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.

Short-term exposure to homocysteine depresses rat aortic contractility by an endothelium-dependent mechanism

2000 ◽  
Vol 78 (6) ◽  
pp. 500-506 ◽  
Author(s):  
S Wang ◽  
G Wright ◽  
J Harrah ◽  
R Touchon ◽  
W McCumbee ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Nitric Oxide Synthase ◽  
Contractile Response ◽  
Fold Increase ◽  
No Production ◽  
Short Term ◽  
Short Term Exposure ◽  
Oxide Synthase

The effect of short-term exposure to homocysteine (Hcy) on the contractile characteristics of rat aortic tissue was assessed both in vitro and in vivo. The contractile response of Hcy-treated aortic rings in culture for 1 or 4 days was unchanged from control responses. By comparison, aortic rings from animals injected with Hcy showed marked attenuation of response compared with controls injected with saline, cysteine or methionine. The contractile response to K+ was decreased within 24 hours of Hcy injection, whereas the response to both K+ (-27%) and noradrenaline (-56%) was significantly decreased by 4 days. In contrast, the contractile response to phorbol-12,13-dibutyrate was not different between Hcy and control groups. Intimal rubbing completely restored the responsiveness of Hcy-treated tissue to K+ and noradrenaline. By comparison, L-NAME only partially restored contractile responsiveness, while the cyclooxygenase inhibitor indomethacin had no effect on contractile attenuation induced by Hcy. Western blot analysis showed a 2-fold increase of endothelial nitric oxide synthase (eNOS) and a 3-fold increase in inducible nitric oxide synthase (iNOS) protein expression in the aortic endothelial cells from Hcy-injected rats. The results indicate an early detectable effect of Hcy on the in vivo contractile properties of vascular smooth muscle. The effect is endothelium-mediated and may vary depending on the agonist studied. The mechanism is uncertain but appears to involve increased nitric oxide (NO) production. Finally, the data suggest that attenuation of contraction may not be due to a direct effect of Hcy but that the compound is modified or acts indirectly in vivo.Key words: nitric oxide, nitric oxide synthase, in vivo, smooth muscle.

Characterization and localization of endothelial nitric oxide synthase using specific monoclonal antibodies

1993 ◽  
Vol 265 (5) ◽  
pp. C1379-C1387 ◽  
Author(s):  
J. S. Pollock ◽  
M. Nakane ◽  
L. D. Buttery ◽  
A. Martinez ◽  
D. Springall ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Smooth Muscle ◽  
Monoclonal Antibodies ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
No Synthase ◽  
Endothelial No Synthase ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

We have produced specific monoclonal antibodies (MAb) against particulate bovine aortic endothelial nitric oxide synthase. In Western blots, native and cultured bovine aortic endothelial cells as well as cultured bovine microvascular endothelial cells possess immunoreactive NO synthase. In dot blots, MAb H210 and H32 detect 1 ng and 100 pg of purified endothelial NO synthase, respectively. Both antibodies are specific to the endothelial NO synthase and do not cross-react with other known isoforms of NO synthase, namely from the brain, from cytokine/endotoxin-induced macrophages, or from cytokine/endotoxin-induced vascular smooth muscle cells. Immunohistochemical studies demonstrated the specificity of endothelial NO synthase for endothelial cells in various bovine and human tissues. Many types of endothelial cells, macrovascular, microvascular, arterial, and venous were found to possess this specific isoform of NO synthase. Electron microscopy showed the enzyme to be associated with the plasma membrane, membranes of cytoplasmic vesicles, and in the cytoplasm in human umbilical vein endothelial cells. The results demonstrate that particulate endothelial NO synthase is present in a site to act rapidly to produce NO for release into the blood or toward the smooth muscle in many vascular beds.

Oxidant stress from uncoupled nitric oxide synthase impairs vasodilation in fetal lambs with persistent pulmonary hypertension

2007 ◽  
Vol 292 (4) ◽  
pp. H1812-H1820 ◽  
Author(s):  
Girija G. Konduri ◽  
Ivane Bakhutashvili ◽  
Annie Eis ◽  
Kirkwood Pritchard
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Hypertension ◽  
Nitric Oxide Synthase ◽  
Pulmonary Artery ◽  
Ductus Arteriosus ◽  
Oxidant Stress ◽  
Pulmonary Arteries ◽  
Persistent Pulmonary Hypertension ◽  
Pulmonary Vasodilation ◽  
Oxide Synthase

