Deguchi K, Murashima S, Nishikawa M, Shirakawa S
College of Medical Science, Mie University.
Nihon Rinsho. 1992 Feb;50(2):297-302.
The aim of this study is to evaluate the relationship between tissue plasminogen activator (tPA)/PA inhibitor (PAI) complex and PAI, and platelet in the circulating blood. tPA/PAI complex and active PAI (act PAI; Teijin Co., Japan), and PAI antigen (PAI ant; Biopool AB, Sweden) were assayed by enzyme immunoassay (EIA). The mean concentrations (ng/10(9) platelets) in supernatant from lysate of platelet rich plasma (PRP) and washed platelets were 27.1 +/- 9.2, 1.5 +/- 1.2 in tPA/PAI complex, 188.7 +/- 46.1, 83.3 +/- 7.5 in act PAI and 236.2 +/- 41.6, 191.9 +/- 45.1 in PAI ant, respectively. PRP was mixed with ADP (10(-5), 10(-4), 10(-3) M), for 3 min and the supernatant after centrifugation then was provided for assay of PAI and tPA/PAI complex. Concentrations of act PAI, PAI ant and tPA/PAI complex dose-dependently increased with ADP. Almost the same results were obtained, when collagen and other agents were used instead of ADP. This study revealed that platelets contained quantities PAI (as free PAI) and released PAI during aggregation, and that a part of the PAI immediately formed a complex with tPA. Those findings suggested that platelets may play an important role on the formation of thrombus, in the way of anti-fibrinolysis, in addition to novel platelet functions, such as aggregation.
本研究旨在评估组织型纤溶酶原激活物（tPA）/PA抑制剂（PAI）复合物与PAI以及循环血液中血小板之间的关系。采用酶免疫测定法（EIA）检测tPA/PAI复合物、活性PAI（act PAI；日本帝人公司）和PAI抗原（PAI ant；瑞典Biopool AB公司）。富含血小板血浆（PRP）和洗涤后血小板裂解物上清液中的平均浓度（ng/10⁹血小板）分别为：tPA/PAI复合物为27.1±9.2、1.5±1.2；act PAI为188.7±46.1、83.3±7.5；PAI ant为236.2±41.6、191.9±45.1。将PRP与ADP（10⁻⁵、10⁻⁴、10⁻³M）混合3分钟，离心后的上清液用于检测PAI和tPA/PAI复合物。act PAI、PAI ant和tPA/PAI复合物的浓度随ADP呈剂量依赖性增加。当使用胶原蛋白和其他试剂代替ADP时，获得了几乎相同的结果。本研究表明，血小板含有一定量的PAI（以游离PAI形式），在聚集过程中释放PAI，并且一部分PAI会立即与tPA形成复合物。这些发现表明，血小板除了具有诸如聚集等新的血小板功能外，可能在血栓形成过程中通过抗纤溶作用发挥重要作用。
