Thromb Haemost 1988; 59(02): 319-322
DOI: 10.1055/s-0038-1642779
Original Articles
Schattauer GmbH Stuttgart

Expression of Fibrinogen on the Surface of ADP-Stimulated Platelets: Comparison of Human and Rabbit Platelets

Elizabeth J Harfenist
The Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
,
Marian A Packham
The Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
,
Fraser J Mustard
*   Department of Pathology, McMaster University, Hamilton, Ontario, Canada
› Institutsangaben
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Publikationsverlauf

Received 04. August 1987

Accepted after revision 28. Dezember 1987

Publikationsdatum:
21. Mai 2018 (online)

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Summary

Fibrinogen is a cofactor in the aggregation of human platelets and must be added to suspensions of washed human platelets forextensive aggregation to occur in response to ADR Although thepatterns of fibrinogen binding and dissociation during plateletaggregation and deaggregation are similar for human and rabbitplatelets, washed rabbit platelets aggregate extensively whenstimulated with ADP even in the absence of added fibrinogen. Todetermine whether secreted fibrinogen was present on the surfaceof ADP-stimulated platelets and available to support aggregation, the binding of 125I-F(ab’)2 fragments of anti-fibrinogen antibodiesto formaldehyde-fixed platelets was measured. Although nofibrinogen was detected on human platelets either before or aftertreatment with ADP, fibrinogen was expressed on the surface ofrabbit platelets after stimulation with ADP. However, thissecreted fibrinogen did not dissociate during deaggregation of theplatelets. Thus, the aggregation of rabbit platelets in the absenceof exogeneous fibrinogen may be supported by secreted fibrino-gen, but a fibrinogen-independent component has not beencompletely ruled out.