Effect of hypoxia on function and metabolism of the alveolar macrophages

Cytophysiological and cytophotometric investigations showed that hypoxic hypoxia equivalent to an altitude of 5000 m effective for 9–11 days inhibits the phagocytic activity of the alveolar macrophages in rabbits. Meanwhile the activity of lactate and glucose-6-phosphate dehydrogenases in the macrophages is increased but the activity of malate dehydrogenase falls; this is indirect evidence of stimulation of glucose metabolism in the pentose shunt and of glycolysis and also of inhibition of metabolism in the Embden-Meyerhof-Krebs cycle. On the basis of experiments in vitro showing that respiration is the main source of energy supplying the phagocytic function of the pulmonary macrophages it is concluded that inhibition of respiration of the macrophages in hypoxia is the cause of the depression of their phagocytic activity.