Summary
Thrombus weight was used as a measure of the thrombus enhancing effect of drugs in
135 rats. The weight of thrombus formed in one hour, on a 20 × 0.5 mm platinum wire,
inserted in the vena cava was taken as a measure of thrombosis. The change in thrombus
weight which followed the injection of ellagic acid to activate the coagulation system,
adenosine diphosphate to activate the platelets, and epsilon-aminocaproic acid to
inhibit the fibrinolytic system, was measured. Pilot studies showed that the drug
doses used brought about the appropriate changes in the factors named. The mean thrombus
weight in 45 control animals was 1.93 mg. Ellagic acid increased it about five-fold,
and epsilon- aminocaproic acid almost two-fold, while adenosine diphosphate reduced
it by almost a half. Concurrent controls were used in each case. Clotting tests (whole
blood clotting time, kaolin-activated whole blood clotting time, thrombin time, and
partial thromboplastin time), performed at the end of the hour, showed no significant
correlation with thrombus weight.
