[Plasminogen depletion and incorporation in experimental venous thrombosis]

The objective of this piece of work is to study (using animals): venous thrombosis, the depletion and incorporation of plasminogen in thrombus of different stages of time, in order to devise better guide lines for the treatment of thrombosis than the conventional treatment. The studies relating to the plasminogen content of the thrombus show us that, on experimental venous thrombosis, as from the fifth day after which it occurred, the content of the plasminogen thrombus is reduced considerably. This data underlines the fact some venous thrombosis of over five days are resistant to conventional thrombolytic treatment. In relation to this we have to report that the mean lifespan according to our experiments of the plasminogen on beagle dogs is approximately sixteen hours. On the other hand the study of the addition of 125Lis-plasminogen, on experimental thrombosis of different stages of oldness show us that the above addition results in a 54% intake into the thrombus on three day, old thrombosis and 17% on five day old thrombosis. In conclusion we can suggest that the resistance to conventional thrombolytic treatment of old venous thrombosis (5-7 days old) is probably due to a reduction of efficiency of the thrombus plasminogen. At the same time the contribution of exogenous lis-plasminogen does not produce a sufficient enrichment of the thrombus in plasminogen. Therefore the therapeutic exogenous plasminogen addition is not advisable for relatively old thrombosis (less than or equal to 5 days old).