scholarly journals Nitric Oxide as an Endogenous Mutagen for Sendai Virus without Antiviral Activity

2004 ◽  
Vol 78 (16) ◽  
pp. 8709-8719 ◽  
Author(s):  
Jun Yoshitake ◽  
Takaaki Akaike ◽  
Teruo Akuta ◽  
Fumio Tamura ◽  
Tsutomu Ogura ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Viral Replication ◽  
Mutation Frequency ◽  
Sendai Virus ◽  
No Synthase ◽  
Mutagenic Potential ◽  
Gfp Gene ◽  
Sw480 Cells

ABSTRACT Nitric oxide (NO) may affect the genomes of various pathogens, and this mutagenesis is of particular interest for viral pathogenesis and evolution. Here, we investigated the effect of NO on viral replication and mutation. Exogenous or endogenous NO had no apparent antiviral effect on influenza A virus and Sendai virus. The mutagenic potential of NO was analyzed with Sendai virus fused to a green fluorescent protein (GFP) gene (GFP-SeV). GFP-SeV was cultured in SW480 cells transfected with a vector expressing inducible NO synthase (iNOS). The mutation frequency of GFP-SeV was examined by measuring loss of GFP fluorescence of the viral plaques. GFP-SeV mutation frequency in iNOS-SW480 cells was much higher than that in parent SW480 cells and was reduced to the level of mutation frequency in the parent cells by treatment with an NO synthase (NOS) inhibitor. Immunocytochemistry showed generation of more 8-nitroguanosine in iNOS-SW480 cells than in SW480 cells without iNOS transfection. Authentic 8-nitroguanosine added exogenously to GFP-SeV-infected CV-1 cells increased the viral mutation frequency. Profiles of the GFP gene mutations induced by 8-nitroguanosine appeared to resemble those of mutations occurring in mouse lungs in vivo. A base substitution that was characteristic of both mutants (those induced by 8-nitroguanosine and those occurring in vivo) was a C-to-U transition. NO-dependent oxidative stress in iNOS-SW480 cells was also evident. Together, the results indicate unambiguously that NO has mutagenic potential for RNA viruses such as Sendai virus without affecting viral replication, possibly via 8-nitroguanosine formation and cellular oxidative stress.

scholarly journals Endothelial dysfunction and body mass index: is there a role for plasma peroxynitrite?

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Theresa Chikopela ◽  
Douglas C. Heimburger ◽  
Longa Kaluba ◽  
Pharaoh Hamambulu ◽  
Newton Simfukwe ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Endothelial Dysfunction ◽  
Body Mass ◽  
Vascular Function ◽  
Aortic Ring ◽  
Normal Weight ◽  
Oxide Synthase ◽  
Weight Groups

Abstract Background Endothelial function is dependent on the balance between vasoconstrictive and vasodilatory substances. The endothelium ability to produce nitric oxide is one of the most crucial mechanisms in regulating vascular tone. An increase in inducible nitric oxide synthase contributes to endothelial dysfunction in overweight persons, while oxidative stress contributes to the conversion of nitric oxide to peroxynitrite (measured as nitrotyrosine in vivo) in underweight persons. The objective of this study was to elucidate the interaction of body composition and oxidative stress on vascular function and peroxynitrite. This was done through an experimental design with three weight groups (underweight, normal weight and overweight), with four treatment arms in each. Plasma nitrotyrosine levels were measured 15–20 h post lipopolysaccharide (LPS) treatment, as were aortic ring tension changes. Acetylcholine (ACh) and sodium nitroprusside (SNP) challenges were used to observe endothelial-dependent and endothelial-independent vascular relaxation after pre-constriction of aortic rings with phenylephrine. Results Nitrotyrosine levels in saline-treated rats were similar among the weight groups. There was a significant increase in nitrotyrosine levels between saline-treated rats and those treated with the highest lipopolysaccharide doses in each of the weight groups. In response to ACh challenge, Rmax (percentage reduction in aortic tension) was lowest in overweight rats (112%). In response to SNP, there was an insignificantly lower Rmax in the underweight rats (106%) compared to the normal weight rats (112%). Overweight rats had a significant decrease in Rmax (83%) in response to SNP, signifying involvement of a more chronic process in tension reduction changes. A lower Rmax accompanied an increase in peroxynitrite after acetylcholine challenge in all weight groups. Conclusions Endothelial dysfunction, observed as an impairment in the ability to reduce tension, is associated with increased plasma peroxynitrite levels across the spectrum of body mass. In higher-BMI rats, an additional role is played by vascular smooth muscle in the causation of endothelial dysfunction.

