[Strategies of adaptation of oxygen transport systems in mammals to life at high altitude].

Like many mammalian species, man responds to exposure to high altitude with an increasing hemoglobin concentration and a decreasing blood O2-affinity. The Lama vicugna of the Andes does not show this kind of adaptation to altitude. Even at high altitude its hematocrit is unusually low and its O2-affinity is the highest known among mammals. Additionally, it is characterized by a high capillary density of the muscles and a large relative heart weight. The consequences of these different strategies of altitude adaptation of the oxygen supply system and the capability for physical performance are discussed.