Morphological and functional features of the blood in humans during a nine-day stay in an oxyargon environment with various oxygen contents

Biochemical parameters of the red blood and oxygen transportation of hemoglobin by erythrocytes were studied in subjects who volunteered for chamber experiments (0.15 MPa) with normal and hypoxic oxygen-nitrogen-argon (O₂-N₂-Ar) gas environments. Erythrocyte metabolism, lipid and phospholipid spectra, and the efficiency of oxygen releasing and retention by hemoglobin were studied in the period of collecting baseline data, on the sixth day of stay in a hyperbaric normoxic O₂-N₂-Ar gas environment (13.7% O₂), on the third day of stay in a hyperbaric hypoxic O₂-N₂-Ar environment (9.9% O₂), and on the first and the tenth days of a postexperimental rehabilitation period. The high pressure, hypoxia, and the subsequent decompression resulted in a decrease in the ATP levels, which is probably due to the changes within the membrane and increased G6PD activity associated with cell repair. Changes in the lipid and phospholipid compositions of the membrane indicate an altered phase state of the plasma membrane, i.e., an increased viscosity, which may be related to possible changes in the membrane’s permeability. As a rule, hyperbaric conditions lead to a decrease in oxygen transportation in the blood of the subjects. Hypoxia against the background of hyperbaria had different effects on the subjects, namely, the absence of changes, a decrease, or an increase in the efficiency of oxygen transportation, which can be explained by the selectivity and individual sensitivity of the subjects to the experimental factors. A decrease in the efficiency of oxygen transportation by hemoglobin is most likely to be related to an increase in the viscosity of the plasma membrane, which may affect the conformation of hemoporphyrin of the membrane-bound hemoglobin and obstruct oxygen transportation through the membrane.