Generation of Prothrombin‐Converting Activity and the Exposure of Phosphatidylserine at the Outer Surface of Platelets

• DOI: 10.1111/j.1432-1033.1982.tb05898.x
• Publication Date: 2005-03-03T21:51:51Z
• Authors: Edouard M. BEVERS; Paul COMFURIUS; Jan L. M. L. VAN ...; H. Coenraad HEMKER; Robert F. A ZWAAL
• Keywords: Prothrombinase; Phosphatidylethanolamine

In the present paper we compare prothrombin‐converting activities of platelets non‐activated, or activated by collagen, thrombin collagen plus in absence and presence added factor V a . all experiments described, rate formation for combined action is greater than that stimulated alone. The enhanced cases, but higher activity observed with remains. When are X prothrombin, lag period approximately 10 min before reaches steady state. Addition an excess this experiment reduces time to 3 min. This interpreted as required generate extra binding sites prothrombinase complex at platelet surface. These explain difference between these either only. exposure phospholipids outer surface was studied phospholipases after various activations platelets. It demonstrated activation accompanied increased susceptibility towards phospholipase A 2 Among degradable phospho‐ lipids 25% phosphatidylserine 30% phosphatidylethanolamine. On other hand, little no exposed membrane exterior thrombin‐treated control We propose essential enhancement under conditions. possibility transbilayer movement result process will be discussed.