temperature and pressure. Auger electron spectroscopy (AES) was used to identify the atomic species present on these surfaces. Results were obtained at reactant partial pressures in the range from 10/sup -9/ to 10/sup -6/ torr and substrate temperatures from -25 to 950/sup 0/C. The interaction of molecular oxygen with the surface was also examined. A qualitative correlation exists between the observed structures and the reported enhancement in the catalytic activity of supported ruthenium after the catalyst had been pretreated with oxygen. (JRD)

  7. Nitric Oxide Regulates Neurogenesis in the Hippocampus following Seizures

    Directory of Open Access Journals (Sweden)

    Bruno P. Carreira


    Full Text Available Hippocampal neurogenesis is changed by brain injury. When neuroinflammation accompanies injury, activation of resident microglial cells promotes the release of inflammatory cytokines and reactive oxygen/nitrogen species like nitric oxide (NO. In these conditions, NO promotes proliferation of neural stem cells (NSC in the hippocampus. However, little is known about the role of NO in the survival and differentiation of newborn cells in the injured dentate gyrus. Here we investigated the role of NO following seizures in the regulation of proliferation, migration, differentiation, and survival of NSC in the hippocampus using the kainic acid (KA induced seizure mouse model. We show that NO increased the proliferation of NSC and the number of neuroblasts following seizures but was detrimental to the survival of newborn neurons. NO was also required for the maintenance of long-term neuroinflammation. Taken together, our data show that NO positively contributes to the initial stages of neurogenesis following seizures but compromises survival of newborn neurons.

  8. Alterations in nitric oxide homeostasis during traumatic brain injury. (United States)

    Kozlov, Andrey V; Bahrami, Soheyl; Redl, Heinz; Szabo, Csaba


    Changes in nitric oxide (NO) levels have been often associated with various forms of trauma, including secondary damage after traumatic brain injury (TBI). Several studies demonstrate the upregulation of NO synthase (NOS) enzymes, and concomitant increases in brain NO levels, which contribute to the TBI-associated glutamate cytotoxicity, including the pathogenesis of mitochondrial dysfunction. TBI is also associated with elevated NO levels in remote organs, indicating that TBI can induce systemic changes in NO regulation, which can be either beneficial or detrimental. Here we review the possible mechanisms responsible for changes in NO metabolism during TBI. Better understanding of the changes in NO homeostasis in TBI will be necessary to design rational therapeutic approaches for TBI. This article is part of a Special Issue entitled: Immune and Metabolic Alterations in Trauma and Sepsis edited by Dr. Raghavan Raju. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Nitric Oxide Donor-Based Cancer Therapy: Advances and Prospects. (United States)

    Huang, Zhangjian; Fu, Junjie; Zhang, Yihua


    The increasing understanding of the role of nitric oxide (NO) in cancer biology has generated significant progress in the use of NO donor-based therapy to fight cancer. These advances strongly suggest the potential adoption of NO donor-based therapy in clinical practice, and this has been supported by several clinical studies in the past decade. In this review, we first highlight several types of important NO donors, including recently developed NO donors bearing a dinitroazetidine skeleton, represented by RRx-001, with potential utility in cancer therapy. Special emphasis is then given to the combination of NO donor(s) with other therapies to achieve synergy and to the hybridization of NO donor(s) with an anticancer drug/agent/fragment to enhance the activity or specificity or to reduce toxicity. In addition, we briefly describe inducible NO synthase gene therapy and nanotechnology, which have recently entered the field of NO donor therapy.

  10. Concentration of nitric oxide metabolites in middle ear effusion. (United States)

    John, E O; Russell, P T; Nam, B H; Jinn, T H; Jung, T T


    Free radicals such as nitric oxide (NO) seem to be important in the pathogenesis of otitis media with effusion (OME). NO can be quantitated by measuring its metabolites, nitrate (NO(3)(-)) and nitrite (NO(2)(-)). The purpose of this study is to determine the concentrations of NO in human middle ear effusion (MEE). Samples of human MEE were collected at the time of myringotomy and tympanostomy tube insertions. The type of MEE was classified as serous (SOM), mucoid (MOM) or purulent (POM) at the time of surgery. Samples of MEE were assayed for NO metabolites (nitrate and nitrite) with colorimetric assay (Griess method). Concentrations of NO metabolites were highest in MOM followed by SOM and POM. This study suggests that NO is present in human MEE and may play an important role in the pathogenesis of OME.

  11. Weaning of inhaled nitric oxide: is there a best strategy?

    Directory of Open Access Journals (Sweden)

    Anita M. Ware


    Full Text Available Background: Inhaled nitric oxide (iNO has been used in the treatment of pulmonary hypertension in neonates for many years. iNO was approved by the FDA in 1999 for hypoxic respiratory failure (HRF in term and near term infants, defined as > 34 weeks gestational age (GA. iNO is used for persistent pulmonary hypertension of the newborn (PPHN, secondary pulmonary hypertension caused by congenital heart disease (CHD, congenital diaphragmatic hernia (CDH, meconium aspiration syndrome (MAS, pneumonia, respiratory distress syndrome (RDS, and other pathologies. iNO has its effect locally on the pulmonary vasculature and has been studied extensively regarding its effect on morbidities such as: need for extracorporeal membrane oxygenation (ECMO, oxygen requirements, and mechanical ventilatory support. However, protocols for weaning iNO and for the duration of iNO weaning have not been studied extensively. It has been shown that an abrupt discontinuation leads to rebound pulmonary hypertension.Methods: Electronic literature search and review of published articles on the use of iNO in the neonate.Results: Electronic databases including Medline and PubMed were searched from the years 1995-2015, using the keywords "iNO", "nitric oxide", "neonate", and "weaning nitric oxide." This search revealed 2,124 articles. Articles were determined to be eligible for review if they included a specific protocol for weaning iNO, and were published in English. 16 articles with specific protocols for iNO weaning have been identified and reviewed. The studies had enrolled a total of 1,735 neonates either at term either preterm and with a mean birth weight of 3.3 kg (± 2 kg. Main diagnoses included MAS, CHD (total anomalous pulmonary venous return [TAPVR], d-transposition of the great vessels [DTGV], atrial septal defect [ASD], pulmonary atresia [PA], hypoplastic left heart syndrome [HLH], pneumonia, RDS, hyaline membrane disease (HMD, PPHN, CDH, sepsis, pulmonary hypoplasia

  12. Identification of free nitric oxide radicals in rat bone marrow

    DEFF Research Database (Denmark)

    Aleksinskaya, Marina A; van Faassen, Ernst E H; Nelissen, Jelly


    Nitric oxide (NO) has been implicated in matrix metallopeptidase 9 (MMP9)-dependent mobilization of hematopoietic stem and progenitor cells from bone marrow (BM). However, direct measurement of NO in the BM remained elusive due to its low in situ concentration and short lifetime. Using NO spin...... trapping and electron paramagnetic resonance (EPR) spectroscopy we give the first experimental confirmation of free NO radicals in rodent BM. NO production was quantified and attributed to enzymatic activity of NO synthases (NOS). Although endothelial NOS (eNOS) accounts for most (66%) of basal NO, we...... identified a significant contribution (23%) from inducible NOS (iNOS). Basal NO levels closely correlate with MMP9 bioavailability in BM of both hypertensive and control rats. Our observations support the hypothesis that inadequate mobilization of BM-derived stem and progenitor cells in hypertension results...

  13. Nitric oxide inhibitory constituents from the barks of Cinnamomum cassia. (United States)

    He, Shan; Zeng, Ke-Wu; Jiang, Yong; Tu, Peng-Fei


    Six new compounds including one γ-butyrolactone, cinncassin A (1), two tetrahydrofuran derivatives, cinncassins B and C (2, 3), two lignans, cinncassins D and E (4, 5), and one phenylpropanol glucoside, cinnacassoside D (6), together with 14 known lignans (7-20) were isolated from the barks of Cinnamomum cassia. The structures of 1-6 were elucidated by extensive 1D and 2D NMR spectroscopic data analysis as well as chemical methods, and the absolute configurations were established by experimental and calculated ECD data. The anti-inflammatory activities of the isolates were evaluated on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Compounds 5, 7, 8, and 15 showed potent inhibition activities with IC50 values of 17.6, 17.7, 18.7, and 17.5μM, respectively. Copyright © 2016. Published by Elsevier B.V.

  14. Nitroxyl (HNO): the Cinderella of the nitric oxide story. (United States)

    Irvine, Jennifer C; Ritchie, Rebecca H; Favaloro, Joanne L; Andrews, Karen L; Widdop, Robert E; Kemp-Harper, Barbara K


    Until recently, most of the biological effects of nitric oxide (NO) have been attributed to its uncharged state (NO*), yet NO can also exist in the reduced state as nitroxyl (HNO or NO(-)). Putatively generated from both NO synthase (NOS)-dependent and -independent sources, HNO is rapidly emerging as a novel entity with distinct pharmacology and therapeutic advantages over its redox sibling, NO*. Thus, unlike NO*, HNO can target cardiac sarcoplasmic ryanodine receptors to increase myocardial contractility, can interact directly with thiols and is resistant to both scavenging by superoxide (*O2-) and tolerance development. HNO donors are protective in the setting of heart failure in which NO donors have minimal impact. Here, we discuss the unique pharmacology of HNO versus NO* and highlight the therapeutic potential of HNO donors in the treatment of cardiovascular disease.

  15. Natural Product Nitric Oxide Chemistry: New Activity of Old Medicines

    Directory of Open Access Journals (Sweden)

    Hong Jiang


    Full Text Available The use of complementary and alternative medicine (CAM as a therapy and preventative care measure for cardiovascular diseases (CVD may prove to be beneficial when used in conjunction with or in place of conventional medicine. However, the lack of understanding of a mechanism of action of many CAMs limits their use and acceptance in western medicine. We have recently recognized and characterized specific nitric oxide (NO activity of select alternative and herbal medicines that may account for many of their reported health benefits. The ability of certain CAM to restore NO homeostasis both through enhancing endothelial production of NO and by providing a system for reducing nitrate and nitrite to NO as a compensatory pathway for repleting NO bioavailability may prove to be a safe and cost-effective strategy for combating CVD. We will review the current state of science behind NO activity of herbal medicines and their effects on CVD.

  16. Nitric oxide as a potential biomarker in inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Nesina Avdagić


    Full Text Available The aim of this study was to investigate changes in serum nitric oxide (NO concentration in inflammatory bowel diseases (IBD patients and its use as potential biomarker in differential diagnosis of ulcerative colitis (UC and Crohn's disease (CD and in disease activity assessment. In 60 patients of both genders - 30 with ulcerative colitis and 30 with Crohn's disease - and 30 controls serum nitric oxide concentration was determined by measuring nitrite concentration, a stable metabolic product of NO with oxygen. Conversion of nitrates (NO3- to nitrites (NO2- was done with elementary zinc. The nitrite concentration was determined by classic colorimetrical Griess reaction. Median serum NO concentration was statistically different (p=0,0005 between UC patients (15.25 µmol/L; 13.47 - 19.88 µmol/L, CD patients (14.54 µmol/L; 13.03 -16.32 µmol/L and healthy controls (13.29 µmol/L; 12.40 - 13.92 µmol/L. When active UC and CD patients were compared with inactive UC and CD patients respectively a significant difference in serum NO level was found (p=0.0005. With a cut-off level of 17.39 µmol/L NO had a sensitivity of 100% and a specificity of 100% in discriminating between active and inactive UC patients. With cut-off value of 14.01 µmol/L serum NO level had a sensitivity of 88% and a specificity of 69% in distinguishing between patients with active CD and inactive CD. Serum NO concentration is a minimally invasive and rapid tool for discriminating between active and inactive IBD patients and could be used as useful biomarker in monitoring of disease activity in IBD patients.


    Wray, D. Walter; Witman, Melissa A. H.; Ives, Stephen J.; McDaniel, John; Trinity, Joel D.; Conklin, Jamie D.; Supiano, Mark A.; Richardson, Russell S.


    This study sought to better define the role of nitric oxide (NO) in brachial artery flow-mediated vasodilation (FMD) in young, healthy humans. Brachial artery blood velocity and diameter were determined (ultrasound Doppler) in eight volunteers (26 ± 1 yrs) before and after 5-min forearm circulatory occlusion with and without intra-arterial infusion of the endothelial nitric oxide synthase (eNOS) inhibitor L-NMMA (0.48 mg/dl/min). Control (CON) and L-NMMA trials were performed with the occlusion cuff placed in the traditional distal position, as well as proximal to the measurement site. FMD was significantly reduced, but not abolished, by L-NMMA in the distal cuff trial (8.9 ± 1.3 to 6.0 ± 0.7%, CON vs. L-NMMA, P = 0.02), with no effect of L-NMMA on FMD with proximal cuff placement (10.6 ± 1.2 to 12.4 ± 1.7%, CON vs. L-NMMA, P = 0.39). When the reduction in shear stimulus following L-NMMA was taken into account, no drug difference was observed for either distal (0.26 ± 0.02 to 0.23 ± 0.03, CON vs. L-NMMA, P = 0.40) or proximal (0.23 ± 0.08 to 0.23 ± 0.03, CON vs. L-NMMA, P = 0.89) FMD trials. These findings challenge the assertion that NO is obligatory for brachial artery FMD, and call into question the sensitivity of this procedure for non-invasive determination of NO bioavailability in young, healthy humans. PMID:23774225

  18. Elevated circulating nitric oxide levels correlates with enhanced oxidative stress in patients with hyperemesis gravidarum. (United States)

    Beyazit, Fatma; Türkön, Hakan; Pek, Eren; Ozturk, Filiz Halici; Ünsal, Mesut


    Since the biochemical and molecular mechanisms responsible for ongoing oxidative stress in hyperemesis gravidarum (HEG) patients have not yet been fully elucidated, the aim of this study was to evaluate the possible role of nitric oxide (NO), malondialdehyde (MDA) and other oxidative stress markers in the disease pathophysiology. Moreover, the relation between oxidative stress markers and Helicobacter pylori (H. pylori) infection was also investigated. Women with pregnancies complicated by HEG (n = 33) were compared with pregnant women without HEG (n = 30) and with healthy non-pregnant women (n = 31). Serum NO, MDA, total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI) and H. pylori infection status were determined for each subject. Serum NO levels and OSI index were found to be increased (p = .001 and .013, respectively) and TAS levels were decreased (p pregnancy. Impact statement What is already known on this subject? Current evidence suggests that oxidative stress is a significant factor responsible for a number of complications during pregnancy. What do the results of this study add? Hyperemesis gravidarum is an oxidative stress condition, as reflected by increased nitric oxide (NO) and decreased total antioxidant status activity, regardless of H. Pylori infection. What are the implications for clinical practice and/or further research? Full disclosure of the association between circulating NO and hyperemesis gravidarum would shed light on underlying biological mechanisms and could help clinical management of similar pregnancy-associated morbidity states.

  19. The Pathophysiology of Nitrogen Dioxide During Inhaled Nitric Oxide Therapy. (United States)

    Petit, Priscilla C; Fine, David H; Vásquez, Gregory B; Gamero, Lucas; Slaughter, Mark S; Dasse, Kurt A

    Administration of inhaled nitric oxide (NO) with the existing compressed gas delivery systems is associated with unavoidable codelivery of nitrogen dioxide (NO2), an unwanted toxic contaminant that forms when mixed with oxygen. The NO2 is generated when NO is diluted with O2-enriched air before delivery to the patient. When NO2 is inhaled by the patient, it oxidizes protective antioxidants within the epithelial lining fluid (ELF) and triggers extracellular damage in the airways. The reaction of NO2 within the ELF triggers oxidative stress (OS), possibly leading to edema, bronchoconstriction, and a reduced forced expiratory volume in 1 second. Nitrogen dioxide has been shown to have deleterious effects on the airways of high-risk patients including neonates, patients with respiratory and heart failure, and the elderly. Minimizing co-delivery of NO2 for the next generation delivery systems will be a necessity to fully optimize the pulmonary perfusion of NO because of vasodilation, whereas minimizing the negative ventilatory and histopathological effects of NO2 exposure during inhaled NO therapy.

  20. Cerebrospinal fluid nitric oxide levels in subacute sclerosing panencephalitis. (United States)

    Yilmaz, Deniz; Yüksel, Deniz; Senbil, Nesrin; Eminzade, Sude; Kilinç, Kamer; Anlar, Banu; Gürer, Yavuz


    Oxidative damage plays a role in neurodegenerative diseases. Levels of cerebrospinal fluid nitrite and nitrate levels (oxidation products that provide an indirect estimation of nitric oxide) were investigated in relation to clinical and laboratory features in subacute sclerosing panencephalitis (n = 47) and age-matched control (n = 43) groups. Significantly decreased levels of nitrite (median, 4.91 micromol/L) and nitrate (median, 6.14 micromol/L) were found in the patients. Nitrite and nitrate levels did not correlate with clinical or laboratory findings, except for presence of myoclonus. Cerebrospinal fluid nitrite levels of subacute sclerosing panencephalitis patients without myoclonic jerks were significantly higher than in those with myoclonus (median, 15.63 vs 4.34 micromol/L, respectively). The higher levels of nitrite in these patients can be explained by short disease duration and early stages of disease. Nitrate levels in subacute sclerosing panencephalitis patients with myoclonus (median, 9.26 micromol/L) were higher than in those without myoclonus (median, 4.25 micromol/L). Microbleeding resulting in conversion of nitrite to nitrate and increased production of superoxide can be suggested as possible mechanisms underlying these findings.

