Abstrakt

The study on the inhibitory effect of rPI-T1 on kallikrein

Hongying Wang, Mei Xu, Na Li, Yan Xue, Dong Sun, Weiqing Di, Zhongfu Ding, Liquan Yang

To comparatively study the effects of rPI-T1 with aprotinin and tranexamic acid, antifibrinolytic hemostatics currently used in clinical settings, by comparatively analyzing their inhibitory activities on plasmin, trypsin and kallikrein. Spectrophotometry was used, that was, OD₄₀₅ was decreased by inhibiting protease hydrolysis of corresponding chromogenic substrates with inhibitors to measure corresponding activities and Ki values. Under the same measurement conditions, kallikrein inhibitory activity of rPI-T1 was approximately 1% of aprotinin. Tranexamic acid lysine analogues, on the other hand, had millimolar inhibitory concentrations because of different mechanism of action, i.e. noncompetitive inhibition. Due to the weak inhibitory effect of rPI-T1 on kallikrein, the potential side effects resulting from inhibiting kallikrein can be avoided. Characterized by high inhibitory concentration and poor specificity, tranexamic acid is prone to cause severe side effects.