Red Blood Cells Take On Many-Sided Shapes:
Red blood cells are real levers of change in body shape, perhaps the most malleable of all cell types , transformation – among other forms – in compressed discs able to pass through capillaries with diameters less than the cell itself blood . While the study of how blood clots John W. contract Weisel , Ph.D. , Professor of Cell and Developmental Biology at the Perelman School of Medicine at the University of Pennsylvania, and his colleagues discovered a new geometry that red blood cells are supposed to when compressed during clot formation .
Although red blood cells were visualized for the first time in the mid-17th century and studied extensively since then , this new study , published online ahead of print in the journal Blood, describes a previously unknown and new function potential of red blood cells . The Penn team found that red blood cells can be compressed into multifaceted structures close together – polyhedral – instead bi – concave , free-flowing form of the disc.
What is more , contrary to expectations , the fibrin and platelet aggregates which form highly clots are mainly employed on the outside of clots , with red blood cells crowded into the clot , while the content of clots are more homogeneous before shrinkage occurs .
Hired clots can form a watertight seal and help prevent vascular obstruction, but confer resistance to penetration of drugs that break down fibrin, the structural component of blood clots , one common treatment option for heart attacks and strokes.
” When I first saw this, he thought :” This can not be biological , ‘”says Weisel . The team first saw the red blood cells shaped polyhedron – when the coagulation process of contraction is studied using a novel MRI technology , with the co -authors of T2 Biosystems, along with co -author Douglas Cines , MD , director of the Coagulation Laboratory and Professor of Pathology and Laboratory Medicine at Penn. They observed a signal indicating tight red blood cells.
The clot network clots are dimensional network of fibers , mainly consisting of the blood protein fibrinogen , which is converted to fibrin during coagulation , and platelets , which aggregate by binding to fibrin once activated . A blood clot must have the proper degree of rigidity and plasticity to stop the flow of blood when tissue is damaged , however , be flexible enough that it does not block the blood flow .
After a clot forms , actin and myosin in platelets initiate the contraction process and cause the clot is reduced to about one third of its original size. This is an important step to stop bleeding , to reduce the blockage in the blood vessel , and to provide a matrix for the migration of cells involved in wound healing . Red blood cells are involved in the contraction process , especially in the venous system , and get pulled by platelets into the clot, blood and the study indicated .
Little is known about the structure of the contracted clots or the role of red blood cells in the contraction process . “We found that the contracted blood clots develop a remarkable structure with a mesh of fibrin and platelet aggregates outside the clot and close packing , tiled matrix of polyhedral erythrocytes compressed inside ,” says Weisel .
The team also saw the same morphology of compacted clots after initiating coagulation activators and also with several clots formed from reconstituted human blood cellular components and blood plasma and mouse . Such matrices polyhedral packing of erythrocytes or polyhedrocytes as researchers dubbed them , were also observed in human arterial thrombi taken from patients who had heart attacks . This form is likely taken up by the red blood cells when contracted or compressed together when platelets clot in order to decrease the volume , surface energy , or the energy of bending , the authors assume .
Cines notes that these findings may have clinical implications . Doctors need to inject tPA as thrombolytic agents to quickly break thrombi , clots that obstruct blood flow , for example, in the coronary arteries to treat a heart attack or arteries leading to the brain to treat stroke. It is well known that thrombi develop time be broken , which is one reason why early intervention resistance is important . The nearly impermeable barrier formed by the red blood cells within contracted clots was observed in the study of the blood can help explain why . Clot contraction could be a target of intervention to prevent the formation of densely packed array polyhedrocytes .