  1. Nitric Oxide Regulation of Mitochondrial Processes: Commonality in Medical Disorders. (United States)

    Stefano, George B; Kream, Richard M


    The vital status of diverse classes of eukaryotic mitochondria is reflected by the high degree of evolutionary modification functionally linked to ongoing multifaceted organelle development. From this teleological perspective, a logistical enhancement of eukaryotic cellular energy requirements indicates a convergence of metabolic processes within the mitochondrial matrix for optimal synthesis of ATP from ADP and inorganic phosphate and necessitates an evolutionarily driven retrofit of the primordial endosymbiont bacterial plasma membrane into the inner mitochondrial membrane. The biochemical complexity of eukaryotic inner membrane electron transport complexes linked to temporally-defined, state-dependent, fluctuations in mitochondrial oxygen utilization is capable of generating deleterious reactive oxygen species. Within this functional context, an extensive neurochemical literature supports the role of the free radical gas nitric oxide (NO) as a key signaling molecule involved in the regulation of multiple aspects of mitochondrial respiration/oxidative phosphorylation. Importantly, the unique chemical properties of NO underlie its rapid metabolism in vivo within a mechanistic spectrum of small oxidative molecules, free and protein-bound thiol adducts, and reversible binding to ferrous heme iron centers. Recent compelling work has identified a medically relevant dual regulation pathway for mitochondrial NO expression mediated by traditionally characterized NO synthases (NOS) and by enzymatic reduction of available cellular nitrite pools by a diverse class of cytosolic and mitochondrial nitrite reductases. Accordingly, our short review presents selected medically-based discussion topics relating to multi-faceted NO regulation of mitochondrial functions in human health and disease states.

  2. Subclinical mastitis causes alterations in nitric oxide, total oxidant and antioxidant capacity in cow milk. (United States)

    Atakisi, Onur; Oral, Hasan; Atakisi, Emine; Merhan, Oguz; Metin Pancarci, S; Ozcan, Ayla; Marasli, Saban; Polat, Bulent; Colak, Armagan; Kaya, Semra


    The aim of this study was to investigate total antioxidant (TAC), and oxidant capacity (TOC) and nitric oxide (NO) levels in milk of cows with subclinical mastitis. Brown Swiss and Holstein breed cows were screened with California Mastitis Test (CMT) to determine mammary glands with subclinical mastitis. Moreover, somatic cell counts (SCC) were determined electronically in all milk samples. Mammary quarters were classified as healthy (n=25) or subclinical mastitis (n=35) based on CMT scores and somatic cell count (SCC: 200,000/ml) in milk. Nitric oxide, TOC and SCC levels were significantly higher (pmastitis compared to those from healthy mammary quarters. In conclusion, subclinical mastitis results in higher NO concentrations, TOC and SCC, and NO and TOC were positively correlated with SCC. Moreover, alterations in NO levels and TOC in milk could be used as an alternative diagnostic tool to screen for subclinical mastitis. Copyright 2010 Elsevier Ltd. All rights reserved.

  3. Gentamicin induced nitric oxide-related oxidative damages on vestibular afferents in the guinea pig. (United States)

    Hong, Sung Hwa; Park, Sook Kyung; Cho, Yang-Sun; Lee, Hyun-Seok; Kim, Ki Ryung; Kim, Myung Gu; Chung, Won-Ho


    Gentamicin is a well-known ototoxic aminoglycoside. However, the mechanism underlying this ototoxicity remains unclear. One of the mechanisms which may be responsible for this ototoxicity is excitotoxic damage to hair cells. The overstimulation of the N-methyl-d-aspartate (NMDA) receptors increases the production of nitric oxide (NO), which induces oxidative stress on hair cells. In order to determine the mechanism underlying this excitotoxicity, we treated guinea pigs with gentamicin by placing gentamicin (0.5 mg) pellets into a round window niche. After the sacrifice of the animals, which occurred at 3, 7 and 14 days after the treatment, the numbers of hair cells in the animals were counted with a scanning electron microscope. We then performed immunostaining using neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS) and nitrotyrosine antibodies. The number of hair cells in the animals was found to decrease significantly after 7 days. nNOS and iNOS expression levels were observed to have increased 3 days after treatment. Nitrotyrosine was expressed primarily at the calyceal afferents of the type I hair cells 3 days after treatment. Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining revealed positive hair cells 3 days after treatment. Our results suggest that inner ear treatment with gentamicin may upregulate nNOS and iNOS to induce oxidative stress in the calyceal afferents of type I hair cells, via nitric oxide overproduction.

  4. Indium Tin Oxide Resistor-Based Nitric Oxide Microsensors (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Gonzalez, Jose M., III; Liu, Chung-Chiun


    A sensitive resistor-based NO microsensor, with a wide detection range and a low detection limit, has been developed. Semiconductor microfabrication techniques were used to create a sensor that has a simple, robust structure with a sensing area of 1.10 0.99 mm. A Pt interdigitated structure was used for the electrodes to maximize the sensor signal output. N-type semiconductor indium tin oxide (ITO) thin film was sputter-deposited as a sensing material on the electrode surface, and between the electrode fingers. Alumina substrate (250 m in thickness) was sequentially used for sensor fabrication. The resulting sensor was tested by applying a voltage across the two electrodes and measuring the resulting current. The sensor was tested at different concentrations of NO-containing gas at a range of temperatures. Preliminary results showed that the sensor had a relatively high sensitivity to NO at 450 C and 1 V. NO concentrations from ppm to ppb ranges were detected with the low limit of near 159 ppb. Lower NO concentrations are being tested. Two sensing mechanisms were involved in the NO gas detection at ppm level: adsorption and oxidation reactions, whereas at ppb level of NO, only one sensing mechanism of adsorption was involved. The NO microsensor has the advantages of high sensitivity, small size, simple batch fabrication, high sensor yield, low cost, and low power consumption due to its microsize. The resistor-based thin-film sensor is meant for detection of low concentrations of NO gas, mainly in the ppb or lower range, and is being developed concurrently with other sensor technology for multispecies detection. This development demonstrates that ITO is a sensitive sensing material for NO detection. It also provides crucial information for future selection of nanostructured and nanosized NO sensing materials, which are expected to be more sensitive and to consume less power.

  5. Mitochondrial Oxidative Stress, Mitochondrial DNA Damage and Their Role in Age-Related Vascular Dysfunction (United States)

    Mikhed, Yuliya; Daiber, Andreas; Steven, Sebastian


    The prevalence of cardiovascular diseases is significantly increased in the older population. Risk factors and predictors of future cardiovascular events such as hypertension, atherosclerosis, or diabetes are observed with higher frequency in elderly individuals. A major determinant of vascular aging is endothelial dysfunction, characterized by impaired endothelium-dependent signaling processes. Increased production of reactive oxygen species (ROS) leads to oxidative stress, loss of nitric oxide (•NO) signaling, loss of endothelial barrier function and infiltration of leukocytes to the vascular wall, explaining the low-grade inflammation characteristic for the aged vasculature. We here discuss the importance of different sources of ROS for vascular aging and their contribution to the increased cardiovascular risk in the elderly population with special emphasis on mitochondrial ROS formation and oxidative damage of mitochondrial DNA. Also the interaction (crosstalk) of mitochondria with nicotinamide adenosine dinucleotide phosphate (NADPH) oxidases is highlighted. Current concepts of vascular aging, consequences for the development of cardiovascular events and the particular role of ROS are evaluated on the basis of cell culture experiments, animal studies and clinical trials. Present data point to a more important role of oxidative stress for the maximal healthspan (healthy aging) than for the maximal lifespan. PMID:26184181

  6. Mitochondrial Oxidative Stress, Mitochondrial DNA Damage and Their Role in Age-Related Vascular Dysfunction

    Directory of Open Access Journals (Sweden)

    Yuliya Mikhed


    Full Text Available The prevalence of cardiovascular diseases is significantly increased in the older population. Risk factors and predictors of future cardiovascular events such as hypertension, atherosclerosis, or diabetes are observed with higher frequency in elderly individuals. A major determinant of vascular aging is endothelial dysfunction, characterized by impaired endothelium-dependent signaling processes. Increased production of reactive oxygen species (ROS leads to oxidative stress, loss of nitric oxide (•NO signaling, loss of endothelial barrier function and infiltration of leukocytes to the vascular wall, explaining the low-grade inflammation characteristic for the aged vasculature. We here discuss the importance of different sources of ROS for vascular aging and their contribution to the increased cardiovascular risk in the elderly population with special emphasis on mitochondrial ROS formation and oxidative damage of mitochondrial DNA. Also the interaction (crosstalk of mitochondria with nicotinamide adenosine dinucleotide phosphate (NADPH oxidases is highlighted. Current concepts of vascular aging, consequences for the development of cardiovascular events and the particular role of ROS are evaluated on the basis of cell culture experiments, animal studies and clinical trials. Present data point to a more important role of oxidative stress for the maximal healthspan (healthy aging than for the maximal lifespan.

  7. Subcellular and cellular locations of nitric-oxide synthase isoforms as determinants of health and disease (United States)

    Villanueva, Cleva; Giulivi, Cecilia


    The effects of nitric oxide in biological systems depend on its steady-state concentration and where it is being produced. The organ where nitric oxide is produced is relevant, and within the organ, which types of cells are actually contributing to this production seem to play a major determinant of its effect. Subcellular compartmentalization of specific nitric-oxide synthase enzymes has been shown to play a major role in health and disease. Pathophysiological conditions affect the cellular expression and localization of nitric oxide synthases, which in turn alter organ cross talk. In this study, we described the compartmentalization of nitric oxide in organs, cells and subcellular organelles, and how its localization relates to several relevant clinical conditions. Understanding the complexity of the compartmentalization of nitric oxide production and the implications of this compartmentalization in terms of cellular targets and downstream effects will eventually contribute toward the development of better strategies for treating or preventing pathological events associated with the increase, inhibition or mislocalization of nitric oxide production. PMID:20388537

  8. Airway nitric oxide and psychological processes in asthma and health: a review. (United States)

    Ritz, Thomas; Trueba, Ana F


    The fraction of exhaled nitric oxide (FeNO) has been widely used as a marker of airway inflammation in asthma in recent years. However, NO serves multiple functions throughout the organism, and various influences on FeNO levels beyond inflammation have been documented. Emerging literature indicates that psychological processes are systematically linked to FeNO. Academic Search Complete, PubMed, PsychArticles, and PsychInfo databases. Relevant studies were identified using keywords exhaled nitric oxide paired with psychological stress, stress psychology, emotion, major depression, anxiety, or psychopathology. Studies measuring FeNO during naturalistic observation of emotion and stress, laboratory stress and emotion-induction protocols, and correlational designs using psychological questionnaires were included. Acute stress, anxiety, and negative affect have been repeatedly linked with higher FeNO levels, whereas more prolonged states of stress, in particular depression, have been associated with lower FeNO levels. The literature on FeNO is paralleled by research on NO in the cardiovascular and central nervous systems, which also shows systematic associations with psychosocial variables. Potential mechanisms of association include stimulation of NO release from different cells, including the epithelia and macrophages, through noradrenaline, interferon-γ, or vascular endothelial growth factor, changes in oxidative stress or arginase levels, or facilitation of diffusion by mechanical factors. Psychosocial factors may need to be considered in the interpretation of longitudinal FeNO changes in monitoring and management of patients with asthma. The distinction between constitutive and inducible sources of NO will be essential for future research. Copyright © 2014 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  9. The Biological Chemistry of Nitric Oxide as It Pertains to the Extrapulmonary Effects of Inhaled Nitric Oxide (United States)

    Gow, Andrew J.


    The chemical properties of nitric oxide (NO) have been studied for over 200 years. However, it is only within the last 20 years that the biological implications of this chemistry have been considered. The classical model of NO action within the vasculature centers on production in the endothelium, diffusion to the smooth muscle, and subsequent activation of guanylate cyclase via binding to its heme iron. In the context of this model, it is difficult to conceptualize extrapulmonary effects of inhaled NO. However, NO possesses complex redox chemistry and is capable of forming a range of nitrogen oxide species and is therefore capable of interacting with a variety of biomolecules. Of particular interest is its reaction with reduced cysteine to form an S-nitrosothiol (SNO). SNOs are formed throughout NO biology and are a post-translational modification that has been shown to regulate many proteins under physiologic conditions. Hemoglobin, which was considered to be solely a consumer of NO, can form SNO in a conformationally dependent manner, which allows for the transport of inhaled NO beyond the realm of the lung. Higher oxides of nitrogen are capable of modifying proteins via nitration of tyrosines, which has been shown to occur under pathologic conditions. By virtue of its redox reactivity, one can appreciate that inhaled NO has a variety of routes by which it can act and that these routes may lead to extrapulmonary effects. PMID:16565423

  10. Aerobic exercise training increases neuronal nitric oxide release and bioavailability and decreases noradrenaline release in mesenteric artery from spontaneously hypertensive rats. (United States)

    Blanco-Rivero, Javier; Roque, Fernanda R; Sastre, Esther; Caracuel, Laura; Couto, Gisele K; Avendaño, María Soledad; Paula, Suliana M; Rossoni, Luciana V; Salaices, Mercedes; Balfagón, Gloria


    To study the effect of aerobic exercise training on sympathetic, nitrergic and sensory innervation function in superior mesenteric artery from spontaneously hypertensive rats (SHRs). De-endothelized vascular rings from sedentary and trained SHRs (treadmill 12 weeks) were used. Vasomotor responses to electrical field stimulation (EFS), noradrenaline, nitric oxide donor DEA-NO and calcitonin gene-related peptide (CGRP) were studied. Neuronal nitric oxide synthase (nNOS) expression and nitric oxide, superoxide anions (O(2.-)), noradrenaline and CGRP levels were also determined. Aerobic exercise training decreased vasoconstrictor response to EFS but increased noradrenaline response. Phentolamine decreased while N(ω)-nitro-(L)-arginine methyl ester ((L)-NAME) increased the response to EFS; the effect of both drugs was greater in trained animals. Training also decreased noradrenaline release and O(2.-) production and increased nNOS expression, nitric oxide release and the vasodilator response to DEA-NO. The O(2.-) scavenger tempol increased DEA-NO-induced vasodilation only in sedentary rats. The EFS-induced contraction was increased to a similar extent in both experimental groups by preincubation with CGRP (8-37). CGRP release and vasodilator response were not modified by training. Aerobic exercise training decreases contractile response to EFS in mesenteric artery from SHRs. This effect is the net result of decreased noradrenaline release, increased sensitivity to the vasoconstrictive effects of noradrenaline and increased neuronal nitric oxide release and bioavailability. These modifications might contribute to the beneficial effects of aerobic exercise training on blood pressure.

  11. Surface plasmon resonance biochip based on ZnO thin film for nitric oxide sensing. (United States)

    Feng, Wei-Yi; Chiu, Nan-Fu; Lu, Hui-Hsin; Shih, Hsueh-Ching; Yang, Dongfang; Lin, Chii-Wann


    In this study, the design of a novel optical sensor that comprises surface plasmon resonance sensing chip and zinc oxide nano-film was proposed for the detection of nitric oxide gas. The electrical and optical properties of zinc oxide film vary in the presence of nitric oxide. This effect was utilized to prepare biochemical sensors with transduction based on surface plasmon resonance. Due to the refractive index of the transparent zinc oxide film that was deposited on the gold film, however, changes will be observed in the surface plasmon resonance spectra. For this reason, the thickness of zinc oxide film will be investigated and determined in this study. The interaction of nitric oxide with a 20 nm zinc oxide layer on gold leads to the shift of the resonance angle. The analysis on the reflectance intensity of light demonstrates that such effect is caused by the variation of conductivity and permittivity of zinc oxide film. Finally, a shift in surface plasmon resonance angle was measured in 25 ppm nitric oxide at 180 C and a calibration curve of nitride oxide concentration versus response intensity was successfully obtained in the range of 250 to 1000 ppm nitric oxide at lower temperature of 150 C. Moreover, these effects are quasi-reversible.

