ИСТИНА

Blood microrheology depends on the properties and constituent components of blood plasma and the interaction between blood cells, i.e., red blood cell (RBC) and platelets aggregation. The aggregation mostly determines the viscosity of blood and finally blood microcirculation that in turn determined the perfusion of body tissues, hemostasis, the quality of nutrient transportation, etc. First, determining the aggregation blood status of a person can and should become an integral part of his/her medical examination, especially in the presence of such socially significant diseases as cardiovascular, oncological, endocrinological (diabetes), etc. Second, the understanding the causes and factors as well as mechanisms of blood cells interaction is an important task that can yield novel information for development of new protocols of correction of the impaired aggregation. In this regard, the development and testing of new effective techniques to monitoring aggregation properties of the cells and to study the mechanisms of the cell interaction is an challenging biophotonics and applied clinical task. The possibilities of using different laser-optic techniques to measure aggregation parameters of RBC and platelets and to study the mechanisms of their interaction are demonstrated and discussed. We used diffuse light scattering, and laser tweezers, fluorescent microscopy, turbidimetry to characterize blood samples obtained from healthy donors or patients suffering arterial hypertension, heart failure and/or diabetes mellitus. Fibrinogen-induced RBC aggregation was assumed to be caused by nonspecific binding of fibrinogen molecules to cell membranes and further leading to molecular bridging between interacting cells. In contrast, platelets are known to have membrane integrin IIb/IIIa glycoproteins highly specific to fibrinogen. In this paper, we present the results of optical study of the effect of integrin IIb/IIIa glycoproteins inhibition on fibrinogen adsorption on RBC membrane. We conclude that there is an inhibition effect which can serve as an evidence of the existence of fibrinogen specific binding sites with IIb/IIIa glycoprotein related structures on RBC membrane. Our results allow us to conclude that the laser-optic methods are an effective tool for studying the intrinsic properties of RBCs and their interactions, as well as for monitoring the pathological changes of their microrheologic parameters in vitro.