Sample records for cerebral nitric oxide

  1. Nitric oxide increases carbon monoxide production by piglet cerebral microvessels

    Leffler, Charles W.; Balabanova, Liliya; Fedinec, Alexander L.; Parfenova, Helena


    Carbon monoxide (CO) and nitric oxide (NO) can be involved in regulation of cerebral circulation. Inhibition of production of either one of these gaseous intercellular messengers inhibits newborn pig cerebral arteriolar dilation to the excitatory amino acid glutamate. Glutamate can increase NO production. Therefore, the present study tests the hypothesis that NO, which is increased by glutamate, stimulates the production of CO by cerebral microvessels. Experiments used freshly isolated cerebr...

  2. Erythropoietin and cerebral vascular protection: role of nitric oxide

    Anantha Vijay R SANTHANAM; Zvonimir S KATUSIC


    Cerebral vasospasm after subarachnoid hemorrhage (SAH) is a major clinical problem causing cerebral ischemia and infarction.The pathogenesis of vasospasm is related to a number of pathological processes including endothelial damage and alterations in vasomotor function leading to narrowing of artefial diameter and a subsequent decrease in cerebral blood flow.Discovery of the tissue protective effects of erythropoietin (EPO) stimulated the search for therapeutic application of EPO for the prevention and treatment of cerebrovascular disease.Recent studies have identified the role of EP0 in vascular protection mediated by the preservation of endothelial cell integrity and stimulation of angiogenesis.In this review, we discuss the EPO-induced activation of endothelial nitric oxide (NO) synthase and its contribution to the prevention of cerebral vasospasm.

  3. Cerebral ischemia—induced neuronal apoptosis mediated by nitric oxide



    To elucidate the cellular and molecular mechanism of cerebral ischemia-induced neuronal apoptosis mediated by nitric oxide (NO) in the brain,we investigated:(1)cell death in hippocampal CA1 neurons of rats after a rransient four vessel occlusion (4VO)/reperfusion and (2) apoptosis induced by NOC18(NO releaser) using SHSY5Y cells,a human neuroblastoma cell line.We found that 4VO caused expression of inducible type of NO synthase (iNOS) in glial cells and neuronal apoptosis in CA1 region of rats.Next we examined in vitro apoptotic effects of NOC18 on SHSY5Y cells and suggest that NO decrease mitochondrial membrane potential,release cytochrome C from mitochondria,activates caspase-3,degrade inhibitor of caspase-activated DNase(Icad),and activated DNase translocate into nucleus and induce DNA fragmentation.Thus we conclude that the excess amount of NO produced by glial iNOS at cerebral ischemia could be involved in neuronal apoptosis in CA1 region.Regarding NO action on neurons,we further obtained that NO propects neuronal apoptosis in PC12 cells perhaps by nitrosylation of caspase,subsequent reduction of proteolytic activity.Taken together,we suggest that NO seem to exert dual effects(toxic and beneficial) on neuronal apoptosis,the one (toxic);apoptosis-induction throuth the decrease in mitochondrial membrane potentials and cytochrome C release and the othe (beneficial);protection against apoptosis through the inhibition of caspase activity.

  4. Sleep-active neuronal nitric oxide synthase-positive cells of the cerebral cortex: a local regulator of sleep?

    Wisor, Jonathan P.; Gerashchenko, Dmitry; Kilduff, Thomas S.


    Our recent report demonstrated that a small subset of GABAergic interneurons in the cerebral cortex of rodents expresses Fos protein, a marker for neuronal activity, during slow wave sleep (Gerashchenko et al., 2008). The population of sleep-active neurons consists of strongly immunohistochemically-stained cells for the enzyme neuronal nitric oxide synthase. By virtue of their widespread localization within the cerebral cortex and their widespread projections to other cortical cell types, cor...


    孙保亮; 张苏明; 夏作理; 杨明峰; 邱平明


    Objective. To investigate the effects of Ginkgo biloba extract (Egb) on cerebral vasospasm (CVS) after subarachnoid hemorrhage(SAH)and its influence on nitric oxide (NO) and endothelin-l(ET-1). Methods. Noncraniotomy models of SAH in Wistar rats were used and animals were divided into sham-operated group, SAH group, saline-treated group and Egb-treated group. Diameter of basilar artery was measured. Regional cerebral blood flow(rCBF),NO and ET-1 levels in blood,and calcium content in brain tissue within 24 hours after SAH were detected. Pathological examination of hippocampus CA1 sub field was also performed. Results. Sham operation did not alter the above parameters. Induction of SAH led to a marked spasm of basilar artery. rCBF decreased obviously and consecutively within 24 hours after SAH. Meanwhile NO level in serum decreased, ET-1 level in plasma and calcium content in brain tissue significantly in creased. Pyramidal cells in hippocampus CA1 subfield were severely damaged. Egb significantly antago nized the pathological alterations of the above parameters. Conclusion. Alterations of NO, and ET-1 play an important role in the development of CVS after SAH. Egb exerts its protective effects on CVS by inhibitng the above pathological alterations.

  6. In vivo stimulatory effect of erythropoietin on endothelial nitric oxide synthase in cerebral arteries.

    Santhanam, Anantha Vijay R; Smith, Leslie A; Nath, Karl A; Katusic, Zvonimir S


    The discovery of tissue protective effects of erythropoietin has stimulated significant interest in erythropoietin (Epo) as a novel therapeutic approach to vascular protection. The present study was designed to determine the cerebral vascular effects of recombinant Epo in vivo. Recombinant adenoviral vectors (10(9) plaque-forming units/animal) encoding genes for human erythropoietin (AdEpo) and beta-galactosidase (AdLacZ) were injected into the cisterna magna of rabbits. After 48 h, basilar arteries were harvested for analysis of vasomotor function, Western blotting, and measurement of cGMP levels. Gene transfer of AdEpo increased the expressions of recombinant Epo and its receptor in the basilar arteries. Arteries exposed to recombinant Epo demonstrated attenuation of contractile responses to histamine (10(-9) to 10(-5) mol/l) (P < 0.05, n = 5). Endothelium-dependent relaxations to acetylcholine (10(-9) to 10(-5) mol/l) were significantly augmented (P < 0.05, n = 5), whereas endothelium-independent relaxations to a nitric oxide (NO) donor 2-(N,N-diethylamino)diazenolate-2-oxide sodium salt remained unchanged in AdEpo-transduced basilar arteries. Transduction with AdEpo increased the protein expression of endothelial NO synthase (eNOS) and phosphorylated the S1177 form of the enzyme. Basal levels of cGMP were significantly elevated in arteries transduced with AdEpo consistent with increased NO production. Our studies suggest that in cerebral circulation, Epo enhances endothelium-dependent vasodilatation mediated by NO. This effect could play an important role in the vascular protective effect of Epo. PMID:16565320

  7. Early changes of endothelin, nitric oxide and arginine-vasopressin in patients with acute cerebral injury

    杨云梅; 黄卫东; 吕雪英


    Objective: To investigate the early changes and clinical significance of plasma endothelin (ET), nitric oxide (NO) and arginine-vasopressin (AVP) in patients with acute moderate or severe cerebral injury. Methods: The early (at 24 hours after injury) plasma concentrations of ET, NO and AVP were measured with radioimmunoassay and Green technique in 48 cases of acute moderate (GCS≤8 in 27cases ) or severe (GCS>8 in 21 cases) cerebral injury (Group A), in 42 cases of non-cerebral injury (Group B) and in 38 normal individuals (Group C), respectively. Results: The early plasma concentrations of ET (109.73 ng/L±12.61 ng/L), NO (92.82 μmol/L±18.21 μmol/L) and AVP (49.78 ng/L±14.29 ng/L) in Group A were higher than those in Group B (67.90 ng/L±11.33 ng/L, 52.66 μmol/L±12.82 μmol/L and 29.93 ng/L±12.11 ng/L, respectively, P<0.01) and Group C (50.65 ng/L±17.12 ng/L, 36.12 μmol/L±12.16 μmol/L and 5.18 ng/L±4.18 ng/L, respectively, P<0.001). The amounts of ET, NO and AVP in patients with severe cerebral injury were 116.18 ng/L±18.12 ng/L, 108.19 μmol/L±13.28 μmol/L and 58.13 ng/L±16.78 ng/L, respectively, which were significantly higher than that of the patients with moderate cerebral injury (92.33 ng/L±16.32 ng/L, 76.38 μmol/L±12.71 μmol/L and 36.18 ng/L±12.13 ng/L respectively, P<0.01). The early levels of ET, NO and AVP in Group A were negatively related to the GCS scales. The amounts of ET, NO and AVP were 126.23 ng/L±15.23 ng/L, 118.18 μmol/L±10.12 μmol/L and 63.49 ng/L±14.36 ng/L respectively in patients with subdural hematoma, which were significantly higher than those in patients with epidural hematoma (81.13 ng/L±12.37 ng/L, 68.02 μmol/L±13.18 μmol/L and 45.63 ng/L±12.41 ng/L respectively, P<0.01). The plasma concentrations of ET, NO and AVP in stable duration (at 336 hours after injury) in Group A and Group B were similar to those in Group C.Conclusions: ET, NO and AVP were related to the pathophysiological process that occurs in

  8. The Traditional Herbal Medicine, Dangkwisoo-San, Prevents Cerebral Ischemic Injury through Nitric Oxide-Dependent Mechanisms

    Ji Hyun Kim


    Full Text Available Dangkwisoo-San (DS is an herbal extract that is widely used in traditional Korean medicine to treat traumatic ecchymosis and pain by promoting blood circulation and relieving blood stasis. However, the effect of DS in cerebrovascular disease has not been examined experimentally. The protective effects of DS on focal ischemic brain were investigated in a mouse model. DS stimulated nitric oxide (NO production in human brain microvascular endothelial cells (HBMECs. DS (10–300 μg/mL produced a concentration-dependent relaxation in mouse aorta, which was significantly attenuated by the nitric oxide synthase (NOS inhibitor L-NAME, suggesting that DS causes vasodilation via a NO-dependent mechanism. DS increased resting cerebral blood flow (CBF, although it caused mild hypotension. To investigate the effect of DS on the acute cerebral injury, C57/BL6J mice received 90 min of middle cerebral artery occlusion followed by 22.5 h of reperfusion. DS administered 3 days before arterial occlusion significantly reduced cerebral infarct size by 53.7% compared with vehicle treatment. However, DS did not reduce brain infarction in mice treated with the relatively specific endothelial NOS (eNOS inhibitor, N5-(1-iminoethyl-L-ornithine, suggesting that the neuroprotective effect of DS is primarily endothelium-dependent. This correlated with increased phosphorylation of eNOS in the brains of DS-treated mice. DS acutely improves CBF in eNOS-dependent vasodilation and reduces infarct size in focal cerebral ischemia. These data provide causal evidence that DS is cerebroprotective via the eNOS-dependent production of NO, which ameliorates blood circulation.

  9. Role of nitric oxide synthases in early blood-brain barrier disruption following transient focal cerebral ischemia.

    Zheng Jiang

    Full Text Available The role of nitric oxide synthases (NOSs in early blood-brain barrier (BBB disruption was determined using a new mouse model of transient focal cerebral ischemia. Ischemia was induced by ligating the middle cerebral artery (MCA at its M2 segment and reperfusion was induced by releasing the ligation. The diameter alteration of the MCA, arterial anastomoses and collateral arteries were imaged and measured in real time. BBB disruption was assessed by Evans Blue (EB and sodium fluorescein (Na-F extravasation at 3 hours of reperfusion. The reperfusion produced an extensive vasodilation and a sustained hyperemia. Although expression of NOSs was not altered at 3 hours of reperfusion, L-NAME (a non-specific NOS inhibitor abolished reperfusion-induced vasodilation/hyperemia and significantly reduced EB and Na-F extravasation. L-NIO (an endothelial NOS (eNOS inhibitor significantly attenuated cerebral vasodilation but not BBB disruption, whereas L-NPA and 7-NI (neuronal NOS (nNOS inhibitors significantly reduced BBB disruption but not cerebral vasodilation. In contrast, aminoguanidine (AG (an inducible NOS (iNOS inhibitor had less effect on either cerebral vasodilation or BBB disruption. On the other hand, papaverine (PV not only increased the vasodilation/hyperemia but also significantly reduced BBB disruption. Combined treatment with L-NAME and PV preserved the vasodilation/hyperemia and significantly reduced BBB disruption. Our findings suggest that nNOS may play a major role in early BBB disruption following transient focal cerebral ischemia via a hyperemia-independent mechanism.

  10. Glutamate-induced activation of nitric oxide synthase is impaired in cerebral cortex in vivo in rats with chronic liver failure.

    Rodrigo, Regina; Erceg, Slaven; Rodriguez-Diaz, Jesus; Saez-Valero, Javier; Piedrafita, Blanca; Suarez, Isabel; Felipo, Vicente


    It has been proposed that impairment of the glutamate-nitric oxide-cyclic guanosine monophosphate (cGMP) pathway in brain contributes to cognitive impairment in hepatic encephalopathy. The aims of this work were to assess whether the function of this pathway and of nitric oxide synthase (NOS) are altered in cerebral cortex in vivo in rats with chronic liver failure due to portacaval shunt (PCS) and whether these alterations are due to hyperammonemia. The glutamate-nitric oxide-cGMP pathway function and NOS activation by NMDA was analysed by in vivo microdialysis in cerebral cortex of PCS and control rats and in rats with hyperammonemia without liver failure. Similar studies were done in cortical slices from these rats and in cultured cortical neurons exposed to ammonia. Basal NOS activity, nitrites and cGMP are increased in cortex of rats with hyperammonemia or liver failure. These increases seem due to increased inducible nitric oxide synthase expression. NOS activation by NMDA is impaired in cerebral cortex in both animal models and in neurons exposed to ammonia. Chronic liver failure increases basal NOS activity, nitric oxide and cGMP but reduces activation of NOS induced by NMDA receptors activation. Hyperammonemia is responsible for both effects which will lead, independently, to alterations contributing to neurological alterations in hepatic encephalopathy. PMID:17286583

  11. Rapid nontranscriptional activation of endothelial nitric oxide synthase mediates increased cerebral blood flow and stroke protection by corticosteroids

    Limbourg, Florian P.; Huang, Zhihong; Plumier, Jean-Christophe; Simoncini, Tommaso; Fujioka, Masayuki; Tuckermann, Jan; Schütz, Günther; Moskowitz, Michael A.; Liao, James K.


    Many cellular responses to corticosteroids involve the transcriptional modulation of target genes by the glucocorticoid receptor (GR). A rapid, non-nuclear effect of GR was found to mediate neuroprotection. High-dose corticosteroids (20 mg/kg intraperitoneally), given within 2 hours of transient cerebral ischemia, acutely increased endothelial nitric oxide synthase (eNOS) activity, augmented regional cerebral blood flow (CBF) by 40% to 50%, and reduced cerebral infarct size by 32%. These neuroprotective effects of corticosteroids were abolished by the GR antagonist RU486 and by inhibition of phosphatidylinositol 3-kinase (PI3K), and were absent in eNOS–/– mice. To determine the mechanism by which GR activated eNOS, we measured the effect of corticosteroids on PI3K and the protein kinase Akt. In a ligand-dependent manner, GR activated PI3K and Akt in vitro and in vivo caused NO-dependent vasodilation, which was blocked by cotreatment with RU486 or the PI3K inhibitor LY294002 but not by transcriptional inhibitors. Indeed, a mutant GR, which cannot dimerize and bind to DNA, still activated PI3K and Akt in response to corticosteroids. These findings indicate that non-nuclear GR rapidly activates eNOS through the PI3K/Akt pathway and suggest that this mechanism mediates the acute neuroprotective effects of corticosteroids through augmentation of CBF. PMID:12464678

  12. Cervical sympathetic trunk transection affects inducible nitric oxide synthase expression in rat hippocampus following focal cerebral ischemia/reperfusion injury

    Liangzhi Xiong; Yan Wang; Qingxiu Wang; Qingshan Zhou


    BACKGROUND: The stellate ganglion block (SGB) plays a protective role in focal cerebral ischemia/reperfusion injury. The human SGB can be simulated by transection of the cervical sympathetic trunk (TCST) in rats.OBJECTIVE: To observe the effects of TCST on inducible nitric oxide synthase (iNOS) levels and cerebral infarct wolume in the hippocampus of rats with cerebral ischemia/reperfusion injury, and to analyze the mechanism of action.DESIGN, TIME AND SETTING: A completely randomized, controlled, neuropathological experiment was performed at the Institute of Neurological Disease, Taihe Hospital, Yunyang Medical College between March and September 2006.MATERIALS: A total of 93 Wistar rats, aged 17-18 weeks, of either gender, were used for this study. 2, 3, 5-triphenyl tetrazolium chloride was purchased from Changsha Hongyuan Biological Reagent Company, China. Rabbit iNOS antibody and goat anti-rabbit lgG antibody were the products of Wuhan Boster Biological Reagent Co., Ltd., China.METHODS: Ten rats were randomly selected for the sham-operated group. Cerebral ischemia/reperfusion injury was induced by middle cerebral artery occlusion (MCAO) using the suture method in the remaining rats. Forty successful rat models were randomly and equally divided into the following two groups: (1) TCST group: subsequent to TCST, MCAO was performed for 2 hours, followed by 24 hours reperfusion; (2) model group: rats underwent experimental procedures similar to the TCST group, with the exception of TCST. Rats in the sham-operated group were subjected to experimental procedures similar to the model group; however, the thread was only introduced to a depth of 10 mm.MAIN OUTCOME MEASURES: Following 24 hours of reperfusion, functional neurological deficits were scored. Brain tissue sections from ten rats of each group were used to measure cerebral infarct volume by TTC staining. Hippocampal tissue sections of an additional ten rats from each group were used to detect iNOS levels using

  13. Changes of cerebral blood flow in rats with acute cerebral ischemia and the effect of nitric oxide donor S-nitroso-N-acetyl-penicillamine

    Feng Gao; Zhiqiang Yi; Guijun Lin


    BACKGROUND: Previous studies show that nitric oxide donor can increase cerebral blood flow and improve the function of neurons in cerebral ischemia, but the change does not happen in all the models of cerebral ischemia. OBJECTIVE: To observe the effects of nitric oxide donor S-nitroso-N-acetyl-penicillamine (SNAP) on the cerebral blood flow, cyclic guanosine monophosphate (cGMP) content in cerebral cortex, infarct volume and blood pressure in acute ischemic rat brain.DESIGN: A randomized and control animal experiment. SETTING: Department of Neurosurgery, Aerospace Central Hospital, Peking University. MATERIALS: Twenty-eight male Wistar rats of SPF grade, weighing 250-300 g, aged 10-12 weeks were randomly divided into control group (n =14) and SNAP-treated group (n =14). SNAP (5 mg/bottle) was provided by Beijing Chemical Reagent Company. Laser Doppler Flowmeter (FLO C1; Omegawave Inc., Tokyo, Japan) and immunoassay kit (Amersham Pharmacia Biotech, UK) were applied.METHODS: ① Model establishment: In the control group, models of cerebral ischemia were induced by ligating right common, internal and external carotid arteries; In the SNAP-treated group, models of cerebral ischemia were induced by ligating right common and external carotid arteries, followed by occluding middle cerebral artery and ligating internal carotid artery. ② Administration: In the SNAP-treated group, SNAP (100 μg/kg) was intravenously infused within 2 minutes, whereas in the control group, phosphate buffered saline (PBS, 1 mL) was intravenously infused (0.5 mL per minute). Six rats were used to measure the volume of cerebral infarction, and the other 8 rats were used to determine other indexes in each group respectively. ③ Determination of indexes: Regional cerebral blood flow (rCBF) was continuously measured by laser-Doppler flowmetry in the ischemic penumbra and contralateral cortex under the continuous monitoring of blood pressure, cGMP concentrations in brain tissue were determined

  14. Selective inhibition of inducible nitric oxide synthase reduces neurological deficit but not cerebral edema following traumatic brain injury.

    Louin, G; Marchand-Verrecchia, C; Palmier, B; Plotkine, M; Jafarian-Tehrani, M


    The role of inducible nitric oxide synthase (iNOS) in cerebral edema and neurological deficit following traumatic brain injury (TBI) is not yet clear-cut. Therefore, the aim of this study was to investigate the effect of three different iNOS inhibitors on cerebral edema and functional outcome after TBI. First, the time courses of blood--brain barrier (BBB) breakdown, cerebral edema, and neurological deficit were studied in a rat model of fluid percussion-induced TBI. The permeability of BBB to Evans blue was increased from 1 h to 24 h after TBI. Consistently, a significant increase in brain water content (BWC) was observed at 6 and 24 h post-TBI. A deficit in sensorimotor neurological functions was also observed from 6 h to 7 days with a maximum 24 h after TBI. Second, a single dose of aminoguanidine (AG; 100 mg/kg, i.p.), L-N-iminoethyl-lysine (L-NIL; 20 mg/kg, i.p.), or N-[3-(aminomethyl)benzyl]acetamide (1400W; 20 mg/kg, s.c.) was administered at 6 h post-TBI. Treatment with AG reduced by 71% the increase in BWC evaluated at 24 h, while L-NIL and 1400W had no effect. In contrast, the three iNOS inhibitors reduced the neurological deficit from 30% to 40%. Third, 1400W (20 mg/kg, s.c.) was administered at 5 min, 8 and 16 h post-TBI. Although this treatment paradigm had no effect on cerebral edema evaluated at 24 h, it significantly reduced the neurological deficit and iNOS activity. In conclusion, iNOS contributes to post-TBI neurological deficit but not to cerebral edema. The beneficial effect of iNOS inhibitors is not due to their anti-edematous effect, and the reduction of cerebral edema by AG is unlikely related to iNOS inhibition. The 6 h therapeutic window of iNOS inhibitors could allow their use in the treatment of functional deficit at the acute phase of TBI. PMID:16242164

  15. Biochemistry of Nitric Oxide

    Habib, Safia; Ali, Asif


    Nitric oxide (NO) a free radical having both cytoprotective as well as tumor promoting agent is formed from l-arginine by converting it to l-citrulline via nitric oxide synthase enzymes. The reaction product of nitric oxide with superoxide generates potent oxidizing agent, peroxynitrite which is the main mediator of tissue and cellular injury. Peroxynitrite is reactive towards many biomolecules which includes amino acids, nucleic acid bases; metal containing compounds, etc. NO metabolites may...

  16. Early changes of endothelin,nitric oxide and arginine—vasopressin in patients with acute cerebral injury

    杨云梅; 黄卫东; 等


    Objective:To ivvestigate the early changes and clinical significance of plasma endothelin(ET),nitric oxide(NO)and arginine-vasopressin(AVP)in patients wisth acute moderate or severe cerebral injury.Metods:The ealy(at24 hours after injury)plasma concentrations of ET,NOand AVP were measured with radionimmunoassay and Green technique in48cases of acute moderate(GCS≤8in27cases)or severe(GCS>8in21cases)cerebral injury(GroupA),in42cases of non-cerebral injury(GroupB)and in38normal individuals(GroupC),respectively,Results:The early plasma concentrations of ET(109.73ng/L±12.61ng/L),NO(92.82μmol/L013218.21μmol/L)andAVP(49.78ng/L±14.29ng/L)inGroup Awere higher than those in Group B(67。013211.33ng/L,52.66μmol/L±12.82μmol/Land29.93ng/L±12.11ng/L,respectiely,P<0.01)andGroupC(50.65ng/L±17.12ng/L,36.12μmol/L013212.16μmol/Land5.18ng/L±4.18ng/L,respectively,P<0.001).The amounts of ET,NOand AVPin patients with severe cerebral injury were 116.18ng/L±18.12ng/L,108.19μmol/L±13.28μmol/Land58.13ng/L±16.78ng/L,respectively,which were significantly higher than that of the patients with moderate cerebral injury(92.33ng/L±16.32ng/L,76.38μmol/L±12.71μmol/Land36.18ng/L±12.13ng/L respectively,P<0.01).The early levels of ET,NO and AVP in Group A were negatively related to the GCS scales.The amounts of ET,NO and AVP were126.23ng/L±15.23ng/L,118.18μmol/L±10.12μmol/Land63.49ng/L±14.36ng/Lrespectively in patients with subdural hematoma,which were significantly higher than those in patients with epidural hematoma(81.13ng/L±12.37ng/L,68.02μmol/L013213.18μmol/Land 45.63ng/L±12.41ng/L respectively,P<0.01).The plasma concentrations of ET,NO and AVP in stable duration(at336 hours after injury)in Group A and Group Bwere similar to those in GroupC.Conclusions:ET,NO and AVP were related to the pathophysiological process that occurs in the early stage of acute cerebral injury and the values of ET.NO and AVP correlate positively with the clinical manifestations,The changes

  17. Nitrate and nitrite anion concentration in the intact cerebral cortex of preterm and nearterm fetal sheep: indirect index of in vivo nitric oxide formation.

