2003 Volume 11 Issue 3+4 Pages 87-95
Fibrinogen irradiated by X-ray (X-fibrinogen) resulted in a delay in the polymerization by the addition of thrombin in an X-ray-dose dependent manner (Koh et al., 1997). The aim of the present study was to visualize and analyze this fibrin with confocal laser-scanning fluorescence microscopy (CLSM). Using CLSM, we analyzed the structures of the networks formed from RITC-labeled X-fibrinogen, FITC-labeled unirradiated normal fibrinogen (N-fibrinogen), and mixtures of the two. The X-network demonstrated an irregular, poorly-organized mass. Composite networks formed by a combination of X- and N-fibrinogen in various amounts were also abnormal in shape, although they were not as irregular as those formed by X-fibrinogen alone, and they contained fibrils with homogeneously mixed colors. The dissolution of the fibrin by plasmin showed similar fluorescence localization in agglomerates at the periphery of the network and in the unraveled network inside the lysing area. Dissolution by urokinase-type plasminogen activator resulted in loosely connecting fibers. Because no changes occurred in the chemical properties of the X- and N-fibrinogens—electrophoretic cross-linking patterns by Factor XIIIa, and quantities of fibrinopeptide A by thrombin activation—those results suggest that X-rays might induce molecular lesions at the sites necessary for polymerization, thus facilitating delayed association of the fibrin monomers.
