The microrheological behavior of young and old red blood cells in athletes

Previous studies have shown a difference in rheological properties of young versus senescent RBCs. There are data that the athletes blood has more young RBCs than untrained people. Our research was a comparative study of the microrheological properties of young and old RBCs in athletes and in untrained people that was as control group. In athletes (men, n=24) and group of the control (men, n=20) the following parameters were measured: RBC aggregation (ARBC; Myrenne aggregometer) and deformability, RBC suspension and plasma viscosity as well as osmolarity, albumin, globulin and fibrinogen concentration, MCHC. Red cells were density (i.e., age) fractionated by the method of Murphy. After centrifugation the top 10% of the packed cell column (RBCtop, relatively young cells) and the bottom 10% (RBCbot, relatively old cells) were resuspended at 40.0+/-0.4% (in plasma) for aggregation, deformation and suspension viscosity measurements. It was found significant difference in aggregation and rigidity of the all RBC subpopulations between athletes and control group. The difference in aggregation was associated with reduced fibrinogen and increased ratio albumin/globulin in athletes. Besides, the correlation between aggregation RBCtop and RBCbot with fibrinogen was decreased in athletes. It was one of the cause of high fluidity of the RBCtop- and RBCbot suspensions and whole blood in athletes and more effective oxygen transport than in untrained people.