Contact activation of blood coagulation is inhibited by plasma factor XIII b-chain

The effect of the purified bovine plasma factor XIII b-chain on contact activation of blood coagulation was studied in human and bovine plasma using either an ellagic acid-phospholipid suspension (Cephotest) or dextran sulfate as activating surface. Contact activation was monitored by the generation of amidolytic activity towards a synthetic chromogenic substrate (S-2302) for factor XIIa and plasma kallikrein. The factor XIII b-chain, which is...