Schematic summary of RIC treatment groups and experimental protocol.

Control groups 1, 3 and 5 were left untreated and underwent handling alone without RIC. Treatment groups 2, 4, and 6 underwent RIC via four cycles of 5 min of femoral artery occlusion, followed by 5 min of reperfusion. Following the treatment protocol, mouse hearts were removed (denoted by *), mounted on a isovolumic Langendorff perfusion apparatus, and subjected to 20 min of equilibration, 30 min of no-flow global ischemia and 60 min of reperfusion. The infarcted area was visualized using TTC following global ischemia in each group.