EFFECT OF THE MODEL OF MECHANIAL STRESS (IN VITRO) ON THE BIOPHYSICAL PROPERTIES OF BIOMEMBRANE OF GRANULOCYTES

Abstract

In the microvasculature the granulocytes function under conditions of force impact from the shifting layers of the moving plasma while the erythrocytes and endothelium cells excrete ATP molecules in the intercellular space acting as para- and autocrine regulators of interactions between the blood cells. It is possible to study interactions between granulocytes and erythrocytes thought purinergic signalling in small vessels under conditions close to physiological ones using the model of mechanical “stress” in vitro. The functional activity of granulocytes is determined by such properties of plasmalemma as stiffness and potential of a surface as well as the force of intercellular adhesion. In connection with the foregoing, the goal of the work was to investigate the biophysical properties of granulocytes’ plasmalemma in the condition of mechanical “stress” in vitro. Atomic force microscopy methods were used in the semi-contact scanning and force spectroscopy mode to achieve this goal. In the condition of mechanical “stress” was found an increase in the ATP concentration by 147% as compared with the control. At the same time, the biophysical properties of the surface of blood cells changed: the potential of surface and stiffness of granulocytes decreased by 32% and 15% respectively, while the negative charge of the erythrocyte’s surface increased by 112% which contributed to increase the adhesion force in the system “erythrocyte-granulocyte” by 55% as compared with the control. Thus, the obtained data allows summarized that the ATP molecule excreting by erythrocytes in the condition of mechanical “stress” is an auto- and paracrine regulator of biophysical properties of erythrocytes’ and granulocytes’ plasmalemma that have an important impact in the study of the mechanisms of intercellular interactions in the microvasculature and searching the pharmacological regulators of vascular tone.