[Can ulinastatin be an effective inhibitor of human polymorphonuclear granulocyte elastase under severe stressed...

The inhibitory effect of ulinastatin (UST), an intrinsic human trypsin inhibitor was investigated on the activity of polymorphonuclear granulocyte elastase (PMNE) with or without alpha 1-protease inhibitor (alpha 1-PI) using the in vitro models. The results of the dodecyl-sulfate-electrophoresis (SDS-PAGE), indicated that splitting-action of crude granulocyte enzyme solution on the plasma fibronectin was inhibited by concentration-dependent UST of an equivalent value for treatment of stressed state. The PMNE-UST complex was competitively replaced by PMNE-alpha 1-PI complex in vitro models of inflammatory focus and circulation, hence UST was weaker than alpha 1-PI in its binding-affinity for PMNE. The PMNE activity was directly inhibited by UST in the inflammatory focus and circulation with or without alpha 1-PI.