Increased urokinase-type plasminogen activator (u-PA) levels in graft liver perfusate and decreased single chain u-PA activation with higher levels of aprotinin.

In orthotopic liver transplantation (OLT) the graft liver is perfused with arterial blood prior to the opening of the hepatocaval anastomosis. In the present investigation we focused on the reperfusion of the graft liver in order to study the hepatic influence in the regulation of urokinase-type plasminogen activator (u-PA levels). Two different aprotinin schedules were used in 43 patients. We measured u-PA levels in the perfusate and in the corresponding systemic circulation. u-PA levels were higher in the perfusate as compared to systemic blood samples despite the dilution of the perfusate sample by the preservation fluid. This suggests u-PA secretion by the graft liver. In the presence of lower aprotinin levels signs of single-chain u-PA (scu-PA) activation was in the perfusate more prominent than systemically--a difference which was not seen in the presence of higher aprotinin levels. This seems to be an argument for the effectiveness of higher dosed aprotinin application in preventing scu-PA activation.