Purpose:Early application of protease inhibitors through the intestinal lumen could increase survival following experimental shock by blocking the pancreatic digestive enzymes.Hence,it was hypothesized that two-route injection (intraintestinal + intravenous) of ulinastatin (UTI),a broad-spectrum protease inhibitor,could better alleviate intestinal injury than single-route injection (either intravenous or intraintestinal).Methods:A sepsis model induced by lipopolysaccharide on rats was established.The rats were randomly divided into five groups:sham,sepsis,UTI intravenous injection (Uiv),UTI intraintestinal injection (Uii),and UTI intraintestinal + intravenous injection (Uii + Uiv) groups.The mucosal barrier function,enzymeblocking effect,levels of systemic inflammatory cytokines,and 5-day survival rate were compared among groups.The small intestinal villus height (VH),crypt depth (CD),and two components of mucosal barrier (E-cadherin and mucin-2) were measured to evaluate the mucosal barrier function.The levels of trypsin and neutrophil elastase (NE) in the intestine,serum,and vital organs were measured to determine the enzyme-blocking effect.Results:Compared with the single-route injection group (Uiv or Uii),the two-route injection (Uii + Uiv)group displayed:(1) significantly higher levels of VH,VH/CD,E-cadherin,and mucin-2;(2) decreased trypsin and NE levels in intestine,plasma,and vital organs;(3) reduced systemic inflammatory cytokine levels;and (4) improved survival of septic rats.Conclusion:Two-route UTI injection was superior to single-route injection in terms of alleviating intestinal injury,which might be explained by extensive blockade of proteases through different ways.