title: Formation of prostacyclin-sensitive platelet aggregates in human whole blood in vitro. Part I. The occurrence of the phenomenon in healthy male volunteers.
abstract: When unstirred citrated blood of young males was left to stand at 21 degrees C, the number of free platelets decreased as measured with a whole blood platelet counter. This decrease indicated spontaneous platelet aggregation (SPA) since it was accompanied by the time-dependent increase in platelet micro-aggregates and plasma beta-thromboglobulin while lactate dehydrogenase level did not change significantly. Addition of PGI2 to whole blood increased free platelet count and decreased the number of platelet micro-aggregates. The de-aggregatory effect of PGI2 (measured as a percentage increase in free platelet number) was correlated with the initial amount of platelet micro-aggregates. Blood storage enhanced SPA and de-aggregatory effect of prostacyclin. Immediately after blood collection de-aggregatory effect of prostacyclin was absent. Our results favour an assumption that prostacyclin-sensitive platelet aggregates in blood of young volunteers are formed in vitro rather than in vivo.
mesh_terms: D000328:Adult; D001081:Apyrase / Q000494:pharmacology; D001769:Blood; D005576:Colforsin / Q000494:pharmacology; D011464:Epoprostenol / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010976:Platelet Count / Q000187:drug effects; D013997:Time Factors; D001620:beta-Thromboglobulin / Q000097:blood
chemical_list: D001620:beta-Thromboglobulin; D005576:Colforsin; D011464:Epoprostenol; D007770:L-Lactate Dehydrogenase; D001081:Apyrase