Comp P C, Esmon C T
J Clin Invest. 1981 Nov;68(5):1221-8. doi: 10.1172/jci110368.
Bovine-activated protein C, administered intravenously to dogs, increases the rate of lysis of whole blood clots. Protein C, bovine prothrombin, and diisopropylfluorophosphate-inactivated protein Ca do not increase the rate of lysis. Repeated infusions of protein Ca sustain rapid blood clot lysis, but neither elevate circulating fibrin-split products nor decrease circulating plasminogen levels. The administration of protein Ca results in the elevation of the levels of lysine-adsorbable plasminogen activator activity in the plasma. When partially purified concentrates of this activator are added to normal dog blood at the levels seen following protein Ca injection, the rate of clot lysis is similar to that seen after protein Ca injection. The addition of protein Ca to citrated whole blood in vitro, with the subsequent neutralization of protein Ca with antibodies, results in increased rates of lysis when plasma made from the treated blood is reinjected into the animal. The generation of fibrinolytic activity is dependent on both cellular and plasma components of blood. A model of protein Ca fibrinolytic activity has a minimum of two components: a secondary messenger formed by protein Ca action on blood cells and plasma, and the subsequent appearance of plasminogen activator in the animal in response to that messenger.
给狗静脉注射牛活化蛋白C可提高全血凝块的溶解速度。蛋白C、牛凝血酶原和二异丙基氟磷酸酯灭活的蛋白Ca则不会提高溶解速度。重复输注蛋白Ca可维持快速的血凝块溶解，但既不会提高循环纤维蛋白降解产物水平，也不会降低循环纤溶酶原水平。注射蛋白Ca会导致血浆中赖氨酸可吸附的纤溶酶原激活物活性水平升高。当以蛋白Ca注射后所观察到的水平将这种激活物的部分纯化浓缩物添加到正常狗的血液中时，血凝块溶解速度与蛋白Ca注射后相似。在体外将蛋白Ca添加到枸橼酸化全血中，随后用抗体中和蛋白Ca，当将经处理血液制成的血浆重新注入动物体内时，溶解速度会加快。纤溶活性的产生依赖于血液中的细胞成分和血浆成分。蛋白Ca纤溶活性模型至少有两个成分：蛋白Ca作用于血细胞和血浆形成的第二信使，以及动物体内随后因该信使而出现的纤溶酶原激活物。
