STUDIES ON THE THROMBOLYTIC ACTIVITY OF HUMAN PLASMA *

Abstract

A sensitive measure of plasma thrombolytic activity is described involving determination of the release of radioactivity from isotopically-labeled human plasma clots immersed in unaltered plasma. The results of studies with this method indicate that plasma from normal adults contains a small amount of plasminogen activator capable of lysing human plasma clots under conditions similar to those in vivo and that the quantity of this material varies in response to stress, drug administration and in disease.