['Complement activation contributes to ischemia and reperfusion (IR)-initiated organ injury. C1 inhibitor (C1 Inh) inhibits the earliest steps of the classical and the mannose binding lectin pathways.', 'To determine whether C1 Inh prevented tissue injury, we performed intestinal IR experiments in BALB/c and C57BL/6 mice.', 'We found that C1 Inh limits mucosal injury in the two strains in a dose dependent manner. Tissue damage was associated with the accumulation of functional polymorphonuclear cells, which was reduced following C1 Inh treatment. Constitutive nitric oxide synthase activity correlated with the development of injury in the C57BL/6 but not in the BALB/c mouse.'] Does human C1 esterase inhibitor attenuate murine mesenteric ischemia/reperfusion induced local organ injury?