Evidence for appearance of "lysis independent" procoagulant activities in collagen or thrombin stimulated platelets.
The availability of procoagulant activities in platelet suspensions lysed by sonication correlated directly with the degree of lysis (loss of LDH and 51Cr). Separate measurements of platelet factor 3 (PF3) and Factor V/Va activity revealed significant differences in appearance of these platelet activities in sonicated cell suspensions. Platelet factor 3 activity increased almost in parallel to the loss of 51Cr, whereas Factor V/Va activity became available at a significant slower rate. This might be explained by the localization of Factor V/Va activities inside the alpha-granules and therefore not immediately available on the surface of the partially lysed platelets. No increase in lactate dehydrogenase or 51Cr-loss was observed during 12 min incubation of platelet suspension with collagen or thrombin, whereas both PF3 and Factor V/Va activities increased. Thus, the high platelet factor 3 activity of 34% (lysed platelets 100%) measured in thrombin stimulated platelet suspensions probably represents "lysis-independent" activity.
D001779:Blood Coagulation Factors / Q000032:analysis*; D001792:Blood Platelets / Q000187:drug effects; D002857:Chromium / Q000378:metabolism; D003094:Collagen / Q000494:pharmacology*; D005165:Factor V / Q000032:analysis*; D015943:Factor Va; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D010974:Platelet Aggregation / Q000187:drug effects*; D010977:Platelet Factor 3 / Q000032:analysis*; D013917:Thrombin / Q000494:pharmacology*
D001779:Blood Coagulation Factors; D002857:Chromium; D010977:Platelet Factor 3; D015943:Factor Va; D005165:Factor V; D003094:Collagen; D007770:L-Lactate Dehydrogenase; D013917:Thrombin