Enhanced activity of carotid body chemoreceptors in rabbits with heart failure: role of nitric oxide

1999 ◽  
Vol 86 (4) ◽  
pp. 1273-1282 ◽  
Author(s):  
Shu-Yu Sun ◽  
W. Wang ◽  
I. H. Zucker ◽  
H. D. Schultz
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
Carotid Body ◽  
Rabbit Model ◽  
Nerve Fibers ◽  
No Synthase ◽  
No Production ◽  
No Donor ◽  
Carotid Body Chemoreceptors

An enhanced peripheral chemoreflex has been documented in patients with chronic heart failure (CHF). This study aimed to examine the characteristics of carotid body (CB) chemoreceptors in response to isocapnic hypoxia in a rabbit model of pacing-induced CHF and to evaluate the possible role that nitric oxide (NO) plays in the altered characteristics. The chemosensitive characteristics of the CB were evaluated by recording single-unit activity from the carotid sinus nerve in both an intact and a vascularly isolated preparation. It was found that the baseline discharge under normoxia (intact preparation: arterial [Formula: see text] 90–95 Torr; isolated preparation: [Formula: see text]100–110 Torr) and the chemosensitivity in response to graded hypoxia ([Formula: see text] 40–70 Torr) were enhanced in CHF vs. sham rabbits. These alterations were independent of the CB preparations (intact vs. isolated). NO synthase inhibition by N ω-nitro-l-arginine increased the baseline discharge and the chemosensitivity in the intact preparation, whereas l-arginine (10−5 M) inhibited the baseline discharge and the chemosensitivity in the isolated preparation in sham but not in CHF rabbits. S-nitroso- N-acetylpenicillamine, an NO donor, inhibited the baseline discharge and the chemosensitivity in both CB preparations in CHF rabbits but only in the isolated preparation in sham rabbits. The amount of NO produced in vitro by the CB under normoxia was less in CHF rabbits than in sham rabbits ( P < 0.05). NO synthase-positive varicosities of nerve fibers within the CB were less in CHF rabbits than in sham rabbits ( P < 0.05). These data indicate that an enhanced input from CB occurs in the rabbit model of pacing-induced CHF and that an impairment of NO production may contribute to this alteration.

scholarly journals An increase in nitric oxide produced by rat peritoneal neutrophils is not involved in cell apoptosis

1995 ◽  
Vol 4 (3) ◽  
pp. 222-228 ◽  
Author(s):  
I. M. Fierro ◽  
C. Barja-Fidalgo ◽  
R. M. Canedo ◽  
F. Q. Cunha ◽  
S. H. Ferreira
Keyword(s):  
Nitric Oxide ◽  
Cell Apoptosis ◽  
No Synthase ◽  
The Other ◽  
Polymorphonuclear Neutrophils ◽  
No Production ◽  
Spontaneous Release ◽  
No Donor ◽  
Carrageenin Injection

Polymorphonuclear neutrophils (PMN) obtained from carrageenin-stimulated peritoneal cavities of rats, but not blood PMN, spontaneously produced nitric oxide (NO) when incubatedin vitro. Incubation of the cells with the NO synthase inhibitors, L-imino-ethyl-L-ornithine (L-NIO) or NG-monomethyl-L-arginine (L-NMMA), inhibited NO production. This inhibition could be reversed by L-arginine. Incubation of PMN with lipopolysaccharide (LPS) failed to enhance NO production. Pretreatment of the rats with dexamethasone (DEXA) prior to carrageenin injection or incubation of PMN with the glucocorticoidin vitropartially inhibited the spontaneous release of NO. On the other hand, when PMN obtained from DEXA pretreated rats were incubatedin vitrowith DEXA, NO synthase activity and hence NO generation were almost abolished. A similar inhibition was also observed following the addition of L-NIO or cycloheximide to cultures of carrageenin-elicited PMN. The NO production by PMN did not appear to be related to cell viability or apoptosis. Indeed, neither the blockade of NO generation by L-NIO nor the incubation of the neutrophils with a NO donor, S-nitroso-acetylpenicillamine (SNAP) modified the pattern of LDH release or DNA fragmentation. In summary, it appears that PMN migration triggers a continuous NO synthesis, and that NO produced by these cells is not related to their apoptosis.

scholarly journals Nitric oxide reduces Cl− absorption in the mouse cortical collecting duct through an ENaC-dependent mechanism