    Reynolds, J D; Zeballos, G A; Penning, D H; Kimura, K A; Atkins, B; Brien, J F


    Pregnant sheep with a microdialysis probe implanted in the fetal cerebral cortex were used to determine if nitrate and nitrite anions (nitrate/nitrite) could be quantitated in the microdialysate as an indirect index of in vivo nitric oxide formation. Pregnant ewes (term, about 147 days) were surgically instrumented at gestational day (GD) 90 (n = 3; preterm) and GD 121 (n = 3; nearterm). Three days later, following an overnight probe equilibration period, five dialysate samples were collected continuously on ice at 1-h intervals (infusion rate of 1 (microl/min). The nitrate/nitrite concentration was determined by reducing a 10-microl aliquot of each dialysate fraction with hot acidic vanadium followed by chemiluminescence quantitation of the nitric oxide product. The lower limit of quantitative sensitivity of the method is 25 picomoles. Nitrate/nitrite concentration was 16.6+/-7.3 microM for the preterm fetus and 19.7+/-1.9 microM for the nearterm fetus. The data demonstrate that nitrate/nitrite, as an index of in vivo nitric oxide formation, can be quantitated in microdialysate samples collected from the intact fetal sheep cerebral cortex. PMID:9741385

  18. Correlation between plasma total nitric oxide levels and cerebral vasospasm and clinical outcome in patients with aneurysmal subarachnoid hemorrhage in Indian population

    Shruthi Shimoga Ramesh


    Full Text Available Context: Cerebral vasospasm remains a major cause of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH. Reduced bioavailability of nitric oxide has been associated with the development of cerebral vasospasm after aSAH. Such data is not available in Indian population. Aims: The objective of the study was to measure the plasma total nitric oxide (nitrite and nitrate-NOx level in aSAH patients and healthy controls treated at a tertiary hospital in India and to investigate a possible association between plasma total nitric oxide level and cerebral vasospasm and clinical outcome following treatment in patients with aSAH. Settings and Design: A case-control study of aSAH patients was conducted. Plasma total NOx levels were estimated in aSAH patients with and without vasospasm and compared the results with NOx levels in healthy individuals. Materials and Methods: aSAH in patients was diagnosed on the basis of clinical and neuro-imaging findings. Plasma total NOx levels in different subject groups were determined by Griess assay. Results: Plasma total NOx level was found to be significantly decreased in patients with aSAH when compared to controls. Plasma total NOx level in the poor-grade SAH group was lower than that in the good-grade SAH group. Plasma total NOx level further reduced in patients with angiographic (P < 0.05 and clinical vasospasm. Conclusions: Reduced plasma NOx level is seen in aSAH patients as compared to normal individuals. In aSAH patients reduced levels are associated with increased incidence of cerebral vasospasm and poor outcome. Plasma total NOx level could be used as a candidate biomarker for predicting vasospasm and outcome for this pathology.

  19. Nitric Oxide: An Overview

    Saleem Shaikh


    Full Text Available The small molecule nitric oxide (NO has a vast number of actions, many of which are poorly understood. Although NO is produced by three distinct isoforms of the enzyme nitric oxide synthase (NOS, most research is directed toward the form, iNOS which is seen following induction. Nitric oxide has been extensively researched in relation to cancer, where it has a multifaceted role. It has also been investigated in relation to oral lesions and tumors like ameloblastoma, salivary gland tumors, periapical lesions, S jogren’s syndrome, etc. This review looks into all these facets of NO and its potential role as a diagnostic and therapeutic modality.

  20. Effects of melatonin on learning abilities, cholinergic fibers and nitric oxide synthase expression in rat cerebral cortex

    Bin Xu; Junpao Chen; Hailing Zhao


    BACKGROUND: Melatonin is a kind of hormones derived from pineal gland. Recent researches demonstrate that melatonin is characterized by anti-oxidation, anti-senility and destroying free radicals. While, effect and pathogenesis of pineal gland on learning ability should be further studied.OBJ ECTIVE: To investigate the effects of pinealectomy on learning abiliy, distribution of cholinesterase and expression of neuronal nitric oxide synthase (nNOS) in cerebral cortex of rats and probe into the effect of melatonin on learning ability, central cholinergic system and nNOS expression.DESIGN: Randomized grouping design and animal study.SETTING: Department of Neurology, the 187 Hospital of Chinese PLA.MATERIALS: A total of 12 male SD rats, of normal learning ability testing with Y-tape maze, of clean grade,weighing 190-210 g, aged 6 weeks, were selected in this study.METHODS: The experiment was carried out in the Department of Neurology, Zhujiang Hospital from July 1997to June 2000. All SD rats were divided into experimental group (n =6,pinealectomy) and control group (n =6, sham operation). Seven days later, rats in both two groups were continuously fed for 33 days. ①Learning ability test: The learning ability of rats was tested by trisection Y-type maze and figured as attempting times. ②Expression of acetylcholinesterase (AchE) was detected by enzyme histochemistry and nNOS was measured by SABC method. ③ Quantitative analysis of AchE fibers: AchE fibers density in unit area (surface density)was surveyed with Leica Diaplan microscope and Leica Quantimet 500+ image analytic apparatus and quantitative parameter was set up for AchE fibers covering density (μm2) per 374 693.656 μm2, moreover, the AchE fibers density was measured in Ⅱ -Ⅳ layers of motor and somatosensory cortex (showing three layers per field of vision at one time), in radiative, lacunaria and molecular layers of CA1, CA2 and CA3 areas, and in lamina multiforms of dentate gyrus. Three tissue slices

  1. Effect of an inhibitor of neuronal nitric oxide synthase 7-nitroindazole on cerebral hemodynamic response and brain excitability in urethane-anesthetized rats

    Brožíčková, Carole; Otáhal, Jakub


    Roč. 62, Suppl.1 (2013), S57-S66. ISSN 0862-8408 R&D Projects: GA ČR(CZ) GAP303/10/0999; GA ČR(CZ) GPP304/11/P386; GA ČR(CZ) GBP304/12/G069 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : cerebral hemodynamic response * brain excitability * neuronal nitric oxide synthase * 7-nitroindazole * rat Subject RIV: FH - Neurology Impact factor: 1.487, year: 2013

  2. Nitric oxide synthase inhibition and cerebrovascular regulation

    Iadecola, C; Pelligrino, D A; Moskowitz, M A;


    There is increasing evidence that nitric oxide (NO) is an important molecular messenger involved in a wide variety of biological processes. Recent data suggest that NO is also involved in the regulation of the cerebral circulation. Thus, NO participants in the maintenance of resting cerebrovascul...

  3. Effect of nitric oxide blockade by NG-nitro-L-arginine on cerebral blood flow response to changes in carbon dioxide tension

    Wang, Qian; Paulson, O B; Lassen, N A


    The importance of nitric oxide (NO) for CBF variations associated with arterial carbon dioxide changes was investigated in halothane-anesthetized rats by using an inhibitor of nitric oxide synthase, NG-nitro-L-arginine (NOLAG). CBF was measured by intracarotid injection of 133Xe. In normocapnia...

  4. Demystified … Nitric oxide

    Stuart-Smith, K


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

  5. Nitric Oxide Synthases and Atrial Fibrillation

    CynthiaAnnCarnes; ArunSridhar; SandorGyorke


    Oxidative stress has been implicated in the pathogenesis of atrial fibrillation. There are multiple systems in the myocardium which contribute to redox homeostasis, and loss of homeostasis can result in oxidative stress. Potential sources of oxidants include nitric oxide synthases, which normally produce nitric oxide in the heart. Two nitric oxide synthase isoforms (1 and 3) are normally expressed in the heart. During pathologies such as heart failure, there is induction of nitric oxide syn...

  6. Role of Cyclooxygenase-2 in Relation to Nitric Oxide and Endothelin-1 on Pathogenesis of Cerebral Vasospasm After Subarachnoid Hemorrhage in Rabbit.

    Munakata, Akira; Naraoka, Masato; Katagai, Takeshi; Shimamura, Norihito; Ohkuma, Hiroki


    Endothelial dysfunctions that include decreased nitric oxide (NO) bioactivity and increased endothelin-1 (ET-1) bioactivity have been considered to be involved in the pathogenesis of cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage (SAH). Recent cardiovascular studies have revealed that cyclooxygenase-2 (COX-2) is involved in a disturbance in cross-talk between NO and ET-1. COX-2 expression was detected in the endothelial cells of a spastic artery after experimental SAH; however, the pathophysiological significance of COX-2 in relation to CVS remains unclear. The aim of this study was to investigate the role of COX-2 in relation to NO and ET-1 in the pathogenesis of CVS by using the COX-2 selective inhibitor, celecoxib. In the SAH group, SAH was simulated using the double-hemorrhage rabbit model. In the celecoxib group, SAH was simulated and celecoxib was administered. The basilar artery was extracted on day 5 and examined. The cross-section area of the basilar artery in the celecoxib group was significantly larger than in the SAH group. An increased expression of COX-2, ET-1, and ETA receptor (ETAR), and a decreased expression of endothelial NO synthase (eNOS) were seen in the SAH group. In the celecoxib group compared to the SAH group, expression of COX-2, ET-1, and ETAR were statistically significantly decreased, and eNOS expression was significantly increased. COX-2 might be involved in the pathogenesis of CVS due to up-regulation of ET-1 and ETAR and down-regulation of eNOS, and celecoxib may potentially serve as an agent in the prevention of CVS after SAH. PMID:27044361

  7. Nitric oxide-related drug targets in headache

    Olesen, Jes


    SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so-called del......SUMMARY: Nitric oxide (NO) is a very important molecule in the regulation of cerebral and extra cerebral cranial blood flow and arterial diameters. It is also involved in nociceptive processing. Glyceryl trinitrate (GTN), a pro-drug for NO, causes headache in normal volunteers and a so...... experimentation make it highly likely that antagonizing NO effects will be effective in the treatment of primary headaches. Nonselective NOS inhibitors are likely to have side effects whereas selective compounds are now in early clinical trials. Antagonizing the rate limiting cofactor tetrahydrobiopterin seems...

  8. Nitric Oxide synthases and atrial fibrillation



    Full Text Available Oxidative stress has been implicated in the pathogenesis of atrial fibrillation. There are multiple systems in the myocardium which contribute to redox homeostasis, and loss of homeostasis can result in oxidative stress. Potential sources of oxidants include nitric oxide synthases, which normally produce nitric oxide in the heart. Two nitric oxide synthase isoforms (1 and 3 are normally expressed in the heart. During pathologies such as heart failure, there is induction of nitric oxide synthase 2 in multiple cell types in the myocardium. In certain conditions, the NOS enzymes may become uncoupled, shifting from production of nitric oxide to superoxide anion, a potent free radical and oxidant. Multiple lines of evidence suggest a role for nitric oxide synthases in the pathogenesis of atrial fibrillation. Therapeutic approaches to reduce atrial fibrillation by modulation of nitric oxide synthase activity may be beneficial, although further investigation of this strategy is needed.

  9. Nitric oxide scavenging by hemoglobin or nitric oxide synthase inhibition by N-Nitro-L-arginine induces cortical spreading ischemia when K+0+ is increased in the subarachnoid space

    Dreier, J.P.; Körner, K.; Ebert, Nathalie;


    Cerebral blood flow, nitric oxide, potassium, spreading depression, vasospasm, migraine, migrainous stroke, mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS)......Cerebral blood flow, nitric oxide, potassium, spreading depression, vasospasm, migraine, migrainous stroke, mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS)...

  10. Inducible nitric oxide synthase and inflammation.

    Salvemini, D; Marino, M H


    Nitric oxide (NO), derived from L-arginine (L-Arg) by the enzyme nitric oxide synthase (NOS), is involved in acute and chronic inflammatory events. In view of the complexity associated with the inflammatory response, the dissection of possible mechanisms by which NO modulates this response will be profitable in designing novel and more efficacious NOS inhibitors. In this review we describe the consequences associated with the induction of inducible nitric oxide synthase (iNOS) and its therapeutic implications. PMID:15991919

  11. Study of Atmospheric Nitric Oxide

    Dalgarno, A.


    We investigated the contribution of energetic nitrogen atoms to the production of nitric oxide in the thermosphere and their influence on the infrared emission spectrum. The nitric oxide molecules are important contributors to the cooling of the atmosphere. We first pointed out that in determining the energy distribution of the nitrogen atoms, it is important to take into account the thermal motion of the atmospheric gases. It had been ignored in all earlier studies. The source spectra are broadened considerably by the center of mass motion of the reactants. We worked out the consequences for the production of nitric oxide at night, using as sources of energetic N atoms, NO(+) + e yield N + O, N(D-2) + O yield N + O. The high energy tail is enhanced by orders of magnitude. We had earlier suggested (Sharma et al. 1993) that the reaction of energetic nitrogen atoms with O2 was responsible for the rotationally enhanced NO identified in the infrared spectrum. Our calculations provided quantitative confirmation of the suggestion. We proceeded to explore the validity of another approximation used in earlier analyses, the hard sphere approximation for the energy loss in elastic collisions. We carried out precise quantum mechanical calculations of the elastic 2 differential scattering of nitrogen atoms in collisions with oxygen atoms and showed that although the hard sphere approximation was nowhere of high precision, reasonable results could be obtained with an effective cross section of 6 x 10(exp 15)sq cm. We also initiated a program to include inelastic energy loss processes in the determination of the energy distribution function. We began a calculation of the rotation and vibrational excitation cross sections of molecular nitrogen and nitrogen atoms and developed a method for including inelastic energy loss as a function of scattering angle in the Boltzmann equation. A procedure for obtaining the solution of the Boltzman equation was worked out.

  12. Novel effects of nitric oxide

    Davis, K. L.; Martin, E.; Turko, I. V.; Murad, F.


    Nitric oxide (NO), a simple free radical gas, elicits a surprisingly wide range of physiological and pathophysiological effects. NO interacts with soluble guanylate cyclase to evoke many of these effects. However, NO can also interact with molecular oxygen and superoxide radicals to produce reactive nitrogen species that can modify a number of macromolecules including proteins, lipids, and nucleic acids. NO can also interact directly with transition metals. Here, we have reviewed the non--3',5'-cyclic-guanosine-monophosphate-mediated effects of NO including modifications of proteins, lipids, and nucleic acids.

  13. Inhaled nitric oxide to prevent bronchopulmonary dysplasia in preterm neonates.

    Mercier, Jean-Christophe; Olivier, Paul; Loron, Gauthier; Fontaine, Romain; Maury, Laure; Baud, Olivier


    Bronchopulmonary dysplasia is a chronic lung disease that affects premature infants and contributes to their morbidity and mortality. With the advent of prenatal steroids and postnatal exogenous surfactant and less aggressive respiratory support, premature infants can develop chronic oxygen dependency without even acute respiratory distress. This 'new bronchopulmonary dysplasia' could be the result of impaired postnatal growth. Several experimental studies have suggested a possible role of the vascular endothelial growth factor/nitric oxide (VEGF/NO) pathway in restoring pulmonary angiogenesis and enhancing distal lung growth. The results of the clinical studies are, however, inconclusive, and it is currently unclear which subsets of premature infants might benefit from inhaled nitric oxide. Besides, severe intracranial haemorrhage and/or cystic periventricular leucomalacia may affect the most immature babies, many of whom are spared from severe initial respiratory disease. Recently, inhaled nitric oxide was shown to significantly decrease the incidence of these neurological events, and to improve the long-term outcome in a few clinical trials. At times neuroprotective, at times neurotoxic, nitric oxide is capable of divergent effects depending upon the extent of cerebral damage, the redox state of the cell, and the experimental model used. Recently, our group found that inhaled nitric oxide had remote effects including angiogenesis and maturation on the developing brain in rodent pups. Thus, we await the results of the recently completed randomised clinical trial of inhaled nitric oxide to prevent bronchopulmonary dysplasia (the European Nitric Oxide or 'EUNO' trial) where, besides the primary endpoint of chronic oxygen dependency reduction at 36 weeks' postconceptional age, long-term lung and brain will be followed-up until 7 years of age. PMID:18986855

  14. Nitric oxide treatment for fulminant pulmonary hypertension.

    Allman, K G; Young, J D; Stevens, J E; Archer, L N


    A 3 year old child with known pulmonary haemosiderosis suffered acute circulatory collapse secondary to raised pulmonary vascular resistance. Nitric oxide inhalation produced a profound improvement in circulatory parameters and gaseous exchange. Nitric oxide may have a therapeutic role in acute pulmonary hypertensive crisis.

  15. Inducible nitric oxide synthase in renal transplantation

    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 induc

  16. Effects of low molecular weight heparin-superoxide dismutase conjugate on serum levels of nitric oxide, glutathione peroxidase, and myeloperoxidase in a gerbil model of cerebral ischemia/reperfusion injury

    Qingde Wang; Guixiang Cui; Hongxia Liu; Yizhao Li; Fengshan Wang


    BACKGROUND: Several studies have demonstrated that low molecular weight heparin-superoxide dismutase (LMWH-SOD) conjugate may exhibit good neuroprotective effects on cerebral ischemia/reperfusion injury though anticoagulation, decreasing blood viscosity, having anti-inflammatory activity, and scavenging oxygen free radicals. OBJECTIVE: To investigate the intervention effects of LMWH-SOD conjugate on serum levels of nitric oxide (NO), glutathione peroxidase (GSH-Px), and myeloperoxidase (MPO) following cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETTING: A randomized, controlled, and neurobiochemical experiment was performed at the Institute of Biochemical Pharmacy, School of Pharmaceutical Sciences, Shandong University between April and July 2004. MATERIALS: A total of 60 Mongolian gerbils of either gender were included in this study. Total cerebral ischemia/reperfusion injury was induced in 50 gerbils by occluding bilateral common carotid arteries. The remaining 10 gerbils received a sham-operation (sham-operated group). Kits of SOD, NO, and MPO were sourced from Nanjing Jiancheng Bioengineering Institute, China. LMWH, SOD, and LMWH-SOD conjugates were provided by Institute of Biochemistry and Biotechnique, Shandong University, China. METHODS: Fifty successful gerbil models of total cerebral ischemia/reperfusion injury were evenly randomized to five groups: physiological saline, LMWH-SOD, SOD, LMWH + SOD, and LMWH. At 2 minutes prior to ischemia, 0.5 mL/65 g physiological saline, 20 000 U/kg LMWH-SOD conjugate, 20 000 U/kg SOD, a mixture of SOD (20 000 U/kg) and LMWH (LMWH dose calculated according to weight ratio, LMWH: SOD = 23.6:51), and LMWH (dose as in the LMWH + SOD group) were administered through the femoral artery in each above-mentioned group, respectively. MAIN OUTCOME MEASURES: Serum levels of NO, MPO, and GSH-Px. RESULTS: Compared with 10 sham-operated gerbils, the cerebral ischemia/reperfusion injury gerbils exhibited decreased serum

  17. Sampling nitric oxide from combustion gases.

    England, C.; Houseman, J.; Teixeira, D. P.


    Experimental study of several sampling tube and probe material compositions and designs aimed at preventing nitric oxide reduction when sampling nitric oxide from combustion gases. A 250,000 Btu/h furnace fired with technical grade methane was used for testing the sampling probes over a wide range of air-fuel mixtures. The results obtained include the finding that the use of stainless steel in probes creates inaccuracies in near-stoichiometric and fuel-rich sampling in hydrocarbon flames. For very fuel-rich flames, water cooling is needed even in quartz probes to prevent significant reduction of nitric oxide.-

  18. Increased density of neurons containing NADPH diaphorase and nitric oxide synthase in the cerebral cortex of patients with HIV-1 infection and drug abuse.

    Kuljis, Rodrigo O; Shapshak, Paul; Alcabes, Philip; Rodríguez de la Vega, Pura; Fujimura, Robert; Petito, Carol K


    To determine whether nitrogen monoxide (nitric oxide; NO) synthase (NOS) and NADPH diaphorase (NDP) co-containing cerebrocortical neurons (NOSN) neurons are affected in patients infected with human immunodeficiency virus type 1 (HIV-1) with and without associated intake of drugs of abuse, we examined the temporal neocortex of 24 individuals: 12 HIV-1 positive (including 3 drug users, 9 non-drug users) and 12 HIV-1 negative (including 6 drug users, and 6 non-drug users). Histochemical labeling for NDP-an enzymatic domain co-expressed in the NOS enzyme-was employed to visualize NOSN. Drug abuse and HIV-1 infection cause independently an increase in NOSN density, but combined they result in up to a 38-fold increase in NOSN density, suggesting that the combination of these factors induces NOS expression powerfully in neurons that normally do not synthesize NDP/NOS. This is associated with an increase in the proportion of NOSN displaying dystrophic changes, indicating that NOSN undergo massive degeneration in association with NOS synthesis induction. The increase in density of NOSN in HIV-1 infected drug abusers may be among the important sources of NO mediating cerebrocortical dysfunction, and the degeneration of NOS-containing local circuit neurons in patients with HIV-1 infection or drug abuse may underlie in part their neuropsychiatric manifestations. PMID:16873197

  19. Nitrogen isotope exchange in between nitric oxide and nitric acid

    The exchange rate law experimentally observed for 15 N/14 N exchange in NO - HNO3 system at low nitric acid concentration, both at atmospheric pressure and at low pressure of NO: R k[H+][NO3-][HNO2], is identical with the rate law for the reaction between NO and HNO3, when HNO2 is formed.The rate of nitrogen isotope exchange between NO and HNO3 has been measured as a function of nitric acid concentration of 1.5 4 M.l-1. The exchange rate law is shown to be R k[HNO3]2[N2O3] and the measured activation energy is E = 67.78 kJ.M-1. It is concluded that N2O3 participates in 15 N/14 N exchange between NO and HNO3 at nitric acid concentration higher than 1.5 M.l-1. The rate of the same isotope exchange in NO - HNO3 system has been also measured as a function of nitric oxide pressure 0.1 0.4 M.Pa for 1 and 2 M.l-1 HNO3. It is demonstrated that 15 N/14 N exchange in this system has a linear dependence on NO pressure as indicated by rate measurements at different NO partial pressures and constant overall pressure, by adding helium in reactor. Using the rate law presented above the nitrogen isotope exchange rate for nitric acid concentration 1.5 10 M.l-1 were calculated. Nitrogen isotope exchange between nitric oxide and concentrated nitric acid with a single stage separation factor = 1.055, for 10 M.l-1 nitric acid, at 25 deg. C, provides the bases for 15 N separation process that is most widely used at the present time, i.e. the method of Spindel and Taylor. In order to know what happens in 15N separation at higher pressure, when the isotopic transport is improved, a stainless steel laboratory experimental plant with a 1000 mm long and 18 mm i.d. column, packed with triangular wire springs of 1.8 x 1.8 x 0.2 mm, was utilised. At 1.5 atm (absolute) and 2.36 flow rate, HETP was 7% smaller than at atmospheric pressure and 1.5 times smaller flow rate. The operation of 15 N separation plant at 1.8 atm (absolute), instead atmospheric pressure, will permit doubling

  20. Nitric Oxide: Role in Human Biology

    Nikhil Omer; Ankur Rohilla; Seema Rohilla; Ashok Kushnoor


    Nitric oxide (NO), a free radical, possesses various modulatory effects on biological systems. NO is synthesized from L-arginine by converting it to L-citrulline via nitric oxide synthase (NOS) enzymes. Moreover, various precursors of NO have been reported that include arginine, citruline, arginine alphaketoglutarate (A-AKG) and arginineketoisocaproate (A-KIC). NO possess various direct and indirect effects that broadly affect various tissues and organ systems inside the body. The present rev...

  1. Oxygen, nitric oxide and articular cartilage

    Fermor, B.; Christensen, S. E.; I Youn; J M Cernanec; C M Davies; Weinberg, J. B.


    Molecular oxygen is required for the production of nitric oxide (NO), a pro-inflammatory mediator that is associated with osteoarthritis and rheumatoid arthritis. To date there has been little consideration of the role of oxygen tension in the regulation of nitric oxide production associated with arthritis. Oxygen tension may be particularly relevant to articular cartilage since it is avascular and therefore exists at a reduced oxygen tension. The superficial zone exists at approximately 6% O...

  2. Nitric oxide synthase in the pineal gland

    Lopez-Figueroa, M.O.; Moller, M.


    The recent discovery of nitric oxide (NO) as a biological messenger molecule with unique characteristics has opened a new field in pineal research. This free radical gas is synthesized by the enzyme nitric oxide synthase (NOS) from L-arginine. The activation of adrenoreceptors in the membrane of the pinealocytes mediates the increase in NO through a mechanism that involves G proteins. In the pinealocyte, NO stimulates guanylyl cyclase resulting in an increased ...

  3. Nitric oxide synthase and neuronal NADPH diaphorase are identical in brain and peripheral tissues.

    Dawson, T. M.; Bredt, D S; M Fotuhi; Hwang, P M; Snyder, S. H.


    NADPH diaphorase staining neurons, uniquely resistant to toxic insults and neurodegenerative disorders, have been colocalized with neurons in the brain and peripheral tissue containing nitric oxide synthase (EC 1.14.23.-), which generates nitric oxide (NO), a recently identified neuronal messenger molecule. In the corpus striatum and cerebral cortex, NO synthase immunoreactivity and NADPH diaphorase staining are colocalized in medium to large aspiny neurons. These same neurons colocalize with...