  12. β3 Adrenergic Stimulation Restores Nitric Oxide/Redox Balance and Enhances Endothelial Function in Hyperglycemia. (United States)

    Karimi Galougahi, Keyvan; Liu, Chia-Chi; Garcia, Alvaro; Gentile, Carmine; Fry, Natasha A; Hamilton, Elisha J; Hawkins, Clare L; Figtree, Gemma A


    Perturbed balance between NO and O2 (•-). (ie, NO/redox imbalance) is central in the pathobiology of diabetes-induced vascular dysfunction. We examined whether stimulation of β3 adrenergic receptors (β3 ARs), coupled to endothelial nitric oxide synthase (eNOS) activation, would re-establish NO/redox balance, relieve oxidative inhibition of the membrane proteins eNOS and Na(+)-K(+) (NK) pump, and improve vascular function in a new animal model of hyperglycemia. We established hyperglycemia in male White New Zealand rabbits by infusion of S961, a competitive high-affinity peptide inhibitor of the insulin receptor. Hyperglycemia impaired endothelium-dependent vasorelaxation by "uncoupling" of eNOS via glutathionylation (eNOS-GSS) that was dependent on NADPH oxidase activity. Accordingly, NO levels were lower while O2 (•-) levels were higher in hyperglycemic rabbits. Infusion of the β3 AR agonist CL316243 (CL) decreased eNOS-GSS, reduced O2 (•-), restored NO levels, and improved endothelium-dependent relaxation. CL decreased hyperglycemia-induced NADPH oxidase activation as suggested by co-immunoprecipitation experiments, and it increased eNOS co-immunoprecipitation with glutaredoxin-1, which may reflect promotion of eNOS de-glutathionylation by CL. Moreover, CL reversed hyperglycemia-induced glutathionylation of the β1 NK pump subunit that causes NK pump inhibition, and improved K(+)-induced vasorelaxation that reflects enhancement in NK pump activity. Lastly, eNOS-GSS was higher in vessels of diabetic patients and was reduced by CL, suggesting potential significance of the experimental findings in human diabetes. β3 AR activation restored NO/redox balance and improved endothelial function in hyperglycemia. β3 AR agonists may confer protection against diabetes-induced vascular dysfunction. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  13. Effects of nitric oxide-releasing nonsteroidal anti-inflammatory drugs (NONO-NSAIDs) on melanoma cell adhesion

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    Cheng, Huiwen [Edison Biotechnology Institute, Ohio University, Athens, OH 45701 (United States); Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701 (United States); Mollica, Molly Y.; Lee, Shin Hee [Edison Biotechnology Institute, Ohio University, Athens, OH 45701 (United States); Wang, Lei [Edison Biotechnology Institute, Ohio University, Athens, OH 45701 (United States); Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701 (United States); Velázquez-Martínez, Carlos A., E-mail: [Chemistry Section, Laboratory of Comparative Carcinogenesis and Basic Research Program, SAIC-Frederick Inc., National Cancer Institute at Frederick, Frederick, MD 21702 (United States); Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton Alberta, Canada T6G 2N8 (Canada); Wu, Shiyong, E-mail: [Edison Biotechnology Institute, Ohio University, Athens, OH 45701 (United States); Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701 (United States)


    A new class of nitric oxide (NO•)-releasing nonsteroidal anti-inflammatory drugs (NONO-NSAIDs) were developed in recent years and have shown promising potential as NSAID substitutes due to their gentle nature on cardiovascular and gastrointestinal systems. Since nitric oxide plays a role in regulation of cell adhesion, we assessed the potential use of NONO-NSAIDs as anti-metastasis drugs. In this regard, we compared the effects of NONO-aspirin and a novel NONO-naproxen to those exerted by their respective parent NSAIDs on avidities of human melanoma M624 cells. Both NONO-NSAIDs, but not the corresponding parent NSAIDs, reduced M624 adhesion on vascular cellular adhesion molecule-1 (VCAM-1) by 20–30% and fibronectin by 25–44% under fluid flow conditions and static conditions, respectively. Only NONO-naproxen reduced (∼ 56%) the activity of β1 integrin, which binds to α4 integrin to form very late antigen-4 (VLA-4), the ligand of VCAM-1. These results indicate that the diazeniumdiolate (NO•)-donor moiety is critical for reducing the adhesion between VLA-4 and its ligands, while the NSAID moiety can impact the regulation mechanism of melanoma cell adhesion. -- Highlights: ► NONO-naproxen, a novel nitric oxide-releasing NSAID, was synthesized. ► NONO-NSAIDs, but not their parent NSAIDs, reduced melanoma adhesion. ► NONO-naproxen, but not NONO-aspirin and NSAIDs, reduced activity of β1 integrin.

  14. Changes in renal hemodynamics and structure in the aging kidney; sexual dimorphism and the nitric oxide system. (United States)

    Baylis, Chris


    With advancing age the kidney shows both functional declines (falls in GFR) and development of structural damage. In most individuals this occurs slowly and does not lead to severe renal impairment unless additional insults are superimposed. There is a pronounced sexual dimorphism with females protected, due both to beneficial effects of the estrogens and damaging effects of androgens, some of which act directly on the glomerular mesangial cell to regulate growth and extracellular matrix production. Nitric oxide is a major factor in regulation of vascular tone and growth and becomes deficient with advancing age, as endothelial dysfunction develops. Although the abundance of the substrate, L-arginine, is well maintained during aging, there are increases in the concentration of circulating endogenous nitric oxide synthase (nNOS) inhibitors, which will contribute, to the endothelial dysfunction. There is a clear sexual dimorphism in the NO system, with pre-menopausal females producing more NO than men. Within the kidney, declines in the abundance and activity of the neuronal form of the nitric oxide synthase (nNOS) correlate with development of disease. In the male rat where injury and dysfunction occurs, nNOS abundance declines markedly, whereas in the protected female, renal nNOS abundance is maintained. Taken together, it is likely that age-dependent declines in NO generation contribute to age-dependent kidney damage.

  15. Experimental Model of Zymosan-Induced Arthritis in the Rat Temporomandibular Joint: Role of Nitric Oxide and Neutrophils

    Directory of Open Access Journals (Sweden)

    Hellíada Vasconcelos Chaves


    Full Text Available Aims. To establish a new model of zymosan-induced temporomandibular joint (TMJ arthritis in the rat and to investigate the role of nitric oxide. Methods. Inflammation was induced by an intra-articular injection of zymosan into the left TMJ. Mechanical hypernociception, cell influx, vascular permeability, myeloperoxidase activity, nitrite levels, and histological changes were measured in TMJ lavages or tissues at selected time points. These parameters were also evaluated after treatment with the nitric oxide synthase (NOS inhibitors L-NAME or 1400 W. Results. Zymosan-induced TMJ arthritis caused a time-dependent leucocyte migration, plasma extravasation, mechanical hypernociception, and neutrophil accumulation between 4 and 24 h. TMJ immunohistochemical analyses showed increased inducible NOS expression. Treatment with L-NAME or 1400 W inhibited these parameters. Conclusion. Zymosan-induced TMJ arthritis is a reproducible model that may be used to assess both the mechanisms underlying TMJ inflammation and the potential tools for therapies. Nitric oxide may participate in the inflammatory temporomandibular dysfunction mechanisms.

  16. Arginine and nitric oxide synthase: regulatory mechanisms and cardiovascular aspects. (United States)

    Lorin, Julie; Zeller, Marianne; Guilland, Jean-Claude; Cottin, Yves; Vergely, Catherine; Rochette, Luc


    L-Arginine (L-Arg) is a conditionally essential amino acid in the human diet. The most common dietary sources of L-Arg are meat, poultry and fish. L-Arg is the precursor for the synthesis of nitric oxide (NO); a key signaling molecule via NO synthase (NOS). Endogenous NOS inhibitors such as asymmetric-dimethyl-L-Arg inhibit NO synthesis in vivo by competing with L-Arg at the active site of NOS. In addition, NOS possesses the ability to be "uncoupled" to produce superoxide anion instead of NO. Reduced NO bioavailability may play an essential role in cardiovascular pathologies and metabolic diseases. L-Arg deficiency syndromes in humans involve endothelial inflammation and immune dysfunctions. Exogenous administration of L-Arg restores NO bioavailability, but it has not been possible to demonstrate, that L-Arg supplementation improved endothelial function in cardiovascular disease such as heart failure or hypertension. L-Arg supplementation may be a novel therapy for obesity and metabolic syndrome. The utility of l-Arg supplementation in the treatment of L-Arg deficiency syndromes remains to be established. Clinical trials need to continue to determine the optimal concentrations and combinations of L-Arg, with other protective compounds such as tetrahydrobiopterin (BH4 ), and antioxidants to combat oxidative stress that drives down NO production in humans. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Nitric oxide and superoxide: interference with hypoxic signaling. (United States)

    Brüne, Bernhard; Zhou, Jie


    Sensing and responding to changes in oxygen partial pressure assures that the cellular oxygen supply is tightly controlled in order to balance the risks of oxidative damage vs. oxygen deficiency. The hypoxia inducible factor (HIF) regulatory system is controlled by prolyl hydroxylases (PHDs), the von Hippel Lindau protein (pVHL), and the 26S proteasome and transduces changes in oxygenation to adequate intracellular adaptive responses. A functional HIF response requires stabilization of the alpha-subunit, e.g. HIF-1alpha, during hypoxia and dimerization with HIF-1beta, to drive target gene activation. Intriguingly, high concentrations of nitric oxide (NO) stabilize HIF-1alpha and thus mimic a hypoxic response under normoxia. Mechanistically, NO blocks PHD activity and attenuates proline hydroxylation of HIF-1alpha. This causes dissociation of pVHL from HIF-1alpha and, consequently, HIF-1alpha accumulates because proteasomal destruction is impaired. However, during hypoxia low concentrations of NO facilitate destruction of HIF-1alpha and thus reverse HIF signaling. Under these conditions, NO impairs respiration and avoids oxygen gradients that limit PHD activity. An additional layer of complexity comprises the interaction of NO with O(2)(-). Signaling qualities attributed to NO are antagonized by compensatory flux rates of O(2)(-) and vice versa to adjust levels of HIF-1alpha under normoxia and hypoxia. The liaison of NO and hypoxia is versatile and ranges from courting to matrimony and divorce.

  18. Hypoxia tolerance, nitric oxide, and nitrite: lessons from extreme animals. (United States)

    Fago, Angela; Jensen, Frank B


    Among vertebrates able to tolerate periods of oxygen deprivation, the painted and red-eared slider turtles (Chrysemys picta and Trachemys scripta) and the crucian carp (Carassius carassius) are the most extreme and can survive even months of total lack of oxygen during winter. The key to hypoxia survival resides in concerted physiological responses, including strong metabolic depression, protection against oxidative damage and-in air-breathing animals-redistribution of blood flow. Each of these responses is known to be tightly regulated by nitric oxide (NO) and during hypoxia by its metabolite nitrite. The aim of this review is to highlight recent work illustrating the widespread roles of NO and nitrite in the tolerance to extreme oxygen deprivation, in particular in the red-eared slider turtle and crucian carp, but also in diving marine mammals. The emerging picture underscores the importance of NO and nitrite signaling in the adaptive response to hypoxia in vertebrate animals. ©2015 Int. Union Physiol. Sci./Am. Physiol. Soc.

  19. Carvedilol stimulates nitric oxide synthesis in rat cardiac myocytes. (United States)

    Kurosaki, K; Ikeda, U; Maeda, Y; Shimada, K


    The purpose of this study was to investigate the effects of the beta-adrenergic blocker carvedilol on nitric oxide (NO) synthesis in cardiac myocytes. We measured the accumulation of nitrite, a stable oxidation product of NO, and the expression of inducible NO synthase (iNOS) protein in cultured neonatal rat cardiac myocytes. Incubation of the cultures with interleukin 1 beta (IL-1 beta; 10 ng/ml) caused a marked increase in nitrite production. Although carvedilol alone showed no effect on nitrite accumulation, it significantly enhanced IL-1 beta-induced nitrite production by cardiac myocytes. The effect of carvedilol was completely abolished in the presence of aminoguanidine or actinomycin D. The nitrite production enhanced by carvedilol was accompanied by increased iNOS protein expression. Unlike carvedilol, other beta-blockers, namely propranolol, atenolol and arotinolol, did not enhance IL-1 beta-induced nitrite production. Addition of isoproterenol significantly increased nitrite production by IL-1 beta-stimulated cardiac myocytes. Atenolol suppressed this isoproterenol-induced nitrite accumulation, while carvedilol further increased the nitrite accumulation. These findings indicate that carvedilol increases NO synthesis in IL-1 beta-stimulated rat cardiac myocytes by a beta-adrenoceptor-independent mechanism. Copyright 2000 Academic Press.

  20. Two-year neurodevelopmental outcomes of ventilated preterm infants treated with inhaled nitric oxide. (United States)

    Walsh, Michele C; Hibbs, Anna Maria; Martin, Camilia R; Cnaan, Avital; Keller, Roberta L; Vittinghoff, Eric; Martin, Richard J; Truog, William E; Ballard, Philip L; Zadell, Arlene; Wadlinger, Sandra R; Coburn, Christine E; Ballard, Roberta A


    In a randomized multi-center trial, we demonstrated that inhaled nitric oxide begun between 7 and 21 days and given for 24 days significantly increased survival without bronchopulmonary dysplasia (BPD) in ventilated premature infants weighing score <70 on the Bayley Scales II), compared with 114 of 234 (49%) in the placebo group (relative risk, 0.92; 95% CI, 0.75-1.12; P = .39). No differences on any subcomponent of neurodevelopmental impairment or growth variables were found between inhaled nitric oxide or placebo. Inhaled nitric oxide improved survival free of BPD, with no adverse neurodevelopmental effects at 2 years of age. Copyright 2010 Mosby, Inc. All rights reserved.

  1. 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 (United States)

    Davisson, R. L.; Shaffer, R. A.; Johnson, A. K.; Lewis, S. J.


    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.

  2. Protein engineering to develop a redox insensitive endothelial nitric oxide synthase

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    Ruslan Rafikov


    Full Text Available The zinc tetrathiolate (ZnS4 cluster is an important structural feature of endothelial nitric oxide synthase (eNOS. The cluster is located on the dimeric interface and four cysteine residues (C94 and C99 from two adjacent subunits form a cluster with a Zn ion in the center of a tetrahedral configuration. Due to its high sensitivity to oxidants this cluster is responsible for eNOS dimer destabilization during periods of redox stress. In this work we utilized site directed mutagenesis to replace the redox sensitive cysteine residues in the ZnS4 cluster with redox stable tetra-arginines. Our data indicate that this C94R/C99R eNOS mutant is active. In addition, this mutant protein is insensitive to dimer disruption and inhibition when challenged with hydrogen peroxide (H2O2. Further, the overexpression of the C94R/C99R mutant preserved the angiogenic response in endothelial cells challenged with H2O2. The over-expression of the C94R/C99R mutant preserved the ability of endothelial cells to migrate towards vascular endothelial growth factor (VEGF and preserved the endothelial monolayer in a scratch wound assay. We propose that this dimer stable eNOS mutant could be utilized in the treatment of diseases in which there is eNOS dysfunction due to high levels of oxidative stress.

  3. Nitric oxide, cytochrome C oxidase, and the cellular response to hypoxia. (United States)

    Taylor, Cormac T; Moncada, Salvador


    Cytochrome c oxidase (CcO; complex IV of the mitochondrial electron transport chain) is the primary site of cellular oxygen consumption and, as such, is central to oxidative phosphorylation and the generation of adenosine-triphosphate. Nitric oxide (NO), an endogenously-generated gas, modulates the activity of CcO. Depending on the intracellular oxygen concentration and the resultant dominant redox state of CcO, the interaction between CcO and NO can have a range of signaling consequences for cells in the perception of changes in oxygen concentration and the initiation of adaptive responses. At higher oxygen concentrations, when CcO is predominantly in an oxidized state, it consumes NO. At lower oxygen concentrations, when CcO is predominantly reduced, NO is not consumed and accumulates in the microenvironment, with implications for both the respiratory rate of cells and the local vascular tone. Changes in the availability of intracellular oxygen and in the generation of reactive oxygen species that accompany these interactions result in cell signaling and in regulation of oxygen-sensitive pathways that ultimately determine the nature of the cellular response to hypoxia.

  4. Oxidant stress from nitric oxide synthase–3 uncoupling stimulates cardiac pathologic remodeling from chronic pressure load


    Takimoto, Eiki; Champion, Hunter C.; Li, Manxiang; Ren, Shuxun; Rodriguez, E. Rene; Tavazzi, Barbara; Lazzarino, Giuseppe; Paolocci, Nazareno; Gabrielson, Kathleen L.; Wang, Yibin; Kass, David A.


    Cardiac pressure load stimulates hypertrophy, often leading to chamber dilation and dysfunction. ROS contribute to this process. Here we show that uncoupling of nitric oxide synthase–3 (NOS3) plays a major role in pressure load–induced myocardial ROS and consequent chamber remodeling/hypertrophy. Chronic transverse aortic constriction (TAC; for 3 and 9 weeks) in control mice induced marked cardiac hypertrophy, dilation, and dysfunction. Mice lacking NOS3 displayed modest and concentric hypert...

  5. Transnitrosylation: A Factor in Nitric Oxide-Mediated Penile Erection (United States)

    Goetz, Tabitha; La Favor, Justin D.; Burnett, Arthur L.


