Fibrinopeptide A cleavage and platelet release in whole blood in vitro. Effects of stimuli, inhibitors, and agitation.

The relationship between platelet release and fibrinopeptide A cleavage from fibrinogen to form fibrin I in vitro was examined in blood allowed to clot undisturbed or with gentle agitation. In undisturbed or agitated blood platelet release and fibrin I formation occurred simultaneously. When hirudin was added to undisturbed blood it prevented platelet release as well as fibrin I formation.

Radioimmunoassay of platelet factor 4 and beta-thromboglobulin: development and application to studies of platelet release in relation to fibrinopeptide A generation.

Platelet and fibrinogen survival and turnover studies have shown that platelet activation and fibrin formation may occur to different degrees in different thrombotic disorders. More direct evidence of differential involvement of platelet activation and fibrin formation should be provided by specifically measuring the products of these reactions, i.e.