The earliest assessment of fibrin network porosity used a liquid permeation system and confocal 3D microscopy, which was later replaced by scanning electron microscopy. Although the methods have extensively been applied in studies of health or disease, there remains debate on the choice of a proper clotting trigger. In this review, we assess published data and convey our opinions with regard to several issues. First, when the coagulation process is initiated by recombinant tissue factor (rTF) and phospholipids, the fibrin network porosity is regulated by the endogenous thrombin based on enzymatic activations of multiple coagulants. If purified thrombin (1.0 IU/mL) is employed as the clotting trigger, fibrin network porosity may be affected by exogenous thrombin, which directly polymerizes fibrinogen in plasma, and additionally by endogenous thrombin stemming from a “positive feedback loop” action of the added thrombin. Second, with use of either endogenous or exogenous thrombin, the concentration and clotting property of available fibrinogen both influence the fibrin network porosity. Third, in the assay systems in vitro, exogenous thrombin but not rTF-induced endogenous thrombin seems to be functional enough to activate factor XIII, which then contributes to a decrease in the fibrin network porosity. Fourth, fibrin network porosity determines the transport of fibrinolytic components into/through the clots and therefore serves as an indicator of the fibrinolysis potential in plasma.

最早的纤维蛋白网络孔隙率评估使用液体渗透系统和共焦 3D 显微镜，后来被扫描电子显微镜取代。尽管这些方法已广泛应用于健康或疾病研究，但关于选择合适的凝血触发因素仍存在争议。在本次审查中，我们评估了已发布的数据并就几个问题表达了我们的意见。首先，当凝血过程由重组组织因子 (rTF) 和磷脂启动时，纤维蛋白网络孔隙率由基于多种凝血剂的酶激活的内源性凝血酶调节。如果使用纯化的凝血酶 (1.0 IU/mL) 作为凝血触发器，纤维蛋白网络孔隙率可能会受到外源性凝血酶的影响，外源性凝血酶直接聚合血浆中的纤维蛋白原，并且另外通过来自添加的凝血酶的“正反馈回路”作用的内源性凝血酶。其次，使用内源性或外源性凝血酶，可用纤维蛋白原的浓度和凝血特性都会影响纤维蛋白网络孔隙率。第三，在体外测定系统中，外源性凝血酶而非 rTF 诱导的内源性凝血酶似乎具有足以激活因子 XIII 的功能，从而有助于降低纤维蛋白网络孔隙率。第四，纤维蛋白网络孔隙率决定了纤维蛋白溶解成分进入/通过凝块的运输，因此可作为血浆中纤维蛋白溶解潜力的指标。可用纤维蛋白原的浓度和凝血特性都会影响纤维蛋白网络的孔隙率。第三，在体外测定系统中，外源性凝血酶而非 rTF 诱导的内源性凝血酶似乎具有足以激活因子 XIII 的功能，从而有助于降低纤维蛋白网络孔隙率。第四，纤维蛋白网络孔隙率决定了纤维蛋白溶解成分进入/通过凝块的运输，因此可作为血浆中纤维蛋白溶解潜力的指标。可用纤维蛋白原的浓度和凝血特性都会影响纤维蛋白网络的孔隙率。第三，在体外测定系统中，外源性凝血酶而非 rTF 诱导的内源性凝血酶似乎具有足以激活因子 XIII 的功能，从而有助于降低纤维蛋白网络孔隙率。第四，纤维蛋白网络孔隙率决定了纤维蛋白溶解成分进入/通过凝块的运输，因此可作为血浆中纤维蛋白溶解潜力的指标。