    Introduction Nitric oxide (NO) signaling can be mediated not only through classical cGMP, but also through S-nitrosylation. The impact of S-nitrosylation on erectile function and in NO regulation and oxidative stress in the penis, however, remains poorly understood. Aims To characterize the role of GSNOR, a major regulator of S-nitrosylation homeostasis, on erection physiology and on eNOS function and oxidative/nitrosative stress in the penis. Materials and Methods Adult GSNOR-deficient and WT mice were used. Erectile function was assessed in response to electrical stimulation of the cavernous nerve. Total NO in penile homogenates was measured by Griess reaction. Protein S-nitrosylation, endothelial NO synthase (eNOS) phosphorylation on Ser-1177 (positive regulatory site), eNOS uncoupling, and markers of oxidative stress (4-hydroxy-2-nonenal [4-HNE], malondialdehyde, and nitrotyrosine) in the penis were measured by Western blot. Main outcome measures Erectile function, eNOS function and oxidative stress in the penis of GSNOR-deficient mice. Results Erectile function was intact in GSNOR-deficient mice. Total S-nitrosylated proteins were increased (p<0.05) in the GSNOR−/− compared to WT mouse penis. While eNOS phosphorylation on Ser-1177 did not differ between the GSNOR−/− and WT mouse penis at baseline, electrical stimulation of the cavernous nerve increased (p<0.05) P-eNOS in the WT mouse penis, but failed to increase P-eNOS in the GSNOR−/− mouse penis. Total NO production was decreased (p<0.05), while eNOS uncoupling, 4-HNE, malondialdehyde, and nitrotyrosine were increased (p<0.05) in the GSNOR-deficient mouse penis compared to that of WT mice. Conclusion Transnitrosylation mechanisms play an important role in regulating NO bioactivity in the penis. Deficiency of GSNOR leads to eNOS dysfunction and increased oxidative damage, suggesting that homeostatic eNOS function in the penis is governed by transnitrosylation. PMID:27114194

  6. Nitrite regulates hypoxic vasodilation via myoglobin-dependent nitric oxide generation. (United States)

    Totzeck, Matthias; Hendgen-Cotta, Ulrike B; Luedike, Peter; Berenbrink, Michael; Klare, Johann P; Steinhoff, Heinz-Juergen; Semmler, Dominik; Shiva, Sruti; Williams, Daryl; Kipar, Anja; Gladwin, Mark T; Schrader, Juergen; Kelm, Malte; Cossins, Andrew R; Rassaf, Tienush


    Hypoxic vasodilation is a physiological response to low oxygen tension that increases blood supply to match metabolic demands. Although this response has been characterized for >100 years, the underlying hypoxic sensing and effector signaling mechanisms remain uncertain. We have shown that deoxygenated myoglobin in the heart can reduce nitrite to nitric oxide (NO·) and thereby contribute to cardiomyocyte NO· signaling during ischemia. On the basis of recent observations that myoglobin is expressed in the vasculature of hypoxia-tolerant fish, we hypothesized that endogenous nitrite may contribute to physiological hypoxic vasodilation via reactions with vascular myoglobin to form NO·. We show in the present study that myoglobin is expressed in vascular smooth muscle and contributes significantly to nitrite-dependent hypoxic vasodilation in vivo and ex vivo. The generation of NO· from nitrite reduction by deoxygenated myoglobin activates canonical soluble guanylate cyclase/cGMP signaling pathways. In vivo and ex vivo vasodilation responses, the reduction of nitrite to NO·, and the subsequent signal transduction mechanisms were all significantly impaired in mice without myoglobin. Hypoxic vasodilation studies in myoglobin and endothelial and inducible NO synthase knockout models suggest that only myoglobin contributes to systemic hypoxic vasodilatory responses in mice. Endogenous nitrite is a physiological effector of hypoxic vasodilation. Its reduction to NO· via the heme globin myoglobin enhances blood flow and matches O(2) supply to increased metabolic demands under hypoxic conditions.

  7. Acute dairy milk ingestion does not improve nitric oxide-dependent vasodilation in the cutaneous microcirculation. (United States)

    Alba, Billie K; Stanhewicz, Anna E; Kenney, W Larry; Alexander, Lacy M


    In epidemiological studies, chronic dairy milk consumption is associated with improved vascular health and reduced age-related increases in blood pressure. Although milk protein supplementation augments conduit artery flow-mediated dilation, whether or not acute dairy milk intake may improve microvascular function remains unclear. We hypothesised that dairy milk would increase direct measurement of endothelial nitric oxide (NO)-dependent cutaneous vasodilation in response to local skin heating. Eleven men and women (61 (sem 2) years) ingested two or four servings (473 and 946 ml) of 1 % dairy milk or a rice beverage on each of 4 separate study days. In a subset of five subjects, an additional protocol was completed after 473 ml of water ingestion. Once a stable blood flow occurred, 15 mm-N G -nitro-l-arginine methyl ester was perfused (intradermal microdialysis) to quantify NO-dependent vasodilation. Red-blood-cell flux (RBF) was measured by laser-Doppler flowmetry, and cutaneous vascular conductance (CVC=RBF/mean arterial pressure) was calculated and normalised to maximum (%CVCmax; 28 mm-sodium nitroprusside). Full expression of cutaneous vasodilation was not different among dairy milk, rice beverage and water, and there was no effect of serving size on the total vasodilatory response. Contrary to our hypothesis, NO-dependent vasodilation was lower for dairy milk than rice beverage (D: 49 (sem 5), R: 55 (sem 5) %CVCmax; Price beverage control.

  8. Bixa orellana leaves extract inhibits bradykinin-induced inflammation through suppression of nitric oxide production. (United States)

    Yoke Keong, Y; Arifah, A K; Sukardi, S; Roslida, A H; Somchit, M N; Zuraini, A


    The present study was conducted to assess the anti-inflammatory effect of a crude aqueous extract of Bixa orellana leaves (AEBO) and to examine the possible involvement of nitric oxide (NO) in its anti-inflammatory mechanism. The air-dried, powdered leaves were soaked in distilled water (1:20 w/v) at 50°C for 24 h and the supernatant obtained was freeze-dried (yield 8.5% w/w). The dosage was recorded as the mass of extract per kg b.w. of rats in all inflammatory assays (bradykinin-induced paw edema, peritoneal vascular permeability and NO assay). Pretreatment with AEBO for 4 consecutive days exhibited significant inhibitory activity against inflammatory models, the bradykinin-induced hind paw edema model and bradykinin-induced increased peritoneal vascular permeability at both doses in dose-dependent manner. In addition, AEBO was also found to significantly suppress the production of NO at doses of 50 and 150 mg/kg. This study provides scientific data to support the traditional use of B. orellana leaves in treating inflammation. Results from this study suggest that AEBO exerts anti-inflammatory effects. Part of this anti-inflammatory effect may be associated with its antibradykinin activity and may be related to a reduction of the NO production. Copyright © 2011 S. Karger AG, Basel.

  9. Short-term exercise training enhances functional sympatholysis through a nitric oxide-dependent mechanism (United States)

    Jendzjowsky, Nicholas G; DeLorey, Darren S


    We tested the hypothesis that short-term mild- (M) and heavy-intensity (H) exercise training would enhance sympatholysis through a nitric oxide (NO)-dependent mechanism. Sprague–Dawley rats (n = 36) were randomly assigned to sedentary (S) or to M (20 m min−1 5% gradient) or H exercise training groups (40 m min−1 5% gradient). Rats assigned to M and H groups trained on 5 days week−1 for 4 weeks, with the volume of training being matched between groups. Rats were anaesthetized and instrumented for stimulation of the lumbar sympathetic chain and the measurement of arterial blood pressure and femoral artery blood flow. The triceps surae muscle group was stimulated to contract rhythmically at 30 and 60% of maximal contractile force (MCF). The percentage change of femoral vascular conductance (%FVC) in response to sympathetic stimulation delivered at 2 and 5 Hz was determined at rest and during contraction at 30 and 60% MCF. The vascular response to sympathetic stimulation was reduced as a function of MCF in all rats (P training augments sympatholysis in a training-intensity-dependent manner and through an NO-dependent mechanism. PMID:23297301

  10. Beyond the inhaled nitric oxide in persistent pulmonary hypertension of the newborn

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    Mei-Yin Lai


    Full Text Available Persistent pulmonary hypertension (PPHN is a consequence of failed pulmonary vascular transition at birth and leads to pulmonary hypertension with shunting of deoxygenated blood across the ductus arteriosus (DA and foramen ovale (FO resulting in severe hypoxemia, and it may eventually lead to life-threatening circulatory failure. PPHN is a serious event affecting both term and preterm infants in the neonatal intensive care unit. It is often associated with diseases such as congenital diaphragmatic hernia, meconium aspiration, sepsis, congenital pneumonia, birth asphyxia and respiratory distress syndrome. The diagnosis of PPHN should include echocardiographic evidence of increased pulmonary pressure, with demonstrable right-to-left shunt across the DA or FO, and the absence of cyanotic heart diseases. The mainstay therapy of PPHN includes treatment of underlying causes, maintenance of adequate systemic blood pressure, optimized ventilator support for lung recruitment and alveolar ventilation, and pharmacologic measures to increase pulmonary vasodilation and decrease pulmonary vascular resistance. Inhaled nitric oxide has been proved to treat PPHN successfully with improved oxygenation in 60–70% of patients and to significantly reduce the need for extracorporeal membrane oxygenation (ECMO. About 14%–46% of the survivors develop long-term impairments such as hearing deficits, chronic lung disease, cerebral palsy and other neurodevelopmental disabilities.

  11. Inhaled nitric oxide partially reverses hypoxic pulmonary vasoconstriction in the dog

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    Romand, J.A.; Pinsky, M.R.; Firestone, L.; Zar, H.A.; Lancaster, J.R. Jr. (Univ. of Pittsburgh, PA (United States))


    Nitric oxide (NO) inhaled during a hypoxia-induced increase in pulmonary vasomotor tone decreases pulmonary arterial pressure (Ppa). The authors conducted this study to better characterize the hemodynamic effects induced by NO inhalation during hypoxic pulmonary vasoconstriction in 11 anesthetized ventilated dogs. Arterial and venous systematic and pulmonary pressures and aortic flow probe-derived cardiac output were recorded, and nitrosylhemoglobin (NO-Hb) and methemoglobin (MetHb) were measured. The effects of 5 min of NO inhalation at 0, 17, 28, 47, and 0 ppm during hyperoxia (inspiratory fracture of O[sub 2] = 0.5) and hypoxia (inspiratory fraction of O[sub 2] = 0.16) were observed. NO inhalation has no measurable effects during hyperoxia. Hypoxia induced an increase in Ppa that reached plateau levels after 5 min. Exposure to 28 and 47 ppm NO induced an immediate (<30 s) decrease in Ppa and calculated pulmonary vascular resistance (P < 0.05 each) but did not return either to baseline hyperoxic values. Increasing the concentration of NO to 74 and 145 ppm further decreased Ppa and pulmonary vascular resistance to baseline values. NO inhalation did not induce decreases in systematic arterial pressure. MetHb remained low, and NO-Hb was ummeasurable. The authors concluded that NO inhalation only partially reversed hypoxia-induced increases in pulmonary vasomotor tone in this canine model. These effects are immediate and selective to the pulmonary circulation. 26 refs., 3 figs., 2 tabs.

  12. Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

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    Xue-ying Chang


    Full Text Available Background. This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. Methods. 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d, 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS/p38 mitogen activated protein kinase (p38MAPK pathway was determined to explore the potential mechanism. Results. Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA and creatinine levels, malonaldehyde (MDA content, and superoxide dismutase (SOD activity in serum and the increases of calcium and alkaline phosphatase (ALP activity in the aorta (P<0.05 and attenuated calcification and calcium accumulation in the medial layer of vasculature in histopathology. Western blot analysis showed that iNOS/p38MAPK pathway was normalized by the quercetin supplementation. Conclusions. Quercetin exerted a protective effect on vascular calcification in adenine-induced chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

  13. The Possible Role of Nitric Oxide and Oxidative Stress in the Enhanced Apoptosis of Cardiac Cells in Cirrhotic Rats

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    Hamed Shafaroodi


    Full Text Available  Cirrhosis has been related with hyperdynamic circulation, manifesting as increased cardiac output and decreased systemic vascular resistance. In the present study we examined the cirrhosis outcome on apoptosis of rat hearts. We also tried to explore the role of nitric oxide (NO and oxidative stress in the probable changed apoptosis of cirrhotic hearts. Twenty eight days after ligation of bile duct, heart tissues were tested for apoptosis. The extent of malondialdehyde (MDA, and the activities of catalase (CAT, glutathione peroxidase (GSHPx and superoxide dismutase (SOD have been calculated in heart tissues. The cirrhotic hearts exhibited structural defects and greater apoptosis. Chronic treatment of cirrhotic rats with L-NAME, a non-selective inhibitor of NO synthase, inhibited heart structural defects and reduced apoptosis of hearts. We also showed that cirrhotic rat hearts had an enhanced level of MDA and reduced activities of CAT, GSHPx and SOD. When the animals were treated by L-NAME chronically, the MDA level reduced and activities of CAT, GSHPx and SOD augmented in cirrhotic heart. In conclusion, increased apoptosis of cirrhotic hearts probably happen due to NO overproduction and increased oxidative stress in hearts of cirrhotic rats.

  14. The Possible Role of Nitric Oxide and Oxidative Stress in the Enhanced Apoptosis of Cardiac Cells in Cirrhotic Rats. (United States)

    Shafaroodi, Hamed; Hashemi, Mehrdad; Sharif, Zahra Nadia; Moezi, Leila; Janahmadi, Zeinab; Dehpour, Ahmad Reza


     Cirrhosis has been related with hyperdynamic circulation, manifesting as increased cardiac output and decreased systemic vascular resistance. In the present study we examined the cirrhosis outcome on apoptosis of rat hearts. We also tried to explore the role of nitric oxide (NO) and oxidative stress in the probable changed apoptosis of cirrhotic hearts. Twenty eight days after ligation of bile duct, heart tissues were tested for apoptosis. The extent of malondialdehyde (MDA), and the activities of catalase (CAT), glutathione peroxidase (GSHPx) and superoxide dismutase (SOD) have been calculated in heart tissues. The cirrhotic hearts exhibited structural defects and greater apoptosis. Chronic treatment of cirrhotic rats with L-NAME, a non-selective inhibitor of NO synthase, inhibited heart structural defects and reduced apoptosis of hearts. We also showed that cirrhotic rat hearts had an enhanced level of MDA and reduced activities of CAT, GSHPx and SOD. When the animals were treated by L-NAME chronically, the MDA level reduced and activities of CAT, GSHPx and SOD augmented in cirrhotic heart. In conclusion, increased apoptosis of cirrhotic hearts probably happen due to NO overproduction and increased oxidative stress in hearts of cirrhotic rats.

  15. Modeling toxic compounds from nitric oxide emission measurements (United States)

    Vallero, Daniel A.; Peirce, Jeffrey; Cho, Ki Don

    Determining the amount and rate of degradation of toxic pollutants in soil and groundwater is difficult and often requires invasive techniques, such as deploying extensive monitoring well networks. Even with these networks, degradation rates across entire systems cannot readily be extrapolated from the samples. When organic compounds are degraded by microbes, especially nitrifying bacteria, oxides or nitrogen (NO x) are released to the atmosphere. Thus, the flux of nitric oxide (NO) from the soil to the lower troposphere can be used to predict the rate at which organic compounds are degraded. By characterizing and applying biogenic and anthropogenic processes in soils the rates of degradation of organic compounds. Toluene was selected as a representative of toxic aromatic compounds, since it is inherently toxic, it is a substituted benzene compound and is listed as a hazardous air pollutant under Section 12 of the Clean Air Act Amendments of 1990. Measured toluene concentrations in soil, microbial population growth and NO fluxes in chamber studies were used to develop and parameterize a numerical model based on carbon and nitrogen cycling. These measurements, in turn, were used as indicators of bioremediation of air toxic (i.e. toluene) concentrations. The model found that chemical concentration, soil microbial abundance, and NO production can be directly related to the experimental results (significant at P contaminants in a complex soil system. It may also be useful in predicting the release of ozone precursors, such as changes in reservoirs of hydrocarbons and oxides of nitrogen. As such, the model may be a tool for decision makers in ozone non-attainment areas.

  16. Role and regulation of autophagy and apoptosis by nitric oxide in hepatic stellate cells during acute liver failure. (United States)

    Jin, Li; Gao, Heng; Wang, JiuPing; Yang, ShuJuan; Wang, Jing; Liu, JingFeng; Yang, Yuan; Yan, TaoTao; Chen, Tianyan; Zhao, Yingren; He, Yingli


    We previously found that hepatic stellate cell activation induced by autophagy maintains the liver architecture to prevent collapse during acute liver failure. Nitric oxide has shown to induce hepatic stellate cell apoptosis. Whether and how nitric oxide is involved in acute liver failure and autophagy remains unclear. Acute liver failure patients were recruited to investigate the correlation between plasma nitric oxide levels and clinical features. Liver tissues were collected from chronic hepatitis patients by biopsy and from acute liver failure patients who had undergone liver transplantation. The expression of nitric oxide synthases and hepatic stellate cell activation (alpha-SMA), and autophagic activity (LC3) were investigated by immunohistochemistry. Autophagy and apoptosis were investigated by immunoblot analysis, confocal microscopy, and flow cytometry in hepatic stellate cells treated with nitric oxide donors. Plasma nitric oxide level was significantly increased in patients with acute liver failure compared to those with cirrhosis (53.60±19.74 μM vs 19.40±9.03 μM, Z=-7.384, Pfailure. At least some Nitric oxide was produced by overexpression of inducible nitric oxide synthases and endothelial nitric oxide synthases, but not neuronal nitric oxide synthases in the liver tissue. In vivo observation revealed that autophagy was inhibited in hepatic stellate cells based on decreased LC3 immunostaining, and in vitro experiments demonstrated that Nitric oxide can inhibit autophagy. Moreover, nitric oxide promoted hepatic stellate cell apoptosis, which was rescued by an autophagy inducer. Increased nitric oxide synthases/ nitric oxide promotes apoptosis through autophagy inhibition in hepatic stellate cells during acute liver failure, providing a novel strategy for the treatment of patients with acute liver failure. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Nitric oxide-cytokinin interplay influences selenite sensitivity in Arabidopsis. (United States)

    Lehotai, Nóra; Feigl, Gábor; Koós, Ágnes; Molnár, Árpád; Ördög, Attila; Pető, Andrea; Erdei, László; Kolbert, Zsuzsanna


