Platelet surface glycoproteins. Studies on resting and activated platelets and platelet membrane microparticles in normal subjects, and observations in patients during adult respiratory distress syndrome and cardiac surgery.

摘要: The accurate definition of surface glycoprotein abnormalities in circulating platelets may provide better understanding bleeding and thrombotic disorders. Platelet glycoproteins were measured on intact whole blood platelet membrane microparticles assayed cell-free plasma using 125I-monoclonal antibodies. (GP) studied were: GP Ib IIb-IIIa, two the major intrinsic glycoproteins; GMP-140, an alpha-granule that becomes exposed following secretion; thrombospondin (TSP), secreted rebinds to surface. Thrombin-induced secretion normal caused appearance GMP-140 TSP surface, increased exposure decreased antibody binding Ib. Patients with adult respiratory distress syndrome had concentration their platelets, demonstrating vivo secretion, but no increase plasma. In contrast, patients after cardiac surgery cardiopulmonary bypass demonstrated changes consistent fragmentation without secretion: a IIb TSP, microparticles. These methods will help define acquired glycoproteins.