In Vitro Formation of Fibrin-Monomer Complexes in the Presence of Isotope Labelled Fibrinogen-Fibrin Degradation Products. An Agarose Gel Filtration Study
Human citrated plasmas were mixed with purified 131I-fibrinogen and 131I-fibrinogen degradation products (FDP) or 125I-fibrin degradation products (fdp). After incubation with small amounts of thrombin (0.01–0.02 imits/ml Pl.), these mixtures were gel filtrated on Biogel A5m columns and the elution patterns of the 131I- and -labelled materials were determined.In control experiments without thrombin incubation, no complex formation between fibrinogen, FDP or fdp in citrated plasmas could be detected. This was even true for fdp with a higher molecular weight than fibrinogen.After thrombin incubation, up to 11% fibrin-monomer complexes were formed. Irrespective of their molecular weights, labelled fdp were not incorporated into these complexes.Only large FDP – presumably derivative X – did partially copolymerize with fibrin-monomer complexes in citrated plasmas.