Detection and characterization of red blood cell rbc aggregation with photoacoustics eno hysi a, ratan k. Detection and characterization of red blood cell rbc. Red blood cell aggregation oguz k baskurt, bjorn neu. Rouleaux are stacks of erythrocytes which form because of the unique discoid shape of the cells in vertebrate body. The aggregation of human red blood cells rbc is a dominant factor of the in vitro rheological properties of blood. The test is usually part of a complete blood count cbc test that measures all the components in. It has previously been unclear, however, if rbc aggregation affects microvascular perfusion. Blood inflammatory biomarkers of cardiovascular disease. Red blood cells in humansand most other mammalshave a tendency to form aggregates with a characteristic facetoface morphology, simi. The hydrodynamic radius rh of individual samples of dextran, polyvinylpyrrolidone, and polyoxyethylene over a range of molecular weights 15002,000,000 were calculated from their intrinsic viscosities using the einstein viscosity relation and directly measured by quasielastic light scattering. We compared red blood cell aggregation characteristics, blood viscosity and hvr at different shear rates between sickle cell anemia and sickle cell hemoglobin c. The aggregation of red blood cells by macromolecular bridging involves energy balance at the cell surface.
Oguz baskurt is a professor of physiology at koc university school of medicine, istanbul turkey. Erythrocyte aggregation is the reversible clumping of red blood cells rbcs under low shear. Changes in the microstruture of blood caused by the red blood cell aggregation phenomenon affect the mechanical properties of the fluid. The hardcover of the red blood cell aggregation by oguz baskurt, bjorn neu, herbert j. Red blood cells and relation to thrombosis intechopen. An rbc count is a blood test thats used to find out how many red blood cells rbcs you have. Red blood cell aggregation by oguz baskurt, bjorn neu. Highly sensitive detection of red blood cell aggregation.
Red blood cell aggregation varies widely between species 242, suggesting that it is not essential for the inflammatory process. Blood viscosity is determined by plasma viscosity, hematocrit volume fraction of red blood cell, which constitute 99. The model combines electrostatic repulsion due to rbc. It thus seems likely that these factors could play a role in sickle cell disease. Rheology of red blood cell aggregation by computer. Red blood cell deformability and aggregation behaviour in. Whole blood viscosity and red blood cell aggregation is in. Mutual interaction of red blood cells influenced by. An approach is thus described for calculating the interaction energy between rbc in polymer solutions.
The disaggregating energies result from electrostatic repulsion between the sialic acids on cell surfaces and mechanical shearing stress. Erythrocytes aggregate in a special way, forming rouleaux. Polymerinduced red blood cell rbc aggregation is of current basic science and clinical interest, and a depletionmediated model for this phenomenon has been suggested. In general the role of the cellular factors for the aggregation was masked increasing the aggregating force between rbc. Explain why red blood cells are reliant on glucose for energy.
Depletionmediated red blood cell aggregation in polymer. Polymerinduced red blood cell rbc aggregation is of current basic science and clinical interest, and a depletionmediated model for this phenomenon has. Known as rouleaux, these aggregates are a normally occurring phenomenon and have a major impact on blood rheology. Depletionmediated red blood cell aggregation in polymer solutions.
Investigation of blood flow analysis and red blood cell. The natural tendency of the human red blood cells rbc 1. Effect of red blood cell aggregation on tube flow ch. Describe the roles of erythropoietin, thrombopoietin, and other cytokines in the production of red blood cells and platelets. Red blood cell rbc aggregates can influence microcirculation 1, especially in pathological conditions 2. The effects of nonionic polymers on human red blood cell rbc aggregation were investigated.
Once it gets moving and builds momentum, it flows fast. This aggregation process is believed to be reversible, but there is still no full understanding on the binding mechanism. The buckling instability of aggregating red blood cells. The hydrodynamic radii of macromolecules and their effect. There are at least two competing models, based either on bridging or on depletion. The deformability of rbcs allows them to flow in microvessels while transporting oxygen and carbon dioxide. Influence of red blood cell aggregation on perfusion of an. Red blood cells harpers illustrated biochemistry, 30e.