In vivo assessment of microvascular nitric oxide production and its relation with blood flow

2001 ◽  
Vol 280 (3) ◽  
pp. H1222-H1231 ◽  
Author(s):  
X. F. Figueroa ◽  
A. D. Martínez ◽  
D. R. González ◽  
P. I. Jara ◽  
S. Ayala ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Plasma Flow ◽  
Subcellular Fractionation ◽  
No Synthase ◽  
Cheek Pouch ◽  
No Production ◽  
Hamster Cheek Pouch ◽  
Membrane Bound

To assess the hypothesis that microvascular nitric oxide (NO) is critical to maintain blood flow and solute exchange, we quantified NO production in the hamster cheek pouch in vivo, correlating it with vascular dynamics. Hamsters (100–120 g) were anesthetized and prepared for measurement of microvessel diameters by intravital microscopy, of plasma flow by isotopic sodium clearance, and of NO production by chemiluminescence. Analysis of endothelial NO synthase (eNOS) location by immunocytochemistry and subcellular fractionation revealed that eNOS was present in arterioles and venules and was 67 ± 7% membrane bound. Basal NO release was 60.1 ± 5.1 pM/min ( n = 35), and plasma flow was 2.95 ± 0.27 μl/min ( n = 29). Local NO synthase inhibition with 30 μM N ω-nitro-l-arginine reduced NO production to 8.6 ± 2.6 pmol/min (−83 ± 5%, n = 9) and plasma flow to 1.95 ± 0.15 μl/min (−28 ± 12%, n = 17) within 30–45 min, in parallel with constriction of arterioles (9–14%) and venules (19–25%). The effects of N ω-nitro-l-arginine (10–30 μM) were proportional to basal microvascular conductance ( r = 0.7, P < 0.05) and fully prevented by 1 mM l-arginine. We conclude that in this tissue, NO production contributes to 35–50% of resting microvascular conductance and plasma-tissue exchange.

Effects of NG-substituted arginines on coronary vascular function after endotoxin

1993 ◽  
Vol 75 (1) ◽  
pp. 424-431 ◽  
Author(s):  
M. J. Winn ◽  
B. Vallet ◽  
N. K. Asante ◽  
S. E. Curtis ◽  
S. M. Cain
Keyword(s):  
Nitric Oxide ◽  
Vascular Function ◽  
Endotoxic Shock ◽  
No Synthase ◽  
Relaxing Factor ◽  
Nos Inhibitors ◽  
Nos Inhibitor ◽  
Endothelium Derived Relaxing Factor ◽  
Constrictor Response

We investigated the responses of canine coronary rings to endothelium-derived relaxing factor-nitric oxide- (EDRF-NO) dependent agonists and NO synthase (NOS) inhibitors 3 h after endotoxic shock was induced in dogs by lipopolysaccharide infusion (LPS; 2 mg/kg). EDRF-NO-dependent relaxation to thrombin [control maximum response produced after administration of thrombin (Emax) was -85.2 +/- 7.0% of the constrictor response produced by the thromboxane analogue U-46619], acetylcholine (control Emax -88.4 +/- 3.4%), or bradykinin (control Emax -80.5 +/- 2.2%) was not inhibited by LPS (Emax thrombin -75.9 +/- 9.5%; Emax acetylcholine -90.2 +/- 2.4%; Emax bradykinin -91.6 +/- 3.4%). The NOS inhibitor NG-monomethyl-L-arginine (L-NMMA) (10(-6)-3 x 10(-4) M) caused constriction of rings with endothelium (Emax 36.3 +/- 5.6%), an effect that was greater after LPS (Emax 59.2 +/- 4.1%; P < 0.05). D-NMMA had no effect in control, but it increased tension after LPS (Emax 20.8 +/- 9.7%). Contrary to expectations, L- and D-NMMA relaxed endothelium-denuded rings (-30.4 +/- 8.7% L-NMMA; -45.1 +/- 11.7% D-NMMA; P < 0.05). However, neither agent caused relaxation after in vivo LPS (10.2 +/- 3.4% L-NMMA; 8.9 +/- 5.2% D-NMMA). N omega-nitro-L-arginine-methylester (L-NAME) and nitro-L-arginine (10(-6)-3 x 10(-4) M) increased tension (Emax 82.3 +/- 23.9 and 73.1 +/- 8.8%, respectively) but only when endothelium was present, and the increases were no greater in LPS-treated groups than in controls (with LPS: Emax L-NAME 87.3 +/- 16.5%; Emax nitro-L-arginine 65.7 +/- 3.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Nitric oxide mediates mitogenic effect of VEGF on coronary venular endothelium

