title: Ristocetin-Willebrand factor activity in dog plasma.
abstract: A sensitive and reproducible method for the quantitation of ristocetin-Willebrand factor activity in canine plasma is described. This assay measures the initial velocity of aggregation of suspensions of canine washed platelets in the presence of ristocetin and ristocetin-Willebrand factor. The washed platelets are stable for 4 h and when prepared from the same donor vary little in their day-to-day response to ristocetin. The calculated mean plasma ristocetin-Willebrand factor activity in 37 normal dogs using this method is 98 +/- 26% (mean +/- SD) Ristocetin-Willebrand activity is 106 +/- 25% in dogs with severe hemophilia A and 45 +/- 13% in dogs with moderate forms of von Willebrand's disease.
mesh_terms: D000818:Animals; D001779:Blood Coagulation Factors / Q000032:analysis*; D001792:Blood Platelets / Q000378:metabolism; D004285:Dogs; D006467:Hemophilia A / Q000097:blood; D010974:Platelet Aggregation; D012310:Ristocetin / Q000097:blood*; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D001779:Blood Coagulation Factors; D014841:von Willebrand Factor; D012310:Ristocetin