Increased endothelin-1 and endothelin receptor expression in myocytes of ischemic and reperfused rat hearts and ventricular myocytes exposed to ischemic conditions and its inhibition by nitric oxide generation

2003 ◽  
Vol 81 (2) ◽  
pp. 105-113 ◽  
Author(s):  
Xiaohong Tracey Gan ◽  
Subrata Chakrabarti ◽  
Morris Karmazyn
Keyword(s):  
Nitric Oxide ◽  
Mrna Expression ◽  
Ventricular Myocytes ◽  
Receptor Expression ◽  
Neonatal Rat ◽  
No Donor ◽  
Myocardial Ischemia And Reperfusion ◽  
Endothelin 1 ◽  
Hypoxic Conditions ◽  
Rat Hearts

Endothelin-1 (ET-1) and nitric oxide (NO) exert opposite effects in the cardiovascular system, and there is evidence that the NO counters the potential deleterious effects of ET-1. We investigated whether NO affects the increased mRNA expression of ET-1 and endothelin receptors induced by (i) 30 min of ischemia with or without 30 min reperfusion in myocytes from isolated rat hearts or (ii) ischemic conditions (acidosis or hypoxia) in cultured rat neonatal ventricular myocytes. Ischemia with or without reperfusion produced more than a twofold increase in mRNA expression of ET-1 as well as the ETAand ETBreceptor (P < 0.05), although these effects were completely blocked by the NO donor 3-morpholinosydnonimine (SIN-1; 1 μM). To assess the possible factors regulating ET expression, myocytes were exposed to acidosis (pH 6.8–6.2) or to hypoxic conditions in an anaerobic chamber for 24 h in the presence or absence of SIN-1. At all acidic pHs, ET-1 and ETAreceptor mRNA expression was significantly (P < 0.05) elevated approximately threefold, although the magnitude of elevation was independent of the degree of acidosis. These effects were completely prevented by SIN-1. ETBreceptor expression was unaffected by acidosis. Hypoxia increased ET-1 as well as ETAand ETBreceptor expression threefold (P < 0.05), although this was unaffected by SIN-1. Our results demonstrate that myocardial ischemia and reperfusion upregulate the ET system, which is inhibited by NO. Although increased expression of the ET system can be mimicked by both acidosis and hypoxia, only the effects of the former are NO sensitive. NO may serve an endogenous inhibitory factor which regulates the expression of the ET system under pathological conditions.Key words: ET-1, ET receptors, NO, neonatal rat ventricular myocytes, hypoxia, acidosis.

scholarly journals Nitric oxide-induced cardioprotection in cultured rat ventricular myocytes

2000 ◽  
Vol 278 (4) ◽  
pp. H1211-H1217 ◽  
Author(s):  
Roby D. Rakhit ◽  
Richard J. Edwards ◽  
James W. Mockridge ◽  
Anwar R. Baydoun ◽  
Amanda W. Wyatt ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ventricular Myocytes ◽  
Culture Conditions ◽  
Neonatal Rat ◽  
No Donor ◽  
Rat Ventricular Myocytes ◽  
Kinase C ◽  
Neonatal Rat Ventricular Myocytes ◽  
Oxide Synthase

The aim of this study was to investigate the role of nitric oxide (NO) in a cellular model of early preconditioning (PC) in cultured neonatal rat ventricular myocytes. Cardiomyocytes “preconditioned” with 90 min of stimulated ischemia (SI) followed by 30 min reoxygenation in normal culture conditions were protected against subsequent 6 h of SI. PC was blocked by N G-monomethyl-l-arginine monoacetate but not by dexamethasone pretreatment. Inducible nitric oxide synthase (NOS) protein expression was not detected during PC ischemia. Pretreatment (90 min) with the NO donor S-nitroso- N-acetyl-l,l-penicillamine (SNAP) mimicked PC, resulting in significant protection. SNAP-triggered protection was completely abolished by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) but was unaffected by chelerythrine or the presence of glibenclamide and 5-hydroxydecanoate. With the use of RIA, SNAP treatment increased cGMP levels, which were blocked by ODQ. Hence, NO is implicated as a trigger in this model of early PC via activation of a constitutive NOS isoform. After exposure to SNAP, the mechanism of cardioprotection is cGMP dependent but independent of protein kinase C or ATP-sensitive K+ channels. This differs from the proposed mechanism of NO-induced cardioprotection in late PC.

