A Rapid Method for the Estimation of Fibrinolytic Changes in the Dog

¹ From the Anemia Research Laboratory and the Cardiovascular Research Department, Harper Hospital, Detroit, Michigan

The fibrinolytic system in the dog was studied for investigating possible etiological factors concerned with the bleeding diathesis observed following surgery and shock. Canine profibrinolysin is poorly activated with streptokinase and therefore provided the basis for the test procedure for fibrinolysin. Marked fibrinolytic activation was observed in dogs as early as 5 minutes after 2.5 mg/kg of protamine sulfate was given intravenously. Heparin produced inhibition of the fibrinolytic system. This protamine activation and heparin inhibition was shown both in vivo and in vitro. Test procedures are presented for the estimation of profibrinolysin, fibrinolysin and antifibrinolysin. Activation of the fibrinolytic system through surgery, hyperventilation or protamine sulfate, was followed by an increase in antilysin but no change in total fibrinolysin concentration was noted.