INFLUENCE OF HEPARIN, HEPARIN PLUS APROTININ AND HIRUDIN ON CONTACT ACTIVATION IN A CARDIOPULMONARY BYPASS MODEL

In the present study we used an in vitro cardiopulmonary bypass model to compare activation of the FXII-plasma kallikrein systems, coagulati on pathway and blood cell changes, with heparin (3 U/ml), heparin plus aprotinin (3 U/ml and 250 KIU/ml) and recombinant hirudin (6 mu g/ml) . After 90 min circulation the results showed that with heparin plus a protinin and with hirudin the activation of these cascade reactions wa s markedly lower. In particular kallikrein-like activities and PMN-Ela stase-alpha(1)-PI levels were significantly lower in the latter two gr oups. The least activation was detected with hirudin. Our results conf irm that the contact systems of blood are activated during CPB with he parin as anticoagulant, that aprotinin reduces this activation, and th at recombinant hirudin may be preferred to heparin as an anticoagulant in cardiac surgery.