Rheologic determinants of human blood viscosity during breathing a hypoxic mixture

: Blood samples of healthy male subjects exposed to three-wk hypoxia were analyzed for deformation and aggregation of erythrocytes. Results of the investigation showed that breathing a hypoxic mixture increases blood viscosity by way of raising rigidity of erythrocytes and fastness of their aggregates. A direct correlation between the deformability index and rate of aggregation was established. The physiological effect of this phenomenon is explained by the compensatory reaction of organism in support of the circulation structure and the breathing function of blood in hypoxic conditions.