Role of N-acetyl-N-nitroso-tryptophan as nitric oxide donor in the modulation of HIF-1-dependent signaling

2010 ◽  
Vol 391 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Utta Berchner-Pfannschmidt ◽  
Suzan Tug ◽  
Jun Hu ◽  
Buena Delos Reyes ◽  
Joachim Fandrey ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mrna Expression ◽  
Animal Studies ◽  
Hypoxia Inducible Factor ◽  
Nitric Oxide Donor ◽  
Strong Increase ◽  
No Donor ◽  
No Donors ◽  
Hypoxic Conditions

Abstract N-Acetyl-N-nitroso-tryptophan (NANT) is well known for its capacity to generate nitric oxide (NO)-releasing compounds. It is unknown, however, whether NANT can be successfully applied as a precursor of NO in a complex biological environment such as a cell culture system. NO donors can be useful to induce the transcription factor hypoxia-inducible factor 1 (HIF-1) that coordinates the protection of cells and tissues from the lack of oxygen, termed hypoxia. HIF-1 degradation is controlled by prolyl hydroxylase 2 (PHD2) which needs to be inhibited for HIF-1 accumulation. Here, the effects of NANT in inhibiting recombinant PHD2 and up-regulating of HIF-1 and HIF-1-mediated carboanhydrase-9 (CA9) mRNA expression were compared in living cells with the NO donors N-nitrosomelatonin (NOMela) and S-nitrosoglutathione (GSNO) under normoxic and hypoxic conditions. In contrast to GSNO, NANT was similar to NOMela being highly effective in inhibiting recombinant PHD2. NANT-mediated activation of HIF-1 in oxygenated cells was comparable to hypoxic activation of HIF-1 in all cases. In contrast, under hypoxia NANT was able to boost hypoxic cellular HIF-1 levels by further reducing the activity of cellular PHD2. The strong increase of HIF-dependent CA9 mRNA expression demonstrated that NANT-induced HIF-1 was transcriptionally active. Finally, the efficacy of NANT to increase both HIF-1 and CA9 mRNA did not depend on the absolute conformation of the tryptophan moiety. In conclusion, NANT appears to be an excellent NO donor for cells in culture and l-NANT should be useful for in vivo animal studies.

Nitric oxide inhibits endothelin-1 production through the suppression of nuclear factor κB

2002 ◽  
Vol 103 (s2002) ◽  
pp. 68S-71S ◽  
Author(s):  
Mamoru OHKITA ◽  
Masanori TAKAOKA ◽  
Yasuko SHIOTA ◽  
Rumi NOJIRI ◽  
Yasuo MATSUMURA
Keyword(s):  
Nitric Oxide ◽  
Mrna Expression ◽  
Vascular Endothelial Cells ◽  
Nuclear Factor Κb ◽  
Inhibitory Effect ◽  
Nuclear Factor ◽  
Ischaemia Reperfusion Injury ◽  
No Donor ◽  
Endothelin 1 ◽  
Tnf Α