1996 ◽  
Vol 270 (1) ◽  
pp. H411-H415 ◽  
Author(s):  
L. Morbidelli ◽  
C. H. Chang ◽  
J. G. Douglas ◽  
H. J. Granger ◽  
F. Ledda ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Growth Factor ◽  
No Synthase ◽  
Mitogenic Effect ◽  
Microvascular Endothelium ◽  
Proliferative Effect

Vascular endothelial growth factor (VEGF) is a secreted protein that is a specific growth factor for endothelial cells. We have recently demonstrated that nitric oxide (NO) donors and vasoactive peptides promoting NO-mediated vasorelaxation induce angiogenesis in vivo as well as endothelial cell growth and motility in vitro; in contrast, inhibitors of NO synthase suppress angiogenesis. In this study we investigated the role of NO in mediating the mitogenic effect of VEGF on cultured microvascular endothelium isolated from coronary postcapillary venules. VEGF induced a dose-dependent increase in cell proliferation and DNA synthesis. The role of NO was determined by monitoring proliferation or guanosine 3',5'-cyclic monophosphate (cGMP) levels in the presence and absence of NO synthase blockers. The proliferative effect evoked by VEGF was reduced by pretreatment of the cells with NO synthase inhibitors. Exposure of the cells to VEGF induced a significant increment in cGMP levels. This effect was potentiated by superoxide dismutase addition and was abolished by NO synthase inhibitors. VEGF stimulates proliferation of postcapillary endothelial cells through the production of NO and cGMP accumulation.

Free radical biology and medicine: it's a gas, man!

2006 ◽  
Vol 291 (3) ◽  
pp. R491-R511 ◽  
Author(s):  
William A. Pryor ◽  
Kendall N. Houk ◽  
Christopher S. Foote ◽  
Jon M. Fukuto ◽  
Louis J. Ignarro ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Free Radical ◽  
Cell Signaling ◽  
Adaptive Responses ◽  
Adaptive Mechanisms ◽  
Low Levels ◽  
Very High ◽  
Ozone Reactions

We review gases that can affect oxidative stress and that themselves may be radicals. We discuss O2 toxicity, invoking superoxide, hydrogen peroxide, and the hydroxyl radical. We also discuss superoxide dismutase (SOD) and both ground-state, triplet oxygen (3O2), and the more energetic, reactive singlet oxygen (1O2). Nitric oxide (·NO) is a free radical with cell signaling functions. Besides its role as a vasorelaxant, ·NO and related species have other functions. Other endogenously produced gases include carbon monoxide (CO), carbon dioxide (CO2), and hydrogen sulfide (H2S). Like ·NO, these species impact free radical biochemistry. The coordinated regulation of these species suggests that they all are used in cell signaling. Nitric oxide, nitrogen dioxide, and the carbonate radical (CO3·−) react selectively at moderate rates with nonradicals, but react fast with a second radical. These reactions establish “cross talk” between reactive oxygen (ROS) and reactive nitrogen species (RNS). Some of these species can react to produce nitrated proteins and nitrolipids. It has been suggested that ozone is formed in vivo. However, the biomarkers that were used to probe for ozone reactions may be formed by non-ozone-dependent reactions. We discuss this fascinating problem in the section on ozone. Very low levels of ROS or RNS may be mitogenic, but very high levels cause an oxidative stress that can result in growth arrest (transient or permanent), apoptosis, or necrosis. Between these extremes, many of the gasses discussed in this review will induce transient adaptive responses in gene expression that enable cells and tissues to survive. Such adaptive mechanisms are thought to be of evolutionary importance.

scholarly journals Nitric Oxide Synthetic Pathway in Patients with Microvascular Angina and Its Relations with Oxidative Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Benedetta Porro ◽  
Sonia Eligini ◽  
Fabrizio Veglia ◽  
Alessandro Lualdi ◽  
Isabella Squellerio ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Pathological Condition ◽  
No Synthase ◽  
Microvascular Angina ◽  
No Formation ◽  
Oxidative Stress Status ◽  
Patient Groups ◽  
Artery Disease ◽  
Reduced Forms

