Lactate during exercise at extreme altitude.

摘要: Maximal exercise at extreme altitude results in profound arterial hypoxemia and, presumably, tissue hypoxia. The best evidence available indicates that the resting PO2 on summit of Mount Everest is about 28 torr and it falls even further during exercise. Nevertheless, some 10 climbers have now reached without supplementary oxygen. Paradoxically, blood lactate for a given work rate high acclimatized subjects essentially same as sea level. Because capacity decreases markedly with increasing altitude, maximal also falls. Extrapolation data up to 6300 m climber who reaches will no increase lactate. cause low not fully understood. One possibility depletion plasma bicarbonate subjects, which reduces buffering large increases H+ concentration release consequent local fall pH may inhibit enzymes, e.g., phosphofructokinase (EC 2.7.1.56), glycolytic pathway.