Nitric oxide synthase regulation during embryonic implantation

1997 ◽  
Vol 9 (5) ◽  
pp. 557 ◽  
Author(s):  
V. Novaro ◽  
E. González ◽  
A. Jawerbaum ◽  
V. Rettori ◽  
G. Canteros ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Receptor Antagonist ◽  
Early Pregnancy ◽  
Embryo Implantation ◽  
Competitive Inhibitor ◽  
No Production ◽  
Physiological Relevance ◽  
Synthase Regulation ◽  
Oxide Synthase

It has previously been demonstrated that uterine nitric oxide synthase (NOS) activity increases before embryonic implantation in rats. The aim of the present work was to investigate the regulation and the physiological relevance of the nitric oxide (NO) system in ovoimplantation. The increase in NOS activity in early pregnancy was found to be independent of the presence of embryos in the uterus. Whereas the Ca2+-dependent isoform of NOS increased gradually in the preimplantation days, the Ca2+-independent isoform increased just at the beginning of implantation (Day 5, 1800 hours); then the activity of both isoforms declined. Oestradiol, whose concentration peaks before implantation, might be regulating NOS activity in the uterus, since treatment of rats with tamoxifen, a receptor antagonist, reduces the activity of both isoforms to preimplantation levels. Intraluminal injections of L-NAME (0·5 mg kg-1), a competitive inhibitor of NOS, reduced by 50% the number of implanted embryos; this suggests that the NO system plays a role during implantation. The data suggest that oestradiol might be a modulator of NOS activity during nidation and that NO production is necessary to achieve a successful embryo implantation.

Endothelin stimulates endothelial nitric oxide synthase expression in the thick ascending limb

2004 ◽  
Vol 287 (2) ◽  
pp. F231-F235 ◽  
Author(s):  
Marcela Herrera ◽  
Jeffrey L. Garvin
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Receptor Antagonist ◽  
Endothelial Nitric Oxide Synthase ◽  
No Production ◽  
Thick Ascending Limb ◽  
Enos Expression ◽  
No Release ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Endothelin-1 (ET-1) acutely inhibits NaCl reabsorption by the thick ascending limb (THAL) by activating the ETB receptor, stimulating endothelial nitric oxide synthase (eNOS), and releasing nitric oxide (NO). In nonrenal tissue, chronic exposure to ET-1 stimulates eNOS expression via the ETB receptor and activation of phosphatidylinositol 3-kinase (PI3K). We hypothesized that ET-1 increases eNOS expression in the THAL by binding to ETB receptors and stimulating PI3K. In primary cultures of medullary THALs treated for 24 h, eNOS expression increased by 36 ± 18% with 0.01 nM ET-1, 123 ± 30% with 0.1 nM ( P < 0.05; n = 5), and 71 ± 30% with 1 nM, whereas 10 nM had no effect. BQ-788, a selective ETB receptor antagonist, completely blocked stimulation of eNOS expression caused by 0.1 nM ET-1 (12 ± 25 vs. 120 ± 40% for ET-1 alone; P < 0.05; n = 5). BQ-123, a selective ETA receptor antagonist, did not affect the increase in eNOS caused by 0.1 nM ET-1. Sarafotoxin c (S6c; 0.1 μM), a selective ETB receptor agonist, increased eNOS expression by 77 ± 30% ( P < 0.05; n = 6). Wortmannin (0.01 μM), a PI3K inhibitor, completely blocked the stimulatory effect of 0.1 μM S6c (77 ± 30 vs. −28 ± 9%; P < 0.05; n = 6). To test whether the increase in eNOS expression heightens activity, we measured NO release in response to simultaneous treatment with l-arginine, ionomycin, and clonidine using a NO-sensitive electrode. NO release by control cells was 337 ± 61 and 690 ± 126 pA in ET-1-treated cells ( P < 0.05; n = 5). Taken together, these data suggest that ET-1 stimulates THAL eNOS, activating ETB receptors and PI3K and thereby increasing NO production.

Angiotensin II decreases inducible nitric oxide synthase expression in rat astroglial cultures

1995 ◽  
Vol 268 (3) ◽  
pp. C700-C707 ◽  
Author(s):  
L. J. Chandler ◽  
K. Kopnisky ◽  
E. Richards ◽  
F. T. Crews ◽  
C. Sumners
Keyword(s):  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Nitric Oxide Synthase ◽  
Receptor Antagonist ◽  
Maximal Response ◽  
No Production ◽  
Dependent Manner ◽  
Ang Ii ◽  
Subsequent Formation ◽  
Oxide Synthase

Consistent with stimulation of expression of an inducible form of nitric oxide synthase (iNOS), exposure of rat astroglial cultures to lipopolysaccharide (LPS) caused a time-dependent increase in the accumulation of nitrite in the culture media. Addition of the peptide angiotensin II (ANG II) with LPS decreased subsequent formation of nitrite in a concentration-dependent manner (concentration inhibiting 50% of maximal response approximately 1 nM). The ANG II effect could be blocked by the ANG II type 1 (AT1 receptor antagonist losartan but not by the ANG II type 2 (AT2) receptor antagonist PD-123177. ANG II had no effect on nitrite formation stimulated by a combination of inflammatory cytokines (interleukin-1 beta, tumor necrosis factor-alpha, and interferon-gamma). A brief 10-min exposure to ANG II was sufficient to cause an approximately 30% inhibition of the LPS response, with maximal inhibition of approximately 65% after 3 h, and occurred only when ANG II was added during the iNOS induction phase. Consistent with partial inhibition of LPS-stimulated expression of iNOS, ANG II reduced the levels of both iNOS mRNA and iNOS protein. These results demonstrate that ANG II can decrease LPS-stimulated NO production in astroglia by inhibiting induction of iNOS expression.

scholarly journals Does Melatonin Exert Its Effect on Ram Sperm Capacitation Through Nitric Oxide Synthase Regulation?

2020 ◽  
Vol 21 (6) ◽  
pp. 2093
Author(s):  
Sara Miguel-Jiménez ◽  
Melissa Carvajal-Serna ◽  
Silvia Calvo ◽  
Adriana Casao ◽  
José Álvaro Cebrián-Pérez ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Acrosome Reaction ◽  
No Production ◽  
Sperm Capacitation ◽  
Synthase Regulation ◽  
Oxide Synthase ◽  
Nos Isoforms ◽  
Ram Sperm

Nitric oxide (NO·), synthesized from L-arginine by nitric oxide synthase (NOS), is involved in sperm functionality. NOS isoforms have been detected in spermatozoa from different species, and an increment in NOS activity during capacitation has been reported. This work aims to determine the presence and localization of NOS isoforms in ram spermatozoa and analyse their possible changes during in vitro capacitation. Likewise, we investigated the effect of melatonin on the expression and localization of NOS and NO· levels in capacitated ram spermatozoa. Western blot analysis revealed protein bands associated with neuronal NOS (nNOS) and epithelial NOS (eNOS) but not with inducible NOS (iNOS). However, the three isoforms were detected by indirect immunofluorescence (IFI), and their immunotypes varied over in vitro capacitation with cAMP-elevating agents. NO· levels (evaluated by DAF-2-DA/PI staining) increased after in vitro capacitation, and the presence of L-arginine in the capacitating medium raised NO· production and enhanced the acrosome reaction. Incubation in capacitating conditions with a high-cAMP medium with melatonin modified the NOS distribution evaluated by IFI, but no differences in Western blotting were observed. Melatonin did not alter NO· levels in capacitating conditions, so we could infer that its role in ram sperm capacitation would not be mediated through NO· metabolism.

scholarly journals Protein kinase Cδ regulates endothelial nitric oxide synthase expression via Akt activation and nitric oxide generation

2008 ◽  
Vol 294 (3) ◽  
pp. L582-L591 ◽  
Author(s):  
Neetu Sud ◽  
Stephen Wedgwood ◽  
Stephen M. Black
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Promoter Activity ◽  
Dominant Negative ◽  
No Production ◽  
Enos Expression ◽  
Akt Activation ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

In this study, we explore the roles of the delta isoform of PKC (PKCδ) in the regulation of endothelial nitric oxide synthase (eNOS) activity in pulmonary arterial endothelial cells isolated from fetal lambs (FPAECs). Pharmacological inhibition of PKCδ with either rottlerin or with the peptide, δV1-1, acutely attenuated NO production, and this was associated with a decrease in phosphorylation of eNOS at Ser1177 (S1177). The chronic effects of PKCδ inhibition using either rottlerin or the overexpression of a dominant negative PKCδ mutant included the downregulation of eNOS gene expression that was manifested by a decrease in both eNOS promoter activity and protein expression after 24 h of treatment. We also found that PKCδ inhibition blunted Akt activation as observed by a reduction in phosphorylated Akt at position Ser473. Thus, we conclude that PKCδ is actively involved in the activation of Akt. To determine the effect of Akt on eNOS signaling, we overexpressed a dominant negative mutant of Akt and determined its effect of NO generation, eNOS expression, and phosphorylation of eNOS at S1177. Our results demonstrated that Akt inhibition was associated with decreased NO production that correlated with reduced phosphorylation of eNOS at S1177, and decreased eNOS promoter activity. We next evaluated the effect of endogenously produced NO on eNOS expression by incubating FPAECs with the eNOS inhibitor 2-ethyl-2-thiopseudourea (ETU). ETU significantly inhibited NO production, eNOS promoter activity, and eNOS protein levels. Together, our data indicate involvement of PKCδ-mediated Akt activation and NO generation in maintaining eNOS expression.

scholarly journals Induction of nitric oxide synthesis in J774 cells lowers intracellular glutathione: effect of modulated glutathione redox status on nitric oxide synthase induction

1997 ◽  
Vol 322 (2) ◽  
pp. 477-481 ◽  
Author(s):  
John S. HOTHERSALL ◽  
Fernando Q. CUNHA ◽  
Guy H. NEILD ◽  
Alberto A. NOROHNA-DUTRA
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
De Novo ◽  
Redox Status ◽  
No Production ◽  
Duration Of Treatment ◽  
Intracellular Glutathione ◽  
J774 Cells ◽  
Oxide Synthase ◽  
Glutathione Redox

Under pathological conditions, the induction of nitric oxide synthase (NOS) in macrophages is responsible for NO production to a cytotoxic concentration. We have investigated changes to, and the role of, intracellular glutathione in NO production by the activated murine macrophage cell line J774. Total glutathione concentrations (reduced, GSH, plus the disulphide, GSSG) were decreased to 45% of the control 48 h after cells were activated with bacterial lipopolysaccharide plus interferon γ. This was accompanied by a decrease in the GSH/GSSG ratio from 12:1 to 2:1. The intracellular decrease was not accounted for by either GSH or GSSG efflux; on the contrary, rapid export of glutathione in control cells was abrogated during activation. The loss of intra- and extracellular glutathione indicates either a decrease in synthesis de novo, or an increase in utilization, rather than competition for available NADPH. All changes in activated cells were prevented by pretreatment with the NOS inhibitor l-N-(1-iminoethyl)ornithine. Basal glutathione levels in J774 cells were manipulated by pretreatment with (1) buthionine sulphoximine (glutathione synthase inhibitor), (2) acivicin (γ-glutamyltranspeptidase inhibitor), (3) bromo-octane (glutathione S-transferase substrate) and (4) diamide/zinc (thiol oxidant and glutathione reductase inhibitor). All treatments significantly decreased the output of NO following activation. The degree of inhibition was dependent on (i) duration of treatment prior to activation, (ii) rate of depletion or subsequent recovery and (iii) thiol end product. The level of GSH did not significantly affect the production of NO, after induction of NOS. Thus, glutathione redox status appears to plays an important role in NOS induction during macrophage activation.

Nitric oxide attenuates epithelial-mesenchymal transition in alveolar epithelial cells

2007 ◽  
Vol 293 (1) ◽  
pp. L212-L221 ◽  
Author(s):  
Shilpa Vyas-Read ◽  
Philip W. Shaul ◽  
Ivan S. Yuhanna ◽  
Brigham C. Willis
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Epithelial Cells ◽  
Epithelial Mesenchymal Transition ◽  
Alveolar Epithelial Cells ◽  
No Production ◽  
Mesenchymal Transition ◽  
Alveolar Epithelial ◽  
Oxide Synthase ◽  
Tgf Β1

Patients with interstitial lung diseases, such as idiopathic pulmonary fibrosis (IPF) and bronchopulmonary dysplasia (BPD), suffer from lung fibrosis secondary to myofibroblast-mediated excessive ECM deposition and destruction of lung architecture. Transforming growth factor (TGF)-β1 induces epithelial-mesenchymal transition (EMT) of alveolar epithelial cells (AEC) to myofibroblasts both in vitro and in vivo. Inhaled nitric oxide (NO) attenuates ECM accumulation, enhances lung growth, and decreases alveolar myofibroblast number in experimental models. We therefore hypothesized that NO attenuates TGF-β1-induced EMT in cultured AEC. Studies of the capacity for endogenous NO production in AEC revealed that endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) are expressed and active in AEC. Total NOS activity was 1.3 pmol·mg protein−1·min−1 with 67% derived from eNOS. TGF-β1 (50 pM) suppressed eNOS expression by more than 60% and activity by 83% but did not affect iNOS expression or activity. Inhibition of endogenous NOS with l-NAME led to spontaneous EMT, manifested by increased α-smooth muscle actin (α-SMA) expression and a fibroblast-like morphology. Provision of exogenous NO to TGF-β1-treated AEC decreased stress fiber-associated α-SMA expression and decreased collagen I expression by 80%. NO-treated AEC also retained an epithelial morphology and expressed increased lamellar protein, E-cadherin, and pro-surfactant protein B compared with those treated with TGF-β alone. These findings indicate that NO serves a critical role in preserving an epithelial phenotype and in attenuating EMT in AEC. NO-mediated regulation of AEC fate may have important implications in the pathophysiology and treatment of diseases such as IPF and BPD.

