[The expression of trypsin in serum and vital organs of septic rats]

Objective: Pancreatic enzymes may spread into the injured intestine, bloodstream,and cause the cascade of inflammatory reactions.Our objective was to explore trypsin expression in serum and vital organs in septic rats. Methods: Trypsin levels in serum,heart,lung and jejunum were tested and compared between Escherichia coli endotoxin injected rats(SS), SS treated with a protease inhibitor(ulinastatin) and control group(SHAM).The correlations between serum trypsin,intestinal proteins and inflammation indices were assessed.Two components of mucosal barrier, i.e. mucin-2 and E-cadherin,were measured to evaluate the intestinal mucosal barrier function.The levels of tumor necrosis factor alpha (TNFα),interleukin-6(IL-6) and neutrophil elastase(NE) were measured to determine the inflammation indices. Results: Compared to SHAM group, trypsin levels in serum[(73.71±9.14) ng/ml vs. (12.12±2.36) ng/ml],heart[(51.60±15.06) ng/ml vs. (6.39±3.53) ng/ml],lung [(54.73±5.57) ng/ml vs. (5.24±3.08) ng/ml] and jejunum(1.19±0.48 vs. 0.40±0.12) were significantly higher in SS group (all P<0.05). The level of serum trypsin had negative correlation with mucin-2 and E-cadherin, and positive correlation with TNFα, IL-6 and NE (all P<0.05). In rats treated with ulinastatin, trypsin levels were significantly decreased compared with those in SS group including in serum [(65.79±4.88)ng/ml]], heart [(26.33±12.03)ng/ml], lung [(28.73±14.46) ng/ml] and jejunum (0.80±0.20) (all P<0.05).Serum TNFα[(247.34±16.97)ng/L vs. (178.78±40.81)ng/L] revealed similar changes in ulinastatin and SS group,whereas mucin-2 (0.58±0.14 vs. 0.89±0.17) and E-cadherin (0.11±0.04 vs. 0.23±0.06) were both significantly elevated after administration of ulinastatin (both P<0.05) . Conclusion: Serum and tissue trypsin is elevated in septic rats. Protease inhibitor ulinastatin protects intestinal function by reducing inflammatory reaction.