scholarly journals eNOS function is developmentally regulated: uncoupling of eNOS occurs postnatally

2006 ◽  
Vol 290 (2) ◽  
pp. L232-L241 ◽  
Author(s):  
Eugenia Mata-Greenwood ◽  
Chrystal Jenkins ◽  
Kathryn N. Farrow ◽  
G. Ganesh Konduri ◽  
James A. Russell ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Soluble Guanylate Cyclase ◽  
Vascular System ◽  
Oxidase Inhibitor ◽  
Superoxide Production ◽  
No Production ◽  
Oxygen Species ◽  
Laminar Shear Stress ◽  
A 23187 ◽  
Stimulation Of

At birth, the transition to gas breathing requires the function of endothelial vasoactive agents. We investigated the function of endothelial nitric oxide synthase (eNOS) in pulmonary artery (PA) vessels and endothelial cells isolated from fetal and young (4-wk) sheep. We found greater relaxations to the NOS activator A-23187 in 4-wk-old compared with fetal vessels and that the NOS inhibitor nitro-l-arginine blocked relaxations in both groups. Relaxations in 4-wk vessels were not blocked by an inhibitor of soluble guanylate cyclase, 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one, but were partially blocked by catalase. We therefore hypothesized that activation of eNOS produced reactive oxygen species in 4-wk but not fetal PA. To address this question, we studied NO and superoxide production by endothelial cells at baseline and following NOS stimulation with A-23187, VEGF, and laminar shear stress. Stimulation of NOS induced phosphorylation at serine 1177, and this event correlated with an increase in NO production in both ages. Upon stimulation of eNOS, fetal PA endothelial cells (PAEC) produced only NO. In contrast 4-wk-old PAEC produced superoxide in addition to NO. Superoxide production was blocked by l-NAME but not by apocynin (an NADPH oxidase inhibitor). l-Arginine increased NO production in both cell types but did not block superoxide production. Heat shock protein 90/eNOS association increased upon stimulation and did not change with developmental age. Cellular levels of total and reduced biopterin were higher in fetal vs. 4-wk cells. Sepiapterin [a tetrahydrobiopterin (BH4) precursor] increased basal and stimulated NO levels and completely blocked superoxide production. We conclude that the normal function of eNOS becomes uncoupled after birth, leading to a developmental adaptation of the pulmonary vascular system to produce oxygen species other than NO. We speculate this may be related to cellular production and/or maintenance of BH4 levels.

scholarly journals In Endothelial Cells, the Activation or Stimulation of Soluble Guanylyl Cyclase Induces the Nitric Oxide Production by a Mechanism Dependent of Nitric Oxide Synthase Activation

2018 ◽  
Vol 21 ◽  
pp. 38-45 ◽  
Author(s):  
Ariane Migliato Martinelli ◽  
Carla Nascimento dos Santos Rodrigues ◽  
Thiago Francisco de Moraes ◽  
Gerson Jhonatan Rodrigues
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Nitric Oxide Synthase ◽  
Soluble Guanylate Cyclase ◽  
Soluble Guanylyl Cyclase ◽  
No Production ◽  
Selective Electrode ◽  
Nos Inhibitor ◽  
Oxide Synthase ◽  
Stimulation Of

Purpose. In endothelial cells, investigate if the soluble guanylate cyclase (sGC) activation or stimulation is able to potentiate the relaxation in vessels. Methods. Aortic and coronary rings with and without endothelium were placed in a myograph and cumulative concentration-effect curves for DETA-NO or ataciguat were performed. Nitric oxide (NO) were measured by fluorescence or by selective electrode in human umbilical endothelial cells (HUVECs) in response to some treatments, including ataciguat, 8-Br-cGMP and A23187. Results. The presence of the endothelium potentiated the relaxation induced by DETA-NO in aortic and coronary rings. In addition, in aortic rings the endothelium potentiated the relaxation induced by ataciguat. In the presence of nitric oxide synthase (NOS) inhibitor, the endothelium effect was abolished to DETA-NO or ataciguat, in both vessels. Ataciguat, 8-Br-cGMP and A23187 were able to induce NO production in HUVECs cells. In the presence of NOS inhibitor, the NO production induced by ataciguat and 8-Br-cGMP was abolished. Conclusions. Our results suggest that in aortic and coronary rings the endothelium potentiates the relaxation induced by activation or stimulation of sGC through a mechanism dependent of NOS activation. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Prohibitin-1 maintains the angiogenic capacity of endothelial cells by regulating mitochondrial function and senescence

2008 ◽  
Vol 180 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Michael Schleicher ◽  
Benjamin R. Shepherd ◽  
Yajaira Suarez ◽  
Carlos Fernandez-Hernando ◽  
Jun Yu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Mitochondrial Function ◽  
Vascular System ◽  
Reactive Oxygen ◽  
Direct Consequence ◽  
Oxygen Species ◽  
Inner Mitochondrial Membrane ◽  
Prohibitin 1

Prohibitin 1 (PHB1) is a highly conserved protein that is mainly localized to the inner mitochondrial membrane and has been implicated in regulating mitochondrial function in yeast. Because mitochondria are emerging as an important regulator of vascular homeostasis, we examined PHB1 function in endothelial cells. PHB1 is highly expressed in the vascular system and knockdown of PHB1 in endothelial cells increases mitochondrial production of reactive oxygen species via inhibition of complex I, which results in cellular senescence. As a direct consequence, both Akt and Rac1 are hyperactivated, leading to cytoskeletal rearrangements and decreased endothelial cell motility, e.g., migration and tube formation. This is also reflected in an in vivo angiogenesis assay, where silencing of PHB1 blocks the formation of functional blood vessels. Collectively, our results provide evidence that PHB1 is important for mitochondrial function and prevents reactive oxygen species–induced senescence and thereby maintains the angiogenic capacity of endothelial cells.

scholarly journals A theoretical model of nitric oxide transport in arterioles: frequency- vs. amplitude-dependent control of cGMP formation

2004 ◽  
Vol 286 (3) ◽  
pp. H1043-H1056 ◽  
Author(s):  
Nikolaos M. Tsoukias ◽  
Mahendra Kavdia ◽  
Aleksander S. Popel
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Smooth Muscle ◽  
Soluble Guanylate Cyclase ◽  
Muscle Tone ◽  
Muscle Relaxation ◽  
Smooth Muscle Relaxation ◽  
No Production ◽  
Cgmp Formation

Nitric oxide (NO) plays many important physiological roles, including the regulation of vascular smooth muscle tone. In response to hemodynamic or agonist stimuli, endothelial cells produce NO, which can diffuse to smooth muscle where it activates soluble guanylate cyclase (sGC), leading to cGMP formation and smooth muscle relaxation. The close proximity of red blood cells suggests, however, that a significant amount of NO released will be scavenged by blood, and thus the issue of bioavailability of endothelium-derived NO to smooth muscle has been investigated experimentally and theoretically. We formulated a mathematical model for NO transport in an arteriole to test the hypothesis that transient, burst-like NO production can facilitate efficient NO delivery to smooth muscle and reduce NO scavenging by blood. The model simulations predict that 1) the endothelium can maintain a physiologically significant amount of NO in smooth muscle despite the presence of NO scavengers such as hemoglobin and myoglobin; 2) under certain conditions, transient NO release presents a more efficient way for activating sGC and it can increase cGMP formation severalfold; and 3) frequency-rather than amplitude-dependent control of cGMP formation is possible. This suggests that it is the frequency of NO bursts and perhaps the frequency of Ca2+ oscillations in endothelial cells that may limit cGMP formation and regulate vascular tone. The proposed hypothesis suggests a new functional role for Ca2+ oscillations in endothelial cells. Further experimentation is needed to test whether and under what conditions in silico predictions occur in vivo.