We have reported previously that the nitric oxide (NO) donor FK409 {(±)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexanamide} improved renal dysfunction as well as renal lesions in rats with ischaemia/reperfusion injury. We also found that FK409 substantially reduced endothelin-1 (ET-1) production in cultured vascular endothelial cells (ECs). Nuclear factor κB (NF-κB) is known to play a key role in the development of ischaemic disorders through regulation of the expression of a variety of genes. In the present study, we examined the effects of FK409 on ET-1 production in cultured pig aortic ECs, and the possible involvement of NF-κB in the inhibitory effect of NO on ET-1 production. FK409 significantly attenuated basal and tumour necrosis factor-α (TNF-α)-induced preproET-1 mRNA expression in ECs. In addition, FK409 diminished basal and TNF-α-stimulated NF-κB activation in ECs. Pretreatment with N-benzyloxycarbonyl-Ile-Glu(O-t-Bu)-Ala-leucinal or BAY 11-7082, both of which are suppressors of NF-κB activation, effectively attenuated basal and TNF-α-induced ET-1 mRNA expression. These findings suggest that the suppression of NF-κB activation is at least partly involved in the FK409-induced inhibition of ET-1 production in ECs. We propose that NF-κB activation plays an important role in ET-1 production.

Nitric oxide decreases endothelin-1 secretion through the activation of soluble guanylate cyclase

2004 ◽  
Vol 286 (5) ◽  
pp. L984-L991 ◽  
Author(s):  
Lisa K. Kelly ◽  
Stephen Wedgwood ◽  
Robin H. Steinhorn ◽  
Stephen M. Black
Keyword(s):  
Nitric Oxide ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Primary Cultures ◽  
No Donor ◽  
Endothelin 1 ◽  
Cgmp Analog ◽  
Pulmonary Arterial ◽  
Long Acting ◽  
Arterial Endothelial Cells

The use of exogenous nitric oxide (NO) has been shown to alter the regulation of other endothelially derived mediators of vascular tone, such as endothelin-1 (ET-1). However, the interaction between NO and ET-1 appears to be complex and remains incompletely understood. One of the major actions of NO is the activation of soluble guanylate cyclase (sGC) with the subsequent generation of cGMP. Therefore, we undertook this study to test the hypothesis that NO regulates ET-1 production via the activation of the sGC/cGMP pathway. The results obtained indicated that the exposure of primary cultures of 4-wk-old ovine pulmonary arterial endothelial cells (4-wk PAECs) to the long-acting NO donor DETA NONOate induced both a dose- and time-dependent decrease in secreted ET-1. This decrease in ET-1 secretion occurred in the absence of changes in endothelin-converting enzyme-1 or sGC expression but in conjunction with a decrease in prepro-ET-1 mRNA. The changes in ET-1 release were inversely proportional to the cellular cGMP content. Furthermore, the NO-independent activator of sGC, YC-1, or treatment with a cGMP analog also produced significant decreases in ET-1 secretion. Conversely, pretreatment with the sGC inhibitor ODQ blocked the NO-induced decrease in ET-1. Therefore, we conclude that exposure of 4-wk PAECs to exogenous NO decreases secreted ET-1 resulting from the activation of sGC and increased cGMP generation.

Cyclic stretch and endothelin-1 mediated activation of chloride channels in cultured neonatal rat ventricular myocytes

2002 ◽  
Vol 103 (s2002) ◽  
pp. 148S-151S ◽  
Author(s):  
Henriëtte W. DE JONGE ◽  
Dick H.W. DEKKERS ◽  
Ben C. TILLY ◽  
Jos M.J. LAMERS
Keyword(s):  
Ventricular Myocytes ◽  
Cyclic Stretch ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Basal Rate ◽  
Rat Ventricular Myocytes ◽  
Endothelin 1 ◽  
Cl Channel ◽  
Cl Channels ◽  
Neonatal Rat Ventricular Myocytes