2013 ◽  
Vol 304 (11) ◽  
pp. F1390-F1397 ◽  
Author(s):  
Vladimir Pech ◽  
Monika Thumova ◽  
Sergey I. Dikalov ◽  
Edith Hummler ◽  
Bernard C. Rossier ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Collecting Duct ◽  
No Synthase ◽  
Apical Plasma Membrane ◽  
No Production ◽  
Cortical Collecting Duct ◽  
No Donor ◽  
Genetic Ablation

Since nitric oxide (NO) participates in the renal regulation of blood pressure, in part, by modulating transport of Na+ and Cl− in the kidney, we asked whether NO regulates net Cl− flux ( JCl) in the cortical collecting duct (CCD) and determined the transporter(s) that mediate NO-sensitive Cl− absorption. Cl− absorption was measured in CCDs perfused in vitro that were taken from aldosterone-treated mice. Administration of an NO donor (10 μM MAHMA NONOate) reduced JCl and transepithelial voltage ( VT) both in the presence or absence of angiotensin II. However, reducing endogenous NO production by inhibiting NO synthase (100 μM NG-nitro-l-arginine methyl ester) increased JCl only in the presence of angiotensin II, suggesting that angiotensin II stimulates NO synthase activity. To determine the transport process that mediates NO-sensitive changes in JCl, we examined the effect of NO on JCl following either genetic ablation or chemical inhibition of transporters in the CCD. Since the application of hydrochlorothiazide (100 μM) or bafilomycin (5 nM) to the perfusate or ablation of the gene encoding pendrin did not alter NO-sensitive JCl, NO modulates JCl independent of the Na+-dependent Cl−/HCO3− exchanger (NDCBE, Slc4a8), the A cell apical plasma membrane H+-ATPase and pendrin. In contrast, both total and NO-sensitive JCl and VT were abolished with application of an epithelial Na+ channel (ENaC) inhibitor (3 μM benzamil) to the perfusate. We conclude that NO reduces Cl− absorption in the CCD through a mechanism that is ENaC-dependent.

Caspase Activation Is Required for Nitric Oxide–Mediated, CD95(APO-1/Fas)–Dependent and Independent Apoptosis in Human Neoplastic Lymphoid Cells

Blood ◽  
1998 ◽  
Vol 91 (11) ◽  
pp. 4311-4320 ◽  
Author(s):  
Katerina Chlichlia ◽  
Marcus E. Peter ◽  
Marian Rocha ◽  
Carsten Scaffidi ◽  
Mariana Bucur ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Present Report ◽  
Lymphoid Cells ◽  
Jurkat Cells ◽  
Target Cells ◽  
No Production ◽  
No Donor ◽  
Synthase Inhibitor ◽  
Inhibitor Of Protein Synthesis

Abstract Nitric oxide (NO), an important effector molecule involved in immune regulation and host defense, was shown to induce apoptosis in lymphoma cells. In the present report the NO donor glycerol trinitrate was found to induce apoptosis in Jurkat cells that are sensitive to CD95-mediated kill. In contrast, a CD95-resistant Jurkat subclone showed substantial protection from apoptosis after exposure to NO. NO induced mRNA expression of CD95 (APO-1/Fas) and TRAIL/APO-2 ligands. Moreover, NO triggered apoptosis in freshly isolated human leukemic lymphocytes which were also sensitive to anti-CD95 treatment. The ability of NO to induce apoptosis was completely blocked by a broad-spectrum ICE (interleukin-1β converting enzyme)-protease/caspase inhibitor and correlated with FLICE/caspase-8 activation. This activation was abrogated in some neoplastic lymphoid cells but not in others by the inhibitor of protein synthesis cycloheximide. Our results were confirmed using an in vitro experimental model of coculture of human lymphoid target cells with activated bovine endothelial cells generating NO as effectors. Furthermore, the inhibition of endogenous NO production with the inducible NO synthase inhibitor NG-monomethyl-L-arginine caused a complete abrogation of the apoptotic effect. Our data provide evidence that NO-induced apoptosis in human neoplastic lymphoid cells strictly requires activation of caspases, in particular FLICE, the most CD95 receptor-proximal caspase. Depending on the cell line tested this activation required or was independent of the CD95 receptor/ligand system.

