Activation of platelets by eosinophil granule proteins.
Two of the four principal cationic proteins of the eosinophil granule, major basic protein (MBP) and eosinophil peroxidase (EPO), were shown to be platelet agonists. Both MBP and EPO evoked a dose-dependent nonlytic secretion of platelet 5-hydroxytryptamine in unstirred platelet suspensions even in the presence of 10 microM indomethacin. MBP also evoked secretion of platelet alpha granule and lysosome components. Secretion by MBP and EPO was inhibited by 1 microM PGE1, but the nature of the inhibition differed from that observed with thrombin. Thus, MBP and EPO can be classified as strong platelet agonists with a distinct mechanism of activation.
Department of Medicine, Mayo Clinic, Rochester, Minnesota 55905.
M S
MS
Rohrbach
C L
CL
Wheatley
N R
NR
Slifman
G J
GJ
Gleich
D000527:Alprostadil / Q000494:pharmacology; D001798:Blood Proteins / Q000494:pharmacology*; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000201:enzymology / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D010544:Peroxidases / Q000494:pharmacology; D015539:Platelet Activation / Q000187:drug effects*; D012260:Ribonucleases; D012701:Serotonin / Q000378:metabolism; D013927:Thrombosis / Q000209:etiology; D013928:Thromboxane A2 / Q000096:biosynthesis
D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D012701:Serotonin; D013928:Thromboxane A2; D010544:Peroxidases; D012260:Ribonucleases; D000527:Alprostadil