Premium
Radioimmunoassay of Platelet Factor 4 and β‐Thromboglobulin: Development and Application to Studies of Platelet Release in Relation to Fibrinopeptide A Generation
Author(s) -
Kaplan Karen L.,
Nossel Hymie L.,
Drillings Michael,
Lesznik George
Publication year - 1978
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1978.tb07135.x
Subject(s) - platelet factor 4 , platelet , thrombin , radioimmunoassay , beta thromboglobulin , chemistry , fibrin , fibrinogen , platelet activation , medicine , endocrinology , biochemistry , immunology
S ummary . 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. released platelet proteins and fibrinopeptide A. Two platelet proteins, platelet factor 4 (PF4) and β‐thromboglobulin (βTG), were isolated and characterized, and sensitive and specific radioimmunoassays were developed to measure them. These assays were employed, along with the radioimmunoassay for fibrinopeptide A (FPA), to study the release of PF4 and βTG in relation to FPA cleavage. PF4 and βTTG were released by ADP and collagen with time course and concentration dependence similar to that of [ 14 C]serotonin release. FPA was not cleaved from fibrinogen during ADP or collagen‐induced platelet release. Thrombin caused release of PF4 and βTTG as well as cleavage of FPA. Cleavage of FPA occurred with concentrations of thrombin about 100 times less than did release of PF4 and βTG, and release of [ 14 C]serotinin required still higher thrombin concentrations. Release of [ 14 C]serotonin and platelet proteins was similar as a function of time. Sodium citrate was found to inhibit platelet release induced by thrombin.