Effects of 90 minutes of ischemia followed by different times of reperfusion (0 hours, 2 hours, 5 hours) on intestinal MPO activity (A), survival rate (B), plasma protease activity (C), and tissue protease activity (D) in sham-operated (SO) (white bars) or I-R (black bars) mice. In B, SO groups showed 100% survival rate (data not shown). In A, C, and D, data represent means ± SEM of 8 to 12 animals per group. *P ≤ 0.05, **P ≤ 0.01, and ***P ≤ 0.001 versus the corresponding SO group; †P ≤ 0.05, ††P ≤ 0.01, and †††P ≤ 0.001 versus the indicated I-R group.