Kane K K
Ann Clin Lab Sci. 1984 Nov-Dec;14(6):443-9.
The function of fibrinolysis is to dissolve fibrin clots. The agent of fibrinolysis is plasmin, a glycoprotein with gram molecular weight (GMW) of 90,000. Under natural conditions, plasminogen is converted to plasmin by tissue plasminogen activator (TPA). Activation occurs on the fibrin surface, thus confining proteolytic activity to the appropriate site. Tissue plasminogen activator, produced by monoclonal methods, has recently been made available for limited therapeutic use. Currently streptokinase and urokinase are widely used therapeutically to activate plasminogen. These agents cause plasmin to be formed which is free in the circulation as well as bound to fibrin, resulting in proteolysis of circulating plasminogen and clotting factors. Fibrinolytic therapy has proven to be more beneficial than anticoagulation alone for deep vein thrombi and for pulmonary emboli. During therapy, laboratory studies demonstrate reduced concentrations of plasminogen, fibrinogen, and of alpha-2 plasmin inhibitor, and prolongation of activated partial thromboplastin time and thrombin time. Laboratory findings must be correlated with the clinical course. Demonstration of circulating plasmin-antiplasmin complex may be a useful indicator of active fibrinolysis.
纤维蛋白溶解的功能是溶解纤维蛋白凝块。纤维蛋白溶解的介质是纤溶酶，它是一种糖蛋白，克分子量（GMW）为90,000。在自然条件下，纤溶酶原通过组织纤溶酶原激活物（TPA）转化为纤溶酶。激活发生在纤维蛋白表面，从而将蛋白水解活性限制在适当的部位。通过单克隆方法生产的组织纤溶酶原激活物最近已可用于有限的治疗用途。目前，链激酶和尿激酶在治疗上被广泛用于激活纤溶酶原。这些药物使纤溶酶形成，纤溶酶在循环中既游离又与纤维蛋白结合，导致循环中的纤溶酶原和凝血因子发生蛋白水解。对于深静脉血栓和肺栓塞，纤维蛋白溶解疗法已被证明比单独抗凝更有益。在治疗期间，实验室研究表明纤溶酶原、纤维蛋白原和α-2纤溶酶抑制剂的浓度降低，活化部分凝血活酶时间和凝血酶时间延长。实验室检查结果必须与临床病程相关。循环中的纤溶酶 - 抗纤溶酶复合物的检测可能是纤维蛋白溶解活性的有用指标。
