SINOPSIS

Using both modern and traditional methods of investigation of the erythrocyte osmotic resistance and membrane proteins, it has been shown that erythrocyte deformability in hemic hypoxia varies depending on the animals' age: the maximum erythrocyte deformability was observed in rats of prepubertal period (40.2%), and the minimum deformability was in the group of old rats (19.7%). Age changes in physical and chemical features of erythrocyte membranes during hypoxia are manifested in increased viscosity of the lipid bilayer (microviscosity index is reduced in old rats compared with young adult animals by 69.5%), and increased percentage of skeletal protein (spectrin by 53.0%), which determines the reduction in deformation capacity of erythrocytes. The relationship between age-related changes in erythrocyte membrane deformation and the state of regional microcirculation has been revealed. In old rats, perfusion volume is reduced by 43.8% compared with young animals; the fractional volume of erythrocytes passing through microcirculation vessels per unit time is reduced by 59.3%; the specific oxygen consumption index in the tissues and perfusion oxygen saturation index decrease by 6.6% and 50.0%, respectively.