Persistent pulmonary hypertension of newborn (PPHN) is associated with decreased NO release and impaired pulmonary vasodilation. We investigated the hypothesis that increased superoxide (O2•−) release by an uncoupled endothelial nitric oxide synthase (eNOS) contributes to impaired pulmonary vasodilation in PPHN. We investigated the response of isolated pulmonary arteries to the NOS agonist ATP and the NO donor S-nitroso- N-acetylpenicillamine (SNAP) in fetal lambs with PPHN induced by prenatal ligation of ductus arteriosus and in sham-ligated controls in the presence or absence of the NOS antagonist nitro-l-arginine methyl ester (l-NAME) or the O2•− scavenger 4,5-dihydroxy-1,3-benzenedisulfonate (Tiron). ATP caused dose-dependent relaxation of pulmonary artery rings in control lambs but induced constriction of the rings in PPHN lambs. l-NAME, the NO precursor l-arginine, and Tiron restored the relaxation response of pulmonary artery rings to ATP in PPHN. Relaxation to NO was attenuated in arteries from PPHN lambs, and the response was improved by l-NAME and by Tiron. We also investigated the alteration in heat shock protein (HSP)90-eNOS interactions and release of NO and O2•− in response to ATP in the pulmonary artery endothelial cells (PAEC) from these lambs. Cultured PAEC and endothelium of freshly isolated pulmonary arteries from PPHN lambs released O2•− in response to ATP, and this was attenuated by the NOS antagonist l-NAME and superoxide dismutase (SOD). ATP stimulated HSP90-eNOS interactions in PAEC from control but not PPHN lambs. HSP90 immunoprecipitated from PPHN pulmonary arteries had increased nitrotyrosine signal. Oxidant stress from uncoupled eNOS contributes to impaired pulmonary vasodilation in PPHN induced by ductal ligation in fetal lambs.

Increased expression of nitric oxide synthase in the myometrium of the pregnant rat uterus

1997 ◽  
Vol 272 (6) ◽  
pp. E1008-E1015 ◽  
Author(s):  
R. K. Riemer ◽  
C. Buscher ◽  
R. K. Bansal ◽  
S. M. Black ◽  
Y. He ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
No Synthase ◽  
Inos Expression ◽  
Rat Uterus ◽  
Pregnant Rat ◽  
Pregnant Uterus ◽  
Uterine Smooth Muscle ◽  
Uterine Contractions ◽  
Oxide Synthase

Nitric oxide (NO) relaxes uterine smooth muscle and is produced by the pregnant uterus. Our previous studies revealed an increase in rat uterine NO synthase (NOS) activity in pregnancy and a decline at term. In the present study, we have examined the distribution of NOS isoform expression to determine whether their regulation is consistent with a role in the inhibition of uterine contractions before term. At day 17-18 of pregnancy, NOS immunohistochemistry revealed expression of two isoforms: endothelial constitutive form of NOS (ecNOS) in vascular endothelium and inducible form of NOS (iNOS) in myometrial and vascular smooth muscle and in decidual epithelium. Immunoblotting revealed that expression of iNOS declined nearly fivefold, whereas ecNOS declined twofold in laboring rats at term. We conclude that iNOS is expressed in myometrium of pregnant rat uterus but not the virgin rat and that iNOS expression declines at term when labor is present. The pattern of changes in myometrial iNOS expression with advancing gestation suggests that NO could act in an autocrine and/or paracrine manner to inhibit uterine contractions before term.

Nitric Oxide Synthase Is Deficient in the Aganglionic Colon of Patients With Hirschsprung's Disease

PEDIATRICS ◽  
1994 ◽  
Vol 93 (4) ◽  
pp. 647-651
Author(s):  
John F. Bealer ◽  
Eileen S. Natuzzi ◽  
Cori Buscher ◽  
Alan W. Flake ◽  
N. Scott Adzick ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Enzyme Activity ◽  
Smooth Muscle ◽  
Nitric Oxide Synthase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Hirschsprung's Disease ◽  
Hirschsprung’S Disease ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
No Synthase ◽  
Oxide Synthase

Objectives. The cause of Hirschsprung's disease is unknown but defects in nonadrenergic, noncholinergic innervation could prevent relaxation of aganglionic colon in patients with this disease. Nonadrenergic, noncholinergic nerves induce relaxation by using nitric oxide synthase to produce the smooth muscle relaxant nitric oxide (NO). In this study we asked whether aganglionic colon in patients with Hirschsprung's disease is deficient in NO synthase-containing nerves. Methodology. Using the tetrazolium blue dye method of demonstrating nicotinamide adenine dinucleotide phosphate-diaphorase enzymes, we examined eight colon specimens (four aganglionic and four ganglionic) from patients with Hirschsprung's disease for the presence of NO synthase. We further quantified NO synthase enzyme activity in these eight specimens by using the [3H]arginine-to-[3H]citrulline conversion assay. Results. The nicotinamide adenine dinucleotide phosphate-diaphorase staining showed that aganglionic colon contained less NO synthase than ganglionic colon. This NO synthase deficiency was located primarily in the nerves of the circular muscle layer of the colon. In addition, there was a striking difference in the NO synthase enzyme activity between aganglionic and ganglionic colon as measured by the [3H]arginine-to-[3H]citrulline conversion assay. Total NO synthase activity, as measured by this assay, was found to be less in aganglionic than in ganglionic colon. When the total activity was divided into its four known isoforms, aganglionic colon was noted to be striking deficient in the isoform derived primarily from nerves. Conclusion. We conclude that aganglionic colon is deficient in NO synthase-containing nerves. This deficiency could prevent smooth muscle relaxation in the aganglionic colon of patients with Hirschsprung's disease.