The nitric oxide donor molsidomine rescues cardiac function in rats with chronic kidney disease and cardiac dysfunction

2010 ◽  
Vol 299 (6) ◽  
pp. H2037-H2045 ◽  
Author(s):  
Lennart G. Bongartz ◽  
Branko Braam ◽  
Marianne C. Verhaar ◽  
Maarten Jan M. Cramer ◽  
Roel Goldschmeding ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Low Dose ◽  
Left Ventricular Systolic Dysfunction ◽  
Systolic Dysfunction ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
No Synthase ◽  
Nitric Oxide Donor ◽  
No Production ◽  
No Donor

We recently developed a rat model of cardiorenal failure that is characterized by severe left ventricular systolic dysfunction (LVSD) and low nitric oxide (NO) production that persisted after temporary low-dose NO synthase inhibition. We hypothesized that LVSD was due to continued low NO availability and might be reversed by supplementing NO. Rats underwent a subtotal nephrectomy and were treated with low-dose NO synthase inhibition with Nω-nitro-l-arginine up to week 8. After 3 wk of washout, rats were treated orally with either the long-acting, tolerance-free NO donor molsidomine (Mols) or vehicle (Veh). Cardiac and renal function were measured on weeks 11, 13, and 15. On week 16, LV hemodynamics and pressure-volume relationships were measured invasively, and rats were killed to quantify histological damage. On week 15, blood pressure was mildly reduced and creatinine clearance was increased by Mols (both P < 0.05). Mols treatment improved ejection fraction (53 ± 3% vs. 37 ± 2% in Veh-treated rats, P < 0.001) and stroke volume (324 ± 33 vs. 255 ± 15 μl in Veh-treated rats, P < 0.05). Rats with Mols treatment had lower end-diastolic pressures (8.5 ± 1.1 mmHg) than Veh-treated rats (16.3 ± 3.5 mmHg, P < 0.05) and reduced time constants of relaxation (21.9 ± 1.8 vs. 30.9 ± 3.3 ms, respectively, P < 0.05). The LV end-systolic pressure-volume relationship was shifted to the left in Mols compared with Veh treatment. In summary, in a model of cardiorenal failure with low NO availability, supplementing NO significantly improves cardiac systolic and diastolic function without a major effect on afterload.

Caspase Activation Is Required for Nitric Oxide–Mediated, CD95(APO-1/Fas)–Dependent and Independent Apoptosis in Human Neoplastic Lymphoid Cells

Blood ◽  
1998 ◽  
Vol 91 (11) ◽  
pp. 4311-4320 ◽  
Author(s):  
Katerina Chlichlia ◽  
Marcus E. Peter ◽  
Marian Rocha ◽  
Carsten Scaffidi ◽  
Mariana Bucur ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Present Report ◽  
Lymphoid Cells ◽  
Jurkat Cells ◽  
Target Cells ◽  
No Production ◽  
No Donor ◽  
Synthase Inhibitor ◽  
Inhibitor Of Protein Synthesis

Nitric oxide (NO), an important effector molecule involved in immune regulation and host defense, was shown to induce apoptosis in lymphoma cells. In the present report the NO donor glycerol trinitrate was found to induce apoptosis in Jurkat cells that are sensitive to CD95-mediated kill. In contrast, a CD95-resistant Jurkat subclone showed substantial protection from apoptosis after exposure to NO. NO induced mRNA expression of CD95 (APO-1/Fas) and TRAIL/APO-2 ligands. Moreover, NO triggered apoptosis in freshly isolated human leukemic lymphocytes which were also sensitive to anti-CD95 treatment. The ability of NO to induce apoptosis was completely blocked by a broad-spectrum ICE (interleukin-1β converting enzyme)-protease/caspase inhibitor and correlated with FLICE/caspase-8 activation. This activation was abrogated in some neoplastic lymphoid cells but not in others by the inhibitor of protein synthesis cycloheximide. Our results were confirmed using an in vitro experimental model of coculture of human lymphoid target cells with activated bovine endothelial cells generating NO as effectors. Furthermore, the inhibition of endogenous NO production with the inducible NO synthase inhibitor NG-monomethyl-L-arginine caused a complete abrogation of the apoptotic effect. Our data provide evidence that NO-induced apoptosis in human neoplastic lymphoid cells strictly requires activation of caspases, in particular FLICE, the most CD95 receptor-proximal caspase. Depending on the cell line tested this activation required or was independent of the CD95 receptor/ligand system.