    Selenite oppositely modifies cytokinin and nitric oxide metabolism in Arabidopsis organs. A mutually negative interplay between the molecules exists in selenite-exposed roots; and their overproduction causes selenite insensitivity. Selenium-induced phytotoxicity is accompanied by developmental alterations such as primary root (PR) shortening. Growth changes are provoked by the modulation of hormone status and signalling. Cytokinin (CK) cooperates with the nitric oxide (NO) in many aspects of plant development; however, their interaction under abiotic stress has not been examined. Selenite inhibited the growth of Arabidopsis seedlings and reduced root meristem size through cell division arrest. The CK-dependent pARR5::GUS activity revealed the intensification of CK signalling in the PR tip, which may be partly responsible for the root meristem shortening. The selenite-induced alterations in the in situ expressions of cytokinin oxidases (AtCKX4::GUS, AtCKX5::GUS) are associated with selenite-triggered changes of CK signalling. In wild-type (WT) and NO-deficient nia1nia2 root, selenite led to the diminution of NO content, but CK overproducer ipt-161 and -deficient 35S:CKX2 roots did not show NO decrease. Exogenous NO (S-nitroso-N-acetyl-DL-penicillamine, SNAP) reduced the pARR5::GFP and pTCS::GFP expressions. Roots of the 35S:CKX and cyr1 plants suffered more severe selenite-triggered viability loss than the WT, while in ipt-161 and gsnor1-3 no obvious viability decrease was observed. Exogenous NO ameliorated viability loss, but benzyladenine intensified it. Based on the results, selenite impacts development by oppositely modifying CK signalling and NO level. In the root system, CK signalling intensifies which possibly contributes to the nitrate reductase-independent NO diminution. A mutually negative CK-NO interplay exists in selenite-exposed roots; however, overproduction of both molecules worsens selenite sensing. Hereby, we suggest novel regulatory interplay and

  18. Exploring second coordination sphere effects in nitric oxide synthase. (United States)

    McQuarters, Ashley B; Speelman, Amy L; Chen, Li; Elmore, Bradley O; Fan, Weihong; Feng, Changjian; Lehnert, Nicolai


    Second coordination sphere (SCS) effects in proteins are modulated by active site residues and include hydrogen bonding, electrostatic/dipole interactions, steric interactions, and π-stacking of aromatic residues. In Cyt P450s, extended H-bonding networks are located around the proximal cysteinate ligand of the heme, referred to as the 'Cys pocket'. These hydrogen bonding networks are generally believed to regulate the Fe-S interaction. Previous work identified the S(Cys) → Fe σ CT transition in the high-spin (hs) ferric form of Cyt P450cam and corresponding Cys pocket mutants by low-temperature (LT) MCD spectroscopy [Biochemistry 50:1053, 2011]. In this work, we have investigated the effect of the hydrogen bond from W409 to the axial Cys ligand of the heme in the hs ferric state (with H4B and L-Arg bound) of rat neuronal nitric oxide synthase oxygenase construct (nNOSoxy) using MCD spectroscopy. For this purpose, wt enzyme and W409 mutants were investigated where the H-bonding network with the axial Cys ligand is perturbed. Overall, the results are similar to Cyt P450cam and show the intense S(Cys) → Fe σ CT band in the LT MCD spectrum at about 27,800 cm-1, indicating that this feature is a hallmark of {heme-thiolate} active sites. The discovery of this MCD feature could constitute a new approach to classify {heme-thiolate} sites in hs ferric proteins. Finally, the W409 mutants show that the hydrogen bond from this group only has a small effect on the Fe-S(Cys) bond strength, at least in the hs ferric form of the protein studied here. Low-temperature MCD spectroscopy is used to investigate the effect of the hydrogen bond from W409 to the axial Cys ligand of the heme in neuronal nitric oxide synthase. The intense S(Cys) → Fe σ-CT band is monitored to identify changes in the Fe-S(Cys) bond in wild-type protein and W409 mutants.

  19. The red-vine-leaf extract AS195 increases nitric oxide synthase-dependent nitric oxide generation and decreases oxidative stress in endothelial and red blood cells. (United States)

    Grau, Marijke; Bölck, Birgit; Bizjak, Daniel Alexander; Stabenow, Christina Julia Annika; Bloch, Wilhelm


    The red-vine-leaf extract AS195 improves cutaneous oxygen supply and the microcirculation in patients suffering from chronic venous insufficiency. Regulation of blood flow was associated to nitric oxide synthase (NOS)-dependent NO (nitric oxide) production, and endothelial and red blood cells (RBC) have been shown to possess respective NOS isoforms. It was hypothesized that AS195 positively affects NOS activation in human umbilical vein endothelial cells (HUVECs) and RBC. Because patients with microvascular disorders show increased oxidative stress which limits NO bioavailability, it was further hypothesized that AS195 increases NO bioavailability by decreasing the content of reactive oxygen species (ROS) and increasing antioxidant capacity. Cultured HUVECs and RBCs from healthy volunteers were incubated with AS195 (100 μmol/L), tert-butylhydroperoxide (TBHP, 1 mmol/L) to induce oxidative stress and with both AS195 and TBHP. Endothelial and red blood cell-nitric oxide synthase (RBC-NOS) activation significantly increased after AS195 incubation. Nitrite concentration, a marker for NO production, increased in HUVEC but decreased in RBC after AS195 application possibly due to nitrite scavenging potential of flavonoids. S-nitrosylation of RBC cytoskeletal spectrins and RBC deformability were increased after AS195 incubation. TBHP-induced ROS were decreased by AS195, and antioxidative capacity was significantly increased in AS195-treated cells. TBHP also reduced RBC deformability, but reduction was attenuated by parallel incubation with AS195. Adhesion of HUVEC was also reduced after AS195 treatment. Red-vine-leaf extract AS195 increases NOS activation and decreases oxidative stress. Both mechanisms increase NO bioavailability, improve cell function, and may thus account for enhanced microcirculation in both health and disease.

  20. Detection of nitric oxide release from single neurons in the pond snail, Lymnaea stagnalis. (United States)

    Patel, Bhavik Anil; Arundell, Martin; Parker, Kim H; Yeoman, Mark S; O'Hare, Danny


    Multiple film-coated nitric oxide sensors have been fabricated using Nafion and electropolymerized polyeugenol or o-phenylenediamine on 30-microm carbon fiber disk electrodes. This is a rare study that utilizes disk electrodes rather than the widely used protruding tip microelectrodes in order to measure from a biological environment. These electrodes have been used to evaluate the differences in nitric oxide release between two different identified neurons in the pond snail, Lymnaea stagnalis. These results show the first direct measurements of nitric oxide release from individual neurons. The electrodes are very sensitive to nitric oxide with a detection limit of 2.8 nM and a sensitivity of 9.46 nA microM-1. The sensor was very selective against a variety of neurochemical interferences such as ascorbic acid, uric acid, and catecholamines and secondary oxidation products such as nitrite. Nitric oxide release was measured from the cell bodies of two neurons, the cerebral giant cell (CGC) and the B2 buccal motor neuron, in the intact but isolated CNS. A high-Ca2+/high-K+ stimulus was capable of evoking reproducible release. For a given stimulus, the B2 neuron released more nitric oxide than the CGC neuron; however, both cells were equally suppressed by the NOS inhibitor l-NAME.

  1. Dobesilate enhances endothelial nitric oxide synthase-activity in macro- and microvascular endothelial cells. (United States)

    Suschek, C; Kolb, H; Kolb-Bachofen, V


    1. Dobesilate is used for normalizing vascular dysfunction in a number of diseases. In search for an effect on endothelial NO production, macrovascular endothelial cells from rat aorta, microvascular endothelial cells from rat exocrine pancreatic tissue, and capillary endothelial cells from rat islets, were cultured in the presence or absence of Mg-Dobesilate. The activity of constitutive nitric oxide synthase (ecNOS) in resident cells as well as of inducible nitric oxide synthase (iNOS) in cytokine-activated cells was measured indirectly by recording the citrulline concentrations in culture supernatants. 2. In each of the different endothelial cells Mg-Dobesilate incubation (0.25-1 mM) for 24 h led to a significant and concentration-dependent increase in ecNOS-activities. With cytokine-activated endothelial cell cultures only moderate effects were seen with little or no concentration-dependency. Addition of the NOS-inhibitor N(G)-monomethyl-L-arginine led to a significant suppression of citrulline formation in all cultures as an evidence for the enzyme specificity of these effects. 3. iNOS- and ecNOS-specific reverse transcription and semi-quantitative polymerase chain reaction (RT-PCR) with RNA from resident or cytokine-activated endothelial cells gave no evidence for an increase in NOS-specific mRNA after Mg-Dobesilate-treatment. Furthermore, Dobesilate-mediated enhancement of NO synthesis in resting endothelial cells was not due to iNOS induction in these cells, as no iNOS-specific signal was found by RT-PCR.

  2. Nitric oxide-driven hypoxia initiates synovial angiogenesis, hyperplasia and inflammatory lesions in mice.

    Directory of Open Access Journals (Sweden)

    Fei Bao

    Full Text Available Rheumatoid arthritis (RA is an inflammatory articular disease with cartilage and bone damage due to hyperplasic synoviocyte invasion and subsequent matrix protease digestion. Although monoclonal antibodies against tumor necrosis factor alpha (TNFα have been approved for clinical use in patients with RA, desired therapeutic regimens suitable for non-responders are still unavailable because etiological initiators leading to RA remain enigmatic and unidentified.Bacteria-induced arthritis (BIA that simulates collagen-induced arthritis (CIA is developed in mice upon daily live bacterial feeding. The morphological lesions of paw erythema and edema together with the histological alterations of synovial hyperplasia and lymphocytic infiltration emerge as the early-phase manifestations of BIA and CIA. Bacteria- or collagen-mediated global upregulation of pro-inflammatory cytokines is accompanied by the burst of nitric oxide (NO. Elevation of the serum NO level is correlated with decline of the blood oxygen saturation percentage (SpO2, reflecting a hypoxic consequence during development towards arthritis. NO-driven hypoxia is further evident from a positive relationship between NO and lactic acid (LA, an end product from glycolysis. Upregulation of hypoxia inducible factor 1 alpha (HIF-1α and vascular endothelial growth factor (VEGF validates hypoxia-induced angiogenesis in the inflamed synovium of modeling mice. Administration of the NO donor compound sodium nitroprusside (SNP causes articular inflammation by inducing synovial hypoxia. Anti-bacteria by the antibiotic cefotaxime and/or the immunosuppressant rapamycin or artesunate that also inhibits nitric oxide synthase (NOS can abrogate NO production, mitigate hypoxia, and considerably ameliorate or even completely abort synovitis, hence highlighting that NO may serve as an initiator of inflammatory arthritis.Like collagen, bacteria also enable synovial lesions via upregulating pro

  3. Asymmetric Dimethylarginine Limits the Efficacy of Simvastatin Activating Endothelial Nitric Oxide Synthase. (United States)

    Hsu, Chiao-Po; Zhao, Jin-Feng; Lin, Shing-Jong; Shyue, Song-Kun; Guo, Bei-Chia; Lu, Tse-Min; Lee, Tzong-Shyuan


    Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase (eNOS), is considered a risk factor for the pathogenesis of cardiovascular diseases. Simvastatin, a lipid-lowering drug with other pleiotropic effects, has been widely used for treatment of cardiovascular diseases. However, little is known about the effect and underlying molecular mechanisms of ADMA on the effectiveness of simvastatin in the vascular system. We conducted a prospective cohort study to enroll 648 consecutive patients with coronary artery disease for a follow-up period of 8 years. In patients with plasma ADMA level ≥0.49 μmol/L (a cut-off value from receiver operating characteristic curve), statin treatment had no significant effect on cardiovascular events. We also conducted randomized, controlled studies using in vitro and in vivo models. In endothelial cells, treatment with ADMA (≥0.5 μmol/L) impaired simvastatin-induced nitric oxide (NO) production, endothelial NO synthase (eNOS) phosphorylation, and angiogenesis. In parallel, ADMA markedly increased the activity of NADPH oxidase (NOX) and production of reactive oxygen species (ROS). The detrimental effects of ADMA on simvastatin-induced NO production and angiogenesis were abolished by the antioxidant, N-acetylcysteine, NOX inhibitor, or apocynin or overexpression of dimethylarginine dimethylaminohydrolase 2 (DDAH-2). Moreover, in vivo, ADMA administration reduced Matrigel plug angiogenesis in wild-type mice and decreased simvastatin-induced eNOS phosphorylation in aortas of apolipoprotein E-deficient mice, but not endothelial DDAH-2-overexpressed aortas. We conclude that ADMA may trigger NOX-ROS signaling, which leads to restricting the simvastatin-conferred protection of eNOS activation, NO production, and angiogenesis as well as the clinical outcome of cardiovascular events. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  4. Evaluation of endogenous nitric oxide synthesis in congenital urea cycle enzyme defects. (United States)

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


    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

  5. The Validity of Exhaled Nitric Oxide (NO) in Breath Condensate in ...

    African Journals Online (AJOL)

    The Validity of Exhaled Nitric Oxide (NO) in Breath Condensate in the Evaluation of Controlled Asthma. Ahmed Elsayed Elhefny, Sahar Mohammad Mourad, Tamer Saeed Morsy, Maher Abdelnbi Kamel, Haydi Moustafa Mohamed ...

  6. Nitric Oxide Plasma Sources for Bio-Decontamination and Plasma Therapy (United States)

    Vasilets, Victor N.; Shekhter, Anatoly B.

    One of the main products generated in atmospheric plasma sources is nitric oxide. The nitric oxide molecule is known as anti-bacterial agent on one hand and the molecule providing signaling and regulation biological functions on the other hand. Human body produces NO to kill invading pathogens. At the same time nitric oxide works as a primary vasoregulator and anti-hypertensive agent. NO also ­regulates: inflammation, collagen production, angiogenesis and apoptosis. Exogenous NO generated by plasma devices could enhance bio-activity of NO-assisted ­processes in human organism. Some applications of nitric oxide for bio-decontamination and plasma therapy will be illustrated and discussed in the paper.

  7. LBA-ECO ND-07 Nitric Oxide Flux from Cerrado Soils, Brasilia, Brazil: 2004 (United States)

    National Aeronautics and Space Administration — This data set reports the results of soil nitric oxide (NO) flux, soil moisture, and soil nitrate (NO3) and ammonium (NH4) concentration measurements on Cerrado...

  8. LBA-ECO ND-07 Nitric Oxide Flux from Cerrado Soils, Brasilia, Brazil: 2004 (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports the results of soil nitric oxide (NO) flux, soil moisture, and soil nitrate (NO3) and ammonium (NH4) concentration measurements on...

  9. Inhaled Nitric Oxide Therapy for Pulmonary Disorders of the Term and Preterm Infant (United States)

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


    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

  10. Arginase-Negative Mutants of Arabidopsis Exhibit Increased Nitric Oxide Signaling in Root Development

    National Research Council Canada - National Science Library

    Teresita Flores; Christopher D. Todd; Alejandro Tovar-Mendez; Preetinder K. Dhanoa; Natalia Correa-Aragunde; Mary Elizabeth Hoyos; Disa M. Brownfield; Robert T. Mullen; Lorenzo Lamattina; Joe C. Polacco


    ...) seedlings and increased nitric oxide (NO) accumulation and efflux, detected by the fluorogenic traps 3-amino,4-aminomethyl-2',7'-difluorofluorescein diacetate and diamino-rhodamine-4M, respectively...

  11. Absorption of nitric oxide into aqueous solutions of ferrous chelates accompanied by instantaneous reaction

    NARCIS (Netherlands)

    Demmink, J.F; vanGils, I.C.F.; Beenackers, A.A C M


    The absorption of nitric oxide (NO) into aqueous solutions of ferrous chelates of nitrilotriacetic acid (NTA), ethylene diaminetetraacetic acid (EDTA), hydroxyethylenediaminetriacetic acid (HEDTA), and diethylenetriaminepentaacetic acid (DTPA) was studied in a stirred cell reactor. Experimental

  12. Nitric oxide mediates insect cellular immunity via phospholipase A2 activation (United States)

    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...

  13. Nitric oxide metabolites during anoxia and reoxygenation in the anoxia-tolerant vertebrate Trachemys scripta

    DEFF Research Database (Denmark)

    Jensen, Frank Bo; Hansen, Marie Niemann; Montesanti, Gabriella


    Moderate elevations of nitrite and nitric oxide (NO) protect mammalian tissues against ischemia (anoxia)-reperfusion damage by inhibiting mitochondrial electron transport complexes and reducing the formation of reactive oxygen species (ROS) upon reoxygenation. Crucian carp appear to exploit...

  14. Arsenic toxicity induced endothelial dysfunction and dementia: Pharmacological interdiction by histone deacetylase and inducible nitric oxide synthase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Bhupesh, E-mail:; Sharma, P.M.