scholarly journals Nitric oxide synthase inhibition decreases tolerance to hyperoxia in newborn rats

1995 ◽  
Vol 4 (6) ◽  
pp. 431-436 ◽  
Author(s):  
M. R. Pierce ◽  
C. A. Voelker ◽  
I. R. S. Sosenko ◽  
S. Bustamante ◽  
S. M. Olister ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Lung Injury ◽  
Pulmonary Artery ◽  
No Synthase ◽  
Internal Diameter ◽  
Postnatal Exposure ◽  
Newborn Rats ◽  
Pregnant Rats ◽  
Untreated Water ◽  
Oxide Synthase

We evaluated the effects of sustained perinatal inhibition of NO synthase (NOS) on hyperoxia induced lung injury in newborn rats. NG-nitro-Larginine-methyl-ester (L-NAME) or untreated water was administered to pregnant rats for the final 7 days of gestation and during lactation; followed by postnatal exposure to hyperoxia (>95% O2) or room air. The survival rate of L-NAME treated pups when placed in > 95% O2at birth was significantly lower than controls from day 4 (L-NAME, 87%; control pups, 100%, p < 0.05) to 14 (L-NAME, 0%; control pups, 53%, p < 0.05). Foetal pulmonary artery vasoconstriction was induced by L-NAME with a decrease in internal diameter from 0.88 ± 0.03 mm to 0.64 ± 0.01 mm in controlvs. L-NAME groups (p < 0.05), respectively. We conclude that perinatal NOS inhibition results in pulmonary artery vasoconstriction and a decreased tolerance to hyperoxia induced lung injury in newborn rats.

scholarly journals Cellular disposition of transported polyamines in hypoxic rat lung and pulmonary arteries

2000 ◽  
Vol 278 (3) ◽  
pp. L610-L617 ◽  
Author(s):  
Pavel Babal ◽  
S. Machelle Manuel ◽  
Jack W. Olson ◽  
Mark N. Gillespie
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Lung Tissue ◽  
Main Pulmonary Artery ◽  
Pulmonary Arteries ◽  
Rat Lung ◽  
Polyamine Transport ◽  
Pulmonary Arterial ◽  
Polyamine Uptake

The polyamines putrescine, spermidine (SPD), and spermine are a family of low-molecular-weight organic cations essential for cell growth and differentiation and other aspects of signal transduction. Hypoxic pulmonary vascular remodeling is accompanied by depressed lung polyamine synthesis and markedly augmented polyamine uptake. Cell types in which hypoxia induces polyamine transport in intact lung have not been delineated. Accordingly, rat lung and rat main pulmonary arterial explants were incubated with [14C]SPD in either normoxic (21% O2) or hypoxic (2% O2) environments for 24 h. Autoradiographic evaluation confirmed previous studies showing that, in normoxia, alveolar epithelial cells are dominant sites of polyamine uptake. In contrast, hypoxia was accompanied by prominent localization of [14C]SPD in conduit, muscularized, and partially muscularized pulmonary arteries, which was not evident in normoxic lung tissue. Hypoxic main pulmonary arterial explants also exhibited substantial increases in [14C]SPD uptake relative to control explants, and autoradiography revealed that enhanced uptake was most evident in the medial layer. Main pulmonary arterial explants denuded of endothelium failed to increase polyamine transport in hypoxia. Conversely, medium conditioned by endothelial cells cultured in hypoxic, but not in normoxic, environments enabled hypoxic transport induction in denuded arterial explants. These findings in arterial explants were recapitulated in rat cultured main pulmonary artery cells, including the enhancing effect of a soluble endothelium-derived factor(s) on hypoxic induction of [14C]SPD uptake in smooth muscle cells. Viewed collectively, these results show in intact lung tissue that hypoxia enhances polyamine transport in pulmonary artery smooth muscle by a mechanism requiring elaboration of an unknown factor(s) from endothelial cells.

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