INTRAVENOUS TRYPSIN: ITS ANTICOAGULANT, FIBRINOLYTIC AND THROMBOLYTIC EFFECTS 1

Abstract

Fibrinogenolysis and prolonged blood coagula-tion have been observed following large intrave-nous doses of crystalline trypsin ( 1).2 The present study was undertaken to evaluate further the ef-fects of intravenous crystalline trypsin upon the protein components of the coagulation mechanism and the fibrin content of artificially induced intra-vascular thrombi, in 60 rabbits and 25 dogs. A striking observation in this study was the lack of untoward reactions, including shock, when the rate and concentration of injected trypsin were kept within carefully calculated limits. MATERIALS 1) Sixty rabbits whose average weight was 2 kg. were fed rabbit food pellets and given water ad libitum. 2) Twenty-five mongrel dogs, including 5 dogs used as controls, were housed together and fed Purina Dog Chow. Their average weight was between 10 to 12 kg. 3) Crystalline trypsin, i.e. Armour Tryptar @ prepara-tion,8 was used in each experiment. 4) 0.5 ml. of 10 per cent sodium morrhuate, or 0.2 ml. (125 units) of topical thrombin (Parke, Davis), or 0.5 ml. of thromboplastin (simplastin) were used to produce thrombi in rabbits and dogs. 5) Bovine fibrinogen (Armour), and topical thrombin (Parke, Davis) were used in antithrombin determinations. METHODS 1) Experimental production of thrombi in rabbits and dogs. Experimental thrombi were produced in one of the marginal ear veins of each of 60 rabbits by injecting 0.5 ml. of 10 per cent sodium morrhuate or 125 units