  4. Processes regulating nitric oxide emissions from soils

    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...

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

    Toda, Noboru; Toda, Hiroshi


    Cigarette smoking is a major risk factor for atherosclerosis, cerebral and coronary vascular diseases, hypertension, and diabetes mellitus. Chronic smoking impairs endothelial function by decreasing the formation of nitric oxide and increasing the degradation of nitric oxide via generation of oxygen free radicals. Nitric oxide liberated from efferent nitrergic nerves is also involved in vasodilatation, increased regional blood flow, and hypotension that are impaired through nitric oxide sequestering by smoking-induced factors. Influence of smoking on nitric oxide-induced blood flow regulation is not necessarily the same in all organs and tissues. However, human studies are limited mainly to the forearm blood flow measurement that assesses endothelial function under basal and stimulated conditions and also determination of penile tumescence and erection in response to endothelial and neuronal nitric oxide. Therefore, information about blood flow regulation in other organs, such as the brain and placenta, has been provided mainly from studies on experimental animals. Nicotine, a major constituent of cigarette smoke, acutely dilates cerebral arteries and arterioles through nitric oxide liberated from nitrergic neurons, but chronically interferes with endothelial function in various vasculatures, both being noted in studies on experimental animals. Cigarette smoke constituents other than nicotine also have some vascular actions. Not only active but also passive smoking is undoubtedly harmful for both the smokers themselves and their neighbors, who should bear in mind that they can face serious diseases in the future, which may result in lengthy hospitalization, and a shortened lifespan. PMID:20868673

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

    Kjeldsen, T H; Rivier, C; Lee, S; Hansen, E W; Christensen, J D; Moesby, Lise


    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 i...

  7. Neural mechanisms in nitric-oxide-deficient hypertension

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


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

  8. Processes regulating nitric oxide emissions from soils

    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 of NO in the atmosphere are anthropogenic emissions (from combustion of fossil fuels) and biogenic emission from soils. NO is both produced and consumed in soils as a result of biotic and abiotic process...

  9. Nitric oxide methods in seed biology

    Nitric oxide (NO) is a gaseous, free radical that is involved in many aspects of plant growth, development, and responses to the environment. Compelling evidence points to a central role for NO in the loss of seed dormancy. NO is highly reactive, toxic at high concentrations, and unstable. Methods f...

  10. Attenuation by methyl mercury and mercuric sulfide of pentobarbital induced hypnotic tolerance in mice through inhibition of ATPase activities and nitric oxide production in cerebral cortex

    Chuu, Jiunn-Jye; Huang, Zih-Ning; Yu, Hsun-Hsin; Chang, Liang-Hao [College of Engineering, Southern Taiwan University, Institute of Biotechnology, Tainan (China); Lin-Shiau, Shoei-Yn [College of Medicine, National Taiwan University, Institute of Pharmacology, Taipei (China)


    This study is aimed at exploring the possible mechanism of hypnosis-enhancing effect of HgS or cinnabar (a traditional Chinese medicine containing more than 95% HgS) in mice treated with pentobarbital. We also examined whether the effect of HgS is different from that of the well-known methyl mercury (MeHg). After a short period (7 days) of oral administration to mice, a nontoxic dose (0.1 g/kg) of HgS not only significantly enhanced pentobarbital-induced hypnosis but also attenuated tolerance induction; while a higher dose (1 g/kg) of HgS or cinnabar exerted an almost irreversible enhancing effect on pentobarbital-hypnosis similar to that of MeHg (2 mg/kg) tested, which was still effective even after 10 or 35 days cessation of administration. To study comparatively the effects of different mercury forms from oral administration of MeHg and HgS on membrane ATPase activities of experimental mice, analysis of the Hg content in the cerebral cortex revealed that correlated with the decrease of Na{sup +}/K{sup +}-ATPase and Ca{sup 2+}-ATPase activities. Furthermore, NO levels of blood but not that of cerebral cortex were also decreased by mercuric compounds. Although pentobarbital alone enhanced cytochrome p450-2C9 in time dependent manner, all of mercurial compounds tested had no such effect. All of these findings indicated that the mercurial compounds including cinnabar, HgS and MeHg exert a long-lasting enhancing hypnotic activity without affecting pentobarbital metabolism, which provides evidence-based sedative effect of cinnabar used in Chinese traditional medicine for more than 2,000 years. The nontoxic HgS dosing (0.1 g/kg/day) for consecutive 7 days is perhaps useful for delaying or preventing pentobarbital-tolerance. (orig.)

  11. Modulatory role of nitric oxide in cardiac performance

    Smiljić Sonja


    Full Text Available Nitric oxide is produced by almost all cardiac cells, endothelial cells, cardiomyocytes and nerve fibers. It is synthesized by an enzyme, a nitric oxide synthase, which occurs in endothelial, neural and inducible form. The distribution of nitric oxide synthase in the heart is characterized by a pronounced non-uniformity. Nitric oxide exerts its effects in physiological and pathophysiological conditions. The physiological effects of low concentrations of nitric oxide, which is released in the normal conditions under the influence of constituent enzymes, occur via cyclic guanosine monophosphate. The synthesized nitric oxide exhibits its effect in the cells where it is produced, in an autocrine manner, or by diffusing into the neighboring cells, in a paracrine manner. Nitric oxide acts by regulating the coronary vessel tonus, affecting the contractility of cardiomyocytes, generating an inotropic effect in a dose-dependent manner and controlling the cellular respiration. Other effects of nitric oxide in the cardiovascular system include the hyperpolarization of the smooth muscle cells in blood vessels, the inhibition of the monocyte adhesion, the inhibition of platelet migration, adhesion and aggregation and the proliferation of smooth muscle cells and fibroblasts. The anti-atherosclerotic effects of nitric oxide are based on these effects. Nitric oxide is a weak free radical in gaseous state, and the cytotoxic and/or the cytoprotective effects of the higher concentrations of nitric oxide are related to the chemical structure of nitric oxide as a free radical. The excessive production of nitric oxide by the activation of inducible nitric oxide synthase can lead to major irregularities in the function of cardiomyocytes and cardiac insufficiency. Understanding the nitric oxide molecular mechanisms of signaling pathways in the heart can provide a new strategic approach to prevention and treatment of cardiovascular diseases.

  12. Effect of glutathione on brain nitric oxide levels in an experimental epilepsy mouse model

    Aylin Akcali; Sadrettin Pence; Naciye Kurtul; Mehmet Bosnak; Munife Neyal


    BACKGROUND: Oxidative stress plays an important role in the pathophysiology of epilepsy. Glutathione, known as one of the compounds of antioxidant defense, has been shown to inhibit convulsions. Nitric oxide has a proconvulsant effect on a pentylenetetrazole-induced animal model. OBJECTIVE: To evaluate the effects of glutathione administration on nitric oxide levels in brain regions of convulsive and kindling pentylenetetrazole-induced seizure models. DESIGN, TIME, AND SETTING: A randomized, controlled, animal experiment. The study was performed at the Department of Physiology, Gaziantep University and Department of Chemistry-Biochemistry, Kahramamaras Sutcu Imam University in 2006.MATERIALS: Pentylenetetrazole and glutathione were purchased from Sigma, USA. METHODS: A total of 80 mice were assigned to 8 groups (n=10): normal control, saline control (1 mL normal saline), convulsive pentylenetetrazole (single intraperitoneal administration of pentylenetetrazole, 60 mg/kg), convulsive pentylenetrazole plus glutathione (single administration of 60 mg/kg pentylenetetrazole and 200 mg/kg glutathione), five-dose glutathione (intraperitoneal injection of 200 mg/kg glutathione respectively at 1, 3, 5, 7, and 10 days), single-dose glutathione (single administration of 200 mg/kg glutathione), pentylenetetrazole kindling (intraperitoneal administration of pentylenetetrazole of 40 mg/kg at 1, 3, 5, 7, and 10 days), and pentylenetetrazole kindling plus glutathione group (intraperitoneal injection of 40 mg/kg pentylenetetrazole and 200 mg/kg glutathione respectively at 1, 3, 5, 7, and 10 days). MAIN OUTCOME MEASURES: All mice were sacrificed 1 hour after the last administration. Brain nitric oxide levels were determined by spectrophotometry. RESULTS: There were no significant differences in nitric oxide levels between the normal control, saline control, five-dose glutathione, and single-dose glutathione groups (P>0.05). Nitric oxide levels in the cerebral hemisphere and


    史源; 李华强; 潘捷; 沈际皋


    In a newborn rat model of sepsis, the changes of nitric oxide and the protective effects of methylene blue or/and dexaraethason were investigated. The results revealed that plasma nitric oxide levels were ele-cted at 6 h and peaked at 12 h after bacterial challenge. The treatment with methylene or/and dexam-etbasone was found to Munt hypoglycenua and hyperlacdcemla, to reduce the occurrence rate of loss ot re-sponse to pain, and to prolong the survival time. Moreover, therapy by dexamethasone was shown to de-crease the 24 h mortality. The results suggested that nitric coide play an important role during the course of fatal P. aeruginosa sepsis, hut it is clear that the clinical value of nitric oxide and its inhibitors need to be further studied.

  14. Nitric oxide rescues thalidomide mediated teratogenicity

    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 lim...

  15. Reactive Nitrogen Species and Nitric Oxide

    D. Procházková; Wilhelmová, N. (Naděžda); Pavlík, M. (Milan)


    Free radical nitric oxide (NO) is a biological messenger with diverse functions in plant physiology, including in stress physiology. Together with NO, related molecules called reactive nitrogen species (RNS), e.g. peroxynitrite or S-nitrosothiols, are associated with plant metabolism under both physiological and stress conditions. These molecules are able to react with wide spectrum of biomolecules, and they may act as a transporters and reservoirs for NO in a broad range of plant cell signal...

  16. Radiation, nitric oxide and cellular death

    The mechanisms of radiation induced cellular death constitute an objective of research ever since the first biological effects of radiation were first observed. The explosion of information produced in the last 20 years calls for a careful analysis due to the apparent contradictory data related to the cellular system studied and the range of doses used. This review focuses on the role of the active oxygen species, in particular the nitric oxides, in its relevance as potential mediator of radiation induced cellular death

  17. Experimental skin flaps and nitric oxide

    Gribbe, Örjan


    Abstract. Surgical flaps are used in plastic surgery to reconstruct tissue defects due to trauma or cancer removal. Occasionally flaps are subjected to ischemia and reperfusion injury leading to flap failure. Nitric oxide (NO), a small gaseous molecule, has vast physiological importance as it participates in the regulation of blood pressure, blood flow, neurotransmission and immune response. NO is synthesized by the enzyme NO synthase (NOS), which exists in both constitutiv...

  18. Nitric Oxide Synthases in Heart Failure

    Carnicer, Ricardo; Crabtree, Mark J; Sivakumaran, Vidhya; Casadei, Barbara; Kass, David A


    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 unde...

  19. Nitric oxide and mitochondria in metabolic syndrome

    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...

  20. Oxygen, nitric oxide and articular cartilage

    B Fermor


    Full Text Available Molecular oxygen is required for the production of nitric oxide (NO, a pro-inflammatory mediator that is associated with osteoarthritis and rheumatoid arthritis. To date there has been little consideration of the role of oxygen tension in the regulation of nitric oxide production associated with arthritis. Oxygen tension may be particularly relevant to articular cartilage since it is avascular and therefore exists at a reduced oxygen tension. The superficial zone exists at approximately 6% O2, while the deep zone exists at less than 1% O2. Furthermore, oxygen tension can alter matrix synthesis, and the material properties of articular cartilage in vitro.The increase in nitric oxide associated with arthritis can be caused by pro-inflammatory cytokines and mechanical stress. Oxygen tension significantly alters endogenous NO production in articular cartilage, as well as the stimulation of NO in response to both mechanical loading and pro-inflammatory cytokines. Mechanical loading and pro-inflammatory cytokines also increase the production of prostaglandin E2 (PGE2. There is a complex interaction between NO and PGE2, and oxygen tension can alter this interaction. These findings suggest that the relatively low levels of oxygen within the joint may have significant influences on the metabolic activity, and inflammatory response of cartilage as compared to ambient levels. A better understanding of the role of oxygen in the production of inflammatory mediators in response to mechanical loading, or pro-inflammatory cytokines, may aid in the development of strategies for therapeutic intervention in arthritis.

  1. Potential neurogenic and vascular roles of nitric oxide in migraine headache and aura.

    Myers, D E


    It has long been known that nitrate and nitrite medications consistently cause significant headache as a side effect. Classical research has shown that cerebral vasodilation accompanies the use of these medications. More modern studies suggest that these vasodilators exert their action on blood vessels via nitric oxide and its second messenger, cyclic guanosine monophosphate. This paper reviews research studies and theoretical articles which address the concept that nitric oxide plays a major role in the vasodilation associated with the headache phase of migraine with aura. A brief discussion of nitric oxide biochemistry and pharmacology follows. In addition, there is a review of evidence examining the possible contributions of nitric oxide to the neurogenic and vascular events associated with spreading cortical depression, an animal model of migraine aura. The paradoxical hypotheses that nitric oxide may contribute to both the propagation of spreading cortical depression and its limitation are presented. Finally, a rationale for the experimental use of nitric oxide agonists and antagonists in the abortion of migraine aura is introduced. PMID:15613204

  2. Preventive non–pharmacological treatment and nitric oxide in chronic migraine

    Ciancarelli, I.; Tozzi–Ciancarelli, M. G.; Di Massimo, C.; Olivieri, L; Carolei, A.


    In chronic migraine the central sensitisation and the changes of regional cerebral blood flow are mediated by nitric oxide (NO) and oxygen free radicals. Biofeedback is considered a preventive non–pharmacological treatment decreasing migraine attacks. We investigated whether biofeedback effectiveness is related to relaxation processes and its influence on oxidative stress. The Migraine Disability Assessment Score (MIDAS) and serum NO stable metabolites (NO x ) were evaluated in 20 patients wi...

  3. [Nitric oxide and the kidneys].

    Dzúrik, R; Spustová, V


    Nitrogen oxide (NO) is one of the crucial modulators of the vascular tonus. Apart from its effect on the cardiovascular system it exerts an effect also on other types of cells and ensures their functions.Specially comprehensive is its synthesis and action in the kidneys: NO is formed in the endothelial cells due to the activity of constitutional endothelial synthase (eNOS), in mesangial cells of inductive synthase (iNOS), in smooth muscle cells (vsmNOS), in tubular cells neuronal NOS (nNOS) and iNOS and in the macula densa nNOS. By modulation of the v.afferens it influences the blood flow through the glomeruli and filtration pressure in the glomeruli. It participates in the tubuloglomerular feedback: the cells of the macula densa produce NO via nNOS, the genetic transcription and translation of which as well as the kationic translation system ensure the transport of the L-arginine precursor and regulate very sensitively NO formation. The latter diffuses via the extraglomerular mesangium into the iuxtaglomerular apparatus where renin is forned.NO reduces proteinuria and renal proliferation. During renal insufficiency NO production is inhibited and in diabetes NO production is increased. Diabetic hyperfiltration and hypertrophy are ascribed to produced NO. Experimental studies contributed substantially to the knowledge of renal effects of NO. At present intensive clinical research has been started which, no doubt, will influence medical practice. PMID:15635855

  4. Hemoglobin Effects on Nitric Oxide Mediated Hypoxic Vasodilation.

    Rong, Zimei; Cooper, Chris E


    The brain responds to hypoxia with an increase in cerebral blood flow (CBF). However, such an increase is generally believed to start only after the oxygen tension decreases to a certain threshold level. Although many mechanisms (different vasodilator and different generation and metabolism mechanisms of the vasodilator) have been proposed at the molecular level, none of them has gained universal acceptance. Nitric oxide (NO) has been proposed to play a central role in the regulation of oxygen supply since it is a vasodilator whose production and metabolism are both oxygen dependent. We have used a computational model that simulates blood flow and oxygen metabolism in the brain (BRAINSIGNALS) to test mechanism by which NO may elucidate hypoxic vasodilation. The first model proposed that NO was produced by the enzyme nitric oxide synthase (NOS) and metabolized by the mitochondrial enzyme cytochrome c oxidase (CCO). NO production declined with decreasing oxygen concentration given that oxygen is a substrate for nitric oxide synthase (NOS). However, this was balanced by NO metabolism by CCO, which also declined with decreasing oxygen concentration. However, the NOS effect was dominant; the resulting model profiles of hypoxic vasodilation only approximated the experimental curves when an unfeasibly low K m for oxygen for NOS was input into the model. We therefore modified the model such that NO generation was via the nitrite reductase activity of deoxyhemoglobin instead of NOS, whilst keeping the metabolism of NO by CCO the same. NO production increased with decreasing oxygen concentration, leading to an improved reproduction of the experimental CBF versus PaO2 curve. However, the threshold phenomenon was not perfectly reproduced. In this present work, we incorporated a wider variety of oxygen dependent and independent NO production and removal mechanisms. We found that the addition of NO removal via oxidation to nitrate mediated by oxyhemoglobin resulted in the

  5. Nitrous oxides desorption from nitric acid (58–60 wt. %)

    Литвиненко, Олександр Олександрович; Печенко, Тамара Ивановна; Подустов, Михаил Алексеевич; Букатенко, Алексей Иванович


    The process of nitrous oxides desorption from nitric acid solutions (in domestic schemes) was considered. It is shown that in the process of desorption (or stripping), the nitrous oxides are not removed from solutions completely, so, the nitric acid does not satisfy the technical requirements in Ukraine.The research objective was to bring the quality of nitric acid to technological standards by removing (stripping) nitrous oxides from its solutions.To achieve the research objective, the balan...

  6. Nitric oxide in the psychobiology of mental disorders

    Essizoglu, Altan; Yıldırım, Ejder Akgün


    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 ...

  7. Nitric oxide in the psychobiology of mental disorders

    Altan Eşsizoğlu; Ejder Akgün Yıldırım


    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...

  8. The kinetics of the 15N/14N isotopic exchange between nitric oxide and nitric acid

    The rate of the 15N isotopic exchange between NO-NHO3 at high nitric acid concentration (2-10M) have been measured. The experimental data were obtained by contacting nitric oxide at atmospheric pressure with nitric acid solution labelled with 15N, in a glass contactor. The measurements were carried out in a glass vessel with magnetic stirrer maintaining always the same stirring rate (17 rot.s-1). The temperature was kept constant at 25 +-0.5 deg C. The reaction vessel was connected to a vacuum line and a purified nitric oxide source. The rate of the isotopic exchange and of the nitric oxide absorption in nitric acid were determined with a gas-burette in the simple apparatus described earlier. (T.G.)

  9. Oxidation of DOPAC by nitric oxide: effect of superoxide dismutase

    Laranjinha, João; Cadenas, Enrique


    This study aimed to characterize the redox interaction between 3,4-dihydroxyphenylacetic acid (DOPAC) and nitric oxide (·NO), and to assess the reductive and oxidative decay pathways of the DOPAC semiquinone originating from this interaction. The reaction between DOPAC and ·NO led to the formation of the DOPAC semiquinone radical, detected by electron paramagnetic resonance (EPR) and stabilized by Mg2+, and the nitrosyl anion detected as nitrosylmyoglobin. The EPR signal corresponding to the ...

  10. The role of nitric oxide in cancer



    Nitric oxide (NO) is a pleiotropic regulator, critical to numerous biological processes, including va-sodilatation, neurotransmission and macrophage-mediated immunity. The family of nitric oxide synthases(NOS) comprises inducible NOS (iNOS), endothelial NOS (eNOS), and neuronal NOS (nNOS). Interest-ingly, various studies have shown that all three isoforms can be involved in promoting or inhibiting theetiology of cancer. NOS activity has been detected in tumour cells of various histogenetic origins and hasbeen associated with tumour grade, proliferation rate and expression of important signaling componentsassociated with cancer development such as the oestrogen receptor. It appears that high levels of NOSexpression (for example, generated by activated macrophages) may be cytostatic or cytotoxic for tumorcells, whereas low level activity can have the opposite effect and promote tumour growth. Paradoxicallytherefore, NO (and related reactive nitrogen species) may have both genotoxic and angiogenic properties.Increased NO-generation in a cell may select mutant p53 cells and contribute to tumour angiogenesis byupregulating VEGF. In addition, NO may modulate tumour DNA repair mechanisms by upregulating p53,poly(ADP-ribose) polymerase (PARP) and the DNA-dependent protein kinase (DNA-PK). An understand-ing at the molecular level of the role of NO in cancer will have profound therapeutic implications for thediagnosis and treatment of disease.

  11. Nitric oxide rescues thalidomide mediated teratogenicity.

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

  12. Melatonin and its precursors scavenge nitric oxide

    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.

  13. Sensory neuropeptides and nitric oxide in nasal vascular regulation

    Rinder, Johan


    Sensory neuropeptides and nitric oxide in nasal vascular regulation By Johan Rinder, M.D. Division of Pharmacology, Department of Physiology and Pharmacology, Karolinska Institute, S- 171 77 Stockholm, Sweden and Department of Oto-Rhino-Laryngology, Karolinska Hospital, S-17176 Stockholm, SwedenThe role of sensory neuropeptides and nitric oxide in vascular regulation was investigated in the pig nasal mucosa...

  14. Catalytic abatement of nitrous oxide from nitric and production

    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 promis

  15. The Iron-Catalyzed Oxidation of Hydrazine by Nitric Acid

    Karraker, D.G.


    To assess the importance of iron to hydrazine stability, the study of hydrazine oxidation by nitric acid has been extended to investigate the iron-catalyzed oxidation. This report describes those results.

  16. Nitric oxide modulators: an emerging class of medicinal agents.

    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

  17. Nitric oxide scavengers as a therapeutic approach to nitric oxide mediated disease.

    Fricker, S P


    The essential role of nitric oxide (NO) in normal physiology and its involvement in the pathophysiology of a variety of diseases render the compound an attractive therapeutic target. NO donor drugs are used in the treatment of hypotension and angina where abnormalities in the L-arginine-nitric oxide pathway have been implicated. Overproduction of NO has been associated with a number of disease states including septic shock, inflammatory diseases, diabetes, ischaemia-reperfusion injury, adult respiratory distress syndrome, neurodegenerative diseases and allograft rejection. NO is produced by a group of enzymes, the nitric oxide synthases. Selective inhibition of the inducible isoform is one approach to the treatment of diseases where there is an overproduction of NO; an alternative approach is to scavenge or remove excess NO. A number of NO scavenger molecules have demonstrated pharmacological activity in disease models, particularly models of septic shock. These include organic molecules such as PTIO (2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), haemoglobin derivatives such as the pyridoxalated haemoglobin polyoxyethylene conjugate (PHP), low molecular weight iron compounds of diethylenetriaminepentaacetic acid and diethyldithiocarbamate and ruthenium polyaminocarboxylate complexes. The data suggest a potential role for NO scavengers in the treatment of NO mediated disease. PMID:15992146

  18. Production of Nitric Oxide and Expression of Inducible Nitric Oxide Synthase in Ovarian Cystic Tumors

    Rosekeila Simões Nomelini


    Full Text Available Tumor sections from nonneoplastic (n=15, benign (n=28, and malignant ovarian tumors (n=20 were obtained from 63 women. Immunohistochemistry of the tumor sections demonstrated that inducible nitric oxide synthase (iNOS expression was increased in ovarian cancer samples compared to nonneoplastic or benign tumor samples. Using the Griess method, nitric oxide (NO metabolite levels were also found to be elevated in malignant tumor samples compared to benign tumor samples (P80 μM were more frequent than NO levels <80 μM, and iNOS expression in well-differentiated carcinomas was greater than in moderately/poorly differentiated carcinomas (P<.05. These data suggest an important role for NO in ovarian carcinogenesis.

  19. Nitric oxide releasing-dendrimers: an overview

    Antonio Carlos Roveda Júnior


    Full Text Available Platforms able to storage, release or scavenge NO in a controlled and specific manner is interesting for biological applications. Among the possible matrices for these purposes, dendrimers are excellent candidates for that. These molecules have been used as drug delivery systems and exhibit interesting properties, like the possibility to perform chemical modifications on dendrimers surface, the capacity of storage high concentrations of compounds of interest in the same molecule and the ability to improve the solubility and the biocompatibility of the compounds bonded to it. This review emphasizes the recent progress in the development and in the biological applications of different NO-releasing dendrimers and the nitric oxide release pathways in these compounds.

  20. Nitric oxide and plant iron homeostasis.

    Buet, Agustina; Simontacchi, Marcela


    Like all living organisms, plants demand iron (Fe) for important biochemical and metabolic processes. Internal imbalances, as a consequence of insufficient or excess Fe in the environment, lead to growth restriction and affect crop yield. Knowledge of signals and factors affecting each step in Fe uptake from the soil and distribution (long-distance transport, remobilization from old to young leaves, and storage in seeds) is necessary to improve our understanding of plant mineral nutrition. In this context, the role of nitric oxide (NO) is discussed as a key player in maintaining Fe homeostasis through its cross talk with hormones, ferritin, and frataxin and the ability to form nitrosyl-iron complexes. PMID:25612116

  1. Nitric oxide flow tagging in unseeded air.

    Dam, N; Klein-Douwel, R J; Sijtsema, N M; Meulen, J J


    A scheme for molecular tagging velocimetry is presented that can be used in air flows without any kind of seeding. The method is based on the local and instantaneous creation of nitric oxide (NO) molecules from N(2) and O(2) in the waist region of a focused ArF excimer laser beam. This NO distribution is advected by the flow and can be visualized any time later by laser-induced fluorescence in the gamma bands. The creation of NO is confirmed by use of an excitation spectrum. Two examples of the application of the new scheme for air-flow velocimetry are given in which single laser pulses are used for creation and visualization of NO. PMID:18033499

  2. The role of nitric oxide in reproduction

    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.

