• I Mark Olfert, Alexander Loeckinger, Benedikt Treml, Martin Faulhaber, Markus Flatz, Martin Burtscher, Susanne Truebsbach, and Axel Kleinsasser.
• Center for Cardiovascular and Respiratory Sciences, Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, USA. molfert@hsc.wvu.edu
• Wilderness Environ Med. 2011 Sep 1;22(3):211-21.

ObjectivesSildenafil and, recently, bosentan have been reported to increase arterial saturation and exercise capacity at altitude. The mechanisms behind this are still poorly defined but may be related to attenuation of hypoxic pulmonary vasoconstriction (HPV) and improved gas exchange. This study was designed to examine and compare the effect of sildenafil and bosentan on pulmonary gas exchange during acute hypoxic exercise in a controlled laboratory setting.MethodsSixteen athletic university students (8 males, 8 females) were examined during exercise in a hypoxic chamber (11% oxygen) before and after the administration of either sildenafil (n=10) or bosentan (n=6). Respiratory and metabolic measurements were taken at rest and during increasing exercise intensity (up to 90% of their individual maximal oxygen uptake [VO(2)max]) in concert with arterial blood gas sampling.ResultsBoth drugs resulted in small, but significant increases in arterial PO(2) (2-3 Torr) and O(2) saturation (3-4%) at rest and during hypoxic exercise, in both men and women. No significant changes in arterial PCO(2) or ventilation were seen at rest or during exercise in hypoxia; however, heart rate (both at rest and during exercise) was increased with both sildenafil and bosentan in both men and women.ConclusionsThese data demonstrate that sildenafil and bosentan equally improve arterial oxygenation in acute hypoxia in both men and women, which could account for improved physical performance at altitude.Copyright © 2011 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

31 keywords...

hide…