To date various types of Cl- currents have been recorded in cardiac myocytes from different regions of the heart and from different species. Most of these are silent under basal conditions, but are rapidly activated under the influence of various agonists or physical stress that, in the long term, also lead to development of hypertrophy. Previously, we identified three different Cl- channel activities in neonatal rat cardiomyocytes: (i) Ca2+ regulated, (ii) cAMP regulated (cystic fibrosis transmembrane conductance regulator Cl- channels) and (iii) osmoregulated Cl- channels. In this study, we examined comparatively the effects of cyclic stretch and endothelin-1 (ET-1) on Cl- channel activity in primary cultures of neonatal rat ventricular myocytes using an 125I-efflux assay. About 4min after the start of the 125I-efflux (mean basal rate amounts 6.3% of total 125I incorporated/min), the addition of 10nM ET-1 or the application of cyclic stretch rapidly and transiently increased 125I-efflux by 3.8%/min and 0.8%/min respectively above the basal rate. The stretch induced 125I-efflux rate could be blocked by 100µM Gd3+ but it had no effect on the ET-1 response. After 24h stimulation by ET-1 or cyclic stretch the myocytes responded by hypertrophy which is detected by increases of 3H-leucine incorporation into protein and protein/DNA ratio. In conclusion, cyclic stretch as well as ET rapidly and transiently activate Cl- channels in rat neonatal cardiomyocytes. The results suggest that the activation of distinct types of Cl- channels (co)transduce the stretch- and agonist-induced hypertrophic responses in these myocytes.

Acute vasodilator effects of Rho-kinase inhibitors in neonatal rats with pulmonary hypertension unresponsive to nitric oxide

2008 ◽  
Vol 294 (2) ◽  
pp. L205-L213 ◽  
Author(s):  
Patrick J. McNamara ◽  
Prashanth Murthy ◽  
Crystal Kantores ◽  
Lilian Teixeira ◽  
Doreen Engelberts ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Hypertension ◽  
Kinase Inhibitors ◽  
Pulmonary Arteries ◽  
Rho Kinase ◽  
Neonatal Rat ◽  
Rock Inhibitor ◽  
No Donor ◽  
Rat Models ◽  
Pulmonary Hemodynamic

Pulmonary hypertension (PHT) in neonates is often refractory to the current best therapy, inhaled nitric oxide (NO). The utility of a new class of pulmonary vasodilators, Rho-kinase (ROCK) inhibitors, has not been examined in neonatal animals. Our objective was to examine the activity and expression of RhoA/ROCK in normal and injured pulmonary arteries and to determine the short-term pulmonary hemodynamic (assessed by pulse wave Doppler) effects of ROCK inhibitors (15 mg/kg ip Y-27632 or 30 mg/kg ip fasudil) in two neonatal rat models of chronic PHT with pulmonary vascular remodeling (chronic hypoxia, 0.13 FiO2, or 1 mg·kg−1·day−1 ip chronic bleomycin for 14 days from birth). Activity of the RhoA/ROCK pathway and ROCK expression were increased in hypoxia- and bleomycin-induced PHT. In both models, severe PHT [characterized by raised pulmonary vascular resistance (PVR) and impaired right ventricular (RV) performance] did not respond acutely to inhaled NO (20 ppm for 15 min) or to a single bolus of a NO donor, 3-morpholinosydnonimine hydrochloride (SIN-1; 2 μg/kg ip). In contrast, a single intraperitoneal bolus of either ROCK inhibitor (Y-27632 or fasudil) completely normalized PVR but had no acute effect on RV performance. ROCK-mediated vasoconstriction appears to play a key role in chronic PHT in our two neonatal rat models. Inhibitors of ROCK have potential as a testable therapy in neonates with PHT that is refractory to NO.

scholarly journals The Effect of Mitochondrial Complex I-Linked Respiration by Isoflurane Is Independent of Mitochondrial Nitric Oxide Production

2018 ◽  
Vol 8 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Fuqi Xu ◽  
Shigang Qiao ◽  
Hua Li ◽  
Yanjun Deng ◽  
Chen Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mitochondrial Respiration ◽  
Complex I ◽  
Adenosine Diphosphate ◽  
Sprague Dawley ◽  
No Donor ◽  
Anesthetic Preconditioning ◽  
Rat Hearts ◽  
Nos Inhibitor

