Carr M E, Krishnamurti C, Alving B M
Medical Service, McGuire Veterans Administration Hospital, Richmond, VA 23249.
Thromb Haemost. 1992 Jan 23;67(1):106-10.
The effect of fibrin on the interaction of human recombinant single-chain tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) was studied in normal rabbit plasma and in plasma with high levels of native PAI-1. t-PA was added to diluted plasma containing calcium (10 mM) and 125I-fibrinogen at 37 degrees C. Clotting was initiated with human thrombin, and lysis was monitored both turbidimetrically and by release of 125I-fibrin degradation products (fdp). The activity of t-PA (50 IU/ml) was rapidly reduced to 15% of the initial value in plasma containing PAI-1 (23 AU/ml). When thrombin and t-PA were added simultaneously to the plasma, more than 70% of the activity was retained through incorporation of t-PA into the fibrin clot. t-PA-induced fibrinolysis in PAI-1 enriched plasma was further delayed when the temperature was reduced from 37 to 25 degrees C. Turbidimetric and 125I-fdp release data provided complementary information. The former technique traced fiber dissolution, while the latter reflected network integrity. These results indicate that t-PA-induced fibrinolysis in PAI-1 enriched plasma is modulated by the presence of fibrin and by temperature.
在正常兔血浆和含有高水平天然纤溶酶原激活物抑制剂-1（PAI-1）的血浆中，研究了纤维蛋白对人重组单链组织型纤溶酶原激活物（t-PA）与纤溶酶原激活物抑制剂-1（PAI-1）相互作用的影响。将t-PA加入到含有钙（10 mM）和125I-纤维蛋白原的稀释血浆中，于37℃孵育。用人凝血酶启动凝血，并通过比浊法和125I-纤维蛋白降解产物（fdp）的释放来监测纤维蛋白溶解。在含有PAI-1（23 AU/ml）的血浆中，t-PA（50 IU/ml）的活性迅速降至初始值的15%。当同时将凝血酶和t-PA加入血浆时，通过将t-PA掺入纤维蛋白凝块中，超过70%的活性得以保留。当温度从37℃降至25℃时，PAI-1富集血浆中t-PA诱导的纤维蛋白溶解进一步延迟。比浊法和125I-fdp释放数据提供了互补信息。前一种技术追踪纤维溶解，而后一种技术反映网络完整性。这些结果表明，PAI-1富集血浆中t-PA诱导的纤维蛋白溶解受纤维蛋白的存在和温度的调节。