scholarly journals Nitric oxide regulates vascular adaptive mitochondrial dynamics

2013 ◽  
Vol 304 (12) ◽  
pp. H1624-H1633 ◽  
Author(s):  
Matthew W. Miller ◽  
Leslie A. Knaub ◽  
Luis F. Olivera-Fragoso ◽  
Amy C. Keller ◽  
Vivek Balasubramaniam ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Mitochondrial Biogenesis ◽  
Disease Risk ◽  
Mitochondrial Dynamics ◽  
Cardiovascular Disease Risk ◽  
No Production ◽  
Voltage Dependent Anion Channel ◽  
Protein Subunits ◽  
Oxide Synthase

Cardiovascular disease risk factors, such as diabetes, hypertension, dyslipidemia, obesity, and physical inactivity, are all correlated with impaired endothelial nitric oxide synthase (eNOS) function and decreased nitric oxide (NO) production. NO-mediated regulation of mitochondrial biogenesis has been established in many tissues, yet the role of eNOS in vascular mitochondrial biogenesis and dynamics is unclear. We hypothesized that genetic eNOS deletion and 3-day nitric oxide synthase (NOS) inhibition in rodents would result in impaired mitochondrial biogenesis and defunct fission/fusion and autophagy profiles within the aorta. We observed a significant, eNOS expression-dependent decrease in mitochondrial electron transport chain (ETC) protein subunits from complexes I, II, III, and V in eNOS heterozygotes and eNOS null mice compared with age-matched controls. In response to NOS inhibition with NG-nitro-l-arginine methyl ester (l-NAME) treatment in Sprague Dawley rats, significant decreases were observed in ETC protein subunits from complexes I, III, and IV as well as voltage-dependent anion channel 1. Decreased protein content of upstream regulators of mitochondrial biogenesis, cAMP response element-binding protein and peroxisome proliferator-activated receptor-γ coactivator-1α, were observed in response to 3-day l-NAME treatment. Both genetic eNOS deletion and NOS inhibition resulted in decreased manganese superoxide dismutase protein. l-NAME treatment resulted in significant changes to mitochondrial dynamic protein profiles with decreased fusion, increased fission, and minimally perturbed autophagy. In addition, l-NAME treatment blocked mitochondrial adaptation to an exercise intervention in the aorta. These results suggest that eNOS/NO play a role in basal and adaptive mitochondrial biogenesis in the vasculature and regulation of mitochondrial turnover.

Recombinant Gene Transfer of Endothelial Nitric Oxide Synthase Augments Coronary Artery Relaxations During Hypoxia

Circulation ◽  
1999 ◽  
Vol 100 (suppl_2) ◽  
Author(s):  
David G. Cable ◽  
Vincent J. Pompili ◽  
Timothy O’Brien ◽  
Hartzell V. Schaff
Keyword(s):  
Nitric Oxide ◽  
Coronary Artery ◽  
Nitric Oxide Synthase ◽  
Gene Transfer ◽  
Coronary Arteries ◽  
Endothelial Nitric Oxide Synthase ◽  
No Production ◽  
Viral Control ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Background —Coronary arteries respond to hypoxia with transient relaxations, which increases coronary blood flow, in part, by release of nitric oxide. We hypothesized that increased expression of nitric oxide synthase might further augment blood vessel relaxation during hypoxia. The present study examined the effect of adenovirus-mediated transfer of bovine endothelial nitric oxide synthase (eNOS) on hypoxia-induced transient relaxations in canine coronary arteries. Methods and Results —Paired segments of coronary arteries were exposed to vehicle (phosphate-buffered saline with albumin) or an adenovirus encoding either E coli β-galactosidase (Ad.CMVLacZ, viral control; 10 10 pfu/mL) or eNOS (Ad.CMVeNOS; 10 10 pfu/mL) for 2 hours at 37°C. Immunohistochemistry with a monoclonal antibody specific for eNOS documented both endothelial and adventitial expression in Ad.CMVeNOS arteries, whereas vehicle and viral controls demonstrated only constitutive expression. Levels of cGMP were increased 5-fold in Ad.CMVeNOS arteries compared with controls. In arteries exposed to Ad.CMVeNOS, maximum contraction to prostaglandin F 2α was reduced compared with viral controls, and this effect was eliminated by pretreatment with a competitive inhibitor of eNOS ( N G -monomethyl- l -arginine, 10 −3 mol/L). Hypoxia-induced transient relaxation (95% N 2 -5% CO 2 ) in Ad.CMVeNOS arteries (45.2±8.8%, n=6) was augmented compared with vehicle (26.3±6.0%) or viral (27.2±7.1%) controls. Conclusions —Adenovirus-mediated gene transfer of nitric oxide synthase reduces receptor-dependent contractions and augments hypoxia-induced relaxations in canine coronary arteries; this method of augmentation of NO production might be advantageous for reduction of coronary artery vasospasm.