    Arsenic toxicity has been reported to damage all the major organs including the brain and vasculature. Dementia including Alzheimer's disease (AD) and vascular dementia (VaD) are posing greater risk to the world population as it is now increasing at a faster rate. We have investigated the role of sodium butyrate, a selective histone deacetylase (HDAC) inhibitor and aminoguanidine, a selective inducible nitric oxide synthase (iNOS) inhibitor in pharmacological interdiction of arsenic toxicity induced vascular endothelial dysfunction and dementia in rats. Arsenic toxicity was done by administering arsenic drinking water to rats. Morris water-maze (MWM) test was used for assessment of learning and memory. Endothelial function was assessed using student physiograph. Oxidative stress (aortic superoxide anion, serum and brain thiobarbituric acid reactive species, brain glutathione) and nitric oxide levels (serum nitrite/nitrate) were also measured. Arsenic treated rats have shown impairment of endothelial function, learning and memory, reduction in serum nitrite/nitrate and brain GSH levels along with increase in serum and brain TBARS. Sodium butyrate as well as aminoguanidine significantly convalesce arsenic induced impairment of learning, memory, endothelial function, and alterations in various biochemical parameters. It may be concluded that arsenic induces endothelial dysfunction and dementia, whereas, sodium butyrate, a HDAC inhibitor as well as aminoguanidine, a selective iNOS inhibitor may be considered as potential agents for the management of arsenic induced endothelial dysfunction and dementia. - Highlights: • As has induced endothelial dysfunction (Edf) and vascular dementia (VaD). • As has increased oxidative stress, AChE activity and decreased serum NO. • Inhibitors of HDAC and iNOS have attenuated As induced Edf and VaD. • Both the inhibitors have attenuated As induced biochemical changes. • Inhibitor of HDAC and iNOS has shown good potential

  15. Longevity of Epidendrum ibaguense Kunth inflorescences treated with nitric oxide

    Directory of Open Access Journals (Sweden)

    Luciana Marques Vieira


    Full Text Available Nitric oxide (NO acts as anti senescence substance, which may extend the postharvest life of fruits, vegetables and flowers when they are treated with micro molar concentrations of compounds like the donor sodium nitroprusside (SNP. This work aimed to evaluate the effect pulsing or spraying of NO on the longevity of cut Epidendrum ibaguense inflorescences. After harvested, the inflorescences were pulsed for 6, 24 or 48 hours with 5, 10, 50, 100 and 500 µM SNP or sprayed until run off with the same mentioned solutions. Controls were treated with distilled water. After the treatment, the flowers were placed in deionized water, which was changed every 2 days. No significant differences were observed on the longevity of flowers treated with 5, 10, 50 or 100 µM SNP, regardless of the mode of application. Inflorescences treated with 500 µM SNP had reduced longevity and increased flower abscission. In inflorescences kept in SNP solution, toxic symptoms such as darkening of the labellum resulting in reduced longevity compared with the control. The longevity of inflorescences sprayed with 500 µM SNP reduced from 6.8±0.57 to 5.1±0.82 days. Collectively, NO treatments were not able to extend the shelf life of E. ibaguense inflorescences and high concentrations of the NO donor compound in vase solution or spraying leads to toxicity symptoms on the flower labellum.

  16. Drugs targeting nitric oxide synthase for migraine treatment. (United States)

    Barbanti, Piero; Egeo, Gabriella; Aurilia, Cinzia; Fofi, Luisa; Della-Morte, David


    Ample evidence that nitric oxide (NO) is a causative molecule in migraine has encouraged research to develop drugs that target the NO-cGMP cascade for migraine treatment. NO synthase (NOS) inhibition is an innovative therapeutic principle. This paper reviews the rationale underlying NOS inhibition in migraine treatment. It also provides a review on the efficacy and safety data for NOS inhibitors (nonselective NOS inhibitor L-N(G)-methyl-arginine hydrochloride [L-NMMA], selective inducible NOS [iNOS] inhibitors GW273629 and GW274150, combined neuronal NOS [nNOS] inhibitor and 5-HT1B/1D receptor agonist NXN-188) in acute or preventive migraine treatment. The data highlighted herein, from four placebo-controlled trials and 1 open-labeled clinical trial using 4 different NOS inhibitors on a total of 705 patients, provide convincing efficacy data only for the nonselective NOS inhibitor L-NMMA. Unfortunately, this NOS inhibitor raises cardiovascular safety concerns and has an unfavorable pharmacokinetic profile. As experimental studies predicted, iNOS inhibitors are ineffective in migraine. Still, upcoming selective nNOS inhibitors are a hope for migraine treatment, with the nNOS isoform being most clearly involved in trigeminovascular transmission and central sensitization. Future studies should help to clarify whether NOS inhibition is equally fruitful in acute and preventive treatment. It should also clarify if nNOS inhibition holds promise as a therapeutic tool for the treatment of chronic migraine and other forms of headache.

  17. Advances in the clinical applications of exhaled nitric oxide measurements. (United States)

    Taylor, D Robin


    This article focuses on recent data which highlight the clinical settings in which exhaled nitric oxide (F(E)NO) is potentially helpful, or not, as a clinical tool. It is becoming clearer that, selectively applied, F(E)NO measurements can provide reliable clinical guidance, particularly when values are low. Such values are associated with high negative predictive values (>90%). Increased F(E)NO levels are associated with much more modest positive predictive values (75%-85%) and these are less reliable. These general principles apply when diagnosing steroid responsiveness in relation to asthma, chronic cough, and COPD. Although randomised trials do not support routine use of exhaled NO measurements in uncomplicated bronchial asthma, there is evidence that in patients with difficult asthma, or asthma associated with pregnancy, F(E)NO enhances overall management, and the decision to commence or increase inhaled steroid therapy (yes/no) may be made more accurately. Exhaled NO is potentially relevant in the assessment of occupational asthma (serial measurements) and also in diagnosing bronchiolitis obliterans in lung transplant patients.

  18. The Role of Nitric Oxide from Neurological Disease to Cancer. (United States)

    Maher, Ahmed; Abdel Rahman, Mohamed F; Gad, Mohamed Z


    Until the beginning of the 1980s, nitric oxide (NO) was just a toxic molecule of a lengthy list of environmental pollutants such as cigarette smoke and smog. In fact, NO had a very bad reputation of being destroyer of ozone, suspected carcinogen and precursor of acid rain. However, by the early 1990s it was well recognized by the medical research community. Over the last two decades, the picture has been totally changed. Diverse lines of evidence have converged to show that this sometime poison is a fundamental player in the everyday business of the human body. NO activity was probed in the brain, arteries, immune system, liver, pancreas, uterus, peripheral nerves, lungs, and almost every system in the human body. NO is a major player in the cardiovascular system as it is involved in regulating blood pressure. In the CNS, it is involved in memory formation and the regulation of cerebral blood flow to ensure adequate supply of blood to the brain. Because NO is involved in many pathways, it has a role in several diseases related to modern life as hypertension, coronary heart diseases, Alzheimer's Disease, stroke and cancer. This chapter focuses on the discussion of the role of NO in neurological diseases and cancer and how can this Janus-faced molecule play a role in the pathology and personalized treatment of these diseases.

  19. Oscillatory shear alters endothelial hydraulic conductivity and nitric oxide levels. (United States)

    Hillsley, Mechteld V; Tarbell, John M


    This study addresses the role of nitric oxide (NO) and downstream signaling pathways in mediating the influences of oscillatory shear stress on the hydraulic conductivity (L(p)) of bovine aortic endothelial cell (BAEC) monolayers. Exposure of BAEC monolayers to 20 dyne/cm2 steady shear stress for 3 h induced a 3.3-fold increase in L(p). When an oscillatory shear amplitude of 10 dyne/cm2 was superimposed on a steady shear of 10 dyne/cm2 to produce a non-reversing oscillatory shear pattern (10+/-10 dyne/cm2), L(p) increased by 3.0-fold within 90 min. When the amplitude was increased to 15 dyne/cm2, resulting in a reversing oscillatory shear pattern (10+/-15 dyne/cm2), the increase in L(p) over 3 h was completely suppressed. Twenty and 10+/-10 dyne/cm2 induced 2.9- and 2.6-fold increases in NO production above non-sheared controls, respectively, whereas 10+/-15 dyne/cm2 stimulated a 14-fold increase in NO production. The inhibition of L(p) with reversing oscillatory shear may be associated with alterations in cyclic guanosine monophosphate (cGMP) production downstream of NO which is up-regulated by reversing oscillatory shear, but is unaffected by steady shear.

  20. Nitric Oxide: A Multitasked Signaling Gas in Plants

    KAUST Repository

    Domingos, Patricia


    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 Ca2+ 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.

  1. Sodium nitrite: the "cure" for nitric oxide insufficiency. (United States)

    Parthasarathy, Deepa K; Bryan, Nathan S


    This process of "curing" food is a long practice that dates back thousands of years long before refrigeration or food safety regulations. Today food safety and mass manufacturing are dependent upon safe and effective means to cure and preserve foods including meats. Nitrite remains the most effective curing agent to prevent food spoilage and bacterial contamination. Despite decades of rigorous research on its safety and efficacy as a curing agent, it is still regarded by many as a toxic undesirable food additive. However, research within the biomedical science community has revealed enormous therapeutic benefits of nitrite that is currently being developed as novel therapies for conditions associated with nitric oxide (NO) insufficiency. Much of the same biochemistry that has been understood for decades in the meat industry has been rediscovered in human physiology. This review will highlight the fundamental biochemistry of nitrite in human physiology and highlight the risk benefit evaluation surrounding nitrite in food and meat products. Foods or diets enriched with nitrite can have profound positive health benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Inducible nitric oxide synthase immunoreactivity in healthy rat pancreas.

    Directory of Open Access Journals (Sweden)

    Nurullah Keklikoglu


    Full Text Available Nitric oxide (NO is produced by NO synthase (NOS isoforms: neuronal NOS (nNOS, endothelial NOS (eNOS and inducible NOS (iNOS. It is believed that, while nNOS and eNOS are effective in regulation of normal physiological processes, iNOS is expressed at an increasing rate especially in inflammatory process. The aim of this study was to determine the presence of iNOS immunoreactivity (iNOS-IR and, to compare the iNOS-IR in islet of Langerhans cells (LC, acinar cells (AC, centroacinar cells (CC and ductal cells (DC by immunohistochemical (IHC method in healthy rat pancreata. This study revealed the presence of iNOS-IR in all cell types except AC. Statistical analysis revealed a highly significant difference (p<0.001 with respect to iNOS-IR in comparison of all cell types. However, binary comparison of cell types revealed no significant differences between LC and DC (p=0.136, significant differences LC and CC, CC and DC (p=0.001 and 0.022, respectively and a highly significant differences LC and AC, AC and DC (P<0.001. The results of this study indicate that iNOS-IR is present in almost all LC. Thus, especially in reseach related to diabetes, it should not be disregarded that iNOS may be constitutively present in pancreatic islets.

  3. Nitric oxide synthase in the vestibulocochlear system of mice. (United States)

    Hess, A; Bloch, W; Arnhold, S; Andressen, C; Stennert, E; Addicks, K; Michel, O


    The exact distribution of nitric oxide-synthases (NOS) and the NO-target enzyme soluble guanylyl cyclase (sGC) in the cochlea and vestibular organ is an issue of current discussion. The existence of NOS-isoforms in the cochlea of the guinea pig has been described recently, while information about the vestibular system are still rare and non-satisfying. In order to gain more information, immunostaining was performed, using specific antibodies to NOS I-III and to sGC, on paraffin sections of complete temporal bones from mice. NOS III could be detected in cochlea and vestibular ganglion cells, in nerve fibres, in outer hair cells of the cochlear and in the sensory epithelium of the maculae. Also, the spiral ligament and the limbus epithelium was positive to NOS III. NOS I was found in the sensory epithelium of the maculae and cristae ampullares, outer and inner hair cells of the cochlea, in nerve fibres and in ganglion cells. In contrast to that NOS II could not be detected at all. Furthermore, a strong NOS I immunoreaction was displayed on the endosteum of the bone, while the periosteum was lacking of NOS. NOS detection was accompanied by immunoreactivity to sGC. The findings imply that NOS I and III-generated NO is involved in neurotransmission and other regulative processes in the vestibulocochlear system. Copyright 1998 Elsevier Science B.V.

  4. Nitric oxide synthase deficiency and the pathophysiology of muscular dystrophy (United States)

    Tidball, James G; Wehling-Henricks, Michelle


    The secondary loss of neuronal nitric oxide synthase (nNOS) that occurs in dystrophic muscle is the basis of numerous, complex and interacting features of the dystrophic pathology that affect not only muscle itself, but also influence the interaction of muscle with other tissues. Many mechanisms through which nNOS deficiency contributes to misregulation of muscle development, blood flow, fatigue, inflammation and fibrosis in dystrophic muscle have been identified, suggesting that normalization in NO production could greatly attenuate diverse aspects of the pathology of muscular dystrophy through multiple regulatory pathways. However, the relative importance of the loss of nNOS from the sarcolemma versus the importance of loss of total nNOS from dystrophic muscle remains unknown. Although most current evidence indicates that nNOS localization at the sarcolemma is not required to achieve NO-mediated reductions of pathology in muscular dystrophy, the question remains open concerning whether membrane localization would provide a more efficient rescue from features of the dystrophic phenotype. PMID:25194047

  5. Circular dichroism in photoelectron images from aligned nitric oxide molecules. (United States)

    Sen, Ananya; Pratt, S T; Reid, K L


    We have used velocity map photoelectron imaging to study circular dichroism of the photoelectron angular distributions (PADs) of nitric oxide following two-color resonance-enhanced two-photon ionization via selected rotational levels of the A (2)Σ(+), v(')=0 state. By using a circularly polarized pump beam and a counter-propagating, circularly polarized probe beam, cylindrical symmetry is preserved in the ionization process, and the images can be reconstructed using standard algorithms. The velocity map imaging set up enables individual ion rotational states to be resolved with excellent collection efficiency, rendering the measurements considerably simpler to perform than previous measurements conducted with a conventional photoelectron spectrometer. The results demonstrate that circular dichroism is observed even when cylindrical symmetry is maintained, and serve as a reminder that dichroism is a general feature of the multiphoton ionization of atoms and molecules. The observed PADs are in good agreement with calculations based on parameters extracted from previous experimental results obtained by using a time-of-flight electron spectrometer.

  6. Nitric oxide synthetase and Helicobacter pylori in patients undergoing appendicectomy.

    LENUS (Irish Health Repository)

    Kell, M R


    BACKGROUND: This study was designed to determine whether Helicobacter pylori forms part of the normal microenvironment of the appendix, whether it plays a role in the pathogenesis of acute appendicitis, and whether it is associated with increased expression of inducible nitric oxide synthetase (iNOS) in appendicular macrophages. METHODS: Serology for H. pylori was performed on 51 consecutive patients undergoing emergency appendicectomy. Appendix samples were tested for urease activity, cultured and stained for H. pylori, graded according to the degree of inflammatory infiltrate, and probed immunohistochemically for iNOS expression. RESULTS: The mean age of the patients was 21 (range 7-51) years. Seventeen patients (33 per cent) were seropositive for H. pylori but no evidence of H. pylori was found in any appendix specimen. However, an enhanced inflammatory cell infiltration was observed in seropositive patients (P < 0.04) and the expression of macrophage iNOS in the mucosa of normal and inflamed appendix specimens was increased (P < 0.01). CONCLUSION: H. pylori does not colonize the appendix and is unlikely to be a pathogenic stimulus for appendicitis. Priming effects on mucosal immunology downstream from the foregut may occur after infection with H. pylori.

  7. Alternatively spliced neuronal nitric oxide synthase mediates penile erection (United States)

    Hurt, K. Joseph; Sezen, Sena F.; Champion, Hunter C.; Crone, Julie K.; Palese, Michael A.; Huang, Paul L.; Sawa, Akira; Luo, Xiaojiang; Musicki, Biljana; Snyder, Solomon H.; Burnett, Arthur L.


    A key role for nitric oxide (NO) in penile erection is well established, but the relative roles of the neuronal NO synthase (nNOS) versus endothelial forms of NOS are not clear. nNOS- and endothelial NOS-deficient mice maintain erectile function and reproductive capacity, questioning the importance of NO. Alternatively, residual NO produced by shorter transcripts in the nNOS−/− animals might suffice for normal physiologic function. We show that the β splice variant of nNOS elicits normal erection despite a decrease in stimulus-response characteristics and a 5-fold increased sensitivity to the NOS inhibitor, l-NAME. Residual nNOSβ generates only 10% of the normal NO level in vitro but produces citrulline and diaphorase staining reflecting in vivo NOS activity in pelvic ganglion nerves that is comparable to WT animals. Thus, alternatively spliced forms of nNOS are major mediators of penile erection and so may be targets for therapeutic intervention. PMID:16488973

  8. Assessment of nitric oxide signals by triiodide chemiluminescence. (United States)

    Hausladen, Alfred; Rafikov, Ruslan; Angelo, Michael; Singel, David J; Nudler, Evgeny; Stamler, Jonathan S


    Nitric oxide (NO) bioactivity is mainly conveyed through reactions with iron and thiols, furnishing iron nitrosyls and S-nitrosothiols with wide-ranging stabilities and reactivities. Triiodide chemiluminescence methodology has been popularized as uniquely capable of quantifying these species together with NO byproducts, such as nitrite and nitrosamines. Studies with triiodide, however, have challenged basic ideas of NO biochemistry. The assay, which involves addition of multiple reagents whose chemistry is not fully understood, thus requires extensive validation: Few protein standards have in fact been characterized; NO mass balance in biological mixtures has not been verified; and recovery of species that span the range of NO-group reactivities has not been assessed. Here we report on the performance of the triiodide assay vs. photolysis chemiluminescence in side-by-side assays of multiple nitrosylated standards of varied reactivities and in assays of endogenous Fe- and S-nitrosylated hemoglobin. Although the photolysis method consistently gives quantitative recoveries, the yields by triiodide are variable and generally low (approaching zero with some standards and endogenous samples). Moreover, in triiodide, added chemical reagents, changes in sample pH, and altered ionic composition result in decreased recoveries and misidentification of NO species. We further show that triiodide, rather than directly and exclusively producing NO, also produces the highly potent nitrosating agent, nitrosyliodide. Overall, we find that the triiodide assay is strongly influenced by sample composition and reactivity and does not reliably identify, quantify, or differentiate NO species in complex biological mixtures.

