Effect of activation of PAR2 on inflammation in the ileum. Mouse ileum was injected with AP (SLIGRL), pancreatic trypsin (T), tryptase (Trypt), trypsin IV (TIV), p23, or vehicle. Inflammation was assessed as before (Figures 1, 3, and 5). (A) All agents increased intestinal secretion, expressed as milligrams per centimeter of loop, with AP having the largest effect. (B) All agents increased tissue MPO, expressed as units MPO per milligram protein, to similar levels. (C) Fluid MPO, expressed as units MPO per milliliter fluid, was most strikingly increased by AP, trypsin, and tryptase. *P < .05 between control and results obtained by activating agents.