ABSTRACT
Physiological changes in the blood play an important role in acclimatization and adaptation to high altitude. This chapter considers the changes in oxygen affinity of hemoglobin and the alterations of the acid–base status of the blood. The question of oxygen affinity of hemoglobin was examined again on the International High Altitude Expedition to Chile in 1935. It was found that the “physiological” dissociation curves were displaced slightly to the left of the sea-level values up to about 4270 m, but above that altitude, the curves were displaced increasingly to the right of the sea-level positions. The oxygen transport properties of vertebrate red blood cells exhibit a high degree of plasticity in adjusting to changes in metabolic demands and/or environmental oxygen availability. High altitude is just one of the oxygen-deprived environments in which animals are found, and it is interesting to consider the variety of strategies that have been adopted to mitigate the problems posed by oxygen deficiency.