  9. Nitric oxide modulates the frog heart ventricle morphodynamics. (United States)

    Acierno, Raffaele; Gattuso, Alfonsina; Guerrieri, Antonio; Mannarino, Cinzia; Amelio, Daniela; Tota, Bruno


    The aim of this work was to investigate in the avascular heart of the frog Rana esculenta the influence of nitric oxide (NO) on ventricular systolic and diastolic functions by using a novel image analysis technique. The external volume variations of the whole ventricle were monitored during the heart cycle by video acquisition(visible light) and analysed by an appropriately developed software with a specific formula for irregular convex solids. The system, which measures the rate of volume changes and the ejection fraction, directly determined the volumetric behaviour of the working frog heart after stimulation or inhibition of NOS-NOcGMP pathway. End-diastolic volume (EDVext), end-systolic volume (ESVext), contraction and relaxation velocities (dV/dtsys and dV/dtdia, respectively), stroke volume (SV) and ejection fraction (EF), were measured before and after perfusion with NOS substrate (L-arginine), NO donor (SIN-1), cGMP analogue (8-Br-cGMP),NOS inhibitors (NG-monomethyl-L-arginine, L-NMMA; L-N(5)-(1-iminoethyl)-ornithine, L-NIO; 7-Nitroindazole,7-NI) and guanylyl cyclase inhibitor (ODQ). The results showed that NO reduces ventricular systolicfunction improving diastolic filling, while NOS inhibition increases contractility impairing ventricular filling capacity. The presence of activated eNOS (p-eNOS) was morphologically documented, further supporting that the mechanical activity of the ventricular pump in frog is influenced by a tonic release of NOS-generated NO.

  10. Regulation of obesity and insulin resistance by nitric oxide. (United States)

    Sansbury, Brian E; Hill, Bradford G


    Obesity is a risk factor for developing type 2 diabetes and cardiovascular disease and has quickly become a worldwide pandemic with few tangible and safe treatment options. Although 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-seem 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. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Nitric oxide destabilizes Pias3 and regulates sumoylation.

    Directory of Open Access Journals (Sweden)

    Jing Qu


    Full Text Available Small ubiquitin-related protein modifiers (SUMO modification is an important mechanism for posttranslational regulation of protein function. However, it is largely unknown how the sumoylation pathway is regulated. Here, we report that nitric oxide (NO causes global hyposumoylation in mammalian cells. Both SUMO E2 conjugating enzyme Ubc9 and E3 ligase protein inhibitor of activated STAT3 (Pias3 were targets for S-nitrosation. S-nitrosation did not interfere with the SUMO conjugating activity of Ubc9, but promoted Pias3 degradation by facilitating its interaction with tripartite motif-containing 32 (Trim32, a ubiquitin E3 ligase. On the one hand, NO promoted Trim32-mediated Pias3 ubiquitination. On the other hand, NO enhanced the stimulatory effect of Pias3 on Trim32 autoubiquitination. The residue Cys459 of Pias3 was identified as a target site for S-nitrosation. Mutation of Cys459 abolished the stimulatory effect of NO on the Pias3-Trim32 interaction, indicating a requirement of S-nitrosation at Cys459 for positive regulation of the Pias3-Trim32 interplay. This study reveals a novel crosstalk between S-nitrosation, ubiquitination, and sumoylation, which may be crucial for NO-related physiological and pathological processes.

  12. Evaluation of Mapleson systems for administration of inhaled nitric oxide. (United States)

    Kukita, I; Okamoto, K; Sato, T; Shibata, Y; Shiihara, K; Kikuta, K


    To assess the safety of nitric oxide (NO) inhalation during manual-controlled ventilation using Mapleson A, D, and F systems, we examined nitrogen dioxide (NO2) production using a chemiluminescence analyzer. The NO concentration was changed from 0 to 19 parts per million (ppm), and at each level of NO the oxygen (O2) concentration was changed from 21% to 100%. The NO2 concentration was observed to increase when either the O2 or NO concentration was increased. The maximum NO2 concentrations (mean ± standard deviation) of the Mapleson A, D, and F systems were 0.20±0.03, 0.15±0.03, and 0.17±0.02 ppm, respectively, when the concentrations of NO and O2 were 19 ppm and 100%, respectively. The NO2 concentrations of the Mapleson A system were significantly higher than those of either the Mapleson D or F system at 4, 8, and 12 ppm NO and 100% O2, and than that of the Mapleson D system at 19 ppm NO and 100% O2. From the viewpoint of NO2 production, we suggest that the Mapleson D and F systems are safer than the Mapleson A system when manual-controlled ventilation is required.


    Sansbury, Brian E.; Hill, Bradford G.


    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

  14. Nasal nitric oxide in sleep-disordered breathing in children. (United States)

    Gut, Guy; Tauman, Riva; Greenfeld, Michal; Armoni-Domany, Keren; Sivan, Yakov


    Inflammation plays a role in the pathogenesis and consequences of sleep-disordered breathing (SDB). The nasal mucosa and paranasal sinuses produce high levels of nitric oxide (NO). In asthma, exhaled NO is a marker of airway inflammation. There is only limited information whether nasal NO (nNO) accompanies also chronic upper airway obstruction, specifically, SDB. The objective of this study was to investigate nNO levels in children with SDB in comparison to healthy non-snoring children. Nasal NO was measured in children who underwent overnight polysomnographic studies due to habitual snoring and suspected SDB and in healthy non-snoring controls. One hundred and eleven children participated in the study: 28 with obstructive sleep apnea (OSA), 60 with primary snoring (PS), and 23 controls. Nasal NO levels were significantly higher in children with OSA and PS compared to controls (867.4 ± 371.5, 902.0 ± 330.9, 644.1 ± 166.5 ppb, respectively, p = 0.047). No difference was observed between children with OSA and PS. No correlations were found between nNO levels and any of the PSG variables, nor with age, BMI percentile or tonsils size. Compared to healthy controls, nNO is increased in children with SDB, but it is not correlated with disease severity. This is probably due to the local mechanical processes and snoring.

  15. Nitric oxide induces morphological changes in cultured neurohypophysial astrocytes. (United States)

    Ramsell, K D; Cobbett, P


    Cultured pituicytes, derived from the neurohypophysis of adult rats, have previously been reported to change from a non-stellate form to a stellate form when incubated in medium containing a beta-adrenoreceptor agonist. This study was designed to determine whether the same morphological change could be induced by direct activation of adenylate cyclase or of soluble guanylate cyclase. The fraction of stellate cells was normally low (< 0.25) when the pituicytes were incubated (90 min) in a HEPES buffered salt solution (HBSS); most pituicytes had an amorphous protoplasmic appearance. The fraction of stellate cells was significantly increased when pituicytes were incubated in HBSS supplemented with isoproterenol (10 microM) or forskolin (5 microM) or with either of the nitric oxide donors nitroprusside (10-25 microM) and 3-morpholinosydnonimine (SIN-1; 10 microM). The effect of forskolin was mimicked by 8-bromo cyclic AMP, a membrane permeable analog of cyclic AMP, but not by the inactive forskolin analog 1, 9 dideoxyforskolin. The effect of nitroprusside was blocked by methylene blue, an inhibitor of soluble guanylate cyclase, and was mimicked by 8-bromo cyclic GMP, a membrane permeable analog of cyclic GMP. These results demonstrate that activation of adenylate cyclase and also of soluble guanylate cyclase can induce pituicytes to undergo morphological changes in vitro. The data suggest that the activity of both enzymes may be important in control of the plastic relationship that exists between neuronal and glial elements in the neurohypophysis in vivo.

  16. Nitric oxide inhibitory xanthones from the pericarps of Garcinia mangostana. (United States)

    Liu, Qianyu; Li, Dan; Wang, Anqi; Dong, Zhen; Yin, Sheng; Zhang, Qingwen; Ye, Yang; Li, Liangchun; Lin, Ligen


    Mangosteen (Garcinia mangostana, Clusiaceae) is called "queen of fruit" in Southeast Asia. In the current study, three dimeric xanthones, garcinoxanthones A-C, and four monomeric xanthones, garcinoxanthones D-G, together with 18 known xanthones, were isolated from the pericarps of G. mangostana, collected in Thailand. The structures of garcinoxanthones A-G were elucidated by analysis of their 1D and 2D NMR and other spectroscopic data, and their absolute configurations were determined by the CD spectra. All seven compounds were tested for nitric oxide (NO) inhibitory activity on lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Garcinoxanthones B and C significantly inhibited NO production with IC 50 values of 11.3 ± 1.7 and 18.0 ± 1.8 μM, respectively, which were comparable with the positive control indomethacin (IC 50 3.9 ± 0.3 μM). Moreover, garcinoxanthone B suppressed inducible NO synthase expression in a dose-dependent manner. These results reveal the presence of rare dimeric xanthones in G. mangostana and their NO inhibitory effect on LPS-stimulated murine macrophage cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Exhaled nitric oxide - circadian variations in healthy subjects

    Directory of Open Access Journals (Sweden)

    Antosova M


    Full Text Available Abstract Objective Exhaled nitric oxide (eNO has been suggested as a marker of airway inflammatory diseases. The level of eNO is influenced by many various factor including age, sex, menstrual cycle, exercise, food, drugs, etc. The aim of our study was to investigate a potential influence of circadian variation on eNO level in healthy subjects. Methods Measurements were performed in 44 women and 10 men, non-smokers, without respiratory tract infection in last 2 weeks. The eNO was detected at 4-hour intervals from 6 a.m. to 10 p.m. using an NIOX analyzer. We followed the ATS/ERS guidelines for eNO measurement and analysis. Results Peak of eNO levels were observed at 10 a.m. (11.1 ± 7.2 ppb, the lowest value was detected at 10 p.m. (10.0 ± 5.8 ppb. The difference was statistically significant (paired t-test, P Conclusions The daily variations in eNO, with the peak in the morning hours, could be of importance in clinical practice regarding the choice of optimal time for monitoring eNO in patients with respiratory disease.

  18. Potential use and perspectives of nitric oxide donors in agriculture. (United States)

    Marvasi, Massimiliano


    Nitric oxide (NO) has emerged in the last 30 years as a key molecule involved in many physiological processes in plants, animals and bacteria. Current research has shown that NO can be delivered via donor molecules. In such cases, the NO release rate is dependent on the chemical structure of the donor itself and on the chemical environment. Despite NO's powerful signaling effect in plants and animals, the application of NO donors in agriculture is currently not implemented and research remains mainly at the experimental level. Technological development in the field of NO donors is rapidly expanding in scope to include controlling seed germination, plant development, ripening and increasing shelf-life of produce. Potential applications in animal production have also been identified. This concise review focuses on the use of donors that have shown potential biotechnological applications in agriculture. Insights are provided into (i) the role of donors in plant production, (ii) the potential use of donors in animal production and (iii) future approaches to explore the use and applications of donors for the benefit of agriculture. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. Hydrogen sulfide and nitric oxide interactions in inflammation. (United States)

    Lo Faro, Maria Letizia; Fox, Bridget; Whatmore, Jacqueline L; Winyard, Paul G; Whiteman, Matthew


    Together with carbon monoxide (CO), nitric oxide (NO) and hydrogen sulfide (H2S) form a group of physiologically important gaseous transmitters, sometimes referred to as the "gaseous triumvirate". The three molecules share a wide range of physical and physiological properties: they are small gaseous molecules, able to freely penetrate cellular membranes; they are all produced endogenously in the body and they seem to exert similar biological functions. In the cardiovascular system, for example, they are all vasodilators, promote angiogenesis and protect tissues against damage (e.g. ischemia-reperfusion injury). In addition, they have complex roles in inflammation, with both pro- and anti-inflammatory effects reported. Researchers have focused their efforts in understanding and describing the roles of each of these molecules in different physiological systems, and in the past years attention has also been given to the gases interaction or "cross-talk". This review will focus on the role of NO and H2S in inflammation and will give an overview of the evidence collected so far suggesting the importance of their cross-talk in inflammatory processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Molecular dynamics simulation of nitric oxide in myoglobin (United States)

    Lee, Myung Won; Meuwly, Markus


    The infrared (IR) spectroscopy and ligand migration of photodissociated nitric oxide (NO) in and around the active sites in myoglobin (Mb) are investigated. A distributed multipolar model for open-shell systems is developed and used, which allows one to realistically describe the charge distribution around the diatomic probe molecule. The IR spectra were computed from the trajectories for two conformational substates at various temperatures. The lines are narrow (width of 3–7 cm–1 at 20–100 K), in agreement with the experimental observations where they have widths of 4–5 cm–1 at 4 K. It is found that within one conformational substate (B or C) the splitting of the spectrum can be correctly described compared with recent experiments. Similar to photodissociated CO in Mb, additional substates exist for NO in Mb, which are separated by barriers below 1 kcal/mol. Contrary to full quantum mechanical calculations, however, the force field and mixed QM/MM simulations do not correctly describe the relative shifts between the B- and C-states relative to gas-phase NO. Free energy simulations establish that NO preferably localizes in the distal site and the barrier for migration to the neighboring Xe4 pocket is ΔGB→C = 1.7–2.0 kcal/mol. The reverse barrier is ΔGB←C = 0.7 kcal/mol, which agrees well with the experimental value of 0.7 kcal/mol, estimated from kinetic data.

  1. First Detection of the Nitric Oxide Dayglow on Mars (United States)

    Stevens, Michael H.; Siskind, David E.; Evans, J. Scott; Fox, Jane L.; Jain, Sonal; Deighan, Justin; Schneider, Nicholas M.; Stewart, A. Ian F.; Crismani, Matteo; Stiepen, Arnaud; Chaffin, Michael S.; McClintock, William E.; Holsclaw, Greg; Lefevre, Franck; Lo, Daniel; Clarke, John T.; Montmessin, Franck; Jakosky, Bruce


    Nitric oxide (NO) is a well-known indicator of solar and auroral activity in the terrestrial upper atmosphere. Direct measurements of NO on Mars can therefore constrain studies of energetic processes controlling the composition and structure of its upper atmosphere (80-200 km). Identifying and quantifying these processes is one of the science objectives of NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission currently orbiting Mars. NO can be observed directly by solar resonance fluorescence in the mid-ultraviolet (MUV). Indeed, this approach has routinely been used to measure terrestrial NO for 50 years. On Mars, this “dayglow” emission is very weak relative to other bright MUV features and thus has confounded attempts at its detection there for nearly the same amount of time. Here, we report the first detection of the NO dayglow in the Martian atmosphere using limb observations by the Imaging Ultraviolet Spectrograph (IUVS) on the MAVEN spacecraft. The detection is enabled by the spectral modeling and removal of the carbon monoxide Cameron bands, which dominate the MUV limb spectra. We focus on the spectral region between 213.0-225.5 nm, where three NO gamma bands emit. We will infer NO densities from the dayglow spectra and compare our observations with predictions from a photochemical model. We will discuss the implications, particularly in the context of previous in situ measurements.

  2. Marine biomolecules inhibit rat brain nitric oxide synthase activity. (United States)

    Venkateswara Rao, J; Desaiah, D; Vig, P J; Venkateswarlu, Y


    A large number of substances of medical importance have been isolated from marine flora and fauna and their chemical structures were elucidated. Among the many compounds isolated in our laboratories only two compounds were identified as neurotoxins as they produced depolarizing effects in nerve fibers. The Xestospongin D and Araguspongin C, isolated and purified to 100% from sponge, Haliclona exigua were tested for their effects on rat brain nitric oxide synthase (NOS) activity in vitro. The results showed that NOS activity was significantly inhibited in a concentration and time dependent manner with an estimated IC50 of 31.5 and 46.5 microM for Xestospongin D and Araguspongin C, respectively, and the maximum inhibition occurred within 3 min of incubation. To explore the mechanism of action of these compounds on NOS, we have conducted kinetic studies with L-arginine, NADPH and Ca2+ in the presence of IC50 concentrations of these two compounds. The maximum velocity (Vmax) and enzyme constant (Km) were calculated using the Michaelis Menten equation. The results show that both compounds are competitive inhibitors of NOS with the substrate, L-arginine and uncompetitive with NADPH and free Ca2+. The NOS inhibition by these two compounds was similar to N omega-nitro-L-arginine methylester (L-NAME), a known inhibitor of NOS. These results suggest that the marine biomolecules Xestospongin D and Araguspongin C are in vitro modulators of neuronal NOS.

  3. Effect of Nitric Oxide on the Growth and Development of Arabidopsis thaliana


    Kuruthukulangarakoola, Gitto Thomas


    Besides the signaling function, nitric oxide can also serve as a source of nitrogen in plants. Fixation of nitric oxide seems to be mediated by non-symbiotic hemoglobins and thereby introducing it into the N-metabolic pathway. These new findings could be important for breeding to generate plants with improved growth. Neben der wichtigen Funktion von Stickstoffmonoxid als Signalmolekül in Pflanzen kann dieses Molekül auch als Stickstoffquelle dienen. Hierbei scheint Stickstoffmonoxid mittel...

  4. The myth of nitric oxide in central cardiovascular control by the nucleus tractus solitarii

    Directory of Open Access Journals (Sweden)

    Talman W.T.


