Membrane Changes Associated with Platelet Activation: EXPOSURE OF ACTIN ON THE PLATELET SURFACE AFTER THROMBIN-INDUCED SECRETION

摘要: Abstract The effect of aggregation and secretion on membrane proteins was studied in washed human platelets. Reversible without stimulated by ADP thrombin the presence EDTA. No loss platelet surface glycoproteins occurred during reversible ADP-induced aggregation, as measured quantitative polyacrylamide gel electrophoresis analysis platelets that were labeled with 125I-diazotized diiodosulfanilic acid (DD125ISA) before stimulation. Also, no new became exposed after determined DD125ISA labeling Thrombin-induced also caused glycoproteins. However, two DD125ISA: (a) actin (b) 149,000-mol wt glycoprotein (termed GP-G), which is contained granules secreted response to thrombin. The identity DD125ISA-labeled confirmed four criteria: comigration three different sodium dodecyl sulfate-polyacrylamide systems, elution from a particulate fraction low ionic strength buffer, (c) co-migration isoelectric focusing, (d) binding DNase I. its appearance thrombin-induced demonstrated greater an anti-actin antibody thrombin-treated platelets, 125I-staphylococcal protein A. Therefore, major changes occur but not aggregation. occurring may be important formation irreversible aggregates final retraction blood clot.