Describe the enzyme systems that protect heme iron from oxidation and reduce methemoglobin. The energy of macromolecular binding to the cell membrane provides the primary aggregating energy. Kolios a adepartment of physics, ryers on university, toronto, canada. Recent evidence suggests that red blood cell aggregation and the ratio of hematocrit to blood viscosity hvr, an index of the oxygen transport potential of blood, might considerably modulate blood flow dynamics in the microcirculation. Erythrocyte aggregation an overview sciencedirect topics. Other major blood components include plasma, white blood cells, and platelets. Red blood cells have unique mechanical behavior, which can be discussed under the terms erythrocyte deformability and erythrocyte aggregation. In addition, red blood cells release adenosine diphosphate adp and thromboxane a2 txa2 which enhances platelet aggregation. Red blood cell aggregation, aggregate strength and oxygen. Activated platelets can directly interact with erythrocytes 3 or affect erythrocytes with. Physical charaterization of red blood cell aggregation. Erythrocyte aggregation is the reversible clumping of red blood cells rbcs under low shear forces or at stasis.
Enhanced rbc aggregation is well known to increase blood viscosity measured in rotational viscometers. The book covers basic, clinical, and physiological aspects of this important biophysical phenomenon and integrates these areas with concepts in bioengineering. In vivo hemodynamics and red blood cell aggregation ch. Application of cationic conjugated polymerouter membrane vesicle complexes in inhibiting red blood cell aggregation ping hea endong zhanga,b ruilian qia fengting lva libing liua,b shu wanga,b abeijing national laboratory for molecular sciences, institute of chemistry, chinese academy of. Red blood cells rbcs exhibit a unique deformability, which enables them to change shape reversibly in response to an external force. The aggregation of red blood cells rbc induced by the interactions between rbcs is a dominant factor of the in vitro rheological properties of blood, and existing models of blood. Meiselman red blood cells in humansand most other mammalshave a tendency to form aggregates with a characteristic facetoface morphology, similar to a stack of coins. Rheology of red blood cell aggregation by computer simulation. Journal of medical and biological engineering, 345. Impact of red blood cell transfusion on platelet aggregation and inflammatory response in anemic coronary and noncoronary patients the transfusion2 study impact of transfusion of red blood cell on platelet activation and aggregation studied with flow cytometry use and light transmission aggregometry. The primary function of red blood cells is to transport oxygen to body cells and deliver carbon dioxide to the lungs. Unlike water, which exhibits much more newtonian properties, blood moves sluggishly at low speeds and is more liquid at fast speeds. Effect of red blood cell aggregation on in vitro blood rheology ch. To evaluate differences in erythrocyte deformability in mammals, three species were investigated, whose erythrocytes have a different aggregation property.
Red blood cells are known to form aggregates in the form of rouleaux. Red blood cells because no rbc aggregation occurs in phosphate buffered saline pbs 21, but blood plasma proteins strongly affect rbc aggregation, the experiments were conducted in. Red blood cells, also called erythrocytes, are the most abundant cell type in the blood. Due to the presence of fibrinogen on cell membranes and globulin in the plasma, rbcs tend to. Red blood cells rbcs have generally been viewed as innocent bystanders in. Red blood cell aggregation crc press book red blood cells in humansand most other mammalshave a tendency to form aggregates with a characteristic facetoface morphology, similar to a stack of coins. Fibrinogen increases blood viscosity and promotes red blood cell aggregation, which may help leukocytes to marginate and start rolling 241. More important than rbc adhesion to endothelial cells as a. The influence of red blood cell rbc aggregation on blood flow in vivo has been under debate since early 1900s, yet a full understanding has still has not been reached. Past studies on rbc aggregation, have confirmed the effects of fibrinogen a crosslinking protein concentration on rbc aggregation. Red blood cells rbcs suspended in plasma form multicellular aggregates under low flow conditions, increasing apparent blood viscosity at low shear rates. Plasma proteins such as fibrinogen induce the aggregation of red blood cells rbc into rouleaux, which are responsible for the pronounced shear thinning behavior of blood. His research is focused on the role of hemorheological factors in in vivo flow dynamics of blood, and he has conducted research on the mechanisms of red blood cell aggregation and hemorheological instrumentation. Pathological erythrocyte aggregation can stimulate abnormal processes by itself and intensify some abnormalities of blood coagulation.
23 865 547 591 1202 941 891 27 1285 1115 102 86 522 1237 509 895 207 121 681 1244 1557 327 714 1496 933 994 1462 852 1413 1542 98 773 399 1423 1554 1450 648 566 893 537 232 535 145 1110