Recombinant t-PA and platelet activity
Richard C. Becker, MDAddress reprint requests to R.C.B., associate director, Coronary Care Unit, director, Thrombosis Research Center, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655.
Platelet-rich coronary arterial occlusions are relatively resistant to thrombolysis with recombinant tissue-type plasminogen activator, or rt-PA, while erythrocyte-rich thrombi are lysed at low doses. The combined administration of rt-PA with a platelet antagonist enhances thrombolysis and can prevent reocclusion, which suggests that platelet activation predominates during thrombus formation and after thrombolysis. In addition to direct effects on platelet activity, rt-PA also acts indirectly through generation of plasmin, which degrades fibrin.