Studies of the Mechanisms of the Human Platelet Release Reaction Induced by Immunologic Stimuli I. Complement-Dependent and Complement-Independent Reactions

摘要: Human platelets in the presence of plasma show a biphasic response to immune complexes (IC) formed from either antigen and antibody or aggregated immunoglobulin. Rapid release serotonin within 1st min is unaffected by cobra venom factor (CVF), EDTA, agents which prevent aggregating action ADP, but inhibited complement (C) components. This appears be direct interaction IC analogous washed C1. Aggregation follows, accompanied second requires ADP CVF EDTA. It dependent on C, activated most probably via classical pathway. Zymosan (Z) causes aggregation with characteristics phase IC-induced release. reaction, occurs after an 8 10 minute lag phase, has absolute requirement for C components may C3 shunt. Z binds necessary such that resulting complex (Z-X) induces platelet system. Divalent metal ions are Z-X.