  3. Nitric oxide formation from nitrite in zebrafish

    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...... nitrite levels for variable time periods, and changes in blood nitrosylhemoglobin (HbNO), methemoglobin (metHb), oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin (deoxyHb) were evaluated by spectral deconvolution. Blood HbNO (a biomarker of internal NO production) was low in controls, increased...... to a stable level around 3.7% of total Hb in fish exposed to 0.6 mmol l-1 nitrite, and to 12.1% (at day 2) in fish exposed to 2 mmol l-1 nitrite. The very high HbNO levels testify to an extensive conversion of nitrite to NO. With deoxyHb-mediated reduction of nitrite being a major NO...

  4. Nitric oxide and mitochondria in metabolic syndrome

    Larisa eLitvinova


    Full Text Available 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.

  5. Serum, urinary, and salivary nitric oxide in rheumatoid arthritis: complexities of interpreting nitric oxide measures

    Weinberg, J. Brice; Lang, Thomas; Wilkinson, William E.; Pisetsky, David S.; St Clair, E. William


    Nitric oxide (NO) may play important roles in rheumatoid arthritis (RA). RA is an inflammatory disease involving joints and other systems including salivary glands. To assess NO production in RA patients, we compared levels of serum, urine, and salivary nitrite and nitrate (NOx) in patients with RA and normal subjects, and we examined the relationships of these measures to disease activity. Serum, urine, and NOx levels as well as renal creatinine, NOx clearance and fractional excretion rates ...

  6. Nitric oxide, stomatal closure, and abiotic stress.

    Neill, Steven; Barros, Raimundo; Bright, Jo; Desikan, Radhika; Hancock, John; Harrison, Judith; Morris, Peter; Ribeiro, Dimas; Wilson, Ian


    Various data indicate that nitric oxide (NO) is an endogenous signal in plants that mediates responses to several stimuli. Experimental evidence in support of such signalling roles for NO has been obtained via the application of NO, usually in the form of NO donors, via the measurement of endogenous NO, and through the manipulation of endogenous NO content by chemical and genetic means. Stomatal closure, initiated by abscisic acid (ABA), is effected through a complex symphony of intracellular signalling in which NO appears to be one component. Exogenous NO induces stomatal closure, ABA triggers NO generation, removal of NO by scavengers inhibits stomatal closure in response to ABA, and ABA-induced stomatal closure is reduced in mutants that are impaired in NO generation. The data indicate that ABA-induced guard cell NO generation requires both nitric oxide synthase-like activity and, in Arabidopsis, the NIA1 isoform of nitrate reductase (NR). NO stimulates mitogen-activated protein kinase (MAPK) activity and cGMP production. Both these NO-stimulated events are required for ABA-induced stomatal closure. ABA also stimulates the generation of H2O2 in guard cells, and pharmacological and genetic data demonstrate that NO accumulation in these cells is dependent on such production. Recent data have extended this model to maize mesophyll cells where the induction of antioxidant defences by water stress and ABA required the generation of H2O2 and NO and the activation of a MAPK. Published data suggest that drought and salinity induce NO generation which activates cellular processes that afford some protection against the oxidative stress associated with these conditions. Exogenous NO can also protect cells against oxidative stress. Thus, the data suggest an emerging model of stress responses in which ABA has several ameliorative functions. These include the rapid induction of stomatal closure to reduce transpirational water loss and the activation of antioxidant defences

  7. Nitric oxide in the psychobiology of mental disorders

    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.

  8. Thermodynamical study of nitric dissolution of uranium oxide

    The purpose of this study is to determine the predominating reaction that takes place during the nitric dissolution of uranium oxide by means of the themkine-chvartzman based on the calculation of the reaction free energies

  9. Nitric oxide damages neuronal mitochondria and induces apoptosis in neurons


    The cytotoxic effect of nitric oxide on primarily cultured rat cerebellar granule cells was studied,and the mechanisms were discussed.The results showed that nitric oxide donor S-nitroso-N-acetyl-penicillamine (SNAP; 500 μmol/L) could induce apoptosis in immature cultures of cerebellar granule cells.Flow cytometry and HPLC analyses revealed that after treatment with SNAP,the mitochondrial transmembrane potential and the cellular ATP content decreased significantly.Nitric oxide scavenger hemoglobin could effectively prevent the neuronal mitochondria from dysfunction and attenuate apoptosis.The results suggested that nitric oxide activated the apoptotic program by inhibiting the activity of mitochondrial respiratory chain and thus decreasing the cellular ATP content.

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

    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.

  11. The Effect of Nitric Oxide Donor in Diabetic Wound Healing

    N Dashti


    Full Text Available Diabetes is characterized by a nitric oxide deficiency at the wound site. Diabetes is a factor that influences all stages of wound healing. In animals with acute experimental diabetes induced by streptozotocin (STZ, the early inflammatory responses after wounding is impaired, fibroblast and endothelial cell proliferation is reduced as well as accumulation of reparative collagen and gain in wound breaking strenght. This study investigated whether exogenous nitric oxide supplimentation with nitric oxide donor DETA NONOate could reverse impaired healing in diabetes. The results suggest nitric oxide donor DETA NONOate can reverse impaired healing associated with diabetes (P<0.001 and urinary nitrate (NO-3 output may reflect the extent of repair in this wound model (P<0.001.

  12. Measurements of fractional exhaled nitric oxide in pediatric asthma

    Youn-Soo Hahn


    Exhaled nitric oxide (NO) has been extensively investigated as a noninvasive marker of airway inflammation in asthma. The increased NO expression induced by inflammatory mediators in airways can be monitored easily in exhaled air from asthmatic children. Based on the relationship between the increased NO expression and eosinophilic airway inflammation, fractional exhaled nitric oxide (FeNO) measurements become an important adjunct for the evaluation of asthma. In addition, the availability of...

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

    Lee, I.


    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. Therefore the diffusion capacity of the lung for nitric oxide (DLNO) should reflect the alveolocapillary membrane diffusing capacity only, and should not be influenced by the vascular component. In this...

  14. Nitric Oxide Inhibits Coxiella burnetii Replication and Parasitophorous Vacuole Maturation

    Howe, Dale; Barrows, Lorraine F.; Lindstrom, Nicole M.; Heinzen, Robert A.


    Nitric oxide is a recognized cytotoxic effector against facultative and obligate intracellular bacteria. This study examined the effect of nitric oxide produced by inducible nitric oxide synthase (iNOS) up-regulated in response to cytokine stimulation, or by a synthetic nitric oxide donor, on replication of obligately intracellular Coxiella burnetii in murine L-929 cells. Immunoblotting and nitrite assays revealed that C. burnetii infection of L-929 cells augments expression of iNOS up-regulated in response to gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α). Infection in the absence of cytokine stimulation did not result in demonstrable up-regulation of iNOS expression or in increased nitrite production. Nitrite production by cytokine-treated cells was significantly inhibited by the iNOS inhibitor S-methylisothiourea (SMT). Treatment of infected cells with IFN-γ and TNF-α or the synthetic nitric oxide donor 2,2′-(hydroxynitrosohydrazino)bis-ethanamine (DETA/NONOate) had a bacteriostatic effect on C. burnetii replication. Inhibition of replication was reversed upon addition of SMT to the culture medium of cytokine-treated cells. Microscopic analysis of infected cells revealed that nitric oxide (either cytokine induced or donor derived) inhibited formation of the mature (large) parasitophorous vacuole that is characteristic of C. burnetii infection of host cells. Instead, exposure of infected cells to nitric oxide resulted in the formation of multiple small, acidic vacuoles usually containing one C. burnetii cell. Removal of nitrosative stress resulted in the coalescence of small vacuoles to form a large vacuole harboring multiple C. burnetii cells. These experiments demonstrate that nitric oxide reversibly inhibits replication of C. burnetii and formation of the parasitophorous vacuole. PMID:12183564

  15. Treatment of severe status asthmaticus with nitric oxide.

    Rishani, R; El-Khatib, M; Mroueh, S


    The paper reports on a 13-year-old girl with chronic asthma who presented in acute respiratory failure following an exacerbation of her disease. Nitric oxide was added to the ventilator circuit at 7 ppm and then 15 ppm after the patient failed to respond to bronchodilators and steroids. This was followed by rapid improvement in respiratory mechanics and blood gases with no adverse effects. Nitric oxide appears to have a direct relaxing effect on the bronchial smooth muscle. PMID:10587422

  16. The Effect of Nitric Oxide Donor in Diabetic Wound Healing

    N Dashti; Ansari, M.; M. Shabani; S Vardasti; Mirsalehian, A.; MH Noori Mughehi; Hatmi ZN


    Diabetes is characterized by a nitric oxide deficiency at the wound site. Diabetes is a factor that influences all stages of wound healing. In animals with acute experimental diabetes induced by streptozotocin (STZ), the early inflammatory responses after wounding is impaired, fibroblast and endothelial cell proliferation is reduced as well as accumulation of reparative collagen and gain in wound breaking strenght. This study investigated whether exogenous nitric oxide supplimentation with ni...

  17. Hemoglobin: A Nitric-Oxide Dioxygenase

    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.

  18. Tapentadol and nitric oxide synthase systems.

    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. PMID:25485639

  19. Nitric oxide and cardiovascular risk factors

    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”.

  20. Nitric oxide negatively regulates mammalian adult neurogenesis

    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.

  1. [Inhalation of nitric oxide - dependence: case report

    Carvalho, W B; Matsumoto, T; Horita, S M; Almeida, N M; Martins, F R


    OBJECTIVE: Describe the hemodynamic response with rebound of pulmonary hypertension after withdrawal of inhaled nitric oxide (NO) in a pediatric patient with acute respiratory distress syndrome (ARDS). METHODS: Case report of a child with ARDS and pulmonary hypertension evaluated through ecocardiografic with dopller, receiving inhaled NO for a period of 21 days. RESULTS: There was a decrease of the pulmonary artery pressure (PAP) from 52 mmHg to 44 mmHg after the initial titulation of NO inhalation dose. After the withdrawal of inhaled NO an elevation of PAP was observed (55 mmHg). It was necessary to reinstall the inhaled NO to obtain a more appropriate value (34 mmHg). A new attempt of interruption of the inhaled NO after prolonged inhalation (20 days) resulted in a new clinic worsening and increase of PAP, with the indication to reinstall the inhaled NO. In the 24th day of permanence in the intensive care unit the patient died due to multiple organ dysfunction. CONCLUSIONS: The possibility of pulmonary hypertension rebound after withdrawal of inhaled NO is a complication that may have important clinical implications for patients who need a prolonged treatment with NO. This case report emphasizes these implications. PMID:14647690

  2. Dietary Nitrate, Nitric Oxide, and Cardiovascular Health.

    Bondonno, Catherine P; Croft, Kevin D; Hodgson, Jonathan M


    Emerging evidence strongly suggests that dietary nitrate, derived in the diet primarily from vegetables, could contribute to cardiovascular health via effects on nitric oxide (NO) status. NO plays an essential role in cardiovascular health. It is produced via the classical L-arginine-NO-synthase pathway and the recently discovered enterosalivary nitrate-nitrite-NO pathway. The discovery of this alternate pathway has highlighted dietary nitrate as a candidate for the cardioprotective effect of a diet rich in fruit and vegetables. Clinical trials with dietary nitrate have observed improvements in blood pressure, endothelial function, ischemia-reperfusion injury, arterial stiffness, platelet function, and exercise performance with a concomitant augmentation of markers of NO status. While these results are indicative of cardiovascular benefits with dietary nitrate intake, there is still a lingering concern about nitrate in relation to methemoglobinemia, cancer, and cardiovascular disease. It is the purpose of this review to present an overview of NO and its critical role in cardiovascular health; to detail the observed vascular benefits of dietary nitrate intake through effects on NO status as well as to discuss the controversy surrounding the possible toxic effects of nitrate. PMID:25976309

  3. Nitric oxide-dependent penile erection in mice lacking neuronal nitric oxide synthase.

    Burnett, A. L.; Nelson, R.J.; Calvin, D. C.; Liu, J. X.; Demas, G E; Klein, S. L.; Kriegsfeld, L. J.; Dawson, V L; Dawson, T. M.; Snyder, S H


    BACKGROUND: Nitric oxide (NO) has been implicated as a mediator of penile erection, because the neuronal isoform of NO synthase (NOS) is localized to the penile innervation and NOS inhibitors selectively block erections. NO can also be formed by two other NOS isoforms derived from distinct genes, inducible NOS (iNOS) and endothelial NOS (eNOS). To clarify the source of NO in penile function, we have examined mice with targeted deletion of the nNOS gene (nNOS- mice). MATERIALS AND METHODS: Mat...

  4. The role of nitric oxide in neurovascular coupling.

    Dormanns, K; Brown, R G; David, T


    Nitric oxide (NO) is a neurotransmitter known to act as a potent cerebral vasodilator. Its role in neurovascular coupling (NVC) is discussed controversially and one of the main unanswered questions is which cell type provides the governing source of NO for the regulation of vasodynamics. Mathematical modelling can be an appropriate tool to investigate the contribution of NO towards the key components of NVC and analyse underlying mechanisms. The lumped parameter model of a neurovascular unit, including neurons (NE), astrocytes (AC), smooth muscle cells (SMC) and endothelial cells (EC), was extended to model the NO signalling pathway. Results show that NO leads to a general shift of the resting regional blood flow by dilating the arteriolar radius. Furthermore, dilation during neuronal activation is enhanced. Simulations show that potassium release is responsible for the fast onset of vascular response, whereas NO-modulated mechanisms maintain dilation. Wall shear stress-activated NO release from the EC leads to a delayed return to the basal state of the arteriolar radius. The governing source of vasodilating NO that diffuses into the SMC, which determine the arteriolar radius, depends on neuronal activation. In the resting state the EC provides the major contribution towards vasorelaxation, whereas during neuronal stimulation NO produced by the NE dominates. PMID:26796228

  5. Concentrations of Nitric Oxide in Rat Brain Tissues after Diffuse Brain Injury and Neuroprotection by the Selective Inducible Nitric Oxide Synthase Inhibitor Aminoguanidine

    Yi-bao Wang; Shao-wu Ou; Guang-yu Li; Yun-hui Liu


    @@ To investigate the effects of nitric oxide (NO) and the selective inducible nitric oxide synthase (iNOS) inhibitor aminoguanidine (AG) on trauma, we explored the concentrations of nitric oxide in rat brain tissues at different time stamps after diffuse brain injury (DBI) with or without AG treatment.

  6. Activation of constitutive nitric oxide synthases by oxidized calmodulin mutants.

    Montgomery, Heather J; Bartlett, Ryan; Perdicakis, Basil; Jervis, Eric; Squier, Thomas C; Guillemette, J Guy


    Several calmodulin (CaM) mutants were engineered in an effort to identify the functional implications of the oxidation of individual methionines in CaM on the activity of the constitutive isoforms of nitric oxide synthase (NOS). Site-directed mutagenesis was used to substitute the majority of methionines with leucines. Substitution of all nine methionine residues in CaM with leucines had minimal effects on the binding affinity or maximal enzyme activation for either the neuronal (nNOS) or endothelial (eNOS) isoform. Selective substitution permitted determination of the functional consequences of the site-specific oxidation of Met(144) and Met(145) on the regulation of electron transfer within nNOS and eNOS. Site-specific oxidation of Met(144) and Met(145) resulted in changes in the CaM concentration necessary for half-maximal activation of nNOS and eNOS, suggesting that these side chains are involved in stabilizing the productive association between CaM and NOS. However, the site-specific oxidation of Met(144) and Met(145) had essentially no effect on the maximal extent of eNOS activation in the presence of saturating concentrations of CaM. In contrast, the site-specific oxidation of Met(144) (but not Met(145)) resulted in a reduction in the level of nNOS activation that was associated with decreased rates of electron transfer within the reductase domain. Thus, nNOS and eNOS exhibit different functional sensitivities to conditions of oxidative stress that are expected to oxidize CaM. This may underlie some aspects of the observed differences in the sensitivities of proteins in vasculature and neuronal tissues to nitration that are linked to NOS activation and the associated generation of peroxynitrite. PMID:12820885

  7. Expression of neuronal nitric oxide synthase gene in the brain tissue of rats with cerebral concussion%神经元型一氧化氮合酶基因在脑震荡大鼠脑组织中的表达

    彭瑞云; 高亚兵; 王德文; 肖兴义; 杨瑞; 陈浩宇; 吴小红; 刘杰; 胡文华; 马俊杰


    BACKGROUND: Cerebral concussion is a mild brain injury. In basic researches, the expression and significance of enkaphalin and dopamine in cerebral concussion remain poorly understood.OBJECTIVE: To observe the expression of neuronal nitric oxide synthase (nNOS) gene in rat models of cerebral concussion and to explore its significance.DESIGN: A randomized controlled trialled study.SETTING and PARTICIPANTS: This study was conducted in the Institute of Radiation Medicine, Academy of Military Medical Sciences. Rat models of cerebral concussion was established in 80 healthy male Wistar rats of clean grade purchased from the Experimental Animal Center of Academy of Military Medical Sciences with free access to food and water. The rats were randomly divided into 4 groups according to the different levels of cerebral impact for model establishment, namely the control group, 50, 100 and 200 g counterweight groups.MAIN OUTCOME MEASURES: Brain tissue samples were taken 1, 3, 7,14 and 30 days after injury respectively, from each group, to examine the changes in the expression of nNOS gene in the course of cerebral concussion by means of immunohistochemistry and in situ hybridization.RESULTS: Rats in 100 g group exhibited typical manifestations of cerebral concussion as seen in the clinical setting. The pathological changes included cerebral vascular dilatation, congestion, edema of the cerebral tissues, neuronal degeneration, necrosis, and decrease or even disappearance of the Nissl bodies. The protein and mRNA of nNOS were increased 3 days after the injury, peaked on the 7th day, and decreased till the 14th days but still remained positive on the 30th day. The positive expression was detected in the plasma of neurons in the cerebral cortex, hippocampus, thalamus and cerebellum.CONCLUSION: Cerebral concussion is pathologically characterized by blood circulation disorder and neural cell degeneration and necrosis. The expression of nNOS gene participates in brain tissue damage

  8. Mapping of cerebral oxidative metabolism with MRI

    Mellon, Eric A.; Beesam, R. Shashank; Elliott, Mark A.; Reddy, Ravinder


    Using a T1ρ MRI based indirect detection method, we demonstrate the detection of cerebral oxidative metabolism and its modulation by administration of the mitochondrial uncoupling agent 2,4-dinitrophenol (DNP) in a large animal model with minimum utilization of gas. The study was performed by inhalation in swine during imaging on clinical MRI scanners. Metabolic changes in swine were determined by two methods. First, in a series of animals, increased metabolism caused by DNP injection was m...

  9. Light activated nitric oxide releasing materials

    Muizzi Casanas, Dayana Andreina

    The ability to control the location and dosage of biologically active molecules inside the human body can be critical to maximizing effective treatment of cardiovascular diseases like angina. The current standard of treatment relies on the metabolism of organonitrate drugs into nitric oxide (NO), which are not specific, and also show problems with densitization with long-term use. There is a need then to create a treatment method that gives targeted release of NO. Metal-nitrosyl (M-NO) complexes can be used for delivery of NO since the release of NO can be controlled with light. However, the NO-releasing drug must be activated with red light to ensure maximum penetration of light through tissue. However, the release of NO from M-NO complexes with red-light activation is a significant challenge since the energy required to break the metal-NO bond is usually larger than the energy provided by red light. The goal of this project was to create red- sensitive, NO-releasing materials based on Ru-salen-nitrosyl compounds. Our approach was to first modify Ru salen complexes to sensitize the photochemistry for release of NO after red light irradiation. Next, we pursued polymerization of the Ru-salen complexes. We report the synthesis and quantitative photochemical characterization of a series of ruthenium salen nitrosyl complexes. These complexes were modified by incorporating electron donating groups in the salen ligand structure at key locations to increase electron density on the Ru. Complexes with either an --OH or --OCH3 substituent showed an improvement in the quantum yield of release of NO upon blue light irradiation compared to the unmodified salen. These --OH and --OCH3 complexes were also sensitized for NO release after red light activation, however the red-sensitive complexes were unstable and showed ligand substitution on the order of minutes. The substituted complexes remained sensitive for NO release, but only after blue light irradiation. The Ru

  10. Nitric Oxide in Astrocyte-Neuron Signaling

    Nianzhen Li


    Astrocytes, a subtype of glial cell, have recently been shown to exhibit Ca{sup 2+} elevations in response to neurotransmitters. A Ca{sup 2+} elevation can propagate to adjacent astrocytes as a Ca{sup 2+} wave, which allows an astrocyte to communicate with its neighbors. Additionally, glutamate can be released from astrocytes via a Ca{sup 2+}-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 Ca{sup 2+} signaling by imaging NO in purified murine cortical astrocyte cultures. Physiological concentrations of a natural messenger, ATP, caused a Ca{sup 2+}-dependent NO production. To test the roles of NO in astrocytic Ca{sup 2+} 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 Ca{sup 2+}, possibly through store-operated Ca{sup 2+} channels. The NO-induced Ca{sup 2+} signaling is cGMP-independent since 8-Br-cGMP, an agonistic analog of cGMP, did not induce a detectable Ca{sup 2+} change. The consequence of this NO-induced Ca{sup 2+} influx was assessed by simultaneously monitoring of cytosolic and internal store Ca{sup 2+} using fluorescent Ca{sup 2+} 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 Ca{sup 2+} release, suggesting that NO modulates internal store refilling. Furthermore, locally photo-release of NO to a single astrocyte led to a Ca{sup 2+} elevation in the stimulated astrocyte and a subsequent Ca{sup 2+} wave to neighbors. Finally, the author tested the role of NO inglutamate-mediated astrocyte-neuron signaling by recording the astrocyte-evoked glutamate-dependent neuronal slow inward current (SIC

  11. Circulating nitric oxide products do not solely reflect nitric oxide release in cirrhosis and portal hypertension

    Afzelius, P.; Bazeghi, N.; Bie, P.; Bendtsen, F.; Vestbo, Jørgen; Moller, S.


    development of this state of vasodilation and pulmonary dysfunction including increased exhaled NO concentrations. Circulating metabolites (NO(x)) may affect the systemic and pulmonary NO-generation. However, the relations of these abnormalities to the haemodynamic changes remain unclear. Aims: The aims of...... NO between patients and controls and no changes from the supine to the sitting position. Exhaled NO in the patients correlated significantly with plasma volume, heart rate and DLCO. NO(x) concentrations were not significantly increased in the patients. NO(x) correlated with portal pressure and......Background: Patients with cirrhosis often develop a systemic vasodilatation and a hyperdynamic circulation with activation of vasoconstrictor systems such as the renin-angiotensin-aldosterone system (RAAS), and vasopressin. Increased nitric oxide (NO) synthesis has been implicated in the...

