On the significance of the fibrinolytic system of the blood

Abstract

Subject to a study in experiments on dogs (involving intravenous administration of nicotinic acid and thromboplastin, blood loss) and in observations of patients (operative interventions, atherosclerosis, thromboembolic disease, etc.) were interrelationships between the blood coagulation, fibrinogen concentration, fibrinolytic and fibrinogenolytic activity. The blood of healthy individuals and dogs showed fibrinolytic activity to be present regularly. Fibrinogenolytic activity, on the other hand, was absent. In stress conditions (surgical intervention, blood loss, nicotinic acid administration) the blood coagulation was accelerated with blood fibrinolytic activity increasing at the same time (no fibrinogenolysis was present). Intensified fibrinolytic activity of the blood is a normal protective body reaction, occurring with acceleration of blood coagulation. This regularity is disturbed in pathological conditions. Association of accelerated blood coagulation with diminished fibrinolysis (atherosclerosis, thromboembolic disease) creates favorable conditions for thrombosis. There is no direct relationship between blood fibrinogen concentration and its fibrinolytic activity. This is explained by the fact that, as a rule, activation of fibrinolytic system in the body leads to the intensification of its fibrinolytic properties, but not of fibrinogenolytic ones.