[Cytospectrophotometric study of hemoglobin in human erythrocytes. II. Methemoglobin formation in acute hypobaric hypoxia].

The percentage of erthrocytes with thorn-shaped protuberances--echinocytes--was calculated in the blood smears of 10 healthy men before and after a 48 hour sharp hypobaric hypoxia in the climatic chamber of Tabai. The absorbtion spectra at the range 400-650 nm were investigated in the smooth erythrocytes and echinocytes. The methemoglobin content in the echinocytes is higher than in the smooth erythrocytes. The sharp hypobaric hypoxia results in the increase in the percentage of echinocytes and erythrocytes with fetal hemoglobin, in the change of osmotic stability and acidic resistance of erythrocytes, and in the rise of peroxid oxidation of lipids. The role of methemoglobin production upon a sharp hypobaric hypoxia is discussed.