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Influence of inhaled nitric oxide on gas exchange during normoxic and hypoxic exercise in highly trained cyclists.
- Source :
-
Journal of applied physiology (Bethesda, Md. : 1985) [J Appl Physiol (1985)] 2001 Mar; Vol. 90 (3), pp. 926-32. - Publication Year :
- 2001
-
Abstract
- This study tested the effects of inhaled nitric oxide [NO; 20 parts per million (ppm)] during normoxic and hypoxic (fraction of inspired O(2) = 14%) exercise on gas exchange in athletes with exercise-induced hypoxemia. Trained male cyclists (n = 7) performed two cycle tests to exhaustion to determine maximal O(2) consumption (VO(2 max)) and arterial oxyhemoglobin saturation (Sa(O(2)), Ohmeda Biox ear oximeter) under normoxic (VO(2 max) = 4.88 +/- 0.43 l/min and Sa(O(2)) = 90.2 +/- 0.9, means +/- SD) and hypoxic (VO(2 max) = 4.24 +/- 0.49 l/min and Sa(O(2)) = 75.5 +/- 4.5) conditions. On a third occasion, subjects performed four 5-min cycle tests, each separated by 1 h at their respective VO(2 max), under randomly assigned conditions: normoxia (N), normoxia + NO (N/NO), hypoxia (H), and hypoxia + NO (H/NO). Gas exchange, heart rate, and metabolic parameters were determined during each condition. Arterial blood was drawn at rest and at each minute of the 5-min test. Arterial PO(2) (Pa(O(2))), arterial PCO(2), and Sa(O(2)) were determined, and the alveolar-arterial difference for PO(2) (A-aDO(2)) was calculated. Measurements of Pa(O(2)) and Sa(O(2)) were significantly lower and A-aDO(2) was widened during exercise compared with rest for all conditions (P < 0.05). No significant differences were detected between N and N/NO or between H and H/NO for Pa(O(2)), Sa(O(2)) and A-aDO(2) (P > 0.05). We conclude that inhalation of 20 ppm NO during normoxic and hypoxic exercise has no effect on gas exchange in highly trained cyclists.
- Subjects :
- Administration, Inhalation
Adult
Bicarbonates blood
Heart Rate drug effects
Humans
Hydrogen-Ion Concentration
Male
Nitric Oxide administration & dosage
Oxygen Consumption drug effects
Oxyhemoglobins metabolism
Partial Pressure
Reference Values
Respiratory Function Tests
Rest
Bicycling physiology
Carbon Dioxide blood
Exercise physiology
Hypoxia physiopathology
Nitric Oxide pharmacology
Oxygen blood
Oxygen Consumption physiology
Respiratory Mechanics drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 8750-7587
- Volume :
- 90
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Journal of applied physiology (Bethesda, Md. : 1985)
- Publication Type :
- Academic Journal
- Accession number :
- 11181602
- Full Text :
- https://doi.org/10.1152/jappl.2001.90.3.926