Abstract
Objective: The purpose of present study was to determine whether ischemic preconