Sodium channels are required during in vivo sodium chloride hyperosmolarity to stimulate increase in intestinal endothelial nitric oxide production

2005 ◽  
Vol 288 (1) ◽  
pp. H89-H95 ◽  
Author(s):  
Brett G. Zani ◽  
H. Glenn Bohlen
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Blood Flow ◽  
Intestinal Blood Flow ◽  
No Production ◽  
Sodium Ions ◽  
Major Mechanism ◽  
Before And After ◽  
Endothelial Nitric Oxide

NaCl hyperosmolarity increases intestinal blood flow during food absorption due in large part to increased NO production. We hypothesized that in vivo, sodium ions enter endothelial cells during NaCl hyperosmolarity as the first step to stimulate an increase in intestinal endothelial NO production. Perivascular NO concentration ([NO]) and blood flow were determined in the in vivo rat intestinal microvasculature at rest and under hyperosmotic conditions, 330 and 380 mosM, respectively, before and after application of bumetanide (Na+-K+-2Cl− cotransporter inhibitor) or amiloride (Na+/H+ exchange channel inhibitor). Suppressing amiloride-sensitive Na+/H+ exchange channels diminished hypertonicity-linked increases in vascular [NO], whereas blockade of Na+-K+-2Cl− channels greatly suppressed increases in vascular [NO] and intestinal blood flow. In additional experiments we examined the effect of sodium ion entry into endothelial cells. We proposed that the Na+/Ca2+ exchanger extrudes Na+ in exchange for Ca2+, thereby leading to the calcium-dependent activation of endothelial nitric oxide synthase (eNOS). We blocked the activity of the Na+/Ca2+ exchanger during 360 mosM NaCl hyperosmolarity with KB-R7943; complete blockade of increased vascular [NO] and intestinal blood flow to hyperosmolarity occurred. These results indicate that during NaCl hyperosmolarity, sodium ions enter endothelial cells predominantly through Na+-K+-2Cl− channels. The Na+/Ca2+ exchanger then extrudes Na+ and increases endothelial Ca2+. The increase in endothelial Ca2+ causes an increase in eNOS activity, and the resultant increase in NO increases intestinal arteriolar diameter and blood flow during NaCl hyperosmolarity. This appears to be the major mechanism by which intestinal nutrient absorption is coupled to increased blood flow.

scholarly journals Identification of Golgi-localized acyl transferases that palmitoylate and regulate endothelial nitric oxide synthase

2006 ◽  
Vol 174 (3) ◽  
pp. 369-377 ◽  
Author(s):  
Carlos Fernández-Hernando ◽  
Masaki Fukata ◽  
Pascal N. Bernatchez ◽  
Yuko Fukata ◽  
Michelle I. Lin ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Cdna Clones ◽  
No Production ◽  
Human Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

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.

scholarly journals Transport of extracellular l-arginine via cationic amino acid transporter is required during in vivo endothelial nitric oxide production

2005 ◽  
Vol 289 (4) ◽  
pp. H1381-H1390 ◽  
Author(s):  
Brett G. Zani ◽  
H. Glenn Bohlen
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Blood Flow ◽  
Amino Acid ◽  
Amino Acid Transporter ◽  
Cationic Amino Acid Transporter ◽  
Cationic Amino Acid ◽  
Arginine Transport ◽  
Endothelial Nitric Oxide

In cultured endothelial cells, 70–95% of extracellular l-arginine uptake has been attributed to the cationic amino acid transporter-1 protein (CAT-1). We tested the hypothesis that extracellular l-arginine entry into endothelial cells via CAT-1 plays a crucial role in endothelial nitric oxide (NO) production during in vivo conditions. Using l-lysine, the preferred amino acid transported by CAT-1, we competitively inhibited extracellular l-arginine transport into endothelial cells during conditions of NaCl hyperosmolarity, low oxygen, and flow increase. Our prior studies indicate that each of these perturbations causes NO-dependent vasodilation. The perivascular NO concentration ([NO]) and blood flow were determined in the in vivo rat intestinal microvasculature. Suppression of extracellular l-arginine transport significantly and strongly inhibited increases in vascular [NO] and intestinal blood flow during NaCl hyperosmolarity, lowered oxygen tension, and increased flow. These results suggest that l-arginine from the extracellular space is accumulated by CAT-1. When CAT-1-mediated transport of extracellular l-arginine into endothelial cells was suppressed, the endothelial cell NO response to a wide range of physiological stimuli was strongly depressed.

scholarly journals The Effects of Bathing in Neutral Bicarbonate Ion Water

2021 ◽  
Author(s):  
Ichiro Saito ◽  
Tomoe Yamazaki ◽  
Ryoko Nakayama-Ushikoshi ◽  
Syakya Supriya ◽  
Daisuke Omagari ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Blood Flow ◽  
Umbilical Vein ◽  
Randomized Study ◽  
No Production ◽  
Double Blind ◽  
Bicarbonate Ions ◽  
Umbilical Vein Endothelial Cells ◽  
Endothelial Nitric Oxide

Abstract Percutaneously absorbed carbon dioxide enhances blood flow. The mechanism by which it does so is unclear, we hypothesized that it involves bicarbonate ions. Balb/c mice were bathed in neutral bicarbonate ionized water (NBIW) and showed increased blood bicarbonate levels and blood flow via phosphorylation of peripheral vascular endothelial nitric oxide synthase (eNOS) and production of nitric oxide (NO). Phosphorylation of eNOS and NO production were also increased in human umbilical vein endothelial cells cultured in medium containing NBIW, and NBIW showed reactive oxygen species scavenging activity. In a double-blind, randomized study in men and women aged 30 to 59 years with subjective cold intolerance, bathing in NBIW elevated body temperature faster than bathing in a control solution and improved chills and sleep quality. Taken together, our results show that percutaneously absorbed bicarbonate ions act directly on endothelial cells, phosphorylation of eNOS increases NO production and thus improves blood flow.

scholarly journals Nitric oxide formation by lymphatic bulb and valves is a major regulatory component of lymphatic pumping

2011 ◽  
Vol 301 (5) ◽  
pp. H1897-H1906 ◽  
Author(s):  
H. Glenn Bohlen ◽  
Olga Yu. Gasheva ◽  
David C. Zawieja
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Stroke Volume ◽  
No Production ◽  
Dependent Manner ◽  
Nitric Oxide Formation ◽  
Valve Housing ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Microscopic lymphatics produce nitric oxide (NO) during contraction as flow shear activates the endothelial cells. The valve leaflets and bulbous valve housing contain a large amount of endothelial nitric oxide synthase (eNOS) due both to many endothelial cells and increased expression of eNOS. Direct NO measurements indicate the valve area has a 30–50% higher NO concentration ([NO]) than tubular regions although both regions generate equivalent relative increases in [NO] with each contraction. We hypothesize that 1) the greater eNOS and [NO] of the bulb region would have greater effects to lower pumping activity of the overall lymphatic than occurs in tubular regions and 2), the elevated [NO] in the bulb region may be because of high NO production in the valve leaflets that diffuses to the wall of the bulb. Measurement of [NO] with a micropipette inside the lymphatic bulb revealed the valve leaflets generate ∼50% larger [NO] than the bulb wall in the in vivo rat mesenteric lymphatics. The valves add NO to the lymph that quickly diffuses to the bulb wall. Bradykinin locally released iontophoretically from a micropipette on both bulbs and tubes increased the [NO] in a dose-dependent manner up to ∼50%, demonstrating agonist activation of the NO pathway. However, pumping output determined by contraction frequency and stroke volume decreased much more for the bulb than tubular areas in response to the bradykinin. In effect, NO generation by the bulb area and its valves limits the pumped flow of the total lymphatic by lowering frequency and stroke volume of individual contractions.

Effects of homocysteine on endothelial nitric oxide production

2000 ◽  
Vol 279 (4) ◽  
pp. F671-F678 ◽  
Author(s):  
Xiaohui Zhang ◽  
Hong Li ◽  
Haoli Jin ◽  
Zachary Ebin ◽  
Sergey Brodsky ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Redox State ◽  
Calcium Ionophore ◽  
No Production ◽  
Cellular Redox ◽  
A Cell ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Peroxynitrite Scavengers

Hyperhomocysteinemia (HHCy) is an independent and graded cardiovascular risk factor. HHCy is prevalent in patients with chronic renal failure, contributing to the increased mortality rate. Controversy exists as to the effects of HHCy on nitric oxide (NO) production: it has been shown that HHCy both increases and suppresses it. We addressed this problem by using amperometric electrochemical NO detection with a porphyrinic microelectrode to study responses of endothelial cells incubated with homocysteine (Hcy) to the stimulation with bradykinin, calcium ionophore, or l-arginine. Twenty-four-hour preincubation with Hcy (10, 20, and 50 μM) resulted in a gradual decline in responsiveness of endothelial cells to the above stimuli. Hcy did not affect the expression of endothelial nitric oxide synthase (eNOS), but it stimulated formation of superoxide anions, as judged by fluorescence of dichlorofluorescein, and peroxynitrite, as detected by using immunoprecipitation and immunoblotting of proteins modified by tyrosine nitration. Hcy did not directly affect the ability of recombinant eNOS to generate NO, but oxidation of sulfhydryl groups in eNOS reduced its NO-generating activity. Addition of 5-methyltetrahydrofolate restored NO responses to all agonists tested but affected neither the expression of the enzyme nor formation of nitrotyrosine-modified proteins. In addition, a scavenger of peroxynitrite or a cell-permeant superoxide dismutase mimetic reversed the Hcy-induced suppression of NO production by endothelial cells. In conclusion, electrochemical detection of NO release from cultured endothelial cells demonstrated that concentrations of Hcy >20 μM produce a significant indirect suppression of eNOS activity without any discernible effects on its expression. Folates, superoxide ions, and peroxynitrite scavengers restore the NO-generating activity to eNOS, collectively suggesting that cellular redox state plays an important role in HCy-suppressed NO-generating function of this enzyme.

scholarly journals Cilostazol Induces eNOS and TM Expression via Activation with Sirtuin 1/Krüppel-like Factor 2 Pathway in Endothelial Cells

2021 ◽  
Vol 22 (19) ◽  
pp. 10287
Author(s):  
Chih-Hsien Wu ◽  
Yi-Lin Chiu ◽  
Chung-Yueh Hsieh ◽  
Guo-Shiang Tsung ◽  
Lian-Shan Wu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Nitric Oxide Synthase ◽  
Umbilical Vein ◽  
Sirtuin 1 ◽  
No Production ◽  
Beneficial Effects ◽  
Umbilical Vein Endothelial Cells ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Cilostazol was suggested to be beneficial to retard in-stent atherosclerosis and prevent stent thrombosis. However, the mechanisms responsible for the beneficial effects of cilostazol are not fully understood. In this study, we attempted to verify the mechanism of the antithrombotic effect of cilostazol. Human umbilical vein endothelial cells (HUVECs) were cultured with various concentrations of cilostazol to verify its impact on endothelial cells. KLF2, silent information regulator transcript-1 (SIRT1), endothelial nitric oxide synthase (eNOS), and endothelial thrombomodulin (TM) expression levels were examined. We found cilostazol significantly activated KLF2 expression and KLF2-related endothelial function, including eNOS activation, Nitric oxide (NO) production, and TM secretion. The activation was regulated by SIRT1, which was also stimulated by cilostazol. These findings suggest that cilostazol may be capable of an antithrombotic and vasculoprotective effect in 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.

