Document Detail

Exhaled nitric oxide during normoxic and hypoxic exercise in endurance athletes.
MedLine Citation:
PMID:  16168006     Owner:  NLM     Status:  MEDLINE    
AIM: Endogenous nitric oxide (NO) through its relaxing effect on smooth muscle cells may be involved in pulmonary gas exchange as well as in the modulation of the hypoxic pulmonary vasoconstriction. As athletes with exercise-induced hypoxaemia (EIH) present pulmonary gas exchange abnormalities in normoxia that could be even greater in hypoxia, we hypothesized that pulmonary NO may be lower in such athletes with EIH.
METHODS: Eleven athletes with EIH [decrease in arterial oxygen blood partial pressure (PaO2) > 12 mmHg] and 9 without EIH (NEIH) exercised at 40%, 60% (10 min) and 90% (5 min) of normoxic maximal power output (Pmax) in normoxia, and at 40% and 60% (10 min) of Pmax in hypoxia (FiO2 = 15%). Exhaled NO concentration during a constant flow exhalation (FENO(0.170)) and arterialized blood gases were measured at every power output.
RESULTS: FENO(0.170) decreased from rest to exercise both in normoxia (-27.8 +/- 22.8% at 90% Pmax, P < 0.001) and hypoxia (-23.8 +/- 17.5% at 60% Pmax, P < 0.001). At 90% Pmax in normoxia, EIH athletes showed lower PaO2 (76.7 +/- 5.4 vs. 82.8 +/- 4.4 mmHg, P = 0.013) and greater FENO(0.170) decrement (-37.0 +/- 24.7% vs. -16.6 +/- 14.6%, P = 0.042) than NEIH athletes. During hypoxic exercise, P(a)O(2) and FENO(0.170) decreases were similar in both groups (P > 0.05).
CONCLUSION: The present study shows lower pulmonary NO in athletes with gas exchange abnormalities during intense exercise in normoxia, while EIH and NEIH athletes have similar decreases in blood gases and pulmonary NO during hypoxic exercise. Decreased pulmonary NO in such conditions may contribute to ventilation-perfusion inequality and/or increase pulmonary vascular tone in athletes.
S Verges; P Flore; A Favre-Juvin; P Lévy; B Wuyam
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Acta physiologica Scandinavica     Volume:  185     ISSN:  0001-6772     ISO Abbreviation:  Acta Physiol. Scand.     Publication Date:  2005 Oct 
Date Detail:
Created Date:  2005-09-19     Completed Date:  2006-05-16     Revised Date:  2014-07-29    
Medline Journal Info:
Nlm Unique ID:  0370362     Medline TA:  Acta Physiol Scand     Country:  England    
Other Details:
Languages:  eng     Pagination:  123-31     Citation Subset:  IM    
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MeSH Terms
Anoxia / physiopathology*
Blood Gas Analysis / methods
Exercise / physiology*
Exercise Test / methods
Nitric Oxide / physiology*
Oxygen Consumption / physiology
Physical Endurance / physiology
Skiing / physiology
Track and Field / physiology
Reg. No./Substance:
31C4KY9ESH/Nitric Oxide
Comment In:
Acta Physiol Scand. 2005 Oct;185(2):87   [PMID:  16168002 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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