Abstract: To investigate the generation and possible significance of plasma trypsinogen activation peptides(TAP) in experimental rats of acute pancreatitis, 90 SD rats were randomly allocated to five groups: group EP and NP with retrograde ductal infusion of 3%and 5%sodium taurocholate ; group TP with Ulinastatin(UTI) treatment; group CP with 0.9%NS retrograde ductal infusion; group OP with sham operation. Plasma TAP was determined by EIA. Result: At times 3 h and 6 h after infusion, plasma TAP concentration of group NP (4.798±0.169、3.999±0.299 nmol/L) were significantly higher than that of group EP(2.416±0.148、3.356±0.211 nmol/L); At 6 h after infusion, plasma TAP concentration of group TP(1.611±0.113 nmol/L) was significantly lower than that of group EP. The result shows that plasma TAP concentration may be used as a marker for the early assessment of the severity of pancreatitis.

Key words: trypsinogen activation peptides, acute pancreatitis, protease inhibitors