ИСТИНА

Microrheology of blood depends on many different factors, i.e., red blood cells (RBCs) aggregation, interaction between blood cells, between RBCs and vascular endothelium, etc [1]. Endothelial cells are the cells that line the interior surface of blood arteries, veins, and capillaries. Endothelium not only forms an insulating layer between blood and tissues, but also plays an important role in the regulation of blood flow in vessels due to the atrombogenicity of the cell membrane under physiological conditions [2]. Factors leading to the development of inflammatory process and other pathological conditions change the anticoagulant state of endothelium into procoagulant one. As far as endothelium interacts directly with blood cells, this interaction may change RBCs aggregation, for instance. RBCs aggregation is the reversible process of linear or more complex structures formation under low shear stress forces. Varying RBCs aggregation can change dramatically the viscosity of blood. It is well known that RBCs aggregation can occur only in the solution with high molecular weight molecules. In blood plasma the fibrinogen protein molecule is the main inducer of RBCs aggregation. Increased concentrations of fibrinogen in blood can cause thrombosis and vascular damage in case of inflammation and several diseases [1]. The main goal of this study was to investigate the interaction of RBCs of healthy donors with endothelial cell monolayer as well as the interaction between RBCs at stationary state at different concentrations of fibrinogen at single cell level in vitro using laser tweezers.