SDS Polyacrylamide Gel Characterization of Serum FDP Produced in Response to Ancrod and Streptokinase/Plasminogen Infusions in Man

S ummary . The serum FDP produced in response to defibrination with ancrod and to thrombolytic therapy with intermittent streptokinase/plasminogen infusion have been characterized using a method of solid phase immuno-precipitation followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. Using this method it is possible to distinguish between the plasmin degradation products of fibrinogen and factor XIIIa induced crosslinked fibrin. During ancrod administration, fragments of similar mobility to fibrinogen fragments X, Y, D and E are present in serum samples taken 24 h after the initiation of treatment, while subsequent samples contain mainly fragments with the same mobility as fibrinogen fiagment D. The intermittent nature of the streptokinase/plasminogen infusions produces fibrinogen fragments X, Y, D and E in the serum 1 h after each daily streptokinase/plasminogen administration. An early clearance of fragment E from the circulation of patients receiving either ancrod or streptokinase/plasminogen infusions accords with the results of other investigations. The presence of the D dimer fragment, which is produced only by plasmin lysis of factor XIIIa crosslinked fibrin, could not be conclusively confirmed in either group of patients.