Characteristics of phospholipids associated with fibrins in partial thromboplastin test

With the aim to obtain information on the role of individual phospholipids in the coagulation process, lipids associated with fibrins formed with partial thromboplastin reagents were examined. In the absence of the partial thromboplastin reagents, phosphatidylethanolamine and phosphatidylserine plus phosphatidylinositol in citrated plasma were incorporated preferentially into fibrin, although the main phospholipid associated with the fibrin was phosphatidylcholine. In the presence of the partial thromboplastin reagents, most phospholipids unseparable from the corresponding fibrins appeared to be derived from the reagents with little selectivity for individual phospholipids, except for lysophosphatidylcholine. These results suggest that phospholipids other than thromboplastic phospholipids may play some role in the coagulation process. The incorporation of lysophosphatidylcholine in the reagent into fibrins was significantly enhanced by the addition of activating agents (celite and ellagic acid), suggesting one role of the activating agents in fibrin formation.