DIFFERENT EFFECT OF 5,6-TRANS-PROSTAGLANDIN E(2) ON PLASMINOGEN ACTIVATION BY UROKINASE AND STREPTOKINASE

We examined the effects of 5,6-trans-prostaglandin E(2) (trans-PG E(2) ) on fibrinolysis and plasminogen activation by either urokinase or st reptokinase. trans-PG E(2) was found to enhance fibrinolysis induced b y urokinase and inhibit the one by streptokinase. These effects were a lso appeared in the method using synthetic chromogenic substrate S-225 1, which suggested that the effects of trans-PG E(2) were induced in t he circumstances without coagulation factors such as fibrinogen, throm bin or fibrin. Moreover, the enhancement effect of trans-PG E(2) on fi brinolysis by urokinase was investigated. The result of SDS-PAGE indic ated that plasmin formation rate from plasminogen by urokinase was acc elerated in the presence of trans-PG E(2). As trans-PG E(2) increased the hydrolyzing rate of S-2288 by urokinase, trans-PG E(2) directly in teracted with urokinase. Therefore, the enhancement effect of trans-PG E(2) on plasminogen activation by urokinase could be explained, at le ast in part, as follows: at first trans-PG E(2) directly exerts its ef fect on urokinase, then it causes the increase of generation rate of p lasmin from plasminogen.