scholarly journals Nitric oxide production duringVibrio choleraeinfection

1997 ◽  
Vol 273 (5) ◽  
pp. G1160-G1167 ◽  
Author(s):  
Edward N. Janoff ◽  
Hiroshi Hayakawa ◽  
David N. Taylor ◽  
Claudine E. Fasching ◽  
Julie R. Kenner ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Epithelial Cells ◽  
Regional Blood Flow ◽  
Fluid Secretion ◽  
The United States ◽  
No Production ◽  
Loop Model ◽  
Ileal Loop

Vibrio cholerae induces massive intestinal fluid secretion that continues for the life of the stimulated epithelial cells. Enhanced regional blood flow and peristalsis are required to adapt to this obligatory intestinal secretory challenge. Nitric oxide (NO) is a multifunctional molecule that modulates blood flow and peristalsis and possesses both cytotoxic and antibacterial activity. We demonstrate that, compared with those in asymptomatic control subjects, levels of stable NO metabolites ([Formula: see text]/[Formula: see text]) are significantly increased in sera from acutely ill Peruvian patients with natural cholera infection as well as from symptomatic volunteers from the United States infected experimentally with V. cholerae. In a rabbit ileal loop model in vivo, cholera toxin (CT) elicited fluid secretion and dose-dependent increases in levels of[Formula: see text]/[Formula: see text]in the fluid ( P < 0.01). In contrast, lipopolysaccharide (LPS) elicited no such effects when applied to the intact mucosa. NO synthase (NOS) catalytic activity also increased in toxin-exposed tissues ( P< 0.05), predominantly in epithelial cells. The CT-induced NOS activity was Ca2+dependent and was not suppressed by dexamethasone. In conclusion, symptomatic V. cholerae infection induces NO production in humans. In the related animal model, CT, but not LPS, stimulated significant production of NO in association with increases in local Ca2+-dependent NOS activity in the tissues.

scholarly journals (−)-Epicatechin induces calcium and translocation independent eNOS activation in arterial endothelial cells

2011 ◽  
Vol 300 (4) ◽  
pp. C880-C887 ◽  
Author(s):  
Israel Ramirez-Sanchez ◽  
Lisandro Maya ◽  
Guillermo Ceballos ◽  
Francisco Villarreal
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Cardiovascular Effects ◽  
Mesenteric Arteries ◽  
No Production ◽  
Human Coronary Artery ◽  
Calmodulin Binding ◽  
Pathway Activation ◽  
Functional Relevance ◽  
Endothelial Nitric Oxide

The consumption of cacao-derived (i.e., cocoa) products provides beneficial cardiovascular effects in healthy subjects as well as individuals with endothelial dysfunction such as smokers, diabetics, and postmenopausal women. The vascular actions of cocoa are related to enhanced nitric oxide (NO) production. These actions can be reproduced by the administration of the cacao flavanol (−)-epicatechin (EPI). To further understand the mechanisms behind the vascular action of EPI, we investigated the effects of Ca2+ depletion on endothelial nitric oxide (NO) synthase (eNOS) activation/phosphorylation and translocation. Human coronary artery endothelial cells were treated with EPI or with bradykinin (BK), a well-known Ca2+-dependent eNOS activator. Results demonstrate that both EPI and BK induce increases in intracellular calcium and NO levels. However, under Ca2+-free conditions, EPI (but not BK) is still capable of inducing NO production through eNOS phosphorylation at serine 615, 633, and 1177. Interestingly, EPI-induced translocation of eNOS from the plasmalemma was abolished upon Ca2+ depletion. Thus, under Ca2+-free conditions, EPI can stimulate NO synthesis independent of calmodulin binding to eNOS and of its translocation into the cytoplasm. We also examined the effect of EPI on the NO/cGMP/vasodilator-stimulated phosphoprotein (VASP) pathway activation in isolated Ca2+-deprived canine mesenteric arteries. Results demonstrate that under these conditions, EPI induces the activation of this vasorelaxation-related pathway and that this effect is inhibited by pretreatment with nitro-l-arginine methyl ester, suggesting a functional relevance for this phenomenon.

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.

Sign in / Sign up

Export Citation Format

Share Document