EVALUATION OF ROLE OF INVIVO PROTEOLYSIS (FIBRINOGENOLYSIS) IN PROLONGING THROMBIN TIME OF HUMAN UMBILICAL-CORD FIBRINOGEN

Abstract

The aggregation rate of cord fibrin compared with that from adult plasma was always delayed when the reaction was carried out under conditions of relatively high ionic strength (e.g., 0.29); this difference was not apparent at relatively low ionic strength (e.g., 0.09). In addition, as assessed by turbidimetric techniques, the maximum absorbance attained by cord fibrin was considerably less than that attained by adult fibrin. Coagulable fibrinogen catabolites (i.e., fraction 1-5) were present in cord plasma and, like their counterparts from adult plasma, lacked various portions of the COOH-terminal region of the A.alpha. chain. Their presence in plasma did not explain the behavioral differences between cord and adult fibrin. Differences revealed by turbidimetric comparison of cord and adult fibrin from plasma fraction 1-2 persisted in fibrin from fraction 1-5; the COOH-terminal region of the A.alpha. chain apparently does not contain the structure(s) accounting for the unique behavior of fetal fibrinogen.