抄録
To clarify the thromobolytic mechanism, the thrombi of 11 cases taken at surgery and autopsy were morphologyically investigated by using urokinase (HMW 54, 000) and plasminogen. These included fresh and old organized thrombi, which were divided into two groups so as to examine whether the thrombolysis due to urokinase depend upon its dose or its incubation time. As a result, the thrombolysis mainly depended upon the incubation time rather than dose of urokinase, furthermore plasminogen was proved to be effective for the thrombolysis.
Morphological findings on these experiments showed that the superfficial fibrin membranes initially disappeared and then each thrombus had porous surface, from which urokinase and plasminogen would get into the thrombi to lyse fibrin. Ultrastructural observation disclosed disappearance, irregularity, shortening, and thinning of fibrin.
It is of great interest that the organized, at least more than 5 days old, thrombi also showed thrombolysis by urokinase and plaminogen.
In the thrombolytic effects on the artificial thrombi, it was the most effective to treat with urokinase and plasminogen from outside similtaneously. As the thrombi were lysed, some of thrombi showed fragmentation, which would lead clinically to hemorrhagic infacrt and/or microinfarct because of traveling of small fragmented thrombi.
