scholarly journals Helicobacter pyloriEradication Lowers Serum Asymmetric Dimethylarginine Levels

2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Selim Aydemir ◽  
Hacı Eren ◽  
Ishak Ozel Tekin ◽  
Ferda Akbay Harmandar ◽  
Nejat Demircan ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Vascular Tone ◽  
Asymmetric Dimethylarginine ◽  
Microbial Pathogens ◽  
Before And After ◽  
Nos Inhibitor ◽  
The Mean ◽  
H Pylori ◽  
Oxide Synthase ◽  
Regulation Of Vascular Tone

Introduction. Microbial pathogens, one of them isHelicobacter pylori(H. pylori), have frequently been implicated in the atherogenesis. Endothelium-derived nitric oxide (NO) is synthesized from L-arginine by nitric oxide synthase (NOS) and plays a pivotal role in the regulation of vascular tone. Asymmetric dimethylarginine (ADMA) is the most potent endogenous NOS inhibitor. Elevated levels of ADMA have been reported in many circumstances associated with a high cardiovascular risk. The aim of the present study was to investigate whether the eradication ofH. pyloriinfection affects serum ADMA levels.Materials and Methods. Forty-twoH. pylori-positive patients were enrolled in the study. Triple therapy for 14 days were given to all patients. Serum ADMA levels were measured at baseline and 2 months after therapy.Results. Eradication was achieved in 34 (81%) patients. The mean serum ADMA levels before and after therapy were and  ng/mL in the group withH. pylorieradicated and and  ng/mL in the noneradicated, respectively. We detected statistically significant decreased serum ADMA levels after therapy inH. pylorieradicated group.Conclusion. These findings have indicated that eradication ofH. pyloriinfection may decrease the risk of atherosclerosis and cardiovascular events.

Differential sympathetic nerve responses to nitric oxide synthase inhibition in anesthetized rats

1995 ◽  
Vol 269 (4) ◽  
pp. R807-R813 ◽  
Author(s):  
T. Hirai ◽  
T. I. Musch ◽  
D. A. Morgan ◽  
K. C. Kregel ◽  
D. E. Claassen ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Sympathetic Nerve ◽  
Sprague Dawley ◽  
Arterial Blood ◽  
Sprague Dawley Rats ◽  
Before And After ◽  
Important Means ◽  
Nos Inhibitor ◽  
Oxide Synthase ◽  
Tonic Excitation

Recent studies have suggested that the interaction between the sympathetic nervous system and nitric oxide (NO) or nitrosyl factors may be an important means by which arterial blood pressure is regulated. We investigated whether NO synthase (NOS) inhibition modulates basal sympathetic nerve discharge (SND) in baroreceptor-innervated and -denervated, chloralose-anesthetized Sprague-Dawley rats. We recorded mean arterial pressure (MAP), renal SND, and lumbar SND before and after administration of the NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 20 mg/kg iv). Two minutes after L-NAME administration in baroreceptor-innervated rats, MAP increased (+23 +/- 3 mmHg), whereas renal (-45 +/- 6%, n = 7) and lumbar (-35 +/- 2%, n = 6) SND significantly decreased from control levels. These changes persisted for up to 20 min after L-NAME administration. In baroreceptor-denervated rats, L-NAME increased MAP (+40 +/- 6 mmHg) and decreased lumbar SND (n = 7) (-37 +/- 10% from control at 20 min post-L-NAME). In contrast, renal SND progressively increased (+33 +/- 8% at 20 min post-L-NAME) from control after L-NAME administration in baroreceptor-denervated rats (n = 7). These results demonstrate that NOS inhibition can produce nonuniform changes in SND in baroreceptor-denervated rats and suggest that endogenous nitrosyl factors provide tonic excitation to lumbar SND, whereas they provide a tonic restraint to renal SND.

Nitric oxide modulation of glutamatergic, baroreflex, and cardiopulmonary transmission in the nucleus of the solitary tract

2005 ◽  
Vol 288 (1) ◽  
pp. H256-H262 ◽  
Author(s):  
Ana Carolina Rodrigues Dias ◽  
Melissa Vitela ◽  
Eduardo Colombari ◽  
Steven W. Mifflin
Keyword(s):  
Nitric Oxide ◽  
Solitary Tract ◽  
Glutamatergic Transmission ◽  
Sprague Dawley ◽  
Renal Sympathetic Nerve Activity ◽  
Sprague Dawley Rats ◽  
Before And After ◽  
Nos Inhibitor ◽  
The Right ◽  
Oxide Synthase

