Abstract
The effect of Nafamostat mesilate (FUT-175), a protease inhibitor, on platelet morphology were analyzed using electron microscopy. Fourteen adult patients undergoing aortocoronary bypass surgery with cardiopulmonary bypass (CPB) were randomly distributed into an FUT treated group (8 patients) and a contol group (6 patients). In the FUT-treated group in addition to the usual treatment with heparin (300 U/kg), FUT-175 was infused continuously at a rate of 2mg/kg/h during CPB. Platelet surface morphology observed by scanning electron microscopy was classified into three grades (Grade A to C). In the control group, Grade A decreased during CPB, reaching 9.0±2.0% at 120 min of CPB. In the FUT-treated group, it showed significantly higher level of 50.4±17.0%. Platelet degranulation cavitation and glycogen storage with transmission electron microscopy at 120 min of CPB increased in the control group compared with that in the FUT-treated group. Ristocetin (1.2mg/min)-induced platelet agglutination in FUT-treated group was significantly preserved, 69.9±5.6% vs. 32.0±11.3% in control group at 60 min of CPB (p<0.05). We conclude that FUT-175 protects alterlations of the morphology of platelets.