Hypoxia inhibits nitric oxide synthesis in isolated rabbit lung

1997 ◽  
Vol 272 (6) ◽  
pp. L1167-L1173 ◽  
Author(s):  
S. P. Kantrow ◽  
Y. C. Huang ◽  
A. R. Whorton ◽  
E. N. Grayck ◽  
J. M. Knight ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Competitive Inhibitor ◽  
Oxidation Products ◽  
No Oxidation ◽  
Severe Hypoxia ◽  
No Production ◽  
Rabbit Lung ◽  
Vasoconstrictor Response ◽  
Hypoxic Vasoconstriction ◽  
Oxide Synthase

Nitric oxide (NO.) has been proposed to modulate hypoxic vasoconstriction in the lung. The activity of nitric oxide synthase (NOS) can be inhibited by hypoxia because molecular oxygen is a necessary substrate for the enzyme. On the basis of this mechanism, we hypothesized that NOS activity has a key role in regulation of pulmonary vascular tone during hypoxia. We measured oxidation products of NO. released into the vasculature of isolated buffer-perfused rabbit lung ventilated with normoxic (21% O2), moderately hypoxic (5% O2), or anoxic (0% O2) gas using two methods. Mean PO2 in perfusate exiting the lung was 25 Torr during anoxic ventilation and 47 Torr during moderately hypoxic ventilation. We found that the amount of the NO. oxidation product nitrite released into the perfusate was suppressed significantly during ventilation with anoxic but not moderately hypoxic gas. During normoxic ventilation, nitrite release was inhibited by pretreatment with NG-monomethyl-L-arginine, a competitive inhibitor of NOS. To confirm that changes in nitrite concentration reflected changes in NO. release into the perfusate, major oxidation products of NO. (NOx) were assayed using a method for reduction of these products to NO. by vanadium(III) Cl. Release of NOx into the perfusate was suppressed by severe hypoxia (anoxic ventilation), and this effect was reversed by normoxia. Pulmonary vasoconstriction was observed during severe but not moderate hypoxia and was related inversely to the rate of nitrite release. These observations provide evidence that decreased NO. production contributes to the pulmonary vasoconstrictor response during severe hypoxia.

scholarly journals Effects of selected endothelium-dependent vasodilators on fetoplacental vasculature: physiological implications

1999 ◽  
Vol 277 (2) ◽  
pp. H842-H847
Author(s):  
Saral Amarnani ◽  
Belinda Sangrat ◽  
Gautam Chaudhuri
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Receptor Antagonist ◽  
Perfusion Pressure ◽  
Ang Ii ◽  
Hoe 140 ◽  
Oxide Synthase

The endothelium-dependent vasodilators ACh, histamine, and bradykinin were studied in the isolated, perfused human placental cotyledon. Histamine caused a decrease in perfusion pressure that was attenuated by cimetidine. Bradykinin, at lower concentrations (10−20 to 10−14 M), produced a concentration-dependent decrease in perfusion pressure, whereas at higher concentrations it produced an increase in perfusion pressure. ACh was without any effect. The decrease in perfusion pressure observed with bradykinin was potentiated by captopril and was significantly attenuated in the presence of HOE-140, the B2-receptor antagonist, or by pretreatment with an inhibitor of nitric oxide synthase, but not by an inhibitor of cyclooxygenase. The decrease in perfusion pressure observed with bradykinin was potentiated by ANG I but not by ANG II. It is concluded that endothelium-dependent vasodilation can be demonstrated with histamine and bradykinin in the fetoplacental vessels, and at least for bradykinin, this is partly mediated by release of nitric oxide. The potentiation of the bradykinin response in the presence of ANG I may serve to buffer the vasoconstriction produced by ANG II in the fetoplacental circulation.

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