ИСТИНА

Reversible spontaneous aggregation of red blood cells (RBC) is an intrinsic microrheologic property of blood determining and controlling the hydrodynamic resistance of the vessels network to the blood flow and the microcirculation, which, in their turn, determine the efficiency of oxygen delivery to tissues. The process of RBC aggregation is described by several parameters that can be quantitatively measured in vitro in whole blood samples by means of diffuse reflection of light. The interaction forces between the RBCs in aggregates can be measured with laser tweezers. It is also possible to estimate the aggregation state of blood in vivo by analyzing the dinamic images of blood flows in the terminal capillaries in several sites of the human body, e.g., in the finger nail bed. We shall discuss the physics behind these measurements and the experimental results obtained with blood samples drawn from healthy human individuals and patients suffering from socially important diseases like diabetes and hypertension. In addition, similar results obtained with blood drawn from healthy and diseased rats.