Nitric oxide synthase inhibition withl-NAME reduces maximal oxygen uptake but not gas exchange threshold during incremental cycle exercise in man

Mitochondria are specialized organelles that control energy metabolism and also activate a multiplicity of pathways that modulate cell proliferation and mitochondrial biogenesis or, conversely, promote cell arrest and programmed cell death by a limited number of oxidative or nitrative reactions. Nitric oxide (NO) regulates oxygen uptake by reversible inhibition of cytochrome oxidase and the production of superoxide anion from the mitochondrial electron transfer chain. In this sense, NO produced by mtNOS will set the oxygen uptake level and contribute to oxidation-reduction reaction (redox)–dependent cell signaling. Modulation of translocation and activation of neuronal nitric oxide synthase (mtNOS activity) under different physiologic or pathologic conditions represents an adaptive response properly modulated to adjust mitochondria to different cell challenges.

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Seasonal variations in body composition, maximal oxygen uptake, and gas exchange threshold in cross-country skiers

Open Access Journal of Sports Medicine ◽

10.2147/oajsm.s154630 ◽

2018 ◽

Vol Volume 9 ◽

pp. 91-97 ◽

Cited By ~ 3

Author(s):

Metin Polat ◽

Selcen Korkmaz Eryılmaz ◽

Sami Aydogan

Keyword(s):

Body Composition ◽

Gas Exchange ◽

Oxygen Uptake ◽

Seasonal Variations ◽

Maximal Oxygen Uptake ◽

Cross Country ◽

Gas Exchange Threshold

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Endothelin-1 stimulation of endothelial nitric oxide synthase in the pathogenesis of hepatopulmonary syndrome

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1999.277.5.g944 ◽

1999 ◽

Vol 277 (5) ◽

pp. G944-G952 ◽

Cited By ~ 20

Author(s):

Ming Zhang ◽

Bao Luo ◽

Shi-Juan Chen ◽

Gary A. Abrams ◽

Michael B. Fallon

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Gas Exchange ◽

Endothelial Nitric Oxide Synthase ◽

Hepatopulmonary Syndrome ◽

Portal Vein Ligation ◽

Biliary Cirrhosis ◽

Endothelin 1 ◽

Oxide Synthase ◽

Endothelial Nitric Oxide

Biliary cirrhosis in the rat triggers intrapulmonary vasodilatation and gas exchange abnormalities that characterize the hepatopulmonary syndrome. This vasodilatation correlates with increased levels of pulmonary microcirculatory endothelial nitric oxide synthase (eNOS) and hepatic and plasma endothelin-1 (ET-1). Prehepatic portal hypertension induced by portal vein ligation (PVL) does not cause similar changes, suggesting that ET-1 in cirrhosis may modulate pulmonary eNOS and vascular tone. We assessed whether ET-1 altered eNOS expression and nitric oxide production in bovine pulmonary artery endothelial cells (BPAECs) and if a 2-wk low-level intravenous ET-1 infusion in PVL animals modulated pulmonary eNOS levels, microcirculatory tone, and gas exchange. ET-1 caused a 2.5-fold increase in eNOS protein in BPAECs, inhibitable with an endothelin B receptor antagonist, and an increase in eNOS mRNA and nitrite production. ET-1 infusion in PVL animals caused increased pulmonary eNOS levels, intrapulmonary vasodilatation, and gas exchange abnormalities without increasing pulmonary arterial pressure. ET-1 produced during hepatic injury may contribute to the hepatopulmonary syndrome by modulating eNOS and inducing pulmonary microcicrulatory vasodilatation.