Regulation of Ca(2+)-dependent nitric oxide synthase in bovine aortic endothelial cells

1995 ◽  
Vol 269 (3) ◽  
pp. C757-C765 ◽  
Author(s):  
B. J. Buckley ◽  
Z. Mirza ◽  
A. R. Whorton
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
No Synthase ◽  
No Production ◽  
Intact Cells ◽  
Aortic Endothelial Cells ◽  
A 23187 ◽  
Transient Rise ◽  
Synthase Inhibitor ◽  
Sustained Increase

Vascular endothelium responds to Ca(2+)-mobilizing agonists by producing nitric oxide (NO), a potent vasodilator and inhibitor of platelet aggregation. Regulation of constitutively expressed endothelial NO synthase (eNOS) in intact cells is not well understood. We investigated the kinetics of NO formation in response to Ca(2+)-mobilizing agonists, the requirement for extracellular L-arginine, and the role of NO in regulating eNOS activity. When endothelial cells were stimulated with bradykinin and ATP in the presence of 100 microM L-arginine, we observed a rapid and transient rise in intracellular Ca2+ concentration ([Ca2+]i) from 50 +/- 8 nM to 698 +/- 74 and 637 +/- 53 nM, respectively, and a rapid and transient rise in NO production from a basal level of 37 pmol.min-1.mg protein-1 to 256 and 275 pmol.min-1.mg protein-1, respectively. When cells were stimulated with A-23187 or thapsigargin in the presence of 100 microM L-arginine, we observed a sustained increase in [Ca2+]i and a sustained increase in NO production. The rate of NO synthesis was linear over 30 min, rising above control levels of 7 pmol/min to 53 pmol/min for A-23187 and 62 pmol/min for thapsigargin. Thapsigargin stimulated NO production and [Ca2+]i with 50% effective concentration values of 0.01 and 0.05 microM, respectively. Ca(2+)-stimulated NO production was attenuated by the NO synthase inhibitor NG-monomethyl-L-arginine, the removal of extracellular L-arginine, and the Ca(2+)-chelator ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. When we exposed cells to NO gas (3.1 mM for 15 min) and S-nitrosoglutathione (10 mM for 1 h) thapsigargin-stimulated NO production was decreased by 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

VEGF upregulates ecNOS message, protein, and NO production in human endothelial cells

1998 ◽  
Vol 274 (3) ◽  
pp. H1054-H1058 ◽  
Author(s):  
John D. Hood ◽  
Cynthia J. Meininger ◽  
Marina Ziche ◽  
Harris J. Granger
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Umbilical Vein ◽  
Northern Blotting ◽  
No Production ◽  
Vascular Endothelial ◽  
Umbilical Vein Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Growth Factor ◽  
Stimulation Of

Vascular endothelial growth factor (VEGF) is an endothelium-specific secreted protein that potently stimulates vasodilation, microvascular hyperpermeability, and angiogenesis. Nitric oxide (NO) is also reported to modulate vascular tone, permeability, and capillary growth. Therefore, we hypothesized that VEGF might regulate endothelial production of NO. The production of nitrogen oxides by human umbilical vein endothelial cells (HUVECs) was measured after 1, 12, 24, and 48 h of incubation with VEGF. VEGF treatment resulted in both an acute (1 h) and chronic (>24 h) stimulation of NO production. Furthermore, Western and Northern blotting revealed a VEGF-elicited, dose-dependent increase in the cellular content of endothelial cell nitric oxide synthase (ecNOS) message and protein that may account for the chronic upregulation of NO production elicited by VEGF. Finally, endothelial cells pretreated with VEGF for 24 h and subsequently exposed to A-23187 for 1 h produced NO at approximately twice the rate of cells that were not pretreated with VEGF. We conclude that VEGF upregulates ecNOS enzyme and elicits a biphasic stimulation of endothelial NO production.

scholarly journals NADPH oxidase-derived reactive oxygen species in skeletal muscle modulates the exercise pressor reflex

2009 ◽  
Vol 107 (2) ◽  
pp. 450-459 ◽  
Author(s):  
Han-Jun Wang ◽  
Yan-Xia Pan ◽  
Wei-Zhong Wang ◽  
Irving H. Zucker ◽  
Wei Wang
Keyword(s):  
Blood Pressure ◽  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Pressor Response ◽  
Oxidase Inhibitor ◽  
Oxygen Species ◽  
Exercise Pressor Reflex ◽  
Pressor Reflex ◽  
Stimulation Of

