Monkey Platelet Membrane Glycoproteins and Aggregation

Abstract

The monkey is classified as close to the human and is important as an experimental animal. The present study, a comparison of human and monkey platelet membrane glycopreteins and aggregation, was undertaken.The major platelet membrane glycoprotein was similarly represented in humans and monkeys by SDS-polyacrylamide gel electrophoresis and PAS staining. Crossed immunoelectrophoresis showed that EDTA dissociated both human and monkey platelet GP IIb/IIIa complex. In monkey platelets, ADP-induced aggregation was slightly weaked than in humans. High concentrations of ristocetin were required to agglutinate monkey platelets. Human and monkey platelets were aggretated by collagen and thrombin in the same manner. Epinephrine did not induce aggregation in monkey platelets. All of five monoclonal antibodies against human platelet GP IIb/IIIa complex bound to monkey platelets, and inhibited monkey platelet aggregation induced by ADP and collagen. A monocolnal anti-human platelet GP Ib antibody which has no effect on either human platelet aggregation induced by thrombin or agglutination induced by ristocetin bound to monkey platelets. But an anti-GP Ib antibody which inhibits human platelet agglutination induced by ristocetin did not bind to monkey platelets. Both of two monoclonal antibodies against human CD9 antigen bound to monkey platelets and aggregated monkey platelets.These rusults indicate that human and monkey platelets are similar in terms of antigenicity and function, especially GP IIb/IIIa complex. It is suggested that the monkey is a useful animal model for analysis of the effects of monoclonal anitbody against human platelets in vivo.