Fibrin deposition and fibrin degradation products in atherosclerotic plaques

Abstract

Soluble fibrin/fibrinogen-related antigens and insoluble fibrin are present in virtually all samples of human aortic intima. Components of the soluble fraction were identified by SDS-PAGE and immunoblotting with specific antisera. The fibrinogen was characterized by increased proportions of low molecular mass (Mr) species (300 and 280 kD), the FDP by fragments DY and DD derived from crosslinked fibrin, and by fragment E that lacked fibrinopeptide A (FPA). Experiments suggest that fibrin is formed in situ, and free thrombin was present in all 10 samples analysed for prothrombin-related antigen (PtRA). Fibrin-derived fragment E is mitogenic, so fibrin degradation may provide continuing stimulation of smooth muscle cell (SMC) proliferation.