Adhesion of human platelets to purified solid-phase von Willebrand factor: studies of normal and Bernard-Soulier platelets.
Thromb Res
; 32(2): 115-22, 1983 Oct 15.
Article
em En
| MEDLINE
| ID: mdl-6419373
ABSTRACT
Human Factor VIII associated von Willebrand factor (VIIIvWF) binds to human platelets in vitro only in the presence of a mediator such as ristocetin, thrombin or ADP. Studies reported here were designed to determine if human platelets will adhere to solid-phase VIIIvWF. Human VIIIvWF was purified from a phosphate precipitate of A1(OH)3 absorbed plasma using 4% agarose and DEAE cellulose. Purified VIIIvWF (90 units of VIIIvWF activity/mg) was coated on dialysis membranes using ultrafiltration (final concentration of 0.4 units/cm2). Membranes (0.5 cm2) were held stationary in human citrated PRP suspension or washed platelet suspensions and stirred continuously for 5 minutes at 37 degrees C. The membranes were then rinsed in phosphate buffered saline, fixed, stained, and examined by light and scanning electron microscopy. Abundant normal platelets adhered to VIIIvWF-coated membranes, while minimal adhesion was seen on uncoated membranes and membranes coated with albumin. Adhesion occurred without ristocetin, thrombin, ADP or other agonist and in the presence of Ca+2/Mg+2 ions. Preincubation of the VIIIvWF coated membranes with monospecific rabbit anti-VIIIvWF inhibited the adhesion reaction. However, preincubation of VIIIvWF coated membranes with naturally occurring human anti-FVIIIc antibodies failed to interfere with platelet adhesion. Platelets from a patient with Bernard-Soulier Syndrome (BSS) which did not bind human VIIIvWF in the presence of ristocetin or aggregate with bovine cryoprecipitate also did not adhere to VIIIvWF-coated membranes.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fatores de Coagulação Sanguínea
/
Fator VIII
/
Fator de von Willebrand
/
Adesividade Plaquetária
/
Trombocitemia Essencial
Limite:
Humans
Idioma:
En
Revista:
Thromb Res
Ano de publicação:
1983
Tipo de documento:
Article