scholarly journals Cognac polyphenolic compounds increase bradykinin-induced nitric oxide production in endothelial cells

2008 ◽  
pp. 885-892
Author(s):  
AS Diallo ◽  
M Sarr ◽  
HA Mostefai ◽  
N Carusio ◽  
M Pricci ◽  
...  

We recently reported that in vitro Cognac polyphenolic compounds (CPC) induce NO-dependent vasorelaxant effects and stimulate cardiac function. In the present study, we aim to investigate the effect of CPC on both nitric oxide (NO) and superoxide anions (O(2)(-)) production in cultured human endothelial cells. In addition, its effect on the bradykinin (BK)-induced NO production was also tested. The role and sources of O(2)(-) in the concomitant effect of BK plus CPC were pharmacologically determined. NO and O(2)(-) signals were measured using electron paramagnetic resonance technique using specific spin trappings. Both, CPC and BK induced an increase in NO production in human endothelial cells. The combination of both further enhanced NO release. The capacity of CPC plus BK to increase NO signal was blunted by the NO synthase inhibitor, N(G)-nitro-L-arginine methyl ester, and was enhanced in the presence either of superoxide dismutase or catalase. Moreover, CPC plus BK response was greater after inhibition of either NADPH oxidase by apocynin or xanthine oxidase by allopurinol but it was not affected by rotenone. CPC did not affect O(2)(-) level either alone or after its increase upon lipopolysaccharide treatment. Finally, the capacity of BK alone to increase NO was enhanced either by apocynin or allopurinol. Altogether, these data demonstrate that CPC is able to directly increase NO production without affecting O(2)(-) and enhances the BK-induced NO production in human endothelial cells. The data highlight the ability of BK to stimulate not only NADPH oxidase- but also xanthine oxidase-inhibitor sensitive mechanisms that reduce its efficiency in increasing NO either alone or in the presence of CPC. These results bring pharmacological evidence for vascular protection by CPC via its potentiating effect of BK response in terms of endothelial NO release.

2010 ◽  
Vol 298 (4) ◽  
pp. L564-L574 ◽  
Author(s):  
Sreedhar Bodiga ◽  
Stephanie K. Gruenloh ◽  
Ying Gao ◽  
Vijay L. Manthati ◽  
Narsimhaswamy Dubasi ◽  
...  

We have shown that 20-hydroxyeicosatetraenoic acid (20-HETE) increases both superoxide and nitric oxide (NO) production in bovine pulmonary artery endothelial cells (BPAECs). The current study was designed to determine mechanisms underlying 20-HETE-stimulated NO release, and particularly the role of NADPH oxidase, reactive oxygen species, and PI3-kinase in stimulated NO release. Intracellular hydrogen peroxide (H2O2) and NO production were detected by dichlorofluorescein or dihydrorhodamine and diaminofluorescein fluorescence, respectively. Activation of endothelial nitric oxide synthase (eNOS) (Ser1179) and Akt (Ser473) was assessed by comparing the ratio of phosphorylated to total protein expression by Western blotting. Addition of 20-HETE to BPAECs caused an increase in superoxide and hydrogen peroxide, but not peroxynitrite. 20-HETE-evoked activation of Akt and eNOS, as well as enhanced NO release, are dependent on H2O2 as opposed to superoxide in that these endpoints are blocked by PEG-catalase and not PEG-superoxide dismutase. Similarly, 20-HETE-stimulated NO production in BPAECs is blocked by NADPH oxidase inhibitors apocynin or gp91 blocking peptide, and by PI3-kinase/Akt blockers wortmannin, LY-294002, or Akt inhibitor, implicating NADPH oxidase, PI3-kinase, and Akt signaling pathways, respectively, in this process. Together, these data suggest the following scheme: 20-HETE stimulates NADPH oxidase-dependent formation of superoxide. Superoxide is rapidly dismutated to hydrogen peroxide, which then mediates activation of PI3-kinase/Akt, phosphorylation of eNOS, and enhanced release of NO from eNOS in response to 20-HETE in BPAECs.


1998 ◽  
Vol 330 (2) ◽  
pp. 695-699 ◽  
Author(s):  
Frédérique LANTOINE ◽  
Lahcen IOUZALEN ◽  
Marie-Aude DEVYNCK ◽  
Elisabeth MILLANVOYE-van BRUSSEL ◽  
Monique DAVID-DUFILHO

The causal relationships between cytosolic free-Ca2+ concentration ([Ca2+]i) increases and production of nitric oxide (NO) have been investigated mostly with indirect methods and remain unclear. Here we demonstrate, by direct real-time measurements of [NO] with a porphyrinic microsensor, that Ca2+ entry, but not an increase in [Ca2+]i, is required for triggering of NO production in human endothelial cells. Histamine, ranging from 0.1 to 100 μM, increased both NO production and [Ca2+]i when given in a single dose. However, histamine caused increased NO release but induced progressively smaller [Ca2+]i changes when cumulatively added. In the absence of a transmembrane Ca2+ gradient, no significant NO release was detectable, despite the marked Ca2+ peak induced by histamine. Inhibition of Ca2+ entry by SK&F 96365 abolished histamine-elicited NO production but only reduced the transient [Ca2+]i rise. The suppression of the sustained [Ca2+]i response under these two conditions suggests that NO release was closely associated with Ca2+ entry from the extracellular space. In addition, membrane depolarization, achieved by increasing the extracellular K+ concentration from 5 to 130 mM, reduced both the amplitude of histamine-induced sustained [Ca2+]i elevation and NO production. These results lead us to propose that the availability of numerous Ca2+ ions around the internal side of the plasma membrane would promote the association between nitric oxide synthase and calmodulin, thereby activating the enzyme.


2006 ◽  
Vol 45 (3) ◽  
pp. e78
Author(s):  
Fan Jiang ◽  
Sarah J. Roberts ◽  
Srinivasa Raju Datla ◽  
Gregory J. Dusting

2003 ◽  
Vol 285 (2) ◽  
pp. H507-H515 ◽  
Author(s):  
G. P. Nase ◽  
J. Tuttle ◽  
H. G. Bohlen

Many studies have suggested that endothelial cells can act as “oxygen sensors” to large reductions in oxygen availability by increasing nitric oxide (NO) production. This study determined whether small reductions in oxygen availability enhanced NO production from in vivo intestinal arterioles, venules, and parenchymal cells. In vivo measurements of perivascular NO concentration ([NO]) were made with NO-sensitive microelectrodes during normoxic and reduced oxygen availability. During normoxia, intestinal first-order arteriolar [NO] was 397 ± 26 nM ( n = 5), paired venular [NO] was 298 ± 34 nM ( n = 5), and parenchymal cell [NO] was 138 ± 36 nM ( n = 3). During reduced oxygen availability, arteriolar and venular [NO] significantly increased to 695 ± 79 nM ( n = 5) and 534 ± 66 nM ( n = 5), respectively, whereas parenchymal [NO] remained unchanged at 144 ± 34 nM ( n = 4). During reduced oxygenation, arteriolar and venular diameters increased by 15 ± 3% and 14 ± 5%, respectively: NG-nitro-l-arginine methyl ester strongly suppressed the dilation to lower periarteriolar Po2. Micropipette injection of a CO2 embolus into arterioles significantly attenuated arteriolar dilation and suppressed NO release in response to reduced oxygen availability. These results indicated that in rat intestine, reduced oxygen availability increased both arteriolar and venular NO and that the main site of NO release under these conditions was from endothelial cells.


2001 ◽  
Vol 170 (2) ◽  
pp. 433-440 ◽  
Author(s):  
L Kalinowski ◽  
LW Dobrucki ◽  
T Malinski

Parathyroid hormone (PTH)-related protein (PTHrP) is produced in smooth muscles and endothelial cells and is believed to participate in the local regulation of vascular tone. No direct evidence for the activation of endothelium-derived nitric oxide (NO) signaling pathway by PTHrP has been found despite attempts to identify it. Based on direct in situ measurements, it is reported here for the first time that the human PTH/PTHrP receptor analogs, hPTH(1--34) and hPTHrP(1--34), stimulate NO release from a single endothelial cell. A highly sensitive porphyrinic microsensor with a response time of 0.1 ms and a detection limit of 1 nmol/l was used for the measurement of NO. Both hPTH(1--34) and hPTHrP(1--34) stimulated NO release at nanomolar concentrations. The peak concentration of 0.1 micromol/l hPTH(1--34)- and 0.1 micromol/l hPTHrP(1--34)-stimulated NO release was 175+/-9 and 248+/-13 nmol/l respectively. This represents about 30%--40% of maximum NO concentration recorded in the presence of (0.1 micromol/l) calcium ionophore. Two competitive PTH/PTHrP receptor antagonists, 10 micromol/l [Leu(11),d -Trp(12)]-hPTHrP(7--34)amide and 10 micromol/l [Nle(8,18),Tyr(34)]-bPTH(3--34)amide, were equipotent in antagonizing hPTH(1--34)-stimulated NO release; [Leu(11),d -Trp(12)]-hPTHrP(7--34)amide was more potent than [Nle(8,18),Tyr(34)]-bPTH(3--34)amide in inhibiting hPTHrP(1--34)-stimulated NO release. The PKC inhibitor, H-7 (50 micromol/l), did not change hPTH(1--34)- and hPTHrP(1--34)-stimulated NO release, whereas the combined effect of 10 micromol/l of the cAMP antagonist, Rp-cAMPS, and 50 micromol/l of the calmodulin inhibitor, W-7, was additive. The present studies show that both hPTH(1--34) and hPTHrP(1--34) activate NO production in endothelial cells. The activation of NO release is through PTH/PTHrP receptors and is mediated via the calcium/calmodulin pathway.