    Full Text Available Considerable evidence suggests that nitroxidergic mechanisms in the nucleus tractus solitarii (NTS participate in cardiovascular reflex control. Much of that evidence, being based on responses to nitric oxide precursors or inhibitors of nitric oxide synthesis, has been indirect and circumstantial. We sought to directly determine cardiovascular responses to nitric oxide donors microinjected into the NTS and to determine if traditional receptor mechanisms might account for responses to certain of these donors in the central nervous system. Anesthetized adult Sprague Dawley rats that were instrumented for recording arterial pressure and heart rate were used in the physiological studies. Microinjection of nitric oxide itself into the NTS did not produce any cardiovascular responses and injection of sodium nitroprusside elicited minimal depressor responses. The S-nitrosothiols, S-nitrosoglutathione (GSNO, S-nitrosoacetylpenicillamine (SNAP, and S-nitroso-D-cysteine (D-SNC produced no significant cardiovascular responses while injection of S-nitroso-L-cysteine (L-SNC elicited brisk, dose-dependent depressor and bradycardic responses. In contrast, injection of glyceryl trinitrate elicited minimal pressor responses without associated changes in heart rate. It is unlikely that the responses to L-SNC were dependent on release of nitric oxide in that 1 the responses were not affected by injection of oxyhemoglobin or an inhibitor of nitric oxide synthesis prior to injection of L-SNC and 2 L- and D-SNC released identical amounts of nitric oxide when exposed to brain tissue homogenates. Although GSNO did not independently affect blood pressure, its injection attenuated responses to subsequent injection of L-SNC. Furthermore, radioligand binding studies suggested that in rat brain synaptosomes there is a saturable binding site for GSNO that is displaced from that site by L-SNC. The studies suggest that S-nitrosocysteine, not nitric oxide, may be an

  5. Conversion of nitrite to nitric oxide at zinc via S-nitrosothiols. (United States)

    Cardenas, Allan Jay P; Abelman, Rebecca; Warren, Timothy H


    Nitrite is an important reservoir of nitric oxide activity in the plasma and cells. Using a biomimetic model, we demonstrate the conversion of zinc-bound nitrite in the tris(pyrazolyl)borate complex (iPr2)TpZn(NO2) to the corresponding S-nitrosothiol RSNO and zinc thiolate (iPr2)TpZn-SR via reaction with thiols H-SR. Decomposition of the S-nitrosothiol formed releases nitric oxide gas.

  6. Nitric Oxide in the Kidney : Its Physiological Role and Pathophysiological Implications


    Lee, JongUn


    Nitric oxide has been implicated in many physiologic processes that influence both acute and long-term control of kidney function. Its net effect in the kidney is to promote natriuresis and diuresis, contributing to adaptation to variations of dietary salt intake and maintenance of normal blood pressure. A pretreatment with nitric oxide donors or L-arginine may prevent the ischemic acute renal injury. In chronic kidney diseases, the systolic blood pressure is correlated with the plasma level ...

  7. Alterations of inducible and constitutive nitric oxide synthase after hippocampal injury in rats. (United States)

    Safari, M; Ghahari, L


    The aim of this study was to study the changes of inducible and constitutive Nitric Oxide Synthase (NOS) after brain injury. In order to brain injury 42 wistar rats were submitted and divided in 7 groups. Nitric oxide synthase activities were assayed at different times after injury. Present results showed that a significant increase of iNOS and cNOS activity 8 h after lesion. In conclusion, both isoformes of NOS increase at different time after brain injury.

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


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


    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...

  9. Hemoglobin α/eNOS coupling at myoendothelial junctions is required for nitric oxide scavenging during vasoconstriction. (United States)

    Straub, Adam C; Butcher, Joshua T; Billaud, Marie; Mutchler, Stephanie M; Artamonov, Mykhaylo V; Nguyen, Anh T; Johnson, Tyler; Best, Angela K; Miller, Megan P; Palmer, Lisa A; Columbus, Linda; Somlyo, Avril V; Le, Thu H; Isakson, Brant E


    Hemoglobin α (Hb α) and endothelial nitric oxide synthase (eNOS) form a macromolecular complex at myoendothelial junctions; the functional role of this interaction remains undefined. To test if coupling of eNOS and Hb α regulates nitric oxide signaling, vascular reactivity, and blood pressure using a mimetic peptide of Hb α to disrupt this interaction. In silico modeling of Hb α and eNOS identified a conserved sequence of interaction. By mutating portions of Hb α, we identified a specific sequence that binds eNOS. A mimetic peptide of the Hb α sequence (Hb α X) was generated to disrupt this complex. Using in vitro binding assays with purified Hb α and eNOS and ex vivo proximity ligation assays on resistance arteries, we have demonstrated that Hb α X significantly decreased interaction between eNOS and Hb α. Fluorescein isothiocyanate labeling of Hb α X revealed localization to holes in the internal elastic lamina (ie, myoendothelial junctions). To test the functional effects of Hb α X, we measured cyclic guanosine monophosphate and vascular reactivity. Our results reveal augmented cyclic guanosine monophosphate production and altered vasoconstriction with Hb α X. To test the in vivo effects of these peptides on blood pressure, normotensive and hypertensive mice were injected with Hb α X, which caused a significant decrease in blood pressure; injection of Hb α X into eNOS(-/-) mice had no effect. These results identify a novel sequence on Hb α that is important for Hb α/eNOS complex formation and is critical for nitric oxide signaling at myoendothelial junctions. © 2014 American Heart Association, Inc.

  10. [Higher nitric oxide levels are associated with disease activity in Egyptian rheumatoid arthritis patients]. (United States)

    Ali, Adel Mahmoud; Habeeb, Reem Abdelmonem; El-Azizi, Noran Osama; Khattab, Dina Aziz; Abo-Shady, Rania Ahmed; Elkabarity, Rania Hamdy


    Oxidative stress generated within inflammatory joints can produce autoimmune phenomena and joint destruction. Radical species with oxidative activity, including reactive nitrogen species, represent mediators of inflammation and cartilage damage. To assess serum nitric oxide as a marker of oxidative stress in Egyptian patients with rheumatoid arthritis and its relation to disease activity. 80 patients with rheumatoid arthritis were divided into 2 groups, according to the DAS-28 score: Group I: 42 patients with disease activity, and Group II: 38 patients with no disease activity. Forty age- and sex-matched individuals were included as control group (Group III). Routine laboratory investigations were done, and nitric oxide was measured using Elisa. Hand plain radiographies were done for radiological status scoring using the Sharp method. A comparison between nitric oxide in all three groups showed a highly significant difference (p < 0.001), significantly higher levels were obtained among rheumatoid arthritis patients in comparison to controls, and higher levels were obtained in patients with active disease (mean±SD 82.38±20.46) in comparison to patients without active disease (35.53±7.15). Nitric oxide in Group I showed a significant positive correlation with morning stiffness (r=0.45), arthritis (r=0.43), platelet count (r=0.46), erythrocyte sedimentation rate (r=0.83), C-reactive protein (r=0.76) and Disease Activity Score (r=0.85). Nitric oxide showed a significant positive correlation (r=0.43) with hand radiographies (Sharp score) in Group I. There are increased levels of nitric oxide in the serum of patients with rheumatoid arthritis. Nitric oxide correlates significantly with disease activity, inflammatory markers and radiological joint status. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

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

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


    (-)-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.

  12. Nitric oxide production upregulates Wnt/β-catenin signaling by inhibiting Dickkopf-1. (United States)

    Du, Qiang; Zhang, Xinglu; Liu, Quan; Zhang, Xianghong; Bartels, Christian E; Geller, David A


    Nitric oxide signaling plays complex roles in carcinogenesis, in part, due to incomplete mechanistic understanding. In this study, we investigated our discovery of an inverse correlation in the expression of the inducible nitric oxide synthase (iNOS) and the Wnt/β-catenin regulator Dickkopf-1 (DKK1) in human cancer. In human tumors and animal models, induced nitric oxide synthesis increased Wnt/β-catenin signaling by negatively regulating DKK1 gene expression. Human iNOS (hiNOS) and DKK1 gene expression were inversely correlated in primary human colon and breast cancers, and in intestinal adenomas from Min (Apc(min/+)) mice. Nitric oxide production by various routes was sufficient to decrease constitutive DKK1 expression, increasing Wnt/β-catenin signaling in colon and breast cancer cells and primary human hepatocytes, thereby activating the transcription of Wnt target genes. This effect could be reversed by RNA interference-mediated silencing of iNOS or treatment with iNOS inhibitors, which restored DKK1 expression and its inhibitory effect on Wnt signaling. Taken together, our results identify a previously unrecognized mechanism through which the nitric oxide pathway promotes cancer by unleashing Wnt/β-catenin signaling. These findings further the evidence that nitric oxide promotes human cancer and deepens insights in the complex control Wnt/β-catenin signaling during carcinogenesis.

  13. S-Adenosylmethionine modulates inducible nitric oxide synthase gene expression in rat liver and isolated hepatocytes. (United States)

    Majano, P L; García-Monzón, C; García-Trevijano, E R; Corrales, F J; Cámara, J; Ortiz, P; Mato, J M; Avila, M A; Moreno-Otero, R


    Hepatocellular availability of S-adenosylmethionine, the principal biological methyl donor, is compromised in situations of liver damage. S-Adenosylmethionine administration alleviates experimental liver injury and increases survival in cirrhotic patients. The mechanisms behind these beneficial effects of S-adenosylmethionine are not completely known. An inflammatory component is common to many of the pathological conditions in which S-adenosylmethionine grants protection to the liver. This notion led us to study the effect of S-adenosylmethionine administration on hepatic nitric oxide synthase-2 induction in response to bacterial lipopolysaccharide and proinflammatory cytokines. The effect of S-adenosylmethionine on nitric oxide synthase-2 expression was assessed in rats challenged with bacterial lipopolysaccharide and in isolated rat hepatocytes treated with proinflammatory cytokines. Interactions between S-adenosylmethionine and cytokines on nuclear factor kappa B activation and nitric oxide synthase-2 promoter transactivation were studied in isolated rat hepatocytes and HepG2 cells, respectively. S-Adenosylmethionine attenuated the induction of nitric oxide synthase-2 in the liver of lipopolysaccharide-treated rats and in cytokine-treated hepatocytes. S-Adenosylmethionine accelerated the resynthesis of inhibitor kappa B alpha, blunted the activation of nuclear factor kappa B and reduced the transactivation of nitric oxide synthase-2 promoter. Our findings indicate that the hepatoprotective actions of S-adenosylmethionine may be mediated in part through the modulation of nitric oxide production.

  14. Elevated nitric oxide in recurrent vulvovaginal candidiasis - association with clinical findings. (United States)

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


    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 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.

  15. 6-Gingerol alleviates exaggerated vasoconstriction in diabetic rat aorta through direct vasodilation and nitric oxide generation. (United States)

    Ghareib, Salah A; El-Bassossy, Hany M; Elberry, Ahmed A; Azhar, Ahmad; Watson, Malcolm L; Banjar, Zainy Mohammed


    The aim of the present study is to investigate the effect and potential mechanism of action of 6-gingerol on alterations of vascular reactivity in the isolated aorta from diabetic rats. Male Wistar rats were divided into two experimental groups, control and diabetics. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg kg(-1)), and the rats were left for 10 weeks to develop vascular complications. The effect of in vitro incubation with 6-gingerol (0.3-3 μM) on the vasoconstrictor response of the isolated diabetic aortae to phenylephrine and the vasodilator response to acetylcholine was examined. Effect of 6-gingerol was also examined on aortae incubated with methylglyoxal as an advanced glycation end product (AGE). To investigate the mechanism of action of 6-gingerol, the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester hydrochloride (100 μM), guanylate cyclase inhibitor methylene blue (5 μM), calcium-activated potassium channel blocker tetraethylammonium chloride (10 mM), and cyclooxygenase inhibitor indomethacin (5 μM) were added 30 minutes before assessing the direct vasorelaxant effect of 6-gingerol. Moreover, in vitro effects of 6-gingerol on NO release and the effect of 6-gingerol on AGE production were examined. Results showed that incubation of aortae with 6-gingerol (0.3-10 μM) alleviated the exaggerated vasoconstriction of diabetic aortae to phenylephrine in a concentration-dependent manner with no significant effect on the impaired relaxatory response to acetylcholine. Similar results were seen in the aortae exposed to methylglyoxal. In addition, 6-gingerol induced a direct vasodilation effect that was significantly inhibited by Nω-nitro-l-arginine methyl ester hydrochloride and methylene blue. Furthermore, 6-gingerol stimulated aortic NO generation but had no effect on AGE formation. In conclusion, 6-gingerol ameliorates enhanced vascular contraction in diabetic aortae, which may be partially

  16. Targeting Pulmonary Endothelial Hemoglobin α Improves Nitric Oxide Signaling and Reverses Pulmonary Artery Endothelial Dysfunction. (United States)

    Alvarez, Roger A; Miller, Megan P; Hahn, Scott A; Galley, Joseph C; Bauer, Eileen; Bachman, Timothy; Hu, Jian; Sembrat, John; Goncharov, Dmitry; Mora, Ana L; Rojas, Mauricio; Goncharova, Elena; Straub, Adam C


    Pulmonary hypertension is characterized by pulmonary endothelial dysfunction. Previous work showed that systemic artery endothelial cells (ECs) express hemoglobin (Hb) α to control nitric oxide (NO) diffusion, but the role of this system in pulmonary circulation has not been evaluated. We hypothesized that up-regulation of Hb α in pulmonary ECs contributes to NO depletion and pulmonary vascular dysfunction in pulmonary hypertension. Primary distal pulmonary arterial vascular smooth muscle cells, lung tissue sections from unused donor (control) and idiopathic pulmonary artery (PA) hypertension lungs, and rat and mouse models of SU5416/hypoxia-induced pulmonary hypertension (PH) were used. Immunohistochemical, immunocytochemical, and immunoblot analyses and transfection, infection, DNA synthesis, apoptosis, migration, cell count, and protein activity assays were performed in this study. Cocultures of human pulmonary microvascular ECs and distal pulmonary arterial vascular smooth muscle cells, lung tissue from control and pulmonary hypertensive lungs, and a mouse model of chronic hypoxia-induced PH were used. Immunohistochemical, immunoblot analyses, spectrophotometry, and blood vessel myography experiments were performed in this study. We find increased expression of Hb α in pulmonary endothelium from humans and mice with PH compared with controls. In addition, we show up-regulation of Hb α in human pulmonary ECs cocultured with PA smooth muscle cells in hypoxia. We treated pulmonary ECs with a Hb α mimetic peptide that disrupts the association of Hb α with endothelial NO synthase, and found that cells treated with the peptide exhibited increased NO signaling compared with a scrambled peptide. Myography experiments using pulmonary arteries from hypoxic mice show that the Hb α mimetic peptide enhanced vasodilation in response to acetylcholine. Our findings reveal that endothelial Hb α functions as an endogenous scavenger of NO in the pulmonary endothelium

  17. Antioxidant Functions of Nitric Oxide Synthase in a Methicillin Sensitive Staphylococcus aureus

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    Manisha Vaish


    Full Text Available Nitric oxide and its derivative peroxynitrites are generated by host defense system to control bacterial infection. However certain Gram positive bacteria including Staphylococcus aureus possess a gene encoding nitric oxide synthase (SaNOS in their chromosome. In this study it was determined that under normal growth conditions, expression of SaNOS was highest during early exponential phase of the bacterial growth. In oxidative stress studies, deletion of SaNOS led to increased susceptibility of the mutant cells compared to wild-type S. aureus. While inhibition of SaNOS activity by the addition of L-NAME increased sensitivity of the wild-type S. aureus to oxidative stress, the addition of a nitric oxide donor, sodium nitroprusside, restored oxidative stress tolerance of the SaNOS mutant. The SaNOS mutant also showed reduced survival after phagocytosis by PMN cells with respect to wild-type S. aureus.

  18. Altered Endometrial Expression of Endothelial Nitric oxide Synthase (eNOS) in women with Unexplained Recurrent Miscarriage and Infertility (United States)

    Najafi, Tohid; Novin, Marefat Ghaffari; Ghazi, Reza; Khorram, Omid


    Background Endothelial nitric oxide synthase (eNOS) has diverse roles in the female reproductive system including a role in blastocyst implantation. Aberrant expression of eNOS could therefore be significant in the pathogenesis of disorders of implantation Materials and Methods eNOS protein and mRNA levels in the endometrium of women with recurrent miscarriages, unexplained infertility, and a control group was determined by compartmental quantitative immunohistochemistry and real time RT-PCR Results eNOS was immunolocalized to all layers of the endometrium and the vascular endothelium. eNOS protein expression was higher in glandular epithelium (P=0.004) and luminal epithelium (P=0.002) but not vascular endothelium and stroma (P=0.14) in women with recurrent miscarriage. Similarly, in women with unexplained infertility eNOS expression was significantly higher (Pinfertility compared with controls Conclusion Increased expression of eNOS in glandular and luminal epithelium of the endometrium in women with recurrent miscarriages and unexplained infertility suggests a detrimental effect of excess nitric oxide in endometrial receptivity and implantation PMID:22877939

  19. Interaction of Hydrogen Sulfide with Nitric Oxide in the Cardiovascular System. (United States)

    Nagpure, B V; Bian, Jin-Song


    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.

  20. Local effects of nitric oxide on vestibular blood flow in the Mongolian gerbil. (United States)

    Arenberg, J G; Komjathy, D A; Seidman, M D; Quirk, W S


    There is a paucity of studies regarding the regulation of vestibular blood flow (VBF), despite the possibility that vascular alterations may contribute to specific vestibulopathies. The current experiments used the Mongolian gerbil as an animal model since it provides easy surgical access to the vestibular end-organs and has been previously used for physiologic studies involving inner ear function. VBF changes were measured in the posterior semicircular canal using laser Doppler flowmetry following round window membrane (RWM) application of the nitric oxide donor 1, 3-propanediamine-N-[4-1-(3-aminopropyl)-2-hydroxy-2-nitrosohydrazi no] butyl (spermine NONOate; SPNO) as a vasodilator. The specificity of the responses induced was tested via pretreatment with an NO scavenger, 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazonline-1-oxyl-3-oxide (carboxy-PTIO; cPTIO). cPTIO, SPNO, vehicle (control) or cPTIO/SPNO were applied to the RWM, during which blood pressure and VBF were monitored for baseline, treatment, and recovery conditions. Results showed concentration-dependent increases in flow, probably resulting from NO's vasodilatory action on local vasculature. cPTIO pretreatment was found to attenuate SPNO-induced VBF increases. These findings support a role of NO in maintaining the vestibular microcirculation.