title: Experimental investigation of the rheological activation of blood platelets.
abstract: In order to define various aspects of platelet rheological activation, samples of whole blood and platelet-rich plasma (PRP) from the same donors were subjected for 5 min to shear rates increasing from 10 to 10000 sec-1 (shear stresses from 10(-2) to 30 Pa approximatively) in a Couette type viscometer. The following parameters were measured: erythrocyte hemolysis; lactic dehydrogenase activity; plasma B-Thromboglobulin (B-TG); adenine nucleotides, and platelet photometric aggregation. The experimental results reveal that: In whole blood, hemolysis only reached at maximum 2% of the total hemolysis. Plasma LDH activity increased regularly beyond 500 sec-1, in close correlation with B-TG plasma concentration. In contrast, ADP and ATP levels remained stable up to 1000 sec-1 then increased slowly. In PRP, the LDH, ADP and ATP levels remain practically stable up to shear rates around 5000 sec-1. In contrast, B-TG appeared to be released in plasma at shear rate values of 3000 sec-1 and its progression is only correlated with the other parameters, when the platelet lysis occurred. Finally, a rapid and complete inhibition of platelet aggregation to ADP was observed from 5000 sec-1.
mesh_terms: D000244:Adenosine Diphosphate / Q000097:blood; D000255:Adenosine Triphosphate / Q000097:blood; D001792:Blood Platelets / Q000502:physiology*; D004912:Erythrocytes / Q000378:metabolism; D006461:Hemolysis; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D010974:Platelet Aggregation; D001620:beta-Thromboglobulin / Q000378:metabolism
chemical_list: D001620:beta-Thromboglobulin; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase