Lijnen H R
Behring Inst Mitt. 1983 Aug(73):43-55.
Fibrinolysis in the blood seems to be regulated by specific molecular interactions between plasminogen activator, plasmin(ogen), fibrin and alpha 2-antiplasmin. Plasmin(ogen) contains structures, called lysine-binding sites, which mediate its interaction with fibrin and with alpha 2-antiplasmin. In plasma normally no systemic plasminogen activation by plasminogen activator occurs and plasmin, if formed, is efficiently neutralized by alpha 2-antiplasmin. When fibrin is formed in plasma a small amount of plasminogen is bound via its lysine-binding sites. Plasminogen activator present or released in the blood is strongly adsorbed to the fibrin and activates bound plasminogen in situ. The formed plasmin, which remains transiently complexed to fibrin, both by its lysine-binding site(s) and active center, is only slowly inactivated by alpha 2-antiplasmin, while plasmin which is released from digested fibrin is rapidly and irreversibly neutralized. The fibrinolytic process thus seems to be triggered by and confined to fibrin. An important consequence of this molecular model for fibrinolysis is that specific thrombolysis is only expected with the use of a specific activator, like the physiological extrinsic plasminogen activator, which confines the activation of plasminogen to the fibrin surface. Recent in vitro and in vivo studies have confirmed that the extrinsic plasminogen activator (tissue-type) might constitute a superior thrombolytic agent compared to urokinase or streptokinase.
血液中的纤维蛋白溶解似乎受纤溶酶原激活物、纤溶酶（原）、纤维蛋白和α2 -抗纤溶酶之间特定分子相互作用的调节。纤溶酶（原）含有称为赖氨酸结合位点的结构，介导其与纤维蛋白以及与α2 -抗纤溶酶的相互作用。在正常血浆中，纤溶酶原激活物不会引起全身性纤溶酶原激活，并且如果形成纤溶酶，会被α2 -抗纤溶酶有效中和。当血浆中形成纤维蛋白时，少量纤溶酶原通过其赖氨酸结合位点结合。血液中存在或释放的纤溶酶原激活物会强烈吸附到纤维蛋白上，并原位激活结合的纤溶酶原。形成的纤溶酶通过其赖氨酸结合位点和活性中心与纤维蛋白短暂结合，仅缓慢地被α2 -抗纤溶酶灭活，而从降解的纤维蛋白中释放的纤溶酶则迅速且不可逆地被中和。因此，纤维蛋白溶解过程似乎由纤维蛋白触发并局限于纤维蛋白。这种纤维蛋白溶解分子模型的一个重要结果是，只有使用特定的激活物，如生理性外源性纤溶酶原激活物，才有望实现特异性溶栓，它将纤溶酶原的激活局限于纤维蛋白表面。最近的体外和体内研究证实，与尿激酶或链激酶相比，外源性纤溶酶原激活物（组织型）可能是一种更优越的溶栓剂。
