In vitro study of inhibitory effect of Ulinastatin against serine protease activity / 中国生化药物杂志

ABSTRACT

Objective To study inhibitory effect of serine protease activity by Ulinastatin in vitro .Methods Different chromogenic peptides were designed and synthesized.Highly sensitive fluorescence detection was performed to optimize the concentration of each serine proteases and their chromogenic substrates.Multi-point method was used for the calculation of half maximal inhibitory concentration of Ulinastatin .ResuIts Ulinastain could inhibit Polymorphonuclear leukocyte elastase ( PMNE ) and plasmin with IC50 lower than 100 U/mL.For factor Xa, and Kallikrein, the IC50 of Ulinastatin was higher than 1000U/mL.No thrombin IC50 could be calculated at the present experiments.ConcIusion Similar to Ulinastatin injection from Japan, domestic Ulinastatin shows the strongest inhibitory effects on PMNE among those serine proteases.As important references, this study gives reliable data for dose range of domestic Ulinastatin in anti-inflammation, coagulation/anti-coagulation and anti-shock therapy.