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Thromb Haemost 1987; 58(03): 911-914
DOI: 10.1055/s-0038-1646014
Original Article
Schattauer GmbH Stuttgart

Platelet Density-Dependent Partition of Platelet- von Willebrand Factor Between Alpha Granule and Non-Alpha Granule Pools

R I Parker
The Hematology Service, Clinical Pathology Department, Clinical Center National Institutes of Health, Bethesda, MD, USA
,
Brenda C Shafer
The Hematology Service, Clinical Pathology Department, Clinical Center National Institutes of Health, Bethesda, MD, USA
,
H R Gralnick
The Hematology Service, Clinical Pathology Department, Clinical Center National Institutes of Health, Bethesda, MD, USA
› Author Affiliations
Further Information

Publication History

Received 27 January 1987

Accepted after revision 11 June 1987

Publication Date:
28 June 2018 (online)

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Summary

In this study, we demonstrate that platelets contain a small hut significant amount of platelet-von Willebrand factor(vWf) not associated with α-granules. When platelets free of plasma proteins are exposed to micromolar concentrations ofdigitonin, plasma membrane permeabilization occurs without disruption of platelet granules. Employing this technique, wehave found that upon exposure of a total platelet population to 8 μM digitonin, 5% of total platelet-vWf is released into the supernatant; this occurs without release of (β-TG from α-granules. When platelets of discrete buoyant density profiles are tested, this extragranular platelet-vWf increased with decreasing platelet density. These findings suggest that a redistribution of platelet-vWf from α-granule to non-granule sites occurs coincident with a decrease inplatelet buoyant density.

Keywords

Platelet-vWf - Platelet density - Alpha granules