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Nitric oxide synthase inhibition speeds oxygen uptake kinetics in horses during moderate domain running

Respiratory Physiology & Neurobiology ◽

10.1016/s1569-9048(02)00068-x ◽

2002 ◽

Vol 132 (2) ◽

pp. 169-178 ◽

Cited By ~ 44

Author(s):

Casey A Kindig ◽

Paul McDonough ◽

Howard H Erickson ◽

David C Poole

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Oxygen Uptake ◽

Oxygen Uptake Kinetics ◽

Uptake Kinetics ◽

Oxide Synthase

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Influence of l-NAME on pulmonary O2 uptake kinetics during heavy-intensity cycle exercise

Journal of Applied Physiology ◽

10.1152/japplphysiol.00381.2003 ◽

2004 ◽

Vol 96 (3) ◽

pp. 1033-1038 ◽

Cited By ~ 40

Author(s):

Andrew M. Jones ◽

Daryl P. Wilkerson ◽

Sally Wilmshurst ◽

Iain T. Campbell

Keyword(s):

Nitric Oxide ◽

Gas Exchange ◽

Phase Ii ◽

Slow Component ◽

Muscle Blood Flow ◽

Primary Component ◽

Cycle Exercise ◽

The Difference ◽

Component Amplitude ◽

Oxide Synthase

We hypothesized that inhibition of nitric oxide synthase (NOS) by NG-nitro-l-arginine methyl ester (l-NAME) would alleviate the inhibition of mitochondrial oxygen uptake (V̇o2) by nitric oxide and result in a speeding of phase II pulmonary V̇o2 kinetics at the onset of heavy-intensity exercise. Seven men performed square-wave transitions from unloaded cycling to a work rate requiring 40% of the difference between the gas exchange threshold and peak V̇o2 with and without prior intravenous infusion of l-NAME (4 mg/kg in 50 ml saline over 60 min). Pulmonary gas exchange was measured breath by breath, and V̇o2 kinetics were determined from the averaged response to two exercise bouts performed in each condition. There were no significant differences between the control (C) and l-NAME conditions (L) for baseline V̇o2, the duration of phase I, or the amplitude of the primary V̇o2 response. However, the time constant of the V̇o2 response in phase II was significantly smaller (mean ± SE: C: 25.1 ± 3.0 s; L: 21.8 ± 3.3 s; P < 0.05), and the amplitude of the V̇o2 slow component was significantly greater (C: 240 ± 47 ml/min; L: 363 ± 24 ml/min; P < 0.05) after l-NAME infusion. These data indicate that inhibition of NOS by l-NAME results in a significant (13%) speeding of V̇o2 kinetics and a significant increase in the amplitude of the V̇o2 slow component in the transition to heavy-intensity cycle exercise in men. The speeding of the primary component V̇o2 kinetics after l-NAME infusion indicates that at least part of the intrinsic inertia to oxidative metabolism at the onset of heavy-intensity exercise may result from inhibition of mitochondrial V̇o2 by nitric oxide. The cause of the larger V̇o2 slow-component amplitude with l-NAME requires further investigation but may be related to differences in muscle blood flow early in the rest-to-exercise transition.

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Localization of endothelial nitric oxide synthase in the normal and failing human atrial myocardium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166397 ◽

1996 ◽

Vol 54 ◽

pp. 786-787

Author(s):

Chi-Ming Wei ◽

Margarita Bracamonte ◽

Shi-Wen Jiang ◽

Richard C. Daly ◽

Christopher G.A. McGregor ◽

...

Keyword(s):

Nitric Oxide ◽

Heart Failure ◽

Nitric Oxide Synthase ◽

Endothelial Nitric Oxide Synthase ◽

Cardiac Tissues ◽

Mammalian Tissues ◽

End Stage Heart Failure ◽

End Stage ◽

Oxide Synthase ◽

Endothelial Nitric Oxide

Nitric oxide (NO) is a potent endothelium-derived relaxing factor which also may modulate cardiomyocyte inotropism and growth via increasing cGMP. While endothelial nitric oxide synthase (eNOS) isoforms have been detected in non-human mammalian tissues, expression and localization of eNOS in the normal and failing human myocardium are poorly defined. Therefore, the present study was designed to investigate eNOS in human cardiac tissues in the presence and absence of congestive heart failure (CHF).Normal and failing atrial tissue were obtained from six cardiac donors and six end-stage heart failure patients undergoing primary cardiac transplantation. ENOS protein expression and localization was investigated utilizing Western blot analysis and immunohistochemical staining with the polyclonal rabbit antibody to eNOS (Transduction Laboratories, Lexington, Kentucky).

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