The influence of thrombin on the platelet-aggregating activity of human factor VIII. A study with insolubilized thrombin.
A study was made of the influence of thrombin on the platelet-aggregating activity of human factor VIII with Ristocetin as cofactor. Purified factor VIII and different amounts of a thrombin-Sepharose 2B complex were mixed and incubated for various periods of time. The factor VIII-related platelet-aggregating activities of the filtrates of the incubation mixtures were determined in a test system using formalin-fixed platelets and Ristocetin as cofactor. The results so obtained indicate that thrombin inactivates the platelet-aggregating activity of factor VIII. The filtrates of the incubation mixtures were also tested by a two-stage test system for the clotting activities. Comparison of the influence of thrombin on the clotting- and the platelet-aggregating activities of factor VIII is presented and discussed.
D000818:Animals; D001780:Blood Coagulation Tests; D002850:Chromatography, Gel; D005169:Factor VIII / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D010974:Platelet Aggregation; D011817:Rabbits; D012685:Sepharose / Q000494:pharmacology; D012995:Solubility; D013917:Thrombin / Q000494:pharmacology*; D013997:Time Factors
D005169:Factor VIII; D012685:Sepharose; D013917:Thrombin