The mechanism of clearance of circulating fibrin monomer was investigated in rabbits through (1) study of decay in plasma concentrations of 125I-labeled monomers with variant fibrinopeptide content and (2) concurrent analysis of decay of the monomers relative to coinjected 131I-fibrinogen. Under the conditions employed, essentially all of the fibrin became distributed in a soluble form in plasm...

In spontaneous fibrinolysis of an alpha 2-plasmin inhibitor-deficient plasma clot or tissue-type plasminogen activator-induced fibrinolysis in a purified system without alpha 2-plasmin inhibitor, the lysis was faster when factor XIII-mediated crosslinking of fibrin to fibrin did not occur. During the initial period, the binding of plasminogen to fibrin steadily increased with incubation time. T...

Objective—A splice variant of fibrinogen, , has an altered C-terminal sequence in its gamma chain. This A/ fibrin is more resistant to lysis than A/ A fibrin. Whether the physical properties of and A fibrin may account for the difference in their fibrinolysis rate remains to be established. Methods and Results—Mechanical and morphological properties of cross-linked purified fibrin, including pe...

Recent studies in our laboratory, as well as others, have suggested that fibrin can regulate cell function in vitro and likely control inflammation in vivo by acting as a potent cell activator. This has led us to hypothesize that during tissue and vascular injury, fibrin can enhance leukocyte recruitment by inducing vascular endothelial cell expression of leukocyte chemotactic factors. To begin...

We explored the retraction or contraction of platelet-fibrin clots under isometric conditions. In the presence of micromolar calcium clots of normal platelet-rich plasma developed tension at an initial rate of 0.1 to 0.2 g/min per cm2 (initial cross-sectional area). Electron microscopy of clots fixed after attaining a force of 1.6 g/cm2 revealed platelets with elongated bodies and pseudopods in...

itor in blood plasma is higher than that in serum obtained from the blood clotted in the presence ofcalcium ions, but is the same as that in serum obtained in the absence of calcium ions. Radiolabeled a2-plasmin inhibitor was covalently bound to fibrin only when calcium ions were present at the time of clotting of plasma or fibrinogen. Whereas, when batroxobin, a snake venom enzyme that lacks t...

vascular fibrin formation were studied; ( I ) patients with preeclampsia; (2) those having treatment with ancrod (Arvin). In preeclampsia, soluble fibrin formation was greatly. increased in comparison with normal pregnant women. The isolated fibrin contained intact a, p and 7 chains; on polyacrylamide gel electrophoresis, no crosslinking of y chains could be found. A positive correlation was fo...

The three unique polypeptide chains of human fibrinogen differ significantly in molecular weight. Cross-linkage of fibrin by fibrin-stabilizing factor results in the rapid formation of cross-links between gamma-chains and a slower formation of cross-links between alpha-chains. beta-Chains are not involved directly in the cross-linking of fibrin. Reduced, cross-linked fibrin contains uncross-lin...

In a previous report we showed that plasmin-dependent lysis of a fibrin polymer, produced from purified components, was totally blocked if annexin II heterotetramer (AIIt) was present during fibrin polymer formation. Here, we show that AIIt inhibits fibrin clot lysis by stimulation of plasmin autodegradation, which results in a loss of plasmin activity. Furthermore, the C-terminal lysine residu...