A decreased nitric oxide (NO) bioavailability and an increased oxidative stress play a pivotal role in different cardiovascular pathologies. As red blood cells (RBCs) participate in NO formation in the bloodstream, the aim of this study was to outline the metabolic profile of L-arginine (Arg)/NO pathway and of oxidative stress status in RBCs and in plasma of patients with microvascular angina (MVA), investigating similarities and differences with respect to coronary artery disease (CAD) patients or healthy controls (Ctrl). Analytes involved in Arg/NO pathway and the ratio of oxidized and reduced forms of glutathione were measured by LC-MS/MS. The arginase and the NO synthase (NOS) expression were evaluated by immunofluorescence staining. RBCs from MVA patients show increased levels of NO synthesis inhibitors, parallel to that found in plasma, and a reduction of NO synthase expression. When summary scores were computed, both patient groups were associated with a positive oxidative score and a negative NO score, with the CAD group located in a more extreme position with respect to Ctrl. This finding points out to an impairment of the capacity of RBCs to produce NO in a pathological condition characterized mostly by alterations at the microvascular bed with no significant coronary stenosis.

Spontaneous Pulmonary Hypertension in Transgenic Sickle Cell Mice - Hemodynamics and Histology Suggest Abnormal Nitric Oxide Production and Scavenging.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 208-208
Author(s):  
Lewis L. Hsu ◽  
Hunter C. Champion ◽  
Elizabeth Manci ◽  
Bhalchandra Diwan ◽  
Daniel Schimel ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Hypertension ◽  
Cardiac Catheterization ◽  
Sickle Cell ◽  
No Synthase ◽  
No Donor ◽  
Vascular Congestion ◽  
No Consumption ◽  
No Bioavailability

Abstract Pulmonary hypertension is increasingly recognized in sickle cell disease (SCD) as a strong risk factor for early mortality. The finding of pulmonary hypertension in other hemolytic anemias suggests that the mechanism is linked to hemolysis and/or thrombosis. Pathophysiologic roles of nitric oxide (NO) consumption and recurrent lung injury have been considered. Transgenic mice expressing exclusively human sickle hemoglobin (sickle mice)(Pastzy 1997) are well established models of severe hemolytic anemia and ischemic organ damage in SCD, and provide the opportunity to examine mechanisms of pulmonary hypertension with invasive studies. Hypotheses: Pulmonary hypertension will spontaneously occur in sickle mice but not age-matched colony controls, and severity will increase as the mice grow older. Methods: Male sickle mice were compared with age-matched hemizygotes from the same colony. Mice had cardiac catheterization for baseline hemodynamics, then challenges to assess pulmonary vascular responsiveness. A pathologist made blinded assessments of the pulmonary histology. Results: Cardiac catheterization showed pulmonary hypertension in all sickle mice, and blunted pulmonary vasodilation to all NO donor compounds as well as authentic NO gas. Computed tomography in vivo detected pulmonary vascular congestion. Older sickle mice had modestly increased vessel wall thickness and vascular congestion but no thrombi by histology. Older mice also appear to be in right heart failure. Sickle mouse lungs had decreased eNOS activity (measured by L-arginine to citrulline turnover) and loss of active eNOS dimer (measured by western blotting). Sickle mouse plasma had high NO consumption, consistent with increased NO scavenging by free hemoglobin released by steady state hemolysis. mean & SD hemizygote control (5 mo & 13 mo) 5 mo sickle 13 mo sickle Pulmonary Arterial Pressure (torr) 9.4 (0.7) 18.2 (0.5) 14.8 (0.3) Pulmonary Vascular Resistance 0.37 (0.6) 0.80 (0.07) 0.75 (0.04) Cardiac Output (ml/min) 14.2 (2) 17.1 (2) 12.2 (2) Vasodilation to NO & NO donors, or bradykinin (endothelium-dependent) normal blunted none Vasodilation to CGRP (NO-independent and endothelium-independent) normal normal blunted Hypoxic vasoconstriction (10%O2) normal enhanced enhanced Discussion: This is one of the few descriptions of spontaneous pulmonary hypertension in an animal, and implicates low NO bioavailability mediated by NO resistance/scavenging. Interestingly, pulmonary thromboembolism was not observed. Combined effects of NO scavenging and the loss of active eNOS dimer may explain paradoxical blunted responses to NO donor agents, blunted responses to NO synthase inhibition, and arginine supplementation observed in patients with SCD, despite increased NO synthase protein expression. It is also likely that aberrant superoxide formation from uncoupled monomeric NO synthase contributes to vascular NO scavenging. In conclusion, pulmonary hypertension, associated with a vasoconstrictor phenotype and low NO bioavailability, develops early in the sickle cell transgenic mouse.

