Summary
Intact and disintegrated human, dog and rabbit leukocytes were studied for their ability to lyse fibrin. It was noted that broken-up rabbit leukocytes fail to lyse bovine or rabbit fibrin. Human and dog leukocytes, on the other hand, readily lyse bovine fibrin.
Prior incubation at pH 1 and pH 8 resulted in maximally active human cell preparations. Similar results were obtained with dog cells upon prior incubation at pH 4 and pH 8. Loss of activity was noted upon prior incubation for 15 minutes at 56° C. Adsorption of human leukocytes with celite and charcoal resulted in a 2 and 21/2 fold increase in activity.
The noted lysis was found to result from proteolytic activity as well as from plasminogen activator activity. The results to these studies suggest that autolysis of relatively few leukocytes will produce a rapid breakdown of considerable amounts of fibrin.
