The thrombolytic action of Protease 1 on experimentally produced venous thrombi in the dog

TWO methods for the production of venous thrombiin vivo are described. In the first instance radiopaque thrombi were formed. The disadvantages of this method are presented and the reasons for abandoning the technique are discussed. In the second method “physiological” thrombi were producedin vivo and a method of radiographically visualising dissolution of the thrombus is described. The advantages of this method and its potential in the evaluation and comparison of thrombolytic agents are demonstrated. The thrombolytic substance used was the Protease 1 of Aspergillus oryzae. Reports that this agent is thrombolytic are confirmed.