ABSTRACT
The present study was performed to investigate the dynamics of Cu,ZnSOD and MnSOD expression following courses of reperfusion after repetitive ischemic preconditioning on the left rectus femoris muscle of Spraque-Dawley rats. Nine or thirty five weeks-old rats were subjected to three, six and ten cycles of ischemic preconditioning that was 5 min ischemia and 5 min reperfusion at the left common iliac artery. Left rectus femoris muscle was isolated 0, 3, 6, 24 and 72 hours of reperfusion after ischemic preconditioning and assayed by immunohistochemical staining with anti-Cu,ZnSOD and anti-MnSOD antibodies. The results were as follows; The immunoreactivities of Cu,ZnSOD and MnSOD were increased in the repectitive three and six cycles of ischemic preconditioning. However, after the repetitive ten cycles of ischemic preconditioning, the Cu,ZnSOD immunoreactivities were decreased in the nine weeks-old rats while MnSOD immunoreactivities were decreased in thirty five weeks-old rats. These findings suggest that severe damayes result from decrease of Cu,ZnSOD in nine weeks-old rats and decrease of MnSOD in thirty five weeks-old rats after ten cycles of ischemic preconditioning.