Download PDF
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

Authors

  • 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
Further Information

Publication History

Received 27 January 1987

Accepted after revision 11 June 1987

Publication Date:
28 June 2018 (online)

 PDF Download  Permissions and Reprints
Preview

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