Effects of arvin in mice. Immunofluorescent and histochemical studies

The in vivo response to injection of a purified fraction of Malayan pit viper venom, Arvin, has been studied in mice. Fibrin "microclots" were localized by means of immunofluorescence mainly in the lungs and to a lesser extent in the kidneys, liver and spleen. Increased fibrinolysis in these organs was demonstrated by means of the histochemical slide method. Inhibition of fibrinolysis in the tissues by soy bean trypsin inhibitor and epsilon-aminocaproic acid prior to Arvin injection was followed by significantly increased deposition of fibrinogen and/or its derivatives with formation of thrombi and death of 50% of the animals. These observations indicate the importance of tissue activation of plasminogen and the rapid lysis of microclots in clinical defibrination by Arvin.