The neuromodulatory effect of NO on glutamatergic transmission has been studied in several brain areas. Our previous single-cell studies suggested that NO facilitates glutamatergic transmission in the nucleus of the solitary tract (NTS). In this study, we examined the effect of the nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (l-NAME) on glutamatergic and reflex transmission in the NTS. We measured mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) from Inactin-anesthetized Sprague-Dawley rats. Bilateral microinjections of l-NAME (10 nmol/100 nl) into the NTS did not cause significant changes in basal MAP, HR, or RSNA. Unilateral microinjection of ( RS)-α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA, 1 pmol/100 nl) into the NTS decreased MAP and RSNA. Fifteen minutes after l-NAME microinjections, AMPA-evoked cardiovascular changes were significantly reduced. N-methyl-d-aspartate (NMDA, 0.5 pmol/100 nl) microinjection into the NTS decreased MAP, HR, and RSNA. NMDA-evoked falls in MAP, HR, and RSNA were significantly reduced 30 min after l-NAME. To examine baroreceptor and cardiopulmonary reflex function, l-NAME was microinjected at multiple sites within the rostro-caudal extent of the NTS. Baroreflex function was tested with phenylephrine (PE, 25 μg iv) before and after l-NAME. Five minutes after l-NAME the decrease in RSNA caused by PE was significantly reduced. To examine cardiopulmonary reflex function, phenylbiguanide (PBG, 8 μg/kg) was injected into the right atrium. PBG-evoked hypotension, bradycardia, and RSNA reduction were significantly attenuated 5 min after l-NAME. Our results indicate that inhibition of NOS within the NTS attenuates baro- and cardiopulmonary reflexes, suggesting that NO plays a physiologically significant neuromodulatory role in cardiovascular regulation.

Inhibition of nitric oxide synthase augments myocardial contractile responses to beta-adrenergic stimulation

1996 ◽  
Vol 271 (6) ◽  
pp. H2646-H2652 ◽  
Author(s):  
J. F. Keaney ◽  
J. M. Hare ◽  
J. L. Balligand ◽  
J. Loscalzo ◽  
T. W. Smith ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Myocardial Contractility ◽  
Adrenergic Stimulation ◽  
Maximum Increase ◽  
Beta Adrenergic ◽  
Before And After ◽  
Nos Inhibitor ◽  
Oxide Synthase

Recent in vitro evidence suggests a role for nitric oxide (NO) in the modulation of myocardial contractility. The specific role of NO in the control of cardiac function in vivo, however, remains unclear. We investigated the effect of NO synthase (NOS) inhibition on myocardial contractility in response to beta-adrenergic stimulation in autonomically blocked dogs. Intracoronary infusions of dobutamine (1-50 micrograms/min) and isoproterenol (0.1 and 0.5 microgram/min) were performed before and after the intracoronary administration of the specific NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Intracoronary dobutamine resulted in a dose-dependent increase in peak first derivative of pressure (dP/dtmax) to a maximum of 195 +/- 10% (P < 0.001). After inhibition of NOS with intracoronary L-NAME at rates of 0.1 and 1 mg/min, the response to dobutamine was significantly enhanced with dP/dtmax, increasing 276 +/- 17 and 317 +/- 26%, respectively (P < 0.001). Intracoronary isoproterenol resulted in a maximum increase in dP/dtmax of 116 +/- 15% (P < 0.001) that further increased to 154 +/- 17 and 157 +/- 18% after NOS inhibition with 0.1 and 1 mg/min L-NAME, respectively (both P < 0.002). L-NAME had no effect on baseline dP/dtmax but did produce a reduction in myocardial guanosine 3',5'-cyclic monophosphate content. These results suggest a role for NO in the control of myocardial contractility in response to beta-adrenergic stimulation in vivo.

Abstract 380: Notch4 Uncouples Endothelial Nitric Oxide Synthase Leading to Arteriovenous Malformations