Muscle metabolic by-products during exercise, such as K+, lactic acid, ATP, H+, and phosphate, are well established to be involved in the reflex cardiovascular response to static muscle contraction. However, the role of muscle reactive oxygen species (ROS), a metabolic by-product during muscle contraction, in the exercise pressor reflex (EPR) has not been investigated in detail. In the present study, we evaluated the role of muscle ROS in the EPR in a decerebrate rat model. We hypothesized that muscle NADPH oxidase-derived ROS contributes to sensitization of the EPR. Thus the rise in blood pressure and heart rate in response to a 30-s static contraction induced by electrical stimulation of L4/L5 ventral roots was compared before and after hindlimb arterial infusion of the redox agents: diethyldithiocarbamate, a superoxide dismutase inhibitor; the superoxide dismutase mimetic 4-hydroxy-2,2,6,6-tetramethyl piperidine 1-oxyl (tempol); the free radical scavenger dimethylthiourea; a NADPH oxidase inhibitor, apocynin; and a xanthine oxidase inhibitor, allopurinol. The EPR-induced pressor response was augmented after treatment with diethyldithiocarbamate and was attenuated after treatment with tempol, dimethylthiourea, and apocynin. Treatment with allopurinol did not affect the EPR function. None of the drug's affected the EPR heart rate response. In addition, neither the pressor response to electrical stimulation of the central end of dorsal roots, nor femoral blood flow was affected by any treatment. These data suggest that NADPH oxidase-derived muscle ROS plays an excitatory role in the EPR control of blood pressure.

Role of calcium and calmodulin in flow-induced nitric oxide production in endothelial cells

1994 ◽  
Vol 266 (3) ◽  
pp. C628-C636 ◽  
Author(s):  
M. J. Kuchan ◽  
J. A. Frangos
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
No Synthase ◽  
Rate Of Change ◽  
No Production ◽  
Rapid Production ◽  
Nos Inhibitor ◽  
Elevated Rate ◽  
Stimulation Of

These experiments demonstrate that exposure of cultured endothelial cells (EC) to well-defined laminar fluid flow results in an elevated rate of NO production. NO production was monitored by release of NOx (NO2- + NO3(2-) and by cellular guanosine 3',5'-cyclic monophosphate (cGMP) concentration. NO synthase (NOS) inhibitor blocked the flow-mediated stimulation of both NOx and cGMP, indicating that both measurements reflect NO production. Exposure to laminar flow increased NO release in a biphasic manner, with an initial rapid production consequent to the onset of flow followed by a less rapid, sustained production. A similar rapid increase in NO production resulted from an increase in flow above a preexisting level. The rapid initial production of NO was not dependent on shear stress within a physiological range (6-25 dyn/cm2) but may be dependent on the rate of change in shear stress. The sustained release of NO was dependent on physiological levels of shear stress. The calcium (Ca2+) or calmodulin (CaM) dependence of the initial and sustained production of NO was compared with bradykinin (BK)-mediated NO production. Both BK and the initial production were inhibited by Ca2+ and CaM antagonists. In contrast, the sustained shear stress-mediated NO production was not affected, despite the continued functional presence of the antagonists. Dexamethasone had no effect on either the initial or the sustained shear stress-mediated NO production. An inducible NOS does not, therefore, explain the apparent Ca2+/CaM independence of the sustained shear stress-mediated NO production.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxyhemoglobin stimulation of endothelin production in cultured endothelial cells

1992 ◽  
Vol 77 (2) ◽  
pp. 274-278 ◽  
Author(s):  
Eliot H. Ohlstein ◽  
Barbara L. Storer
Keyword(s):  
Endothelial Cells ◽  
Subarachnoid Hemorrhage ◽  
Cerebral Vasospasm ◽  
Soluble Guanylate Cyclase ◽  
Content Type ◽  
Cultured Endothelial Cells ◽  
Oxide Synthase ◽  
Median Effective Concentration ◽  
Fine Print ◽  
Stimulation Of

✓ Oxyhemoglobin and endothelin have both been linked to the development of the severe and sustained cerebral vasospasm associated with subarachnoid hemorrhage. The effects of oxyhemoglobin on endothelin biosynthesis in cultured endothelial cells were evaluated. Oxyhemoglobin (0.01 to 100 µM) produced concentration-dependent increases in immunoreactive endothelin levels in bovine pulmonary artery endothelial cell-conditioned medium. The median effective concentration for oxyhemoglobin-induced increases in immunoreactive endothelin levels was approximately 0.5 µM, and the maximum stimulation of immunoreactive endothelin levels was approximately 5.5-fold over basal conditions. In addition to directly stimulating basal production of immunoreactive endothelin, oxyhemoglobin significantly augmented immunoreactive endothelin production following platelet-mediated stimulation of endothelin production. An l-arginine analog inhibitor of nitric oxide synthase, L-NG-monomethyl arginine (L-NMMA, 200 µM), did not significantly affect basal immunoreactive endothelin levels. However, L-NMMA significantly augmented platelet-induced immunoreactive endothelin production. Methylene blue (10 µM), an inhibitor of soluble guanylate cyclase, did not significantly affect basal immunoreactive endothelin levels, nor did it significantly affect the platelet-mediated stimulation of immunoreactive endothelin production in cultured endothelial cells. The present results reveal that oxyhemoglobin can directly stimulate endothelin biosynthesis in cultured endothelial cells. This newly identified property of oxyhemoglobin suggests a potential mechanism for the sustained and severe cerebral vasospasm associated with subarachnoid hemorrhage.

Inhibition of guanylate cyclase stimulation by NO and bovine arterial relaxation to peroxynitrite and H2O2

1999 ◽  
Vol 277 (3) ◽  
pp. H978-H985 ◽  
Author(s):  
Takafumi Iesaki ◽  
Sachin A. Gupte ◽  
Pawel M. Kaminski ◽  
Michael S. Wolin
Keyword(s):  
Nitric Oxide ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Superoxide Production ◽  
No Donor ◽  
Arterial Relaxation ◽  
Stimulation Of

The inhibitor of soluble guanylate cyclase (sGC) stimulation by nitric oxide (NO), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), was examined for its effects on the prolonged relaxation of endothelium-removed bovine coronary (BCA) and pulmonary (BPA) arteries to peroxynitrite (ONOO−) and on H2O2-elicited relaxation and sGC stimulation. Our previous studies suggest that ONOO− causes a prolonged relaxation of BPA by regenerating NO and that a 2-min exposure of BCA or BPA to 50 nM NO causes an ONOO−-elicited relaxation. The relaxation of K+-precontracted BCA to 50 nM NO or 100 μM ONOO− was essentially eliminated by 10 μM ODQ. ODQ also eliminated relaxation to 0.1 nM-10 μM of NO donor S-nitroso- N-acetyl-penicillamine (SNAP), but it did not alter relaxation to 1–300 μM H2O2. Similar responses were also observed in BPA. ODQ did not increase lucigenin-detectable superoxide production in BCA, and it did not alter luminol-detectable endogenous ONOO− formation observed during a 2-min exposure of BCA to 50 nM NO. In addition, ODQ did not affect tissue release of NO after 2 min exposure of BCA to 50 nM NO. The activity of sGC in BPA homogenate that is stimulated by endogenous H2O2was not altered by ODQ, whereas sGC activity in the presence of 10 μM SNAP (+fungal catalase) was reduced by ODQ. Thus relaxation of K+-precontracted BCA and BPA to ONOO− appears to be completely mediated by NO stimulation of sGC, whereas the actions of ODQ suggest that NO is not involved in H2O2-elicited relaxation and sGC stimulation. This study did not detect evidence for the participation of additional mechanisms potentially activated by ONOO− in the responses studied.

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