Nitric oxide regulates endothelium-dependent vasodilator responses in rabbit hindquarters vascular bed in vivo

1996 ◽  
Vol 271 (1) ◽  
pp. H133-H139 ◽  
Author(s):  
G. A. Cohen ◽  
A. J. Hobbs ◽  
R. M. Fitch ◽  
M. J. Zinner ◽  
G. Chaudhuri ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Physiological Role ◽  
No Synthase ◽  
No Donor ◽  
Aortic Endothelial Cells ◽  
Vascular Bed ◽  
Feedback Modulator ◽  
Vasodilator Action

The objective of this study was to determine whether nitric oxide (NO) could function as a negative feedback modulator of endothelium-dependent vasodilation in vivo. To this end, the influence of exogenous NO on vasodilator responses in the rabbit hindquarters vascular bed was determined. Previous in vitro studies have demonstrated that NO inhibits both neuronal NO synthase from rat cerebellum as well as NO synthase derived from bovine aortic endothelial cells. The present study was conducted in the rabbit hindquarters vascular bed under conditions of constant blood flow so that changes in pressure directly reflected changes in vascular resistance. Under these in vivo conditions, the NO donor agent S-nitroso-N-acetylpenicillamine (SNAP) reversibly attenuated responses to the endothelium-dependent vasodilators, acetylcholine and bradykinin. In contrast, SNAP did not influence the endothelium-independent vasodilator response to SNAP itself or to 8-bromoguanosine 3',5'-cyclic monophosphate. These observations indicate clearly that NO interferes with endothelium-dependent vasodilator action and support the view that endogenous NO may actually play a physiological role in regulating vascular tone.

Nitric oxide-dependent inhibition of alveolar fluid clearance in hydrostatic lung edema

2007 ◽  
Vol 293 (4) ◽  
pp. L859-L869 ◽  
Author(s):  
Stephanie M. Kaestle ◽  
Christian A. Reich ◽  
Ning Yin ◽  
Helmut Habazettl ◽  
Jorg Weimann ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
No Synthase ◽  
Lung Edema ◽  
No Production ◽  
Alveolar Fluid Clearance ◽  
Alveolar Space ◽  
Edema Formation ◽  
Fluid Reabsorption ◽  
Mouse Lungs

Formation of cardiogenic pulmonary edema in acute left heart failure is traditionally attributed to increased fluid filtration from pulmonary capillaries and subsequent alveolar flooding. Here, we demonstrate that hydrostatic edema formation at moderately elevated vascular pressures is predominantly caused by an inhibition of alveolar fluid reabsorption, which is mediated by endothelial-derived nitric oxide (NO). In isolated rat lungs, we quantified fluid fluxes into and out of the alveolar space and endothelial NO production by a two-compartmental double-indicator dilution technique and in situ fluorescence imaging, respectively. Elevation of hydrostatic pressure induced Ca2+-dependent endothelial NO production and caused a net fluid shift into the alveolar space, which was predominantly attributable to impaired fluid reabsorption. Inhibition of NO production or soluble guanylate cyclase reconstituted alveolar fluid reabsorption, whereas fluid clearance was blocked by exogenous NO donors or cGMP analogs. In isolated mouse lungs, hydrostatic edema formation was attenuated by NO synthase inhibition. Similarly, edema formation was decreased in isolated mouse lungs of endothelial NO synthase-deficient mice. Chronic heart failure results in endothelial dysfunction and preservation of alveolar fluid reabsorption. These findings identify impaired alveolar fluid clearance as an important mechanism in the pathogenesis of hydrostatic lung edema. This effect is mediated by endothelial-derived NO acting as an intercompartmental signaling molecule at the alveolo-capillary barrier.

Suppressed impact of nitric oxide on renal arteriolar function in rats with chronic heart failure

1999 ◽  
Vol 276 (1) ◽  
pp. F79-F87 ◽  
Author(s):  
Hideki Ikenaga ◽  
Naohito Ishii ◽  
Sean P. Didion ◽  
Kun Zhang ◽  
Kurtis G. Cornish ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
No Synthase ◽  
Coronary Artery Ligation ◽  
Ang Ii ◽  
Artery Ligation ◽  
Renal Microvasculature ◽  
Arteriolar Diameter ◽  
Baseline Diameter

