Hepatic histopathology following I/R. Wild-type and P/I null mice subjected to the sham operation or 90 minutes of liver ischemia followed by various reperfusion times. The ischemic liver sections were prepared and stained with H&E. Figures A and B represent the sham mice; there is essentially normal hepatic histology; and C, D, E, and F represent mice subjected to I/R. A pattern of reperfusion damage is evident by loss of hepatocytes in the pericentral and midzonal regions, with relative sparing of the periportal areas. Note the presence of neutrophils in the midzonal region around the central vein. Figures G and H show immunohistochemical staining of neutrophils using a specific anti-neutrophil antibody, i.e., subjected to 90 minutes of ischemia followed 6 h of reperfusion. Neutrophils are indicated by dark brown color stain. (A) Wild-type mouse, 6 hour sham; (B) P/I null mouse, 6 hour sham; (C and E) Wild-type mice subjected to 90 minutes of ischemia followed by 6 and 15 h of reperfusion respectively; (D and F) P/I null mouse subjected to 90 minutes of ischemia followed by 6 and 15 h of reperfusion, respectively.