Background: Anesthetic preconditioning (APC) of the myocardium is mediated in part by reversible alteration of mitochondrial function. Nitric oxide (NO) inhibits mitochondrial respiration and may mediate APC-induced cardioprotection. In this study, the effects of isoflurane on different states of mitochondrial respiration during the oxidation of complex I-linked substrates and the role of NO were investigated. Methods: Mitochondria were isolated from Sprague-Dawley rat hearts. Respiration rates were measured polarographically at 28ºC with a computer-controlled Clark-type O2 electrode in the mitochondria (0.5 mg/mL) with complex I substrates glutamate/malate (5 mM). Isoflurane (0.25 mM) was administered before or after adenosine diphosphate (ADP)-initiated state 3 respiration. The NO synthase (NOS) inhibitor L-N5-(1-iminoethyl)-ornithine (L-NIO, 10 μM) and the NO donor S-nitroso-N-acetylpenicillamine (SNAP, 1 μM) were added before or after the addition of ADP. Results: Isoflurane administered in state 2 increased state 2 respiration and decreased state 3 respiration. This attenuation of state 3 respiration by isoflurane was similar when it was given during state 3. L-NIO did not alter mitochondrial respiration or the effect of isoflurane. SNAP only, added in state 3, decreased state 3 respiration and enhanced the isoflurane-induced attenuation of state 3 respiration. Conclusion: Isoflurane has clearly distinguishable effects on different states of mitochondrial respiration during the oxidation of complex I substrates. The uncoupling effect during state 2 respiration and the attenuation of state 3 respiration may contribute to the mechanism of APC-induced cardioprotection. These effects of isoflurane do not depend on endogenous mitochondrial NO, as the NOS inhibitor L-NIO did not alter the effects of isoflurane on mitochondrial respiration.

Hypoxia enhances a cGMP-independent nitric oxide relaxing mechanism in pulmonary arteries

2003 ◽  
Vol 285 (2) ◽  
pp. L296-L304 ◽  
Author(s):  
Christopher J. Mingone ◽  
Sachin A. Gupte ◽  
Takafumi Iesaki ◽  
Michael S. Wolin
Keyword(s):  
Nitric Oxide ◽  
Sarcoplasmic Reticulum ◽  
Myosin Light Chain ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Cyclopiazonic Acid ◽  
No Donor ◽  
No Donors ◽  
Hypoxic Conditions ◽  
Guanylate Cyclase Activation

Nitric oxide (NO) donors generally relax vascular preparations through cGMP-mediated mechanisms. Relaxation of endothelium-denuded bovine pulmonary arteries (BPA) and coronary arteries to the NO donor S-nitroso- N-acetyl-penicillamine (SNAP) is almost eliminated by inhibition of soluble guanylate cyclase activation with 10 μM 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ), whereas only a modest inhibition of relaxation is observed under hypoxia (PO2 = 8–10 Torr). This effect of hypoxia is independent of the contractile agent used and is also observed with NO gas. ODQ eliminated SNAP-induced increases in cGMP under hypoxia in BPA. cGMP-independent relaxation of BPA to SNAP was not attenuated by inhibition of K+ channels (10 mM tetraethylammonium), myosin light chain phosphatase (0.5 μM microcystin-LR), or adenylate cyclase (4 μM 2′,5′-dideoxyadenosine). SNAP relaxed BPA contracted with serotonin under Ca2+-free conditions in the presence of hypoxia and ODQ, and contraction to Ca2+ readdition was also attenuated. The sarcoplasmic reticulum Ca2+-reuptake inhibitor cyclopiazonic acid (0.2 mM) attenuated SNAP-mediated relaxation of BPA in the presence of ODQ. Thus hypoxic conditions appear to promote a cGMP-independent relaxation of BPA to NO by enhancing sarcoplasmic reticulum Ca2+ reuptake.

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