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Lawrence Huang ◽  
Matthew A Nystoriak ◽  
Ji Youn Youn ◽  
Manuel F Navedo ◽  
Hua Cai ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Notch Signaling ◽  
Endothelial Nitric Oxide Synthase ◽  
Vascular Tone ◽  
Superoxide Production ◽  
Nos Inhibitor ◽  
Av Shunt ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Notch is distinctively expressed in arterial but not venous endothelial cells. Notch signaling regulates arteriovenous (AV) specification, and mutations in Notch signaling lead to AV malformation (AVM) in mice. AVMs are characterized by abnormal AV shunts that displace capillaries. Mechanisms underlying AVM pathogenesis remain poorly understood, hindering therapeutic development. We reported that endothelial expression of constitutively active Notch4 (Notch4*) in mice initiates AVMs de novo through enlargement of microvessels without an increase in endothelial cell number or proliferation. Here, we hypothesized that Notch4* disrupts endothelial nitric oxide synthase (eNOS) signaling and vascular tone, thereby permitting vessel enlargement and AV shunting. We show that arteries isolated from Notch4* mutant mice exhibited decreased arterial tone compared to controls, suggesting that Notch4* impaired vascular tone. Administering the NOS inhibitor N G -nitro-L-arginine abolished Notch4*-mediated vascular tone impairment. Deletion of the eNOS gene and administration of the NOS inhibitor N G -nitro-L-arginine in the Notch4* mutant mice attenuated Notch4*-induced AVM initiation, measured by decreased AV shunt diameter, delayed AV shunting, reduced hemorrhage, pathological lesions, and improved survival, suggesting that eNOS is essential for Notch4* action. In addition, uncoupled eNOS-derived superoxide production was elevated in the Notch4* mice. Our results show that inhibition of eNOS signaling attenuates Notch4*-mediated AVM formation. Furthermore, Notch4* impairs eNOS activity, leading to superoxide production, which results in arterial dysfunction and AV shunt formation.

scholarly journals Low plasma concentrations of arginine and asymmetric dimethylarginine in premature infants with necrotizing enterocolitis

2007 ◽  
Vol 97 (5) ◽  
pp. 906-911 ◽  
Author(s):  
Milan C. Richir ◽  
Michiel P. C. Siroen ◽  
Ruurd M. van Elburg ◽  
Willem P. F. Fetter ◽  
Freeke Quik ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Birth Weight ◽  
Necrotizing Enterocolitis ◽  
Premature Infants ◽  
Gestational Age ◽  
Neonatal Intensive Care ◽  
Asymmetric Dimethylarginine ◽  
Plasma Concentrations ◽  
Nos Inhibitor ◽  
Oxide Synthase

Several studies have described reduced plasma concentrations of arginine, the substrate for nitric oxide synthase (NOS) in infants with necrotizing enterocolitis (NEC). No information on the plasma concentrations of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) in patients with NEC is currently available. We investigated whether plasma concentrations of arginine, ADMA, and their ratio differ between premature infants with and without NEC, and between survivors and non-survivors within the NEC group. In a prospective case–control study, arginine and ADMA concentrations were measured in ten premature infants with NEC (median gestational age 193 d, birth weight 968 g), and ten matched control infants (median gestational age 201 d, birth weight 1102 g), who were admitted to the Neonatal Intensive Care Unit. In the premature infants with NEC, median arginine and ADMA concentrations (μmol/l), and the arginine:ADMA ratio were lower compared to the infants without NEC: 21·4 v. 55·9, P = 0·001; 0·59 v. 0·85, P = 0·009 and 36·6 v. 72·3, P = 0·023 respectively. In the NEC group, median arginine (μmol/l) and the arginine:ADMA ratio were lower in non-surviving infants than in surviving infants: 14·7 v. 33·8, P = 0·01 and 32·0 v. 47·5, P = 0·038 respectively. In premature infants with NEC not only the NOS substrate arginine, but also the endogenous NOS inhibitor ADMA and the arginine:ADMA ratio were lower than in infants without NEC. In addition, low arginine and arginine:ADMA were associated with mortality in infants with NEC. Overall, these data suggest that a diminished nitric oxide production may be involved in the pathophysiology of NEC, but this needs further investigation.

scholarly journals Acute Decrease in Cerebral Nitric Oxide Levels after Subarachnoid Hemorrhage

2000 ◽  
Vol 20 (3) ◽  
pp. 604-611 ◽  
Author(s):  
Fatima A. Sehba ◽  
Amit Y. Schwartz ◽  
Igor Chereshnev ◽  
Joshua B. Bederson
Keyword(s):  
Nitric Oxide ◽  
Cerebral Cortex ◽  
Subarachnoid Hemorrhage ◽  
Brain Stem ◽  
Brain Regions ◽  
Ischemic Insult ◽  
Before And After ◽  
Wet Weight ◽  
Nos Inhibitor ◽  
Oxide Synthase