We performed experiments to test the hypothesis that experimental heart failure (HF) is associated with altered nitric oxide (NO)-dependent influences on the renal microvasculature, including diminished modulation of constrictor responses to ANG II. Eight to ten weeks after inducing HF in rats by coronary artery ligation, we administered enalaprilat to suppress ANG II synthesis and studied renal arteriolar function using the in vitro blood-perfused juxtamedullary nephron technique. In kidneys from sham-operated rats, NO synthase inhibition [100 μM N ω-nitro-l-arginine (l-NNA)] reduced afferent arteriolar diameter by 4.1 ± 0.6 μm and enhanced ANG II responsiveness (10 nM ANG II decreased afferent diameter by 10.1 ± 1.4 μm before and 12.8 ± 1.6 μm duringl-NNA treatment; P < 0.05). In kidneys from HF rats,l-NNA did not alter afferent arteriolar baseline diameter or ANG II responsiveness (10 nM ANG II decreased diameter by 12.5 ± 1.5 μm before and 12.5 ± 2.3 μm during l-NNA). The effects of l-NNA on efferent arteriolar function were also abated in HF rats. In renal cortex of HF rats, NO synthase activity was decreased by 63% and superoxide dismutase activity was diminished by 39% relative to tissue from sham-operated rats. Urinary nitrate/nitrite excretion was also reduced in HF rats. Thus both diminished synthesis and augmented degradation are likely to contribute to a decreased renal microvascular impact of endogenous NO during chronic HF, the consequences of which include loss of NO-dependent modulation of ANG II-induced vasoconstriction.

Nitric Oxide in Pulp Cell Growth, Differentiation, and Mineralization

2007 ◽  
Vol 86 (2) ◽  
pp. 163-168 ◽  
Author(s):  
R. Yasuhara ◽  
T. Suzawa ◽  
Y. Miyamoto ◽  
X. Wang ◽  
M. Takami ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Alkaline Phosphatase ◽  
Ascorbic Acid ◽  
No Synthase ◽  
Membrane Glycoprotein ◽  
No Donor ◽  
Mrna And Protein Expression ◽  
Pulp Cells ◽  
Cells Cultured

Dental preparation sometimes causes transient congestion, edema, and necrosis of the pulp. We hypothesized that nitric oxide (NO) is involved in the pathophysiological changes in pulp after preparation. The mRNA and protein expression of the inducible isoform of NO synthase (iNOS) was examined in murine pulp after dental preparation. The effects of NO on the proliferation, mineralization, and apoptosis of pulp cells were also studied in vitro. We found that not only iNOS, but also mRNAs for alkaline phosphatase and plasma membrane glycoprotein-1, were expressed in the pulp after preparation. NOC-18, an NO donor, suppressed the proliferation of pulp cells without inducing cell death, whereas it promoted the mineralization of cells cultured in the presence of β-glycerophosphate, ascorbic acid, dexamethasone, and KH2PO4. Under these conditions, NOC-18 induced the apoptosis of pulp cells. These results suggest that NO regulates the growth, apoptosis, and mineralization of pulp cells.

scholarly journals On the protective mechanisms of nitric oxide in acute pancreatitis

Gut ◽  
1998 ◽  
Vol 43 (3) ◽  
pp. 401-407 ◽  
Author(s):  
J Werner ◽  
C Fernández-del Castillo ◽  
J A Rivera ◽  
N Kollias ◽  
K B Lewandrowski ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Acute Pancreatitis ◽  
No Synthase ◽  
Amylase Secretion ◽  
Capillary Perfusion ◽  
No Donor ◽  
Pancreatic Acini ◽  
No Donors ◽  
Trypsinogen Activation

Background—Ectopic protease activation, microcirculatory changes, and leucocyte activation are the main events in the pathogenesis of acute pancreatitis. Nitric oxide (NO) is known to be a key mediator in the normal and inflamed pancreas.Aims—To investigate the targets on which NO exerts its effect in caerulein induced pancreatitis.Methods—Acute pancreatitis was induced in rats which additionally received either the NO synthase substrate, l-arginine; the NO donor, sodium nitroprusside; or the NO synthase inhibitor, N-nitro-l-arginine methyl ester (l-NAME). At six hours, pancreatic injury (oedema, leucocyte content, ectopic trypsinogen activation) was analysed and pancreatic oxygenation and perfusion were determined. A direct influence of NO on amylase secretion and trypsinogen activation was evaluated separately in vitro.Results—Both NO donors reduced the grade of inflammation. l-NAME increased the severity of inflammation, while decreasing pancreatic tissue oxygenation. Although neither amylase secretion nor intracellular trypsinogen activation in caerulein stimulated pancreatic acini was influenced by either NO donors or inhibitors, both NO donors decreased intrapancreatic trypsinogen activation peptide (TAP) and pancreatic oedema in vivo, andl-NAME increased TAP.Conclusions—NO protects against injury caused by pancreatitis in the intact animal but has no discernible effect on isolated acini. It is likely that in pancreatitis NO acts indirectly via microcirculatory changes, including inhibition of leucocyte activation and preservation of capillary perfusion.

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