  12. Interventional effect of magnesium sulfate on nitric oxide synthase activity after acute craniocerebral injury

    Ximin Yang; Jiangong Zhu; Zongchun Tang


    BACKGROUND: Abnormal changes in magnesium ion are closely related to cerebral injury. At present,some evidence indicates that magnesium reagent can improve nerve function and prognosis of patients with cerebral injury.OBJECTIVE: To observe the effect of magnesium sulfate on changes in nitric oxide synthase (NOS)activity in brain tissue of rats with acute craniocerebral injury.DESIGN: Completely randomized grouping design and randomly controlled study.SETTING: Laboratory of Neurosurgery, the Third Hospital of Chinese PLA.MATERIALS: Fifty-four male SD rats of clean grade and weighing 220 - 250 g were randomly divided into normal control group (n =6), cerebral injury group (n =24) and magnesium sulfate group (n =24). Especially,rats in cerebral injury group and magnesium sulfate group were equally divided into four subgroups and observed at 0.5, 2, 6 and 24 hours after model establishment. A solution of 125 g/L of magnesium sulfate was provided by the Seventh Pharmaceutical Factory of Wuxi and the NOS assay kit by Nanjing Jiancheng Bioengineering Institute.METHODS: The experiment was carried out in the Institute of Neurosurgery, the Third Hospital of Chinese PLA from August 2000 to August 2002. ① Rats in the cerebral injury group and magnesium sulfate group were anesthetized to establish cerebral injury models based on modified Feeney technique; magnesium sulfate group were intraperitoneally injected 600 mg/kg magnesium sulfate (125 g/L), but rats in the normal control group remained untreated. ② At 0.5, 2, 6 and 24 hours after cerebral injury, rats in cerebral injury group and magnesium sulfate group were decapitated and brains were dissected. Cerebral cortex of rats in cerebral injury group was selected for NOS assay; in addition, at 0.5 hour after cerebral injury, a portion of the parietal lobe was selected from the brains of rats in the normal control group. Brain samples were homogenized, the homogenated centrifuged and the supernatants were used to measure

  13. Nitric oxide production and the expression of two nitric oxide synthases in the avian retina.

    Tekmen-Clark, Merve; Gleason, Evanna


    Nitric oxide (NO) is known to exert multiple effects on the function of many retinal neurons and their synapses. Therefore, it is equally important to understand the potential sources of NO within the retina. To explore this, we employ a combination of 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM) based NO detection and immunohistochemistry for the NO synthetic enzymes, neuronal and endothelial nitric oxide synthase (nNOS and eNOS). We find DAF signals in photoreceptors, horizontal cells, amacrine cells, efferent synapses, Müller cells, and cells in the ganglion cell layer (GCL). nNOS immunoreactivity was consistent with the DAF signal with the exception that horizontal cells and Müller cells were not clearly labeled. eNOS-like immunoreactivity (eNOS-LI) was more widespread with photoreceptors, horizontal cells, occasional bipolar cells, amacrine cells, Müller cells, and cells in the GCL all showing labeling. Double labeling with antibodies raised against calretinin, syntaxin, and glutamine synthetase confirmed that horizontal cells, amacrine cells, and Müller cells (respectively) were expressing eNOS-LI. Although little or no nNOS labeling is observed in horizontal cells or Müller cells, the expression of eNOS-LI is consistent with the ability of these cells to produce NO. Together these results suggest that the capability to produce NO is widespread in the chicken retina. We propose that multiple forms of regulation for nNOS and eNOS play a role in the patterning of NO production in the chicken retina. PMID:23721886

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

    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.

  15. Parameters controlling nitric oxide emissions from gas turbine combustors

    Heywood, J. B.; Mikus, T.


    Nitric oxide forms in the primary zone of gas turbine combustors where the burnt gas composition is close to stoichiometric and gas temperatures are highest. It was found that combustor air inlet conditions, mean primary zone fuel-air ratio, residence time, and the uniformity of the primary zone are the most important variables affecting nitric oxide emissions. Relatively simple models of the flow in a gas turbine combustor, coupled with a rate equation for nitric oxide formation via the Zeldovich mechanism are shown to correlate the variation in measured NOx emissions. Data from a number of different combustor concepts are analyzed and shown to be in reasonable agreement with predictions. The NOx formation model is used to assess the extent to which an advanced combustor concept, the NASA swirl can, has produced a lean well-mixed primary zone generally believed to be the best low NOx emissions burner type.

  16. [Level of nitric oxide in the kidneys during apoptosis activation].

    Komarievtseva, I O; Orlova, O A; Blahodarenko, Ie A


    The content of nitric oxide stable metabolites in a tissue of kidneys of rats in conditions of activation of apoptosis was investigated. Research was carried out in two models: acute renal failure and a hypertrophy of a unique kidney after a unilateral nephrectomy. Detection of apoptosis was carried out by definition of DNA fragmentation. Substantial increase of the nitric oxide stable metabolites contents is revealed at activation of apoptosis in both models. Change of a ratio of the contents of nitrite--anions in relation to the general contents of NO2- + NO3- is revealed, indicating the role of peroxide processes in effect of nitric oxide and its metabolites on the cell. PMID:14964872

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

    Wang, Dan; Strandgaard, Svend; Iversen, Jens; Wilcox, Christopher S


    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...

  18. Possible role of adrenomedullin and nitric oxide in major depression.

    Akpinar, Abdullah; Yaman, Gozde Bacik; Demirdas, Arif; Onal, Suleyman


    Adrenomedullin (ADM) and nitric oxide (NO) have been implicated in the pathogenesis of certain psychiatric disorders such as schizophrenia and bipolar disorder. ADM induces vasorelaxation by activating adenylate cyclase and stimulating the release of NO. These two molecules are known to influence cerebral activity. In this study, we aimed to examine the serum levels of ADM and NO in patients with major depression (MD). We enrolled 50 patients with MD and 50 healthy control subjects. The diagnosis of MD was established on the basis of a structured clinical interview using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The severity of depressive symptoms was evaluated using Hamilton's 17-item Depression Rating Scale. The mean serum levels of ADM and NO in patients with MD were significantly higher than those in healthy subjects (p=0.001, for both). The severity of psychomotor retardation in patients with MD was significantly correlated with the ADM (r=0.37, p=0.007) and NO levels (r=0.29, p=0.038). The patients with obvious psychomotor retardation had significantly higher levels of ADM and NO than did the patients with no psychomotor retardation (p=0.025, p=0.030). A significantly positive correlation was found between ADM and NO levels in patients with MD (r=0.79, p=0.001). Serum levels of ADM and NO levels were not correlated with the severity or duration of depression or depressive symptoms (except psychomotor retardation). In conclusion, our study indicates that serum levels of ADM and NO are elevated in patients with MD and that increased serum levels of ADM and NO may be associated with psychomotor retardation. The ADM-NO system may serve as a new target in the treatment of patients with MD and psychomotor retardation. PMID:23867466

  19. Investigation of products of molybdenite oxidation by nitric acid

    Physicochemical study of products of oxidation by nitric acid of molybdenum concentrate containing 98% MoS2 is carried out. It is shown that appearing molybdenum oxide forms block oxidizer access to the surface of sulfide phase and hinder its complete oxidation. When complexing reagents (H2SO4, H3PO4, HCl) are introduced in the solution the bulk of oxidized molybdenum transfers into solution in the form of a stable complex, at that. The effect of internal diffusion decreases and a considerable increase of MoS2 oxidation rate and completeness is achieved

  20. Inhibitors of nitric oxide synthase in inflammatory arthritis.

    Boughton-Smith, N K; Tinker, A C


    There is considerable evidence that excessive nitric oxide (NO) synthesized from L-arginine by inducible nitric oxide synthase (iNOS) plays an important pathological role in inflammatory arthritis. Since NO synthesized by constitutive isoforms of NOS has a physiological role, a great deal of activity has been directed at identifying inhibitors of NOS that are selective for the induced isoform. The major chemical areas that have been described so far in the search for such selective iNOS inhibitors and the activity of some of these compounds in animal models of arthritis are reviewed. PMID:18465556


    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 occlusi...

  2. Inhaled nitric oxide protects males but not females from neonatal mouse hypoxia-ischemia brain injury.

    Zhu, Changlian; Sun, Yanyan; Gao, Jianfeng; Wang, Xiaoyang; Plesnila, Nikolaus; Blomgren, Klas


    It was recently discovered that while under normal conditions inhaled nitric oxide (iNO) does not affect cerebral blood flow, it selectively dilates arterioles in the ischemic penumbra during experimental cerebral ischemia, thereby increasing collateral blood flow and reducing ischemic brain damage. The mechanism was verified in multiple models, but only in male animals. Our aim was to evaluate the effects of iNO on brain injury in neonatal males and females. Nine-day-old mice were subjected to unilateral hypoxia-ischemia (HI), using 10% oxygen balanced with nitrogen, with or without 50 ppm NO. Brain injury 72 h after HI was reduced by iNO as judged by percentage of injury (-21.7%), atrophy (-23.7%), and total pathological score (-29%). The injury was significantly reduced in males (-32.4%, pbrain injury in a gender-related manner. PMID:24323275

  3. Different sources of nitric oxide mediate neurovascular coupling in the lateral geniculate nucleus of the cat

    Carmen De Labra


    Full Text Available Understanding the link between neuronal responses and metabolic signals is fundamental to our knowledge of brain function and it is a milestone in our efforts to interpret data from modern non invasive optical techniques such as fMRI, which are based on the close coupling between metabolic demand of active neurons and local changes in blood flow. The challenge is to unravel the link. Here we show, using spectrophotometry to record oxyhemoglobin (OxyHb and metahemoglobin (MetHb (surrogate markers of cerebral flow and nitric oxide levels respectively together with extracellular neuronal recordings in vivo and applying a multiple polynomial regression model, that the markers are able to predict up about 80% of variability in neuronal response. Furthermore, we show that the coupling between blood flow and neuronal activity is heavily influenced by nitric oxide (NO. While neuronal responses show the typical saturating response, blood flow shows a linear behaviour during contrast-response curves, with nitric oxide from different sources acting differently for low and high intensity.

  4. Pentylentetrazole-induced loss of blood-brain barrier integrity involves excess nitric oxide generation by neuronal nitric oxide synthase.

    Danjo, Sonoko; Ishihara, Yasuhiro; Watanabe, Masatomo; Nakamura, Yu; Itoh, Kouichi


    Dysfunction of the blood-brain barrier (BBB) is one of the major pathophysiological consequences of epilepsy. The increase in the permeability caused by BBB failure is thought to contribute to the development of epileptic outcomes. We developed a method by which the BBB permeability can be demonstrated by gadolinium-enhanced T1 weighted imaging (GdET1WI). The present study examined the changes in the BBB permeability in mice with generalized convulsive seizures (GCS) induced by acute pentylentetrazole (PTZ) injection. At 15min after PTZ-induced GCS, the BBB temporarily leaks BBB-impermeable contrast agent into the parenchyma of the diencephalon, hippocampus and cerebral cortex in mice, and the loss of BBB integrity was gradually recovered by 24h. The temporary BBB failure is a critical link to the glutamatergic activities that occur following the injection of PTZ. PTZ activates the glutamatergic pathway via the NMDA receptor, then nitric oxide (NO) is generated by NMDA receptor-coupled neuronal NO synthase (nNOS). To examine the influence of nNOS-derived NO induced by PTZ on the increases of the BBB permeability, GdET1WI was performed using conventional nNOS gene-deficient mice with or without PTZ injection. The failure of the BBB induced by PTZ was completely protected by nNOS deficiency in the brain. These results suggest that nNOS-derived excess NO in the glutamatergic pathway plays a key role in the failure of the BBB during PTZ-induced GCS. The levels of NO synthetized by nNOS in the brain may represent an important target for the future development of drugs to protect the BBB. PMID:23831997

  5. The energy-conserving nitric-oxide-reductase system in Paracoccus denitrificans. Distinction from the nitrite reductase that catalyses synthesis of nitric oxide and evidence from trapping experiments for nitric oxide as a free intermediate during denitrification.

    Carr, G J; Page, M D; Ferguson, S J


    1. A Clark-type electrode that responds to nitric oxide has been used to show that cytoplasmic membrane vesicles of Paracoccus denitrificans have a nitric-oxide reductase activity. Nitrous oxide is the reaction product. NADH, succinate or isoascorbate plus 2,3,5,6-tetramethyl-1,4-phenylene diamine can act as reductants. The NADH-dependent activity is resistant to freezing of the vesicles and thus the NADH:nitric-oxide oxidoreductase activity of stored frozen vesicles provides a method for calibrating the electrode by titration of dissolved nitric oxide with NADH. The periplasmic nitrite reductase and nitrous-oxide reductase enzymes are absent from the vesicles which indicates that nitric-oxide reductase is a discrete enzyme associated with the denitrification process. This conclusion was supported by the finding that nitric-oxide reductase activity was absent from both membranes prepared from aerobically grown P. denitrificans and bovine heart submitochondrial particles. 2. The NADH: nitric-oxide oxidoreductase activity was inhibited by concentrations of antimycin or myxothiazol that were just sufficient to inhibit the cytochrome bc1 complex of the ubiquinol--cytochrome-c oxidoreductase. The activity was deduced to be proton translocating by the observations of: (a) up to 3.5-fold stimulation upon addition of an uncoupler; and (b) ATP synthesis with a P:2e ratio of 0.75. 3. Nitrite reductase of cytochrome cd1 type was highly purified from P. denitrificans in a new, high-yield, rapid two- or three-step procedure. This enzyme catalysed stoichiometric synthesis of nitric oxide. This observation, taken together with the finding that the maximum rate of NADH:nitric-oxide oxidoreductase activity catalysed by the vesicles was comparable with that of NADH:nitrate-oxidoreductase, is consistent with a role for nitric-oxide reductase in the physiological conversion of nitrate or nitrite to dinitrogen gas. 4. Intact cells of P. denitrificans also reduced nitric oxide in an


    M. Swamy, Mohd Jamsani Mat Salleh, K. N .S. Sirajudeen, Wan Roslina Wan Yusof, G. Chandran


    Full Text Available Nitric oxide is postulated to be involved in the pathophysiology of neurological disorders due to hypoxia/ anoxia in brain due to increased release of glutamate and activation of N-methyl-D-aspartate receptors. Reactive oxygen species have been implicated in pathophysiology of many neurological disorders and in brain function. To understand their role in anoxia (hypobaric hypoxia and reperfusion (reoxygenation, the nitric oxide synthase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase and arginase activities along with the concentration of nitrate /nitrite, thiobarbituric acid reactive substances and total antioxidant status were estimated in cerebral cortex, cerebellum and brain stem of rats subjected to anoxia and reperfusion. The results of this study clearly demonstrated the increased production of nitric oxide by increased activity of nitric oxide synthase. The increased activities of argininosuccinate synthetase and argininosuccinate lyase suggest the increased and effective recycling of citrulline to arginine in anoxia, making nitric oxide production more effective and contributing to its toxic effects. The decreased activity of glutamine synthetase may favor the prolonged availability of glutamic acid causing excitotoxicity leading to neuronal damage in anoxia. The increased formation of thiobarbituric acid reactive substances and decreased total antioxidant status indicate the presence of oxidative stress in anoxia and reperfusion. The increased arginase and sustained decrease of GS activity in reperfusion group likely to be protective.

  7. Kinetics and mechanism of nitric oxidation of carbon black

    After some generalities about carbon blacks (preparation by various processes, structure, industrial use), the author notices that carbon black is often dispersed in aqueous solutions and, as it is hydrophobic, must therefore be submitted to treatment to become hydrophilic. Oxidation in liquid phase suits perfectly, and oxidation by nitric acid gives good results. Thus, this research thesis reports the study of the oxidation reaction mechanism in the case of oxidation of carbon black by nitric acid in aqueous solution. After having defined the different types of carbon blacks used in this study, and given an overview of the oxidation process (methods, purification and purity control of the obtained blacks, determination of the efficiency in terms of oxidised or purified black, difficulties faced during the elemental analysis of oxidised blacks), the author discusses the mechanism of formation of carbon dioxide during the oxidation of Philblack 0 carbon black by nitric acid. He reports the study of the oxidation kinetics, and the study of a thermal treatment of oxidised carbon blacks. The last part reports the study of the evolution of various properties of carbon blacks during oxidation: specific surface (BET method), density, examination by electronic microscopy and X-rays, magnetic susceptibility

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

    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 the......, 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...

  9. Endothelial cell nitric oxide production in acute chest syndrome.

    Hammerman, S I; Klings, E S; Hendra, K P; Upchurch, G R; Rishikof, D C; Loscalzo, J; Farber, H W


    Acute chest syndrome (ACS) is the most common form of acute pulmonary disease associated with sickle cell disease. To investigate the possibility that alterations in endothelial cell (EC) production and metabolism of nitric oxide (NO) products might be contributory, we measured NO products from cultured pulmonary EC exposed to red blood cells and/or plasma from sickle cell patients during crisis. Exposure to plasma from patients with ACS caused a 5- to 10-fold increase in S-nitrosothiol (RSNO) and a 7- to 14-fold increase in total nitrogen oxide (NO(x)) production by both pulmonary arterial and microvascular EC. Increases occurred within 2 h of exposure to plasma in a concentration-dependent manner and were associated with increases in endothelial nitric oxide synthase (eNOS) protein and eNOS enzymatic activity, but not with changes in nitric oxide synthase (NOS) III or NOS II transcripts, inducible NOS (iNOS) protein nor iNOS enzymatic activity. RSNO and NO(x) increased whether plasma was obtained from patients with ACS or other forms of vasoocclusive crisis. Furthermore, an oxidative state occurred and oxidative metabolites of NO, particularly peroxynitrite, were produced. These findings suggest that altered NO production and metabolism to damaging oxidative molecules contribute to the pathogenesis of ACS. PMID:10516198

  10. Effects of simulated microgravity on arterial nitric oxide synthase and nitrate and nitrite content

    Ma, Jin; Kahwaji, Chadi I.; Ni, Zhenmin; Vaziri, Nosratola D.; Purdy, Ralph E.


    The aim of the present work was to investigate the alterations in nitric oxide synthase (NOS) expression and nitrate and nitrite (NOx) content of different arteries from simulated microgravity rats. Male Wistar rats were randomly assigned to either a control group or simulated microgravity group. For simulating microgravity, animals were subjected to hindlimb unweighting (HU) for 20 days. Different arterial tissues were removed for determination of NOS expression and NOx. Western blotting was used to measure endothelial NOS (eNOS) and inducible NOS (iNOS) protein content. Total concentrations of NOx, stable metabolites of nitric oxide, were determined by the chemiluminescence method. Compared with controls, isolated vessels from simulated microgravity rats showed a significant increase in both eNOS and iNOS expression in carotid arteries and thoracic aorta and a significant decrease in eNOS and iNOS expression of mesenteric arteries. The eNOS and iNOS content of cerebral arteries, as well as that of femoral arteries, showed no differences between the two groups. Concerning NOx, vessels from HU rats showed an increase in cerebral arteries, a decrease in mesenteric arteries, and no change in carotid artery, femoral artery and thoracic aorta. These data indicated that there were differential alterations in NOS expression and NOx of different arteries after hindlimb unweighting. We suggest that these changes might represent both localized adaptations to differential body fluid redistribution and other factors independent of hemodynamic shifts during simulated microgravity.

  11. Arginine, citrulline and nitric oxide metabolism in sepsis

    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...

  12. The levels of nitric oxide in megaloblastic anemia

    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.

  13. On EPR detection of nitric oxide in vivo

    van Faassen, E.E.H.


    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.

  14. Nitric oxide and almitrine: the definitive answer for hypoxemia.

    Payen, D M; Muret, J


    Hypoxia-induced by acute lung injury results from abnormal ventilation/perfusion ratio distribution towards shunt or low ventilation/perfusion zones. Pharmacological modification of pulmonary blood flow distribution improving ventilation/perfusion ratio should correct hypoxia. The development of inhaled nitric oxide therapy had confirmed this concept, but with a relatively high proportion of 'non responders'. Then development of other drugs used alone or in association with nitric oxide may reinforce the benefit of nitric oxide. This has been tested with almitrine bismesylate, a lipophilic drug that reinforce hypoxic pulmonary vasoconstriction. Using inhaled nitric oxide in combination with almitrine, several studies in adult respiratory distress syndrome or acute lung injury patients have shown spectacular results in term of PaO2 and pulmonary shunt reduction. Moreover, the proportion of responders to this combination seems largely great than those observed for each drug alone. In conclusion, pulmonary blood flow manipulation improving ventilation/perfusion mismatching is one of the major strategies to correct severe hypoxia. PMID:17013295

  15. Nitric oxide: A regulator of stem cell proliferation and differentiation

    Čížková, D.; Rosocha, J.; Vanický, I.; Jergová, S.; Nagyová, M.; Juhásová, Jana; Čížek, M.

    Kerala: Transworld Research Network, 2009 - (Lukáčová, N.), s. 27-39 ISBN 978-81-7895-416-5 Institutional research plan: CEZ:AV0Z50450515 Keywords : stem cells * nitric oxide Subject RIV: FH - Neurology

  16. Oxidation of coal-based raw materials by nitric acid

    Novák, J.; Novák, František; Madronová, L.; Machovič, V.; Kozler, J.

    New York : Nova Science Publisher, 2011 - (Madronová, L.), s. 105-123 ISBN 978-1-61668-965-0. - ( Chemistry Research and Applications ) Institutional research plan: CEZ:AV0Z60660521 Keywords : oxidation * coal-based raw materials * nitric acid Subject RIV: CB - Analytical Chemistry , Separation

  17. Dexmedetomidine inhibits vasoconstriction via activation of endothelial nitric oxide synthase

    Nong, Lidan; Ma, Jue; Zhang, Guangyan; Deng, Chunyu; Mao, Songsong; Li, Haifeng


    Despite the complex vascular effects of dexmedetomidine (DEX), its actions on human pulmonary resistance arteries remain unknown. The present study tested the hypothesis that DEX inhibits vascular tension in human pulmonary arteries through the endothelial nitric oxide synthase (eNOS) mediated production of nitric oxide (NO). Pulmonary artery segments were obtained from 62 patients who underwent lung resection. The direct effects of DEX on human pulmonary artery tension and changes in vascular tension were determined by isometric force measurements recorded on a myograph. Arterial contractions caused by increasing concentrations of serotonin with DEX in the presence or absence of L-NAME (endothelial nitric oxide synthase inhibitor), yohimbine (α2-adrenoceptor antagonist) and indomethacin (cyclooxygenase inhibitor) as antagonists were also measured. DEX had no effect on endothelium-intact pulmonary arteries, whereas at concentrations of 10–8~10–6 mol/L, it elicited contractions in endothelium-denuded pulmonary arteries. DEX (0.3, 1, or 3×10–9 mmol/L) inhibited serotonin-induced contraction in arteries with intact endothelium in a dose-dependent manner. L-NAME and yohimbine abolished DEX-induced inhibition, whereas indomethacin had no effect. No inhibitory effect was observed in endothelium-denuded pulmonary arteries. DEX-induced inhibition of vasoconstriction in human pulmonary arteries is mediated by NO production induced by the activation of endothelial α2-adrenoceptor and nitric oxide synthase. PMID:27610030


    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.

  19. Nitric oxide as a potent fumigant for postharvest pest control

    There is a great demand for safe and effective alternative fumigants to replace methyl bromide and other toxic fumigants for pest control. Nitric oxide, a common signal molecule in biological systems, was found to be effective and safe to control insects under ultralow oxygen conditions. Fumigatio...

  20. Identification of free nitric oxide radicals in rat bone marrow

    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...

  1. Nitric oxide and the autonomic regulation of cardiac excitability. The G.L. Brown Prize Lecture.

    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. PMID:11429613

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

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

  3. Inhibition of Sevoflurane Postconditioning Against Cerebral Ischemia Reperfusion-Induced Oxidative Injury in Rats

    Shi-Dong Zhang


    Full Text Available The volatile anesthetic sevoflurane is capable of inducing preconditioning and postconditioning effects in the brain. In this study, we investigated the effects of sevoflurane postconditioning on antioxidant and immunity indexes in cerebral ischemia reperfusion (CIR rats. Rats were randomly assigned to five separate experimental groups I–V. In the sham group (I, rats were subjected to the same surgery procedures except for occlusion of the middle cerebral artery and exposed to 1.0 MAC sevoflurane 90 min after surgery for 30 min. IR control rats (group II were subjected to middle cerebral artery occlusion (MCAO for 90 min and exposed to O2 for 30 min at the beginning of reperfusion. Sevoflurane 0.5, 1.0 and 1.5 groups (III, IV, V were all subjected to MCAO for 90 min, but at the beginning of reperfusion exposed to 0.5 MAC, 1.0 MAC or 1.5 MAC sevoflurane for 30 min, respectively. Results showed that sevoflurane postconditioning can decrease serum tumor necrosis factor-alpha (TNF-α, interleukin-1 beta (IL-1β, nitric oxide (NO, nitric oxide synthase (NOS and increase serum interleukin-10 (IL-10 levels in cerebral ischemia reperfusion rats. In addition, sevoflurane postconditioning can still decrease blood lipid, malondialdehyde (MDA levels, infarct volume and increase antioxidant enzymes activities, normal pyramidal neurons density in cerebral ischemia reperfusion rats. It can be concluded that sevoflurane postconditioning may decrease blood and brain oxidative injury and enhance immunity indexes in cerebral ischemia reperfusion rats.

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

    A.C. Pereira


    Full Text Available During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP production, which in turn leads to protein kinase G (PKG activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca2+ signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could contribute to vascular diseases. Nitrosyl ruthenium complexes have been studied as a new class of NO donors with potential therapeutic use in order to supply the NO deficiency. In this context, this article shall provide a brief review of the effects exerted by the NO that is enzymatically produced via endothelial NO-synthase (eNOS activation and by the NO released from NO donor compounds in the vascular smooth muscle cells on both conduit and resistance arteries, as well as veins. In addition, the involvement of the nitrite molecule as an endogenous NO reservoir engaged in vasodilatation will be described.

