Oxygen consumption as an indicator of the adaptation of animals to altitude hypoxia

Altitude chamber experiments have shown that the quantity of oxygen consumption in the posthypoxic period as an index of adaptation to hypoxia is of a low informative value: during the normal course of adaptation, oxygen consumption changes insignificantly or decreases slightly; it increases somewhat if the hypoxic atmosphere contains CO2 (pCO2 = 19 - 27 mm Hg) and declines significantly (by 22.6%) only if adaptation is disordered. At the same time oxygen consumption can be a highly informative index, characterizing the efficiency of adaptation to hypoxia only if it is measured immediately after exposure to acute hypoxia. In this experimental design the magnitude of oxygen consumption increases with increasing oxygen debt which, as follows from our experiments, shows the degree of conditioning to altitude hypoxia.