Document Detail


Effects of sildenafil on exercise capacity in hypoxic normal subjects.
MedLine Citation:
PMID:  17584010     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The phosphodiesterase-5 inhibitor sildenafil has been reported to improve hypoxic exercise capacity, but the mechanisms accounting for this observation remain incompletely understood. Sixteen healthy subjects were included in a randomized, double-blind, placebo-controlled, cross-over study on the effects of 50-mg sildenafil on echocardiographic indexes of the pulmonary circulation and on cardiopulmonary cycle exercise in normoxia, in acute normobaric hypoxia (fraction of inspired O2, 0.1), and then again after 2 weeks of acclimatization at 5000 m on Mount Chimborazo (Ecuador). In normoxia, sildenafil had no effect on maximum VO2 or O2 saturation. In acute hypoxia, sildenafil increased maximum VO2 from 27 +/- 5 to 32 +/- 6 mL/min/kg and O2 saturation from 62% +/- 6% to 68% +/- 9%. In chronic hypoxia, sildenafil did not affect maximum VO2 or O2 saturation. Resting mean pulmonary artery pressure increased from 16 +/- 3 mmHg in normoxia to 28 +/- 5 mmHg in normobaric hypoxia and 32 +/- 6 mmHg in hypobaric hypoxia. Sildenafil decreased pulmonary vascular resistance by 30% to 50% in these different conditions. We conclude that sildenafil increases exercise capacity in acute normobaric hypoxia and that this is explained by improved arterial oxygenation, rather than by a decrease in right ventricular afterload.
Authors:
Vitalie Faoro; Michel Lamotte; Gael Deboeck; Adriana Pavelescu; Sandrine Huez; Hervé Guenard; Jean-Benoît Martinot; Robert Naeije
Publication Detail:
Type:  Controlled Clinical Trial; Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  High altitude medicine & biology     Volume:  8     ISSN:  1527-0297     ISO Abbreviation:  High Alt. Med. Biol.     Publication Date:  2007  
Date Detail:
Created Date:  2007-06-22     Completed Date:  2007-09-21     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901183     Medline TA:  High Alt Med Biol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  155-63     Citation Subset:  IM; S    
Affiliation:
Laboratory of Physiology, Faculty of Medicine, Free University of Brussels, Belgium.
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MeSH Terms
Descriptor/Qualifier:
Adult
Altitude*
Anoxia / drug therapy*
Cross-Over Studies
Double-Blind Method
Exercise / physiology
Exercise Tolerance / drug effects*
Female
Heart Rate / drug effects
Humans
Male
Middle Aged
Phosphodiesterase Inhibitors / pharmacology*
Piperazines / pharmacology*
Pulmonary Artery / drug effects
Pulmonary Circulation / drug effects
Purines / pharmacology
Reference Values
Sulfones / pharmacology*
Tidal Volume / drug effects
Vasodilator Agents / pharmacology*
Chemical
Reg. No./Substance:
0/Phosphodiesterase Inhibitors; 0/Piperazines; 0/Purines; 0/Sulfones; 0/Vasodilator Agents; 139755-83-2/sildenafil

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


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