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

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


    During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO) as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC) modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP) production, which in turn leads to protein kinase G (PKG) activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca(2+) signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could contribute to vascular diseases. Nitrosyl ruthenium complexes have been studied as a new class of NO donors with potential therapeutic use in order to supply the NO deficiency. In this context, this article shall provide a brief review of the effects exerted by the NO that is enzymatically produced via endothelial NO-synthase (eNOS) activation and by the NO released from NO donor compounds in the vascular smooth muscle cells on both conduit and resistance arteries, as well as veins. In addition, the involvement of the nitrite molecule as an endogenous NO reservoir engaged in vasodilatation will be described. PMID:21755266

  6. Coordinate Properties of Nitric Oxide in Hemoglobin Solution Containing a Minimal Amount of Nitric Oxide


    Nitric oxide (NO) has a very important physiological function, and it is the unique small diffusible signaling molecule.When NO molecules bind to heme irons in α subunits in hemoglobin (Hb), they have two coordinate forms for Fe2+: one is 5-coordinate, and the other is 6-coordinate.However, there is only 6-coordinate for Fe2+ when NO molecules bind to heme irons in β subunits.When the amount of NO is at a minimal concentration, NO molecules mainly bind to α subunits.The results show that NO molecules do not transfer from heme irons of nitrosylhemoglobin (HbNO) to the thiol groups of Cysteine residues β93 (Cysβ93) to form s-nitrosohemoglobin (Hb-SNO) in the presence of minimal NO in hemoglobin solution.The presence of minimal NO in hemoglobin solution does not decrease the transportation of oxygen, but it does improve its transport ability.It is still under further research whether this mechanism is underlying in the therapy for the disease of cardiovascular system.

  7. NOSTRIN: A protein modulating nitric oxide release and subcellular distribution of endothelial nitric oxide synthase

    Zimmermann, Kirstin; Opitz, Nils; Dedio, Jürgen; Renné, Christoph; Müller-Esterl, Werner; Oess, Stefanie


    Activity and localization of endothelial nitric oxide synthase (eNOS) is regulated in a remarkably complex fashion, yet the complex molecular machinery mastering stimulus-induced eNOS translocation and trafficking is poorly understood. In a search by the yeast two-hybrid system using the eNOS oxygenase domain as bait, we have identified a previously uncharacterized eNOS-interacting protein, dubbed NOSTRIN (for eNOS traffic inducer). NOSTRIN contains a single polypeptide chain of 506-aa residues of 58 kDa with an N-terminal cdc15 domain and a C-terminal SH3 domain. NOSTRIN mRNA is abundant in highly vascularized tissues such as placenta, kidney, lung, and heart, and NOSTRIN protein is expressed in vascular endothelial cells. Coimmunoprecipitation experiments demonstrated the eNOS–NOSTRIN interaction in vitro and in vivo, and NOSTRIN's SH3 domain was essential and sufficient for eNOS binding. NOSTRIN colocalized extensively with eNOS at the plasma membrane of confluent human umbilical venous endothelial cells and in punctate cytosolic structures of CHO-eNOS cells. NOSTRIN overexpression induced a profound redistribution of eNOS from the plasma membrane to vesicle-like structures matching the NOSTRIN pattern and at the same time led to a significant inhibition of NO release. We conclude that NOSTRIN contributes to the intricate protein network controlling activity, trafficking, and targeting of eNOS. PMID:12446846

  8. Discovery of nitric oxide in marine ecological system and the chemical characteristics of nitric oxide

    ZHANG Zhengbin; XING Lei; WU Zhenzhen; LIU Chunying; LIN Cai; LIU Liansheng


    Nitric oxide was discovered in both the lab and the alga culture pond of Daya Bay (1-300 m3) before the growth of alga reached the maximum. The results included: (1) NO was detectd before the growth of alga reached the maximum in the case of red tide alga and food alga, and the concentration of NO decreased rapidly after the growth maximum; (2) the curve between NO concentration and time indicated that the concentration of NO in the daytime was more than that at night,and the maximal concentration of NO appeared in the midday (1-3 pm); (3) the growth of alga reached the maximum in the alga culture pond of Daya Bay in about 8- 10 d, and NO was discovered in 5-7 d; (4) the measured NO concentration was 10-9 mol/L, 10-9-10-8 mol/L, and 10-8 mol/L for Haeterosigma akashiwo, mixed alga in Daya Bay and Chaetoceros Curvisetus individually; (5) the relation of illumination with NO production was discussed.

  9. Guidelines for the safe administration of inhaled nitric oxide.

    Miller, O I; Celermajer, D S; Deanfield, J. E.; MacRae, D. J.


    Inhaled nitric oxide (NO) is a selective pulmonary vasodilator, potentially useful in the treatment of pulmonary hypertension and ventilation-perfusion mismatch. High doses of inhaled NO and its oxidative product nitrogen dioxide (NO2) may cause acute lung injury. Using a standard infant ventilator, ventilator circuit and test lung, an administration and monitoring strategy has been defined for inhaled NO and these observations validated in eight ventilated infants. In 90% oxygen, doses of in...

  10. Correlation of exhaled nitric oxide, nasal nitric oxide and atopic status: A cross-sectional study in bronchial asthma and allergic rhinitis

    Nitesh Gupta; Nitin Goel; Raj Kumar


    Objective: Exhaled nitric oxide (FE NO ) and nasal nitric oxide (n NO) measurement is an area of ongoing research in the study of airway inflammation. The atopic status is known to influence the levels of FE NO and n NO. This study was undertaken to study the relationship between nitric oxide measurements in bronchial asthma and allergic rhinitis along with their correlation with atopic profile of Indian population. Materials and Methods: Ninety subjects were recruited for the study comprisin...

  11. Nitric Oxide Generated from Isoniazid Activation by KatG: Source of Nitric Oxide and Activity against Mycobacterium tuberculosis

    Timmins, Graham S.; Master, Sharon; Rusnak, Frank; Deretic, Vojo


    Isonicotinic acid hydrazide (INH) is a frontline antituberculosis agent. Once taken up by Mycobacterium tuberculosis, INH requires activation by the catalase-peroxidase KatG, converting INH from its prodrug form into a range of bactericidal reactive species. Here we used 15N-labeled INH together with electron paramagnetic resonance spin trapping techniques to demonstrate that nitric oxide (NȮ) is generated from oxidation at the hydrazide nitrogens during the activation of INH by M. tuberculos...

  12. The role of nitrite in nitric oxide homeostasis

    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 regulation...... and cytoprotection from a comparative viewpoint, with focus on mammals and fish. Constitutive nitric oxide synthase activity results in similar plasma nitrite levels in mammals and fish, but nitrite can also be taken up across the gills in freshwater fish, which has implications for nitrite/NO levels...... and nitrite utilization in hypoxia. The nitrite reductase activity of deoxyhemoglobin is a major mechanism of NO generation from nitrite and may be involved in hypoxic vasodilation. Nitrite is readily transported across the erythrocyte membrane, and the transport is enhanced at low O2 saturation in...

  13. Nitric oxide turnover in permeable river sediment

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


    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 the net NO production rate in steady state. This initial NO production rate is in the same range as the net ammonia oxidation rate, indicating that NO is transiently the main product of ammonia oxidizers. Stable isotope labeling experiments with the 15N-labeled chemical NO donor S...

  14. 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

    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.

  15. Nitric Oxide Loaded Echogenic Liposomes for Nitric Oxide Delivery and Inhibition of Intimal Hyperplasia

    Huang, Shao-Ling; Kee, Patrick H.; Kim, Hyunggun; Moody, Melanie R.; Chrzanowski, Stephen M.; MacDonald, Robert C.; McPherson, David D.


    Objective To develop a new bioactive gas delivery method using echogenic liposomes (ELIP) as the gas carrier. Background Nitric oxide (NO) is a bioactive gas with potent therapeutic effects. Bioavailability of NO by systemic delivery is low with potential systemic effects. Methods Liposomes containing phospholipids and cholesterol were prepared using a new freezing under pressure method. The encapsulation and release profile of NO from NO containing-ELIP (NO-ELIP) or a mixture of NO/Argon (NO/Ar-ELIP was studied. Uptake of NO from NO-ELIP by cultured vascular smooth muscle cells (VSMC) both in the absence and presence of hemoglobin was determined. The effect of NO-ELIP delivery to attenuate intimal hyperplasia in a balloon-injured artery was determined. Results Coencapsulation of NO with argon (Ar) enabled the adjustment the amount of encapsulated NO. A total of 10 µl of gas can be encapsulated into 1 mg liposomes. The release profile of NO from NO-ELIP demonstrated an initial rapid release followed by a slower release over 8 hours. Sixty-eight percent of cells remained viable when incubated with 80 µg/ml of NO/Ar-ELIP for 4 hours. NO delivery to VSMC using NO/Ar-ELIP was 7-fold higher than unencapsulated NO. NO/Ar-ELIP remained effective NO delivery to VSMC even in the presence of hemoglobin. Local NO-ELIP administration to balloon-injured carotid arteries attenuated the development of intimal hyperplasia and reduced arterial wall thickening by 41±9%. Conclusions Liposomes can protect and deliver a bioactive gas to target tissues with the potential for both visualization of gas delivery and controlled therapeutic gas release. PMID:19660697

  16. Refractory Oxide Coatings on Titanium for Nitric Acid Applications

    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.

  17. Neuronal nitric oxide synthase and N-methyl-D-aspartate neurons in experimental carbon monoxide poisoning

    We measured changes in nitric oxide (·NO) concentration in the cerebral cortex during experimental carbon monoxide (CO) poisoning and assessed the role for N-methyl-D-aspartate receptors (NMDARs), a glutamate receptor subtype, with progression of CO-mediated oxidative stress. Using microelectrodes, ·NO concentration was found to nearly double to 280 nM due to CO exposure, and elevations in cerebral blood flow, monitored as laser Doppler flow (LDF), were found to loosely correlate with ·NO concentration. Neuronal nitric oxide synthase (nNOS) activity was the cause of the ·NO elevation based on the effects of specific NOS inhibitors and observations in nNOS knockout mice. Activation of nNOS was inhibited by the NMDARs inhibitor, MK 801, and by the calcium channel blocker, nimodipine, thus demonstrating a link to excitatory amino acids. Cortical cyclic GMP concentration was increased due to CO poisoning and shown to be related to ·NO, versus CO, mediated guanylate cyclase activation. Elevations of ·NO were inhibited when rats were infused with superoxide dismutase and in rats depleted of platelets or neutrophils. When injected with MK 801 or 7-nitroindazole, a selective nNOS inhibitor, rats did not exhibit CO-mediated nitrotyrosine formation, myeloperoxidase (MPO) elevation (indicative of neutrophil sequestration), or impaired learning. Similarly, whereas CO-poisoned wild-type mice exhibited elevations in nitrotyrosine and myeloperoxidase, these changes did not occur in nNOS knockout mice. We conclude that CO exposure initiates perivascular processes including oxidative stress that triggers activation of NMDA neuronal nNOS, and these events are necessary for the progression of CO-mediated neuropathology

  18. Measurements of Fractional Exhaled Nitric Oxide in Pediatric Asthma

    Youn-Soo Hahn


    Full Text Available Exhaled nitric oxide (NO has been extensively investigated as a noninvasive marker of airway inflammation in asthma. The increased NO expression induced by inflammatory mediators in airways can be monitored easily in exhaled air from asthmatic children. Based on the relationship between the increased NO expression and eosinophilic airway inflammation, fractional exhaled nitric oxide (FeNO measurements become an important adjunct for the evaluation of asthma. In addition, the availability of portable devices makes it possible to measure FeNO more easily and frequently in the routine pediatric practice. Despite various confounding factors affecting its levels, FeNO can be applicable in diagnosing asthma, monitoring treatment response, evaluating asthma control, and predicting asthma exacerbations. Thus, although pulmonary function tests are the standard tools for objective measurements of asthmatic control, FeNO can broaden the way of asthma monitoring and supplement standard clinical asthma care guidelines.



    Objective To examine the effects of insulin on cell proliferation, nitric oxide (NO) release and nitric oxide synthase (NOS) gene expression in bovine aortic endothelial cells ( BAEC ) . Methods The mi togenesis was assessed by MTT method; the products of NO in the culture media, by Griess reaction; and the levels of NOS mRNA in BAEC , by RT/PCR tech nique. Results BAEC were not responsive to the growth-promoting effects of insulin. Stimulation with insulin resulted a dose-dependent rise of NO in the culture supernatants 2h later, with a maximum at 12~24h and a decline at 24h. This rise was inhibited by an inhibitor of NOS (L-NAME). NOS mRNA increased slightly in BAEC without statistical significance. Conelu sion The study suggested that the insulin-induced NO release might be caused directly by NOS activation.

  20. Nitric oxide: Orchestrator of endothelium-dependent responses

    Félétou, Michel; Köhler, Ralf; Vanhoutte, Paul M


    interventions may improve the bioavailability of NO and thus prevent/cure endothelial dysfunction. Then, the role of other endothelium-derived mediators (endothelium-derived hyperpolarizing (EDHF) and contracting (EDCF) factors, endothelin-1) and signals (myoendothelial coupling) is summarized also, with......Abstract The present review first summarizes the complex chain of events, in endothelial and vascular smooth muscle cells, that leads to endothelium-dependent relaxations (vasodilatations) due to the generation of nitric oxide (NO) by endothelial nitric oxide synthase (eNOS) and how therapeutic...... special emphasis on their interaction(s) with the NO pathway, which make the latter not only a major mediator but also a key regulator of endothelium-dependent responses....

  1. Nitric oxide availability in deeply hypoxic crucian carp

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


    order to decipher NO metabolites in plasma and several tissues. We also compared NO metabolite changes during acute (10 min) and chronic (1 day) exposures to three different O2 levels. Plasma [nitrite] decreased with decreasing [O2], while the cellular concentrations of nitrite and nitros......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 that the...

  2. Nitric oxide metabolites in goldfish under normoxic and hypoxic conditions

    Hansen, Marie N.; Jensen, Frank Bo


    Nitric oxide (NO), produced by nitric oxide synthases (NOS enzymes), regulates multiple physiological functions in animals. NO exerts its effects by binding to iron (Fe) of heme groups (exemplified by the activation of soluble guanylyl cyclase) and by S-nitrosylation of proteins – and it is...... metabolized to nitrite and nitrate. Nitrite is used as a marker for NOS activity but it is also a NO donor that can be activated by various cellular proteins under hypoxic conditions. Here, we report the first systematic study of NO metabolites (nitrite, nitrate, S-nitroso, N-nitroso and Fe-nitrosyl compounds...... hypoxia levels was assessed from metabolic and respiratory variables. In normoxic goldfish, the concentrations of NO metabolites in plasma and tissues were comparable with values reported in mammals, indicative of similar NOS activity. Exposure to hypoxia [at PO2 (partial pressure of O2) values close to...

  3. Measurement of arginine metabolites: regulators of nitric oxide metabolism.

    Augustine, Molly S; Rogers, Lynette K


    Arginine is the substrate for nitric oxide synthases (NOS), and arginine availability regulates the production of nitric oxide. Through the activity of methyltransferases, arginine can be methylated to form monomethylarginine (NMMA), asymmetrical dimethylarginine (ADMA), and symmetrical dimethylarginine (SDMA). NMMA and ADMA directly inhibit NOS, whereas SDMA inhibits the cellular import of arginine through the cationic amino acid transporter. Increased levels of methylarginine compounds have been associated with many diseases including atherosclerosis, renal failure, pulmonary hypertension, and preeclampsia. Previous HPLC methods to measure these molecules rely on derivatization with ortho-phthalaldehyde, which is unstable and requires immediate pre- or post-column reactions. We have identified a new fluorometric agent that is stable for at least 1 week and provides chromatographic properties that facilitate separation of these chemically similar compounds by reverse phase chromatography. PMID:24510541

  4. Participación del óxido nítrico, proteína Fos y el tallo cerebral en la retención de glucosa encefálica durante la hipoxia Involvement of the nitric oxide, Fos protein and brain stem in the retention of brain glucose during hypoxia

    Mónica Lemus Vidal


    Full Text Available Se ha descrito que el núcleo del tracto solitario (NTS, estructura del tallo cerebral y vía de relevo de las aferencias del los quimiorreceptores del senocuerpo carotídeo (RSCC, participa en el aumento en la retención de glucosa por el cerebro (RGC ante una hipoxia. Es probable que en esta respuesta participe el óxido nítrico (NO y la proteína Fos. En este trabajo se analiza el papel del NO en el NTS sobre la modificación de la RGC y la expresión de la proteína inmunorreactiva Fos (Fos-ir en ratas in vivo. La inyección de un donador del NO como es el nitroprusiato de sodio (NPS en el NTS, 4 min antes de la estimulación de los RSCC, disminuyó la RGC, pero incrementó la expresión de Fos-ir en un mayor número de neuronas en el NTS con respecto a las ratas control, que sólo recibieron líquido cefalorraquídeo artificial (LCRa antes de la estimulación RSCC. En contraste, un inhibidor selectivo del NO como el N?-nitro-L-arginina metil éster (L-NAME en el NTS 4 min antes de la estimulación RSCC con NaCN, aumentó la RGC, pero disminuyó el número de neuronas Fos-ir comparados con el control o con NPS. La detección inmunohistoquímica de la expresión de Fos-ir en las células del tallo cerebral indica que la estimulación RSCC activa vías dependientes de NO en el NTS, para regular la RGC. El estudio de esta población de células en el NTS, será importante para definir su caracterización.It has been said that the nucleus tractus solitarii (NTS, one structure of the brain stem and path of apherences of chemoreceptors of carotid sinus-body, is involved in the increased glucose retention by the brain in case of hypoxia. It is likely that nitric oxide and Fos protein also take part in this response. This paper analyzes the role of nitric oxide in the NTS on the change of glucose retention by the brain and the expression of inmunoreactive protein Fos (ir-Fos in rats in vivo. The injection of a NO donor such as sodium nitroprusiate

  5. The clinical value of exhaled nitric oxide in asthma

    Pisi, Roberta


    Bronchial asthma is an inflammatory disease and measurement of biomarkers in exhaled breath has recently become an attractive approach to non-invasively monitor airway inflammation. In bronchial asthma, increased fractional exhaled nitric oxide (FeNO) concentration in exhaled breath has been shown to reflect the extent of eosinophilic inflammation. Moreover, the increase of FeNO levels are suppressed by inhaled corticosteroids (ICS). Therefore, monitoring of FeNO is a useful marker of inf...

  6. Exhaled nitric oxide measurements: clinical application and interpretation

    Taylor, D R; Pijnenburg, M W; Smith, A. D.


    The use of exhaled nitric oxide measurements (FEno) in clinical practice is now coming of age. There are a number of theoretical and practical factors which have brought this about. Firstly, FEno is a good surrogate marker for eosinophilic airway inflammation. High FEno levels may be used to distinguish eosinophilic from non‐eosinophilic pathologies. This information complements conventional pulmonary function testing in the assessment of patients with non‐specific respiratory symptoms. Secon...

  7. Nitric oxide synthase is induced in sporulation of Physarum polycephalum

    Golderer, Georg; Werner, Ernst R.; Leitner, Stefan; Gröbner, Peter; Werner-Felmayer, Gabriele


    The myxomycete Physarum polycephalum expresses a calcium-independent nitric oxide (NO) synthase (NOS) resembling the inducible NOS isoenzyme in mammals. We have now cloned and sequenced this, the first nonanimal NOS to be identified, showing that it shares < 39% amino acid identity with known NOSs but contains conserved binding motifs for all NOS cofactors. It lacks the sequence insert responsible for calcium dependence in the calcium-dependent NOS isoenzymes. NOS expression was strongly up-r...

  8. Opposite actions of nitric oxide on cholinergic synapses: which pathways?

    Mothet, J P; Fossier, P; Tauc, L; Baux, G


    Nitric oxide (NO) produced opposite effects on acetylcholine (ACh) release in identified neuroneuronal Aplysia synapses depending on the excitatory or the inhibitory nature of the synapse. Extracellular application of the NO donor, SIN-1, depressed the inhibitory postsynaptic currents (IPSCs) and enhanced the excitatory postsynaptic currents (EPSCs) evoked by presynaptic action potentials (1/60 Hz). Application of a membrane-permeant cGMP analog mimicked the effect of SIN-1 suggesting the par...

  9. Nitric oxide and phytohormone interactions: current status and perspectives

    Luciano eFreschi


    Nitric oxide (NO) is currently considered a ubiquitous signal in plant systems, playing significant roles in a wide range of plant responses to environmental and endogenous cues. During the signaling events leading to these plant responses, NO frequently interacts with plant hormones and other endogenous molecules, at times originating remarkably complex signaling cascades. Accumulating evidence indicates that virtually all major classes of plant hormones may influence, at least to some degre...

  10. Interactions between nitric oxide and plant hormones in aluminum tolerance

    He, Huyi; He, Longfei; Gu, Minghua


    Nitric oxide (NO) is involved, together with plant hormones, in the adaptation to Al stress in plants. However, the mechanism by which NO and plant hormones interplay to improve Al tolerance are still unclear. We have recently shown that patterns of plant hormones alteration differ between rye and wheat under Al stress. NO may enhance Al tolerance by regulating hormonal equilibrium in plants, as a regulator of plant hormones signaling. In this paper, some unsolved issues are discussed based o...

  11. Nitric oxide and phytohormone interactions: current status and perspectives

    Freschi, Luciano


    Nitric oxide (NO) is currently considered a ubiquitous signal in plant systems, playing significant roles in a wide range of responses to environmental and endogenous cues. During the signaling events leading to these plant responses, NO frequently interacts with plant hormones and other endogenous molecules, at times originating remarkably complex signaling cascades. Accumulating evidence indicates that virtually all major classes of plant hormones may influence, at least to some degree, the...

  12. Computation of Plasma Hemoglobin Nitric Oxide Scavenging in Hemolytic Anemias

    Jeffers, Anne; Gladwin, Mark T.; Kim-Shapiro, Daniel B.


    Intravascular hemoglobin limits the amount of endothelial-derived nitric oxide (NO) available for vasodilation. Cell-free hemoglobin scavenges NO more efficiently than red blood cell encapsulated hemoglobin. Hemolysis has recently been suggested to contribute to endothelial dysfunction based on a mechanism of NO scavenging by cell-free hemoglobin. Although experimental evidence for this phenomenon has been presented, support from a theoretical approach has, until now, been missing. Indeed, du...

  13. Rate of Nitric Oxide Scavenging by hemoglobin bound to haptoglobin

    Azarov, Ivan; He, Xiaojun; Jeffers, Anne; Basu, Swati; Ucer, Burak; Hantgan, Roy R.; Levy, Andrew; Kim-Shapiro, Daniel B.


    Cell-free hemoglobin, released from the red cell, may play a major role in regulating the bioavailability of nitric oxide. The abundant serum protein haptoglobin, rapidly binds to free hemoglobin forming a stable complex accelerating its clearance. The haptoglobin gene is polymorphic with two classes of alleles denoted 1 and 2. We have previously demonstrated that the haptoglobin 1 protein-hemoglobin complex is cleared twice as fast as the haptoglobin 2 protein-hemoglobin complex. In this rep...

  14. New nitric oxide donors based on ruthenium complexes

    C.N. Lunardi; R. S. da Silva; L.M. Bendhack


    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...

  15. Nitric oxide inhibits cutaneous vasoconstriction to exogenous norepinephrine

    Shibasaki, Manabu; David A Low; Davis, Scott L.; Crandall, Craig G.


    Previously, we found that nitric oxide (NO) inhibits cutaneous vasoconstrictor responsiveness evoked by whole body cooling, as well as an orthostatic stress in the heat-stressed human (Shibasaki M, Durand S, Davis SL, Cui J, Low DA, Keller DM, Crandall CG. J Physiol 585: 627–634, 2007). However, it remains unknown whether this response occurs via NO acting through presynaptic or postsynaptic mechanisms. The aim of this study was to test the hypothesis that NO is capable of impairing cutaneous...

  16. The effect of nitric oxide donors on human performance

    Bescós García, Raúl


    [eng] Nitric oxide or nitrogen monoxide (NO) is a tiny free radical gas. The discovery of this intriguing molecule has revolutionized physiology and pharmacology research during the last 20 years. Currently, it is known that NO is endogenously synthesized by several molecules and tissues via two pathways: the synthase-dependent pathway and the synthase-independent pathway. In the first, the amino acid L-arginine is the main donnor of NO synthesis. In the second, inorganic nitrate is the main ...


    Nachuraju, Parimala; Friedman, Adam J.; Friedman, Joel M.; Cabrales, Pedro


    This study investigated the systemic and microvascular hemodynamic changes related to increased nitric oxide (NO) availability following significant hemorrhage, made available by administration of NO releasing nanoparticles (NO-nps). Hemodynamic responses to hemorrhagic shock were studied in the hamster window chamber. Acute hemorrhage was induced by arterial controlled bleeding of 50% of blood volume, and the resulting hemodynamic parameters were followed over 90 min. Exogenous NO was admini...

  18. A Dirofilaria immitis Polyprotein Up-Regulates Nitric Oxide Production

    Tezuka, Hiroyuki; Imai, Shinjiro; Tsukidate, Setsuko; Fujita, Koichiro


    We investigated the effect of recombinant Dirofilaria immitis polyprotein (rDiAg) on nitric oxide (NO) production by peritoneal macrophages. rDiAg induced NO production by macrophages from wild-type and lipopolysaccharide-hyporesponsive C3H/HeJ, but not CD40−/−, mice. These results suggest that CD40 is involved in rDiAg-driven NO production by murine macrophages. PMID:12183583

  19. Nitric oxide inhibition sustains vasopressin-induced vasoconstriction.

    Dworkin, M. J.; Carnochan, P.; Allen-Mersh, T G


    Hepatic parenchymal vasoconstriction increases cytotoxic drug uptake into hepatic metastases by increasing the tumour to liver blood flow ratio. Prolonged infusion of the vasoconstrictor vasopressin does not result in sustained vasoconstriction, and this may limit the benefit of vasopressin in infusional chemotherapy. We have assessed whether loss of vasopressin-induced vasoconstriction is mediated by nitric oxide. Hepatic and tumour blood flow were continuously monitored, in an animal hepati...

