Abstract
Experimental and clinical studies were carried out to determine the effective dosage of uronase, a preparation of urokinase for blood clot lysis. In vitro study showed that canine and human clots were lysed with about 20-30 units of uronase per ml. Uronase was used in a circulating model, in which an isolated canine liver was perfused for 24 hours. In the perfusion system, a mesh was inserted to remove fibrin during the study. Practically no fibrin was caught on the mesh when uronase was added to the perfusion fluid at the dose as used in the in vitro study. Uronase was administered in 17 cases with acute thromboembolism of the lower extremities with and without surgery. Nine of 11 cases, to which over 30, 000 units were given as an initial dose and then 10, 000 units as a maintenance dose for about a week showed clot lysis, while 3 of 6 cases which received less initial and maintenance dosages of uronase showed less clot lysis.
