Effects of hypoxia and hyperoxia of short duration on the pulmonary circulation of highlanders (HL) and lowlanders (LL) living at 3,750 m

Abstract

Summary. We have done brief O₂ and N₂ inhalations in order to analyze the mechanism responsible for the pulmonary artery hypertension observed at high altitude in normal residents and newcomers. The reactivity of the pulmonary vascular bed is approximately two times less in highlanders. We conclude that the functional vascular reactivity in lowlanders is the predominant factor while this reactivity is secondary in the highlanders. In the latter, the structural changes seem to be the principal factor.