Disturbances in the nitric oxide (NO) vasodilatory pathway have been implicated in acute vasoconstriction and ischemia after subarachnoid hemorrhage (SAH). The authors hypothesize that blood released during SAH leads to vasoconstriction by scavenging NO and limiting its availability. This was tested by measuring the major NO metabolites nitrite and nitrate in five different brain regions before and after experimental SAH. The basal NO metabolites levels were as follows (mean ± SD, μmol/mg wet weight): brain stem, 0.14 ± 0.07; cerebellum, 0.12 ± 0.08; ventral convexity cortex, 0.22 ± 0.15; dorsal convexity cortex, 0.16 ± 0.11; and hippocampus, 0.26 ± 0.17. In sham-operated animals, no effect of the nitric oxide synthase (NOS) inhibitor lG-nitro-L-arginine-methyl-ester (30 mg/kg) was found on NO metabolites 40 minutes after administration, but a significant decrease was seen after 120 minutes. The NO metabolites decreased significantly 10 minutes after SAH in all brain regions except for hippocampus, and recovered to control levels in cerebellum at 60 minutes and in brain stem and dorsal cerebral cortex 180 minutes after SAH, while remaining low in ventral convexity cortex. Nitrite recovered completely in all brain regions at 180 minutes after SAH, whereas nitrate remained decreased in brain stem and ventral convexity cortex. Our results indicate that SAH causes acute decreases in cerebral NO levels by a mechanism other than NOS inhibition and provide further support for the hypothesis that alterations in the NO vasodilatory pathway contribute directly to the ischemic insult after SAH.

The Effect on Health of Some Cardiovascular Risk Factors

2017 ◽  
Vol 68 (10) ◽  
pp. 2237-2242
Author(s):  
Germaine Savoiu Balint ◽  
Mihaiela Andoni ◽  
Ramona Amina Popovici ◽  
Laura Cristina Rusu ◽  
Ioana Citu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Vascular Reactivity ◽  
Vascular Wall ◽  
Dose Effect ◽  
Organ Bath ◽  
Before And After ◽  
Specific Receptors ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Relaxing Response

Arterial endothelium produces a large ramge of active factors which are indispensable for modulation of vasomotor tone and maintenance of vascular wall integrity. From these factors, nitric oxide (NO), wich is released by the endothelial cells as a response to acetylcholine or adenosine action on specific receptors, plays an important role.NO is the result of oxidation process of L-arginine into L-citrulline, under the action of endothelial nitric oxide synthase (NOSe), wich is activated by intracelluar Ca2+ - calmodulin complex . Our study, performed in isolated organ bath, analyzed vascular reactivity of 12 guinea pigs� thoracic aorta rings. After phenylephrine -PHE 10-5 mol/L precontraction, the dose-effect curves for acetylcoline � ACH, adenosine 5� phosphate - 5�ADP and sodium nitroprusside � SNP were determined, before and after incubation of preparation, for 1 hour, with 5% hydrosoluble cigarettes smoke extract (CSE). Statistic analysis, performed with the use of t pair test and ANOVA parametric test, showed that incubation of vascular preparation with 5% CSE has increased the contractile response to PHE 10-5 mol/L (p[0.05), has reduced the endothelium-dependent relaxing response to ATP 10-5 mol/L (p[0.001) and 5�ADP 10-5 molo/L (p[0.001), but has not significantly modified the endothelium-independent relaxing response to SNP 10-5 mol/L (p=0.05). As a conclusion, vascular rings incubation with 5% CSE induced a decrease of endothelium NO synthesis under the action of AXH and 5�ADP, but did not change the smooth muscle fiber respomse in the presence of NO released by SNP.

The Signaling Pathways in Nitric Oxide Production by Neutrophils Exposed to N-nitrosodimethylamine

2018 ◽  
Vol 16 (2) ◽  
pp. 194-199
Author(s):  
Wioletta Ratajczak-Wrona ◽  
Ewa Jablonska
Keyword(s):  
Nitric Oxide ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Polymorphonuclear Neutrophils ◽  
Microbial Pathogens ◽  
Human Neutrophils ◽  
No Production ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Background: Polymorphonuclear neutrophils (PMNs) play a crucial role in the innate immune system’s response to microbial pathogens through the release of reactive nitrogen species, including Nitric Oxide (NO). </P><P> Methods: In neutrophils, NO is produced by the inducible Nitric Oxide Synthase (iNOS), which is regulated by various signaling pathways and transcription factors. N-nitrosodimethylamine (NDMA), a potential human carcinogen, affects immune cells. NDMA plays a major part in the growing incidence of cancers. Thanks to the increasing knowledge on the toxicological role of NDMA, the environmental factors that condition the exposure to this compound, especially its precursors- nitrates arouse wide concern. Results: In this article, we present a detailed summary of the molecular mechanisms of NDMA’s effect on the iNOS-dependent NO production in human neutrophils. Conclusion: This research contributes to a more complete understanding of the mechanisms that explain the changes that occur during nonspecific cellular responses to NDMA toxicity.

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