Suppressive effect of ulinastatin on plasma fibronectin depression after cardiac surgery.

Plasma fibronectin, an opsonic glycoprotein, is known to modulate the reticuloendothelial phagocytic clearance of nonbacterial and, possibly, bacterial particulates. The decreased plasma fibronectin levels seen after cardiac surgery have been considered to derive mainly from opsonic consumption. In the present study, we demonstrated that the administration of ulinastatin, a human urinary trypsin inhibitor, to patients after cardiac surgery not only inhibited the postoperative depression of plasma fibronectin levels, but also maintained the plasma fibronectin level within the normal range. This effect apparently resulted from the inhibitory activity of ulinastatin on the proteolytic enzymes released after operation. This result suggests that the decreased plasma fibronectin level noted after cardiac surgery may derive mostly from excessive proteolytic enzymes. Our observation also indicates that the prophylactic administration of ulinastatin to patients undergoing major operations will result in a favorably functional reticuloendothelial phagocytic system.