Microvascular and hepatocellular injury. (A) Sinusoidal perfusion was measured as a parameter of microvascular hepatic I/R injury. Microvascular perfusion failure is presented as the number of nonperfused sinusoids in sham-operated mice, JAM-A^+/+ mice after I/R (I/R-JAM^+/+), JAM-A^-/- mice after I/R (I/R-JAM^-/-), and endothelial JAM-A^-/- mice after I/R (I/R-eJAM^-/-). Ischemia time: 90 minutes; reperfusion time: 30 minutes (▪) and 120 minutes (□). (B) Serum activity of the liver enzymes AST and ALT was determined as a marker of hepatocellular necrotic injury after 90 minutes of ischemia followed by 140 minutes of reperfusion. (C) TUNEL-positive apoptotic hepatocytes were quantified in 10 high-power fields at microscope magnification × 400 in livers undergoing 90 minutes of ischemia followed by 140 minutes of reperfusion. n = 6 animals per group; mean ± SEM; ^*P < .05 versus sham-operated group; #P < .05 versus IR-JAM-A^+/+ group.