Fibrinolysis in the Animal Organism

Abstract

IT is now known that the action of the fibrinolytic substance produced by certain streptococci is due to its properties as an activator for the transformation of a proenzyme present in blood serum and plasma into a proteolytic enzyme acting on the fibrin. This activation can also be carried out by treatment with chloroform (for references see Christensen¹ and Kaplan²). Considerable confusion concerning the nomenclature for the substances interacting in the fibrinolysis exists ; but it seems most logical to use the proposal of Loomis, George and Ryder³. According to this, the name 'fibrinolysin' is used for the active fibrinolytic enzyme, while the inactive precursor is termed 'profibrinolysin'. The activating principle produced by streptococci, and previously termed fibrinolysin, is called 'streptokinase'. This nomenclature expresses thus the similarity between the system in question and certain other enzyme systems, for example, the formation of trypsin and thrombin.