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

2013 ◽  
Vol 304 (7) ◽  
pp. R473-R487 ◽  
Author(s):  
Daniela Salvemini ◽  
Sangwon F. Kim ◽  
Vincenzo Mollace
Keyword(s):  
Nitric Oxide ◽  
Arachidonic Acid ◽  
State Of The Art ◽  
No Synthase ◽  
In Vivo Studies ◽  
Clinical Implications ◽  
Reciprocal Regulation ◽  
Receptor Targets

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

scholarly journals Nitric oxide inhibits basolateral 10-pS Cl− channels through the cGMP/PKG signaling pathway in the thick ascending limb of C57BL/6 mice

2016 ◽  
Vol 310 (8) ◽  
pp. F755-F762 ◽  
Author(s):  
Peng Wu ◽  
Zhongxiuzi Gao ◽  
Shiwei Ye ◽  
Zhi Qi
Keyword(s):  
Nitric Oxide ◽  
Soluble Guanylyl Cyclase ◽  
Inhibitory Effect ◽  
No Synthase ◽  
Thick Ascending Limb ◽  
Channel Activity ◽  
No Donor ◽  
Cgmp Analog ◽  
Synthase Inhibitor

We used patch-clamp techniques to examine whether nitric oxide (NO) decreases NaCl reabsorption by suppressing basolateral 10-pS Cl− channels in the thick ascending limb (TAL). Both the NO synthase substrate l-arginine (l-Arg) and the NO donor S-nitroso- N-acetylpenicillamine significantly inhibited 10-pS Cl− channel activity in the TAL. The inhibitory effect of l-Arg on Cl− channels was completely abolished in the presence of the NO synthase inhibitor or NO scavenger. Moreover, inhibition of soluble guanylyl cyclase abrogated the effect of l-Arg on Cl− channels, whereas the cGMP analog 8-bromo-cGMP (8-BrcGMP) mimicked the effect of l-Arg and significantly decreased 10-pS Cl− channel activity, indicating that NO inhibits basolateral Cl− channels by increasing cGMP production. Furthermore, treatment of the TAL with a PKG inhibitor blocked the effect of l-Arg and 8-BrcGMP on Cl− channels, respectively. In contrast, a phosphodiesterase 2 inhibitor had no significant effect on l-Arg or 8-BrcGMP-induced inhibition of Cl− channels. Therefore, we conclude that NO decreases basolateral 10-pS Cl− channel activity through a cGMP-dependent PKG pathway, which may contribute to the natriuretic and diuretic effects of NO in vivo.

In vivo treatment with endotoxin induces nitric oxide synthase in rat main pulmonary artery

1995 ◽  
Vol 268 (3) ◽  
pp. L509-L518 ◽  
Author(s):  
M. J. Griffiths ◽  
S. Liu ◽  
N. P. Curzen ◽  
M. Messent ◽  
T. W. Evans
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Contractile Response ◽  
Main Pulmonary Artery ◽  
Pulmonary Arteries ◽  
No Synthase ◽  
Oxide Synthase ◽  
Lps Treatment

Our aim was to demonstrate increased NO activity from inducible NO synthase (iNOS) in pulmonary arteries (PA) from rats treated with endotoxin [lipopolysaccharide (LPS), 20 mg/kg ip]. LPS treatment diminished the contractile response of PA to potassium chloride (KCl) and phenylephrine (PE) and increased levels of guanosine 3',5'-cyclic monophosphate (cGMP) in endothelium-denuded vessels. Both the NO synthase (NOS) antagonists NG-monomethyl-L-arginine (L-NMMA; nonselective) and aminoguanidine (selective for iNOS) enhanced PE-induced contraction in endothelium-denuded vessels from LPS-treated rats. Furthermore, L-NMMA-induced contraction of endothelium-denuded vessels from LPS-treated rats was stereospecifically antagonized by L-arginine and associated with decreased cGMP levels. These data suggest that NO is produced in increased amounts from PA smooth muscle after LPS treatment. LPS treatment caused increased expression of mRNA for iNOS in PA. This effect of LPS was attenuated by pretreatment with dexamethasone, suggesting that induction of NOS in PA smooth muscle underlies the increased NO activity associated with LPS administration.

Sign in / Sign up

Export Citation Format

Share Document