THE EFFECT OF VARIOUS CONTRAST-MEDIA ON THE ACTIVATION OF PLASMINOGENBY STREPTOKINASE OR RECOMBINANT TISSUE-PLASMINOGEN ACTIVATOR IN-VITRO

RATIONALE AND OBJECTIVES. Radiologic contrast media (CM) may influence processes of coagulation and fibrinolysis. In the current study, the effects of various CM on the formation of plasmin were examined in an in vitro buffer system. METHODS. The effects of three clinically relev ant concentrations of seven different iodine-containing CM and gadolin ium-DTPA on streptokinase (SK) or recombinant tissue plasminogen activ ator (rt-PA)-induced plasmin formation was monitored using a plasmin-s ensitive chromogenic substrate. RESULTS. Contrast media generally had an inhibitory effect at the plasminogen activation step; this effect w as particularly noticeable with the ionic CM. CONCLUSIONS. Contrast me dia influence plasminogen activation by SK and rt-PA in vitro. Ionic C M have a more pronounced inhibitory effect than the nonionic media. Th e ionic Gd-DTPA shows a less inhibitory effect than the ionic iodine-c ontaining CM. However, they must be regarded separately because of the different chemical composition of the magnetic resonance imaging and x-ray CM.