Chemoreflex ventilatory response to CO₂ in man at low and high altitudes

Abstract

Abstract. On man, a peripheral chemoreflex ventilatory response curve was obtained by measuring ventilatory reactions to the transient inhalation of a CO₂-rich mixture. Experiments have been performed. 1) on lowlanders in normoxia, in acute hypoxia and during acclimatization at an altitude of 3660 m (La Paz, Bolivia). 2) on native highlanders. In lowlanders, acute and chronic hypoxia is characterized by an increase in the slope of the VE/PAco₂ curve. Acclimatization is marked by a shift of this curve to a lower PAco₂ and a higher ventilation. This shift is achieved within two days. Highland natives at high or low altitude have a very low peripheral chomoreflex CO₂ drive.