Harfenist E J, Packham M A, Mustard J F
Thromb Haemost. 1985 Apr 22;53(2):183-7.
Because fibrin, formed at a site of vessel wall injury, is involved in the formation and stabilization of a platelet aggregate or thrombus, we have studied reactions of fibrin with rabbit platelets. Gly-Pro-Arg-Pro, an inhibitor of fibrin polymerization, was used to prepare soluble fibrin. Fibrin alone did not cause aggregation of washed platelets, but addition of ADP caused aggregation and deaggregation identical to those observed in the presence of fibrinogen. Specific binding of 125I-fibrin to ADP-stimulated platelets was similar to that of 125I-fibrinogen, but 125I-fibrin did not dissociate, even in the presence of high concentrations of apyrase. High non-specific binding of 125I-fibrin was observed that was not associated with aggregation. EDTA, prostaglandin E1 (PGE1) and creatine phosphate/creatine phosphokinase prevented ADP-induced aggregation in the presence of fibrin and caused rapid deaggregation when added after ADP. They also inhibited 125I-fibrin binding when added before ADP, and EDTA or PGE1 caused partial dissociation of bound 125I-fibrin. In vivo, fibrin may bind to stimulated platelets, polymerize, form a gel, and interact with components of the plasma, the platelet aggregate, and the exposed subendothelium.
由于在血管壁损伤部位形成的纤维蛋白参与血小板聚集体或血栓的形成与稳定，我们研究了纤维蛋白与兔血小板的反应。使用纤维蛋白聚合抑制剂甘氨酰-脯氨酰-精氨酰-脯氨酸制备可溶性纤维蛋白。单独的纤维蛋白不会引起洗涤过的血小板聚集，但添加二磷酸腺苷（ADP）会导致聚集和解聚，这与在纤维蛋白原存在下观察到的情况相同。125I标记的纤维蛋白与ADP刺激的血小板的特异性结合与125I标记的纤维蛋白原相似，但即使在高浓度的腺苷三磷酸双磷酸酶存在下，125I标记的纤维蛋白也不会解离。观察到125I标记的纤维蛋白有较高的非特异性结合，且与聚集无关。在纤维蛋白存在的情况下，乙二胺四乙酸（EDTA）、前列腺素E1（PGE1）和磷酸肌酸/肌酸磷酸激酶可防止ADP诱导的聚集，并在ADP添加后导致快速解聚。当在ADP之前添加时，它们还会抑制125I标记的纤维蛋白的结合，并且EDTA或PGE1会导致结合的125I标记的纤维蛋白部分解离。在体内，纤维蛋白可能会与受刺激的血小板结合、聚合、形成凝胶，并与血浆成分、血小板聚集体和暴露的内皮下层相互作用。
