No abstract

Platelet-free plasma of human blood (sodium citrate and EDTA as an anticoagulant) and serum were stored at 4˚C, room temperature (25˚C) and at 37˚C for 24 hours. RBC aggregation decreased after incubation of plasma and serum at 37˚C for 4 hours. The RBC shape was changed at the same time: discocytes transformed to echinocytes. Storage of plasma and serum at 4˚C and room temperature did not lead to significant alterations of RBC aggregation. The RBC shape did not change in influence of such plasma and serum. The most considerable decrease of RBC aggregation and change of their shapes were observed in the plasma and serum incubated at 37˚C for 24 hours. Dilution of incubated plasma by fresh plasma led to consistent restoration of erythrocyte shape and their aggregation.

A novel approach to the study of erythrocytes instability based on assessment fusability of their plasma membrane is presented. The fusability of erythrocytes normal blood, stored for 7 days at 4˚C, and type 2 patients with diabetes were studied. Human erythrocytes were fused by incubation with La 3+ at final concentrations from 50 to 200 µM. Erythrocytes aggregates were incubated at 37˚C for 120 min. The fusability of erythrocytes was evaluated using a light microscope. It was shown that La 3+ induced extensive fusion of erythrocytes after 7 days of blood storage and erythrocytes of patients with diabetes. Incubation of normal erythrocytes at 37˚C for 120 min does not induce cell fusion.