2000 ◽  
Vol 381 (7) ◽  
pp. 575-582 ◽  
Author(s):  
Petra Meineke ◽  
Ursula Rauen ◽  
Herbert de Groot ◽  
Hans-Gert Korth ◽  
Reiner Sustmann

Abstract Fluorescent Nitric Oxide Cheletropic Traps (FNOCTs) were applied to specifically trap nitric oxide (NO) with high sensitivity. The fluorescent oquinoid ?electron system of the FNOCTs (? = 460 nm, ? = 600 nm) reacts rapidly with NO to a fluorescent phenanthrene system (? = 380 nm, ? = 460 nm). The cyclic nitroxides thus formed react further to nonradical products which exhibit identical fluorescence properties. Using the acid form of the trap (FNOCT-4), NO release by spermine NONOate and by lipopolysaccharide (LPS) activated alveolar macrophages were studied. A maximum extracellular release of NO of 37.5 nmol h[-1] (10[6] cells)[-1] from the macrophages was determined at 11 h after activation. Furthermore, intracellular NO release by LPSactivated macrophages and by microvascular omentum endothelial cells stimulated by the Ca[2+] ionophore A-23187, respectively, was monitored on the single cell level by means of fluorescence microscopy. After loading the cells with the membranepermeating acetoxymethylester derivative FNOCT-5,which is hydrolyzed to a nonpermeating dicarboxylate by intracellular hydrolases, NO formation by the endothelial cells started immediately upon stimulation, whereas start of NO production by the macrophages was delayed with a variation between 4 and 8 h for individual cells. These results demonstrate that the FNOCTs can be used to monitor NO release from single cells, as well as from NOdonating compounds, with high sensitivity and with temporal and spatial resolution.


2006 ◽  
Vol 174 (3) ◽  
pp. 369-377 ◽  
Author(s):  
Carlos Fernández-Hernando ◽  
Masaki Fukata ◽  
Pascal N. Bernatchez ◽  
Yuko Fukata ◽  
Michelle I. Lin ◽  
...  

Lipid modifications mediate the subcellular localization and biological activity of many proteins, including endothelial nitric oxide synthase (eNOS). This enzyme resides on the cytoplasmic aspect of the Golgi apparatus and in caveolae and is dually acylated by both N-myristoylation and S-palmitoylation. Palmitoylation-deficient mutants of eNOS release less nitric oxide (NO). We identify enzymes that palmitoylate eNOS in vivo. Transfection of human embryonic kidney 293 cells with the complementary DNA (cDNA) for eNOS and 23 cDNA clones encoding the Asp-His-His-Cys motif (DHHC) palmitoyl transferase family members showed that five clones (2, 3, 7, 8, and 21) enhanced incorporation of [3H]-palmitate into eNOS. Human endothelial cells express all five of these enzymes, which colocalize with eNOS in the Golgi and plasma membrane and interact with eNOS. Importantly, inhibition of DHHC-21 palmitoyl transferase, but not DHHC-3, in human endothelial cells reduces eNOS palmitoylation, eNOS targeting, and stimulated NO production. Collectively, our data describe five new Golgi-targeted DHHC enzymes in human endothelial cells and suggest a regulatory role of DHHC-21 in governing eNOS localization and function.


Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
R. Preston Mason ◽  
Robert F Jacob ◽  
Tadeusz Malinski

Introduction: Nebivolol is a β1-adrenergic receptor antagonist that stimulates endothelial nitric oxide (NO) release through β3-adrenergic receptor activation, ATP-mediated stimulation of purinergic P2Y receptors, and inhibition of membrane lipid oxidation. Valsartan is an angiotensin II receptor blocker (ARB) that selectively inhibits angiotensin II type 1 (AT1) receptors, thereby exerting no direct effect at type 2 (AT2) receptors, which have been shown to stimulate NO synthase activity through a bradykinin-mediated pathway. As NO is a key regulator of blood pressure and these two antihypertensive agents promote NO release through distinct mechanisms, we compared their individual and combined effects on NO release from human endothelial cells. Methods: Human umbilical vein endothelial cells (HUVECs) were incubated for 1 hr with vehicle, nebivolol or valsartan alone (each at 1.0 μM), or nebivolol (1.0 μM) and valsartan (0.5-5.0 μM) combined. The comparative effects of these agents on maximal NO release were measured in individual cells using porphyrinic nanosensors following stimulation with calcium ionophore (1.0 μM). Results: Nebivolol treatment increased HUVEC NO release by 49% (509 ± 18 nM, mean ± SD) as compared to vehicle treatment alone (342 ± 26 nM; p<0.001). Valsartan had a more modest effect, increasing NO release by 13% (385 ± 19 nM) as compared to vehicle-treated controls (p<0.01). Treatment with both agents at 1.0 μM increased HUVEC NO release by 91% (655 ± 19 nM) as compared to vehicle alone (p<0.001) and was 29% (p<0.001) and 70% (p<0.001) greater than the separate effects observed for nebivolol and valsartan, respectively. The additive effect of valsartan was dose-dependent and was also observed at 0.5 and 5.0 μM in combination with nebivolol. Conclusions: These data suggest that nebivolol and valsartan, when applied in combination, increase the ability of endothelial cells to release NO in a synergistic manner. The exact mechanism of this process remains unclear but, considering the importance of NO in regulating blood pressure, merits further study.


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