Increased Resistance to Plasmic Degradation of Fibrin With Highly Crosslinked a-Polymer Chains Formed at High Factor XIII Concentrations

We have previously demonstrated that increasing factor XIII concentrations above that present in plasma (1 U/mI) results in the formation of very high molecular weight a fate polyacrylamide and agarose gel electrophoresis (SDSPAGE). In this report. we have examined the effect of such crosslinking on plasmic susceptibility of fibrin prepared from purified fibrinogen and from plasma in the presence of factor XIII concentrations between 0 and 10 U/mI. The crosslinking achieved with purified fibrinogen at 1 U/mI factor XIII increased resistance to plasmic degradation by 32% as measured in a radiolabeled clot lysis system. However, further increases in plasmic resistance occurred at factor XIII concentrations of 2 and 10 U/mI, the latter decreasing the lysis rate to 45% of that which occurred in the absence of factor XIII. To achieve the same rate of clot