  20. Nitric oxide metabolites in cystic fibrosis lung disease

    Grasemann, H; Ioannidis, I.; Tomkiewicz, R; de Groot, H.; Rubin, B; Ratjen, F


    Although the activity of nitric oxide (NO) synthases are increased in lung tissue of patients with cystic fibrosis, the concentrations of nasal and exhaled NO have recently been found to be decreased in cystic fibrosis. This could either be due to reduced NO formation or metabolism of NO within airway fluids. In this study, the stable NO metabolites, nitrate and nitrite, were determined in the saliva and sputum of 18 stable cystic fibrosis patients, 21 cystic fibrosis pat...

  1. Salivary Nitric Oxide, a Biomarker for Stress and Anxiety?

    Gammoh, Omar Salem; Al-Smadi, Ahmed Mohammad; Ashour, Ala Fawzi; Al-Awaida, Wajdy


    Objective To investigate if salivary nitrate correlates to the daily psychological stress and anxiety in a group of human subjects. Methods The convenient sample recruitment method was employed; data from seventy three subjects were analyzed. The Perceived Stress Scale (PSS) and Hamilton Anxiety Rating Scale (HAM-A) inventories were used to determine stress and anxiety scores respectively. Salivary nitric oxide was measured through nitrate (NOx) levels using the Griess reaction method. Result...

  2. Nitric oxide removal by wastewater bacteria in a biotrickling filter

    Niu, Hejingying; 牛何晶英.


    Nitric oxide (NO) is one of the most important air pollutants in atmosphere mainly emitted from combustion exhaust gas. In this research, a biotrickling filter was designed and operated to remove this pollutant from an air stream using bacteria extracted from the sewage sludge of a municipal sewage-treatment plant. The bacteria were cultured and enriched by either petri dish’s cultivation or liquid cultivation. The adsorption capacity of the ceramic material, which was used as the packing ma...

  3. Nitric oxide produced by ultraviolet-irradiated keratinocytes stimulates melanogenesis.

    Roméro-Graillet, C; Aberdam, E; Clément, M.; Ortonne, J P; Ballotti, R


    Ultraviolet (UV) radiation is the main physiological stimulus for human skin pigmentation. Within the epidermal-melanin unit, melanocytes synthesize and transfer melanin to the surrounding keratinocytes. Keratinocytes produce paracrine factors that affect melanocyte proliferation, dendricity, and melanin synthesis. In this report, we show that normal human keratinocytes secrete nitric oxide (NO) in response to UVA and UVB radiation, and we demonstrate that the constitutive isoform of keratino...

  4. Protective role of nitric oxide in ocular toxoplasmosis.

    Hayashi, S; Chan, C. C.; Gazzinelli, R T; Pham, N. T.; Cheung, M K; Roberge, F. G.


    AIMS: To evaluate the role of nitric oxide (NO) in ocular involvement during systemic toxoplasmosis. METHODS: C57B1/6 mice were infected with Toxoplasma gondii strain ME49. The synthesis of NO was inhibited by an intraperitoneal injection of aminoguanidine every 8 hours, starting on the day of infection. Control infected mice received phosphate buffered saline vehicle alone. After 14 days, the ocular lesions were evaluated by histopathological examination. The expression of NO synthase induce...

  5. A Cellular Model for Screening Neuronal Nitric Oxide Synthase Inhibitors

    Fang, Jianguo; Silverman, Richard B.


    Nitric oxide synthase (NOS) inhibitors are potential drug candidates because it has been well demonstrated that excessive production of NO critically contributes to a range of diseases. Most inhibitors have been screened in vitro using recombinant enzymes, leading to the discovery of a variety of potent compounds. To make inhibition studies more physiologically relevant and bridge the gap between the in vitro assay and in vivo studies, we report here a cellular model for screening NOS inhibit...

  6. Endothelial nitric oxide synthase mediates lymphangiogenesis and lymphatic metastasis

    Lahdenranta, Johanna; Hagendoorn, Jeroen; Padera, Timothy P; Hoshida, Tohru; Nelson, Gregory; Kashiwagi, Satoshi; Jain, Rakesh K.; Fukumura, Dai


    Lymphatic metastasis is a critical determinant of cancer prognosis. Recently, several lymphangiogenic molecules such as vafscular endothelial growth factor (VEGF)-C and -D were identified. However, the mechanistic understanding of lymphatic metastasis is still in infancy. Nitric oxide (NO) plays a crucial role in regulating blood vessel growth and function as well as lymphatic vessel function. NOS expression correlates with lymphatic metastasis. However, causal relationship between NOS and ly...

  7. Modeling of nitric oxide emissions from temperate agricultural ecosystems.

    Rolland, Marie-Noëlle; Gabrielle, Benoît; Laville, Patricia; Serça, Dominique; Cortinovis, Jérôme; Larmanou, Eric; Lehuger, Simon; Cellier, Pierre


    48 p. Arable soils are a significant source of nitric oxide (NO), most of which is derived from nitrogen fertilizers. Precise estimates of NO emissions from these soils are thus essential to devise strategies to mitigate the impact of agriculture on tropospheric ozone regulation. This paper presents the implementation of a soil NO emissions submodel within the environmentally-orientated soil crop model, CERES-EGC. The submodel simulates the NO production via nitrification pathway, as modul...

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

    Ling Cui; Erica P. Murray


    The influence of electrode configuration on the impedancemetric response of nitric oxide (NO) gas sensors was investigated for solid electrochemical cells [Au/yttria-stabilized zirconia (YSZ)/Au)]. Fabrication of the sensors was carried out at 1050 °C in order to establish a porous YSZ electrolyte that enabled gas diffusion. Two electrode configurations were studied where Au wire electrodes were either embedded within or wrapped around the YSZ electrolyte. The electrical response of the sen...

  9. Nitric oxide mediates sexual behavior in female rats.

    Mani, S K; Allen, J M; Rettori, V; McCann, S M; O'Malley, B W; Clark, J H


    Nitric oxide (NO), an active free radical formed during the conversion of arginine to citrulline by the enzyme NO synthase (NOS), mediates vasorelaxation, cytotoxicity, and neurotransmission. Neurons containing NOS (NOergic) are located in the hypothalamus. These NOergic neurons control the release of several hypothalamic peptides. Release of NO from these NOergic neurons stimulates pulsatile release of luteinizing hormone-releasing hormone (LHRH) in vivo and LHRH release in vitro. LHRH not o...

  10. Nitric oxide and the resolution of inflammation: implications for atherosclerosis

    Shaw, Catherine A; Taylor, Emma L.; Megson, Ian L.; Rossi, Adriano G


    The ubiquitous free radical, nitric oxide (NO), plays an important role in many biological processes including the regulation of the inflammatory response. Alterations in NO synthesis by endogenous systems likely influence inflammatory processes occurring in a wide range of diseases including many in the cardiovascular system (e.g. atherosclerosis). Progression of inflammatory conditions depends not only upon the recruitment and activation of inflammatory cells but also upon their subsequent ...

  11. Role of N-Nitro-L-Arginine-Methylester as anti-oxidant in transient cerebral ischemia and reperfusion in rats

    Awooda Hiba A


    Full Text Available Abstract Background Previous reports assessing the neuroprotective role of nonselective Nitric Oxide synthase (NOS inhibitor N-nitro-L-arginine-methylester (L-NAME following cerebral ischemia/reperfusion are contradictory. The aim of this work was to examine the potential benefits of L-NAME on rats subjected to transient focal cerebral ischemia/reperfusion. Methods The study involved 30 adult male Wistar rats divided into three groups 10 rats in each: First group was sham-operated and served as a control, a ischemia/reperfusion (I/R group of rats infused with 0.9% normal saline intraperitoneally 15 minutes prior to 30 minutes of left common carotid artery (CCA occlusion and a test group infused with L-NAME intraperitoneally 15 minutes prior to ischemia. Neurobehavioral assessments were evaluated and quantitative assessment of malondialdehyde (MDA, Nitric oxide (NO metabolites and total antioxidant capacity (TAC in both serum and the affected cerebral hemisphere were achieved. Results Rats’ neurological deficit and TAC were significantly decreased while NO and MDA were significantly increased in the I/R compared with the control group (P Conclusions L-NAME pretreatment for rats undergoing cerebral ischemia/reperfusion significantly improves neurological deficit while reducing oxidative stress biomarkers in the affected cerebral hemisphere.

  12. L-citrulline immunostaining identifies nitric oxide production sites within neurons

    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.

  13. Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates

    Opländer, C.; Volkmar, C.M.; Paunel-Görgülü, A; van Faassen, E.E.H.; Heiss, C


    Rationale: Human skin contains photolabile nitric oxide derivates like nitrite and S-nitroso thiols, which after UVA irradiation, decompose and lead to the formation of vasoactive NO. Objective: Here, we investigated whether whole body UVA irradiation influences the blood pressure of healthy volunteers because of cutaneous nonenzymatic NO formation. Methods and Results: As detected by chemoluminescence detection or by electron paramagnetic resonance spectroscopy in vitro with human skin speci...

  14. Nitric-phosphoric acid oxidation of organic waste materials

    A wet chemical oxidation technology has been developed to address issues facing defense-related facilities, private industry, and small-volume generators such as university and medical laboratories. Initially tested to destroy and decontaminate a heterogenous mixture of radioactive-contaminated solid waste, the technology can also remediate other hazardous waste forms. The process, unique to Savannah River, offers a valuable alternative to incineration and other high-temperature or high-pressure oxidation processes. The process uses nitric acid in phosphoric acid; phosphoric acid allows nitric acid to be retained in solution well above its normal boiling point. The reaction converts organics to carbon dioxide and water, and generates NOx vapors which can be recycled using air and water. Oxidation is complete in one to three hours. In previous studies, many organic compounds were completely oxidized, within experimental error, at atmospheric pressure below 180 degrees C; more stable compounds were decomposed at 200 degrees C and 170 kPa. Recent studies have evaluated processing parameters and potential throughputs for three primary compounds: EDTA, polyethylene, and cellulose. The study of polyvinylchloride oxidation is incomplete at this time

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

    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.

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

    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

  17. Role of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal injury in neonatal rats

    Hui LU; Bing Zhu; Xin-Dong Xue


    AIM: To investigate the dynamic change and role of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis (NEC) is associated with the levels of nitric oxide synthase (NOS) in the mucosa of the affected intestine tissue.METHODS: Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide (LPS). Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined.RESULTS: The LPS-injected pups showed a significant increase in injury scores versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury.CONCLUSION: nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.

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

    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 proc

  19. Nitric oxide modulates interleukin-2-induced proliferation in CTLL-2 cells

    Padrón, J.; Glaría, L.; Martinez, O.; Torres, M.; Lopez, E.; Delgado, R.; Caveda, L.; Rojas, A.


    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...

  20. Chronic nitroglycerine administration reduces endothelial nitric oxide production in rabbit mesenteric resistance artery

    Yamamoto, Tamao; Kajikuri, Junko; Watanabe, Yoshimasa; Suzuki, Yoshikatsu; Suzumori, Kaoru; Itoh, Takeo


    We investigated whether 10 days' in vivo treatment with nitroglycerine (NTG) would inhibit nitric oxide production by the endothelial cells of resistance arteries ex vivo and, if so, what the underlying mechanism might be.ACh increased the intracellular nitric oxide concentration ([NO]i; estimated using the nitric oxide-sensitive fluorescent dye diaminofluorescein-2) within the endothelial cells of rabbit mesenteric resistance arteries. This effect was significantly smaller in arteries isolat...

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

    Tohid Najafi; Marefat Ghaffari Novin; Jalil Pakravesh; Khadijeh Foghi; Fatemeh Fadayi; Gelareh Rahimi


    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...

  2. Inducible nitric-oxide synthase attenuates vasopressin-dependent Ca2+ signaling in rat hepatocytes

    Patel, S.; Gaspers, L. D.; Boucherie, S.; Memin, E.; Stellato, K. A.; Guillon, G; Combettes, L; Thomas, A P


    Increases in both Ca2+ and nitric oxide levels are vital for a variety of cellular processes; however, the interaction between these two crucial messengers is not fully understood. Here, we demonstrate that expression of inducible nitric-oxide synthase in hepatocytes, in response to inflammatory mediators, dramatically attenuates Ca2+ signaling by the inositol 1,4,5-trisphosphate-forming hormone, vasopressin. The inhibitory effects of induction were reversed by nitric oxide inhibitors and mim...

  3. Histochemical study of the nitric oxide synthase activity in experimental trichinellosis.

    Hadaś, E; Gustowska, L; Boczoń, K; Janczewska, D


    Nitric oxide plays a critical role in a variety of biological activities. It has been nicknamed a "killer" and "mediator" due to its toxic and signalling properties. Apart from its regular physiological function, nitric oxide indirectly participates in infectious diseases. Our report seems to be the first presentation of the nitric oxide synthase participation in the host biochemical defence mechanisms and in morphological transformation of muscle cells in trichinellosis. PMID:16883715

  4. The Effect of Acute Fluoride Poisoning on Nitric Oxide and Methemoglobin Formation in the Guinea pig

    ŞİRELİ, Meltem


    To study the effect of acute fluoride poisoning on nitric oxide and methemoglobin formation, 250 mg/kg bw sodium fluoride was applied alone and verapamil was applied together with fluoride. Blood nitric oxide (Griess reaction) and calcium levels; hemoglobin, methemoglobin and hematocrit values; and erythrocyte counts were determined and compared with those of the controls. After the fluoride application it was found that there was a relative relationship between the increase in nitric oxide a...

  5. Novel methods of measuring nitric oxide and nitrite concentrations using cobinamide and cobalamin

    Duan, Kailin Catherine


    Nitric oxide (NO) is an important signaling molecule produced by isoforms of nitric oxide synthase in mammals. Methods of measuring NO must take into consideration the low concentrations (nanomolar to micromolar) at which it is found in the body. We developed a novel method of direct nitric oxide measurement by measuring the absorbance change of the binding of nitric oxide to cobinamide(II) (Cbi), a vitamin B12 analogue. The absorbance values of NO-Cbi change linearly at 366 nm and 469 nm as ...

  6. Nitric oxide and thermogenesis--challenge in molecular cell physiology.

    Otasevic, Vesna; Korac, Aleksandra; Buzadzic, Biljana; Stancic, Ana; Jankovic, Aleksandra; Korac, Bato


    Only recently we can link thermogenesis, mitochondria, nitric oxide, and redox regulation in biochemical terms. Currently, we are discussing these processes from the aspect of fundamental principles of molecular physiology. Thus, the present article highlights both cell physiology and the principles of the maintenance of energy homeostasis in organisms. Energy homeostasis means much more than simple combustion; adipose tissues at this point of evolution development are related to a broad spectrum of metabolic disturbances and all aspects of cellular remodeling (i.e. structural, metabolic and endocrine changes). Therefore, this paper addresses not only thermogenesis but also energy homeostasis, oxidative phosphorylation and ATP production, proliferation and differentiation of brown adipocytes, their life and death, mitochondriogenesis and angiogenesis. These processes will be united by molecular players of oxidation/reduction reactions, thus creating the principles based on the redox regulation. PMID:21622264

  7. Nanomaterials-based electrochemical sensors for nitric oxide

    Electrochemical sensing has been demonstrated to represent an efficient way to quantify nitric oxide (NO) in challenging physiological environments. A sensing interface based on nanomaterials opens up new opportunities and broader prospects for electrochemical NO sensors. This review (with 141 refs.) gives a general view of recent advances in the development of electrochemical sensors based on nanomaterials. It is subdivided into sections on (i) carbon derived nanomaterials (such as carbon nanotubes, graphenes, fullerenes), (ii) metal nanoparticles (including gold, platinum and other metallic nanoparticles); (iii) semiconductor metal oxide nanomaterials (including the oxides of titanium, aluminum, iron, and ruthenium); and finally (iv) nanocomposites (such as those formed from carbon nanomaterials with nanoparticles of gold, platinum, NiO or TiO2). The various strategies are discussed, and the advances of using nanomaterials and the trends in NO sensor technology are outlooked in the final section. (author)

  8. Pharmacological evidence for connection of nitric oxide-mediated pathways in neuroprotective mechanism of ischemic postconditioning in mice

    Puja Gulati


    Full Text Available Introduction: Postconditioning (PoCo is an adaptive phenomenon whereby brief repetitive cycles of ischemia with intermittent reperfusion instituted immediately after prolonged ischemia at the onset of prolonged reperfusion elicit tissue protection. PoCo is noted to exert a protective effect in various organs like heart, liver, kidney and brain. Various triggers, mediators and end effectors are suggested to contribute to the protective effect of PoCo. However, the neuroprotective mechanism of PoCo is poorly understood. Objectives: The present study has been designed to investigate the role of nitric oxide pathway in the neuroprotective mechanism of ischemic postconditioning (iPoCo employing a mouse model of global cerebral ischemia and reperfusion-induced injury. Materials and Methods: Bilateral carotid artery occlusion (BCAO of 12 min followed by reperfusion for 24 h was employed to produce ischemia and reperfusion (I/R-induced cerebral injury in mice. Cerebral injury was assessed in the terms of cerebral infarct, memory impairment and motor in-coordination. Brain nitrite/nitrate; acetylcholinesterase activity, thiobarbituric acid reactive species (TBARS and glutathione level were also estimated. Results: BCAO followed by reperfusion produced a significant rise in cerebral infarct size, memory impairment and motor incoordination. Further a rise in acetylcholinesterase activity and TBARS level along with fall in brain nitrite/nitrate and glutathione levels was also noted. iPoCo consisting of three episodes of 10 s carotid artery occlusion and reperfusion (instituted immediately after BCAO significantly attenuated infarct size, memory impairment, motor incoordination as well as altered biochemicals. iPoCo-induced neuroprotective effects were significantly abolished by pretreatment of L-NAME, a nonselective NOS inhibitor. Conclusion: It may be concluded that the nitric oxide pathway probably plays a vital role in the neuroprotective mechanism of iPoCo.

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

    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.

  10. Nitric Oxide is Protective Against Mercury Induced Depression

    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.

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

    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?

  12. Nitric Oxide Signaling in Plant Responses to Abiotic Stresses

    Weihua Qiao; LiuMin Fan


    Nitric oxide (NO) plays important roles in diverse physiological processes In plants. NO can provoke both beneficial and harmful effects, which depend on the concentration and location of NO in plant cells. This review is focused on NO synthesis and the functions of NO in plant responses to abiotic environmental stresses. Abiotic stresses mostly induce NO production in plants. NO alleviates the harmfulness of reactive oxygen species, and reacts with other target molecules, and regulates the expression of stress responsive genes under various stress conditions.

  13. Alternatively spliced neuronal nitric oxide synthase mediates penile erection

    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 erec...

  14. Nasal airway nitric oxide : Methodological aspects and influence of inflammation

    Palm, Jörgen


    Nitric oxide (NO) is an endogenously formed free radical gas involved in numerous biological processes. In 1991 NO was discovered to be present in exhaled air of humans. Soon after, it was reported that the largest amounts of NO were found in the upper airways, and that the levels of NO were increased in the lower airways of patients with asthma. The high levels of NO in the nasal region are believed to be involved in functions as various as primary host defence, including k...

  15. Arginine affects appetite via nitric oxide in ducks.

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


    The objective of the study was to investigate the mechanism by which arginine regulates feed intake in Pekin ducks. In experiment 1, one hundred forty-four 1-d-old male Pekin ducks were randomly allotted to 3 dietary treatments with 6 replicate pens of 8 birds per pen. Birds in each group were fed a corn-corn gluten meal diet containing 0.65, 0.95, and 1.45% arginine. Ducks fed the diet containing 0.65% arginine had lower feed intake and plasma nitric oxide level (P Pekin ducks. PMID:24902706

  16. Inaccuracies of nitric oxide measurement methods in biological media

    Hunter, Rebecca A.; Storm, Wesley L.; Coneski, Peter N.; Schoenfisch, Mark H.


    Despite growing reports on the biological action of nitric oxide (NO) as a function of NO payload, the validity of such work is often questionable due to the manner in which NO is measured and/or the solution composition in which NO is quantified. To highlight the importance of measurement technique for a given sample type, NO produced from a small molecule NO donor (N-diazeniumdiolated l-proline, PROLI/NO) and a NO-releasing xerogel film were quantified in a number of physiological buffers a...

  17. Inhaled Nitric Oxide in preterm infants: a systematic review and individual patient data meta-analysis

    Schreiber Michael D


    Full Text Available Abstract Background Preterm infants requiring assisted ventilation are at significant risk of both pulmonary and cerebral injury. Inhaled Nitric Oxide, an effective therapy for pulmonary hypertension and hypoxic respiratory failure in the full term infant, has also been studied in preterm infants. The most recent Cochrane review of preterm infants includes 11 studies and 3,370 participants. The results show a statistically significant reduction in the combined outcome of death or chronic lung disease (CLD in two studies with routine use of iNO in intubated preterm infants. However, uncertainty remains as a larger study (Kinsella 2006 showed no significant benefit for iNO for this combined outcome. Also, trials that included very ill infants do not demonstrate significant benefit. One trial of iNO treatment at a later postnatal age reported a decrease in the incidence of CLD. The aim of this individual patient meta-analysis is to confirm or refute these potentially conflicting results and to determine the extent to which patient or treatment characteristics may explain the results and/or may predict benefit from inhaled Nitric Oxide in preterm infants. Methods/Design The Meta-Analysis of Preterm Patients on inhaled Nitric Oxide (MAPPiNO Collaboration will perform an individual patient data meta-analysis to answer these important clinical questions. Studies will be included if preterm infants receiving assisted ventilation are randomized to receive inhaled Nitric Oxide or to a control group. The individual patient data provided by the Collaborators will be analyzed on an intention-to-treat basis where possible. Binary outcomes will be analyzed using log-binomial regression models and continuous outcomes will be analyzed using linear fixed effects models. Adjustments for trial differences will be made by including the trial variable in the model specification. Discussion Thirteen (13 trials, with a total of 3567 infants are eligible for inclusion

  18. Nitric oxide-oxygen radicals interactions in atherosclerosis.

    Rubbo, H; Batthyany, C; Radi, R


    Atherosclerosis is one of the most common diseases and the principal cause of death in western civilization. The pathogenesis of this disease can be explained on the basis of the 'oxidative-modification hypothesis,' which proposes that low-density lipoprotein (LDL) oxidation represents a key early event. Nitric oxide (*NO) regulates critical lipid membrane and lipoprotein oxidation events by a) contributing to the formation of more potent secondary oxidants from superoxide (i.e.: peroxynitrite), and b) its antioxidant properties through termination reactions with lipid radicals to possibly less reactive secondary nitrogen-containing products (LONO, LOONO). Relative rates of production and steady state concentrations of superoxide and *NO and cellular sites of production will profoundly influence the expression of differential oxidant injury-enhancing and protective effects of *NO. Full understanding of the physiological roles of *NO, coupled with detailed insight into *NO regulation of oxygen radical-dependent reactions, will yield a more rational basis for intervention strategies directed toward oxidant-dependent atherogenic processes. PMID:15693284

  19. Current concepts in the pathophysiology of fibromyalgia: the potential role of oxidative stress and nitric oxide.

    Ozgocmen, Salih; Ozyurt, Huseyin; Sogut, Sadik; Akyol, Omer


    Fibromyalgia (FM) is a common chronic pain syndrome with an unknown etiology. Recent years added new information to our understanding of FM pathophysiology. Researches on genetics, biogenic amines, neurotransmitters, hypothalamic-pituitary-adrenal axis hormones, oxidative stress, and mechanisms of pain modulation, central sensitization, and autonomic functions in FM revealed various abnormalities indicating that multiple factors and mechanisms are involved in the pathogenesis of FM. Oxidative stress and nitric oxide may play an important role in FM pathophysiology, however it is still not clear whether oxidative stress abnormalities documented in FM are the cause or the effect. This should encourage further researches evaluating the potential role of oxidative stress and nitric oxide in the pathophysiology of FM and the efficacy of antioxidant treatments (omega-3 and -6 fatty acids, vitamins and others) in double blind and placebo controlled trials. These future researches will enhance our understanding of the complex pathophysiology of this disorder. PMID:16328420

  20. Role of inducible nitric oxide synthase-derived nitric oxide in lipopolysaccharide plus interferon-γ-induced pulmonary inflammation

    Exposure of mice to lipopolysaccharide (LPS) plus interferon-γ (IFN-γ) increases nitric oxide (NO) production, which is proposed to play a role in the resulting pulmonary damage and inflammation. To determine the role of inducible nitric oxide synthase (iNOS)-induced NO in this lung reaction, the responses of inducible nitric oxide synthase knockout (iNOS KO) versus C57BL/6J wild-type (WT) mice to aspirated LPS + IFN-γ were compared. Male mice (8-10 weeks) were exposed to LPS (1.2 mg/kg) + IFN-γ (5000 U/mouse) or saline. At 24 or 72 h postexposure, lungs were lavaged with saline and the acellular fluid from the first bronchoalveolar lavage (BAL) was analyzed for total antioxidant capacity (TAC), lactate dehydrogenase (LDH) activity, albumin, tumor necrosis factor-α (TNF-α), and macrophage inflammatory protein-2 (MIP-2). The cellular fraction of the total BAL was used to determine alveolar macrophage (AM) and polymorphonuclear leukocyte (PMN) counts, and AM zymosan-stimulated chemiluminescence (AM-CL). Pulmonary responses 24 h postexposure to LPS + IFN-γ were characterized by significantly decreased TAC, increased BAL AMs and PMNs, LDH, albumin, TNF-α, and MIP-2, and enhanced AM-CL to the same extent in both WT and iNOS KO mice. Responses 72 h postexposure were similar; however, significant differences were found between WT and iNOS KO mice. iNOS KO mice demonstrated a greater decline in total antioxidant capacity, greater BAL PMNs, LDH, albumin, TNF-α, and MIP-2, and an enhanced AM-CL compared to the WT. These data suggest that the role of iNOS-derived NO in the pulmonary response to LPS + IFN-γ is anti-inflammatory, and this becomes evident over time

  1. Nitric Oxide Signaling in Hypergravity-Induced Neuronal Plasticity

    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.

  2. Hyperbaric oxygen upregulates cochlear constitutive nitric oxide synthase

    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.

  3. Applications of plasma sources for nitric oxide medicine

    Vasilets, Victor; Shekhter, Anatoly; Pekshev, Alexander


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

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

    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.

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

    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.

  6. Exhaled nitric oxide in stable chronic obstructive pulmonary disease

    The objective of the study was to test the hypothesis that fraction of exhaled nitric oxide (FENO) is elevated in nonsmoking subjects with stable chronic obstructive pulmonary disease (COPD) and compare it with the results in patients with asthma and a control population. Pulmonology Clinic at a University Hospital. Twenty five control subjects, 25 steroid naive asthmatics and 14 COPD patients were studied. All the patients were nonsmokers and stable at the time of the study. All subjects completed a questionnaire and underwent spirometry. Exhaled nitric oxide was measured online by chemiluminescence, using single-breath technique. All the study subjects were males. Subjects with stable COPD had significantly higher values of FENO than controls (56.54+ - 28.01 vs 22.00 + -6.69; P =0.0001) but lower than the subjects with asthma (56.54+ - 28.01 vs 84.78+ - 39.32 P 0.0285). The FENO values in COPD subjects were inversely related to the FEV 1 /FVC ratio. There was a significant overlap between the FENO values in COPD and the control subjects. There is a significant elevation in FENO in patients with stable COPD, but the elevation is less than in asthmatic subjects. Its value in clinical practice may be limited by the significant overlap with control subjects. (author)

  7. How to protect liver graft with nitric oxide

    Hassen Ben Abdennebi; Mohamed Amine Zaoualí; Izabel Alfany-Fernandez; Donia Tabka; Joan Roselló-Catafau


    Organ preservation and ischemia reperfusion injury associated with liver transplantation play an important role in the induction of graft injury. One of the earliest events associated with the reperfusion injury is endothelial cell dysfunction. It is generally accepted that endothelial nitric oxide synthase (e-NOS) is cell-protective by mediating vasodilatation, whereas inducible nitric oxide synthase mediates liver graft injury after transplantation. We conducted a critical review of the literature evaluating the potential applications of regulating and promoting e-NOS activity in liver preservation and transplantation, showing the most current evidence to support the concept that enhanced bioavailability of NO derived from e-NOS is detrimental to ameliorate graft liver preservation, as well as preventing subsequent graft reperfusion injury. This review deals mainly with the beneficial effects of promoting "endogenous" pathways for NO generation, via e-NOS inducer drugs in cold preservation solution, surgical strategies such as ischemic preconditioning, and alternative "exogenous" pathways that focus on the enrichment of cold storage liquid with NO donors. Finally, we also provide a basic bench-to-bed side summary of the liver physiology and cell signalling mechanisms that account for explaining the e-NOS protective effects in liver preservation and transplantation.

  8. Salmonella typhimurium mutants that downregulate phagocyte nitric oxide production.

    Eriksson, S; Björkman, J; Borg, S; Syk, A; Pettersson, S; Andersson, D I; Rhen, M


    To examine the potential and strategies of the facultative intracellular pathogen Salmonella typhimurium to increase its fitness in host cells, we applied a selection that enriches for mutants with increased bacterial growth yields in murine J774-A.1 macrophage-like cells. The selection, which was based on intracellular growth competition, rapidly yielded isolates that out-competed the wild-type strain during intracellular growth. J774-A.1 cells responded to challenge with S. typhimurium by mounting an inducible nitric oxide synthase (iNOS) mRNA and protein expression and a concomitant nitric oxide (NO) production. Inhibition of NO production with the use of the competitive inhibitor N-monomethyl-L-arginine (NMMA) resulted in a 20-fold increase in bacterial growth yield, suggesting that the NO response prevented bacterial intracellular growth. In accordance with this observation, five out of the nine growth advantage mutants isolated inhibited production of NO from J774-A.1 cells, despite an induction of iNOS mRNA and iNOS protein. Accompanying bacterial phenotypes included alterations in lipopolysaccharide structure and in the profiles of proteins secreted by invasion-competent bacteria. The results indicate that S. typhimurium has the ability to mutate in several different ways to increase its host fitness and that inhibition of iNOS activity may be a major adaptation. PMID:11207580

  9. Shear-Induced Nitric Oxide Production by Endothelial Cells.

    Sriram, Krishna; Laughlin, Justin G; Rangamani, Padmini; Tartakovsky, Daniel M


    We present a biochemical model of the wall shear stress-induced activation of endothelial nitric oxide synthase (eNOS) in an endothelial cell. The model includes three key mechanotransducers: mechanosensing ion channels, integrins, and G protein-coupled receptors. The reaction cascade consists of two interconnected parts. The first is rapid activation of calcium, which results in formation of calcium-calmodulin complexes, followed by recruitment of eNOS from caveolae. The second is phosphorylation of eNOS by protein kinases PKC and AKT. The model also includes a negative feedback loop due to inhibition of calcium influx into the cell by cyclic guanosine monophosphate (cGMP). In this feedback, increased nitric oxide (NO) levels cause an increase in cGMP levels, so that cGMP inhibition of calcium influx can limit NO production. The model was used to predict the dynamics of NO production by an endothelial cell subjected to a step increase of wall shear stress from zero to a finite physiologically relevant value. Among several experimentally observed features, the model predicts a highly nonlinear, biphasic transient behavior of eNOS activation and NO production: a rapid initial activation due to the very rapid influx of calcium into the cytosol (occurring within 1-5 min) is followed by a sustained period of activation due to protein kinases. PMID:27410748

  10. Exhaled nitric oxide in stable chronic obstructive pulmonary disease

    Beg Mohammed


    Full Text Available Study Objective : The objective of the study was to test the hypothesis that fraction of exhaled nitric oxide (FENO is elevated in nonsmoking subjects with stable chronic obstructive pulmonary disease (COPD and compare it with the results in patients with asthma and a control population. Design : Cross-sectional study. Materials and Methods : Pulmonology Clinic at a University Hospital. Twenty five control subjects, 25 steroid naοve asthmatics and 14 COPD patients were studied. All the patients were nonsmokers and stable at the time of the study. All subjects completed a questionnaire and underwent spirometry. Exhaled nitric oxide was measured online by chemiluminescence, using single-breath technique. Results : All the study subjects were males. Subjects with stable COPD had significantly higher values of FENO than controls (56.54±28.01 vs 22.00±6.69; P =0.0001 but lower than the subjects with asthma (56.54±28.01 vs 84.78±39.32 P = 0.0285.The FENO values in COPD subjects were inversely related to the FEV 1 /FVC ratio. There was a significant overlap between the FENO values in COPD and the control subjects. Conclusion : There is a significant elevation in FENO in patients with stable COPD, but the elevation is less than in asthmatic subjects. Its value in clinical practice may be limited by the significant overlap with control subjects.

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

    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.

  12. Nitric Oxide and eNOS Gene in Essential Hypertension

    Kamna Srivastava


    Full Text Available Background: Currently hypertension grips around 25% of the entire world population. More than 90% of the hypertensive patients suffer from essential hypertension. In Asian Indians hypertension is the predominant risk factor for Coronary Artery Disease among others. Nitric Oxide (NO is synonymous with endothelial derived relaxation factor. Acting via cGMP (cyclic guanosine monophosphate it causes smooth muscle relaxation, prevents platelet aggregation and acts as an anti-inflammatory agent. iNOS (inducible Nitric oxide synthase, nNOS(neuronal nitric oxide synthase and eNOS (endothelial nitric oxide synthase are the three enzymes producing the gas nitric oxide in the human body. eNOS is the main source of NO under physiological conditions. It is known to have a number of polymorphisms. The most well known ones being the G to T polymorphism in exon 7, the T to C polymorphism in the promoter region and the a/b polymorphism in the intron 4. While the G to T polymorphism has been associated with hypertension in many races including the north Indian population, the association of other polymorphisms has been more of a controversy. Not much study has been done on the Asians especially those in India regarding these polymorphisms. Aims: To elucidate the association between the intron4a/b polymorphism in the eNOS gene and nitric oxide levels and essential hypertension. Objectives: 1. To determine the genotype frequencies of the above mentioned polymorphism in patients and controls2. To study the levels of NO in the plasma of the patients and controls3. To find out correlation if any between this polymorphism and plasma NO levels4. To find a correlation if any between this polymorphism and essential hypertension Materials and Methods: The study design was a case control study. 10 ml of venous blood was taken from 45 patients (selected from the department of Cardiology All India Institute of Medical Sciences, ages between 25 to 55 yrs and not on any

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

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


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

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

    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.

  15. Enhancement of nitric oxide generation by low frequency electromagnetic field.

    Yoshikawa; Tanigawa; Tanigawa; Imai; Hongo; Kondo


    Oxidative stress is implicated in the intracellular signal transduction pathways for nitric oxide synthase (NOS) induction. The electromagnetic field (EMF) is believed to increase the free radical lifespan [S. Roy, Y. Noda, V. Eckert, M.G. Traber, A. Mori, R. Liburdy, L. Packer, The phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst in rat peritoneal neutrophils is increased by a 0.1 mT (60 Hz) magnetic field, FEBS Lett. 376 (1995) 164-6; F.S. Prato, M. Kavaliers, J.J. Carson, Behavioural evidence that magnetic field effects in the land snail, Cepaea nemoralis, might not depend on magnetite or induced electric currents, Bioelectromagnetics 17 (1996) 123-30; A.L. Hulbert, J. Metcalfe, R. Hesketh, Biological response to electromagnetic fields, FASEB 12 (1998) 395-420]. We tested the effects of EMF on endotoxin induced nitric oxide (NO) generation in vivo. Male BALB/C mice were injected with lipopolysaccharide (LPS) intraperitoneously (i.p.), followed by the exposure to EMF (0.1 mT, 60 Hz). Five hours and 30 min after the LPS administration, mice were administered with a NO spin trap, ferrous N-methyl-D-glucaminedithiocarbamate (MGD-Fe). Thirty minutes later, mice were sacrificed, and their livers were removed. The results were compared to three control groups: group A (LPS (-) EMF(-)); group B (LPS(-) EMF(+)); group C (LPS(+) EMF(-)). The ESR spectra of obtained livers were examined at room temperature. Three-line spectra of NO adducts were observed in the livers of all groups. In groups A and B very weak signals were observed, but in groups C and D strong spectra were observed. The signal intensity of the NO adducts in Group D was also significantly stronger than that in Group C. EMF itself did not induce NO generation, however, it enhanced LPS induced NO generation in vivo. PMID:10927193

  16. Interaction of caveolin-1, nitric oxide, and nitric oxide synthases in hypoxic human SK-N-MC neuroblastoma cells.

    Shen, Jiangang; Lee, Waisin; Li, Yue; Lau, Chi Fai; Ng, Kwong Man; Fung, Man Lung; Liu, Ke Jian


    Neuroblastoma cells are capable of hypoxic adaptation, but the mechanisms involved are not fully understood. We hypothesized that caveolin-1 (cav-1), a plasma membrane signal molecule, might play a role in protecting neuroblastoma cells from oxidative injury by modulating nitric oxide (NO) production. We investigated the alterations of cav-1, cav-2, nitric oxide synthases (NOS), and NO levels in human SK-N-MC neuroblastoma cells exposed to hypoxia with 2% [O2]. The major discoveries include: (i) cav-1 but not cav-2 was up-regulated in the cells exposed to 15 h of hypoxia; (ii) NO donor 1-[N, N-di-(2-aminoethyl) amino] diazen-1-ium-1, 2-diolate up-regulated the expression of cav-1, whereas the non-selective NOS inhibitor N(G)-nitro-L-arginine methyl ester and inducible NOS (iNOS) inhibitor 1400W each abolished the increase in cav-1 expression in the hypoxic SK-N-MC cells. These results suggest that iNOS-induced NO production contributes to the up-regulation of cav-1 in the hypoxic SK-N-MC cells. Furthermore, we studied the roles played by cav-1 in regulating NO, NOS, and apoptotic cell death in the SK-N-MC cells subjected to 15 h of hypoxic treatment. Both cav-1 transfection and cav-1 scaffolding domain peptide abolished the induction of iNOS, reduced the production of NO, and reduced the rates of apoptotic cell death in the hypoxic SK-N-MC cells. These results suggest that increased expression of cav-1 in response to hypoxic stimulation could prevent oxidative injury induced by reactive oxygen species. The interactions of cav-1, NO, and NOS could be an important signal pathway in protecting the neuroblastoma cells from oxidative injury, contributing to the hypoxic tolerance of neuroblastoma cells. PMID:18717816

  17. Lipopolysaccharide induces nitric oxide synthase expression and platelet-activating factor increases nitric oxide production in human fetal membranes in culture

    Seyffarth Gunter


    Full Text Available Abstract Background Platelet-activating factor and nitric oxide may be involved in the initiation of human labour as inflammatory mediators. The aim of this study was to test whether platelet-activating factor and lipopolysaccharide were able to induce nitric oxide synthase expression and stimulate the production of nitric oxide in human fetal membrane explants in culture. Methods Fetal membranes were collected from Caesarean sections at term. RNA was extracted from membranes and subjected to a qualitative RT-PCR to assess the baseline expression of iNOS. Discs of fetal membranes were cultured for 24 hours in the presence of platelet-activating factor at a dose range of 0.1 nanomolar – 1 micomolar or 1 microgram/ml lipopolysaccharide. Nitric oxide production was measured via nitrite ions in the culture medium and mRNA for iNOS was detected by RT-PCR. Results Culturing the membrane discs in medium containing serum induced nitric oxide synthase expression and platelet-activating factor significantly stimulated the production of nitric oxide under these conditions. When cultured without serum inducible nitric oxide synthase expression was induced by lipopolysaccharide, but not by platelet-activating factor. Conclusion Platelet-activating factor may have a role in the initiation of labour, at term or preterm, via the increased local production of nitric oxide as an inflammatory mediator. In this model of intrauterine infection, lipopolysaccharide was found to induce iNOS expression by fetal membranes, and this mechanism could be involved in preterm labour.

  18. The use of aminoguanidine, a selective inducible nitric oxide synthase inhibitor, to evaluate the role of nitric oxide on periapical healing

    Ali Reza Farhad; Seyed Mohammad Razavi; Parnian Alavi Nejad


    Background: Nitric oxide (NO) is one of the many chemical mediators involved in inflammatory processes. In addition to periapical inflammation, NO can have a role in periapical healing. The purpose of this study was to evaluate the effect of aminoguanidine (AG) as a selective inhibitor of inducible nitric oxide synthase (iNOS) on the degree of healing response of periapical lesions of the canine teeth of cats. Methods: In this interventional experimental study, the root canals of 48 cat c...




    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 c

  20. Expression of inducible nitric oxide synthase in trigeminal ganglion cells during culture

    Jansen-Olesen, Inger; Zhou, MingFang; Zinck, Tina Jovanovic; Xu, Cang-Bao; Edvinsson, Lars


    Nitric oxide (NO) is an important signalling molecule that has been suggested to be a key molecule for induction and maintenance of migraine attacks based on clinical studies, animal experimental studies and the expression of nitric oxide synthase (NOS) immunoreactivity within the trigeminovascul...

  1. The inflammatory and cytotoxic effects of a nitric oxide releasing cream on normal skin.

    Ormerod, A D; Copeland, P; Hay, I; Husain, A; Ewen, S W


    We describe the pro-inflammatory and cytotoxic effects of nitric oxide in vivo in human skin. Nitrite and ascorbic acid were mixed on the skin of 12 normal volunteers, three times daily, to release nitric oxide. Exposure to nitric oxide was varied by randomizing the concentration of nitrite and duration of application. Nitric oxide treated skin showed significant increases in cells expressing CD3, CD4, CD8, CD68, neutrophil elastase, ICAM-1, VCAM-1, nitrosotyrosine, p53, and apoptotic cells compared with skin treated with ascorbic acid alone. There was no significant increase in mast cells. Following application of nitric oxide there were significantly fewer CD1a positive Langerhans cells in the epidermis. These appeared to lose dendritic morphology and migrate from the epidermis. There was no significant difference in staining for Ki-67, a marker related to proliferating cell nuclear antigen, between active and control skin but staining was greater after exposure to higher dose nitric oxide than the low dose. Apoptosis, cytotoxicity, and p53 staining were relatively greater after 48 h exposure than after 24 h. These results suggest that nitric oxide is pro-inflammatory and is toxic to DNA, leading to the accumulation of p53 and subsequent apoptosis. High-dose nitric oxide paradoxically led to a smaller increase in macrophages and T cells than low dose suggesting an immunosuppressive effect of higher levels. PMID:10469339

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

    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.

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

    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

  4. Behavioral impairments and changes of nitric oxide and inducible nitric oxide synthase in the brains of molarless KM mice.

    Pang, Qian; Hu, Xingxue; Li, Xinya; Zhang, Jianjun; Jiang, Qingsong


    More studies showed that as a common disorder in senior population, loss of teeth could adversely affect human cognitive function, and nitric oxide (NO) might play an important role in the cognitive function. However, the underlying mechanism has not yet been well-established. The objectives of this study are to evaluate behavior changes of KM mice after loss of molars, and levels of NO and inducible nitric oxide synthase (iNOS) in the brain in molarless condition. It is hypothesized that loss of molars of the mice tested results in the cognitive impairments and that the process is mediated by NO in the brain through the signaling pathways. Morris water maze is used to test the behavioral changes after 8 weeks of the surgery. The changes of NO and iNOS are evaluated by using Griess assay, western blot, and immunohistochemistry method. The results show that 8 weeks after loss of molars, the spatial learning and memory of KM mice impair and the levels of NO and iNOS in mice hippocampus increase. These findings suggest that molar extraction is associated with the behavioral impairment, and that the changes of NO and iNOS in the hippocampus may be involved in the behavioral changes in the molarless condition. PMID:25447296

  5. mtDNA haplogroup J Modulates telomere length and Nitric Oxide production

    Fernández-Moreno Mercedes; Tamayo María; Soto-Hermida Angel; Mosquera Alejandro; Oreiro Natividad; Fernández-López Carlos; Fernández José Luis; Rego-Pérez Ignacio; Blanco Francisco J


    Abstract Background Oxidative stress due to the overproduction of nitric oxide (NO) and other oxygen reactive species (ROS), play a main role in the initiation and progression of the OA disease and leads to the degeneration of mitochondria. Therefore, the goal of this work is to describe the difference in telomere length of peripheral blood leukocytes (PBLs) and Nitric Oxide (NO) production between mitochondrial DNA (mtDNA) haplogroup J and non-J carriers, as indirect approaches of oxidative ...

  6. 电针对脑缺血再灌注损伤大鼠海马诱导型一氧化氮合酶mRNA表达的影响%Effect of electroacupuncture on inducible nitric oxide synthase mRNA expression in hippocampus of the rats with cerebral ischemia-reperfusion injury

    周爽; 黄建华; 方邦江; 袁凌松


    注后大鼠海马诱导型一氧化氮合酶mRNA表达,从而减少一氧化氮的产生,有助于减轻脑缺血再灌注损伤.%BACKGROUND: Researches indicate that inducible nitric oxide synthase(iNOS) plays an important role in relieving destruction of blood brain barrier and protecting vascular endothelium and brain tissue in cerebral ischemia-reperfusion injury.OBJECTIVE: To observe the effect of Shuigou (DU26), Neiguan (PC6)and Zusanli (ST36) on the expression of inducible nitric oxide synthase messenger ribonucleic acid (iNOS mRNA) in hippocampus of the rats with cerebral ischemia-reperfusion.DESIGN: Randomized controlled study.SETTING: Shanghai University of Traditional Chinese Medicine, Shanghai Institute of Acupuncture and Meridian and Huashan Hospital Affiliated to Fudan University.METHODS: The experiment was completed at the Experimental Animal Center in Shanghai University of Traditional Chinese Medicine, Threegrade Acupuncture Immunological Laboratory of Shanghai Research Institute of Acupuncture and Meridian and Huashan Hospital Affiliated to Fudan University from December 2003 to December 2004. Totally 40 SD rats were randomly divided as normal group, sham operation group, model group and electroacupuncture group with 10 in each group. The hypertension model rats were induced with bi-kidney-bi-clip method, then the focal cerebral ischemia-reperfusion rat model was induced by reversible occlusion for a middle cerebral artery with a thread on the stroke prone renovascular hypertensive model rat. While the rats in sham operation group were operated without thread insertion. Shuigou (Du 26), bilateral Neiguan(PC 6) and bilateral Housanli (Zusanli, ST 36) were located according to"Atlas of Experimental Animal Acupoints" made by Hua's. Shuigou (Du26): 1 mm below nasal apex right on the Labium leporinum, be punctured 1 mm obliquely upward; Neiguan (PC 6): at the lateral palm of the forearm3 mm above wrist joint, between ulna and radius, be punctured 1 mm

  7. Nitric oxide inhibitory constituents from the barks of Cinnamomum cassia.

    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. PMID:27223848

  8. Solar cycle variation of thermospheric nitric oxide at solstice

    Gerard, J.-C.; Fesen, C. G.; Rusch, D. W.


    A coupled, two-dimensional, chemical-diffusive model of the thermosphere is used to study the role of solar activity in the global distribution of nitric oxide. The model calculates self-consistently the zonally averaged temperature, circulation, and composition for solstice under solar maximum and solar minimum conditions. A decrease of the NO density by a factor of three to four in the E region is predicted from solar maximum to solar minimum. It is found that the main features of the overall morphology and the changes induced by the solar cycle are well reproduced in the model, although some details are not satisfactorily predicted. The sensitivity of the NO distribution to eddy transport and to the quenching of metastable N(2D) atoms by atomic oxygen is also described.

  9. Nitric oxide induces caspase activity in boar spermatozoa.

    Moran, J M; Madejón, L; Ortega Ferrusola, C; Peña, F J


    Nitric oxide (NO) is a highly reactive free radical that plays a key role in intra- and intercellular signaling. Production of radical oxygen species and an apoptotic-like phenomenon have recently been implicated in cryodamage during sperm cryopreservation. The objective of the present study was to evaluate the effect of sodium nitroprusside (SNP), an NO donor, on boar sperm viability. Semen samples were pooled from four boars that were routinely used for artificial insemination. Flow cytometry was used to compare semen incubated with SNP to control semen. Specifically, NO production was measured using the NO indicator dye diaminofluorescein diacetate, and caspase activity was determined using the permeable pan-caspase inhibitor Z-VAD linked to FITC. SNP induced a significant increase in the percentage of sperm cells showing caspase activity, from 9.3% in control samples to 76.2% in SNP-incubated samples (Pboar sperm damage. PMID:18433854

  10. Generation of nitric oxide from nitrite by carbonic anhydrase

    Aamand, Rasmus; Dalsgaard, Thomas; Jensen, Frank B;


    In catalyzing the reversible hydration of CO2 to bicarbonate and protons, the ubiquitous enzyme carbonic anhydrase (CA) plays a crucial role in CO2 transport, in acid-base balance, and in linking local acidosis to O2 unloading from hemoglobin. Considering the structural similarity between...... bicarbonate and nitrite, we hypothesized that CA uses nitrite as a substrate to produce the potent vasodilator nitric oxide (NO) to increase local blood flow to metabolically active tissues. Here we show that CA readily reacts with nitrite to generate NO, particularly at low pH, and that the NO produced in...... effectively in catalysis. Taken together, our results reveal a novel nitrous anhydrase enzymatic activity of CA that would function to link the in vivo main end products of energy metabolism (CO2/H+) to the generation of vasoactive NO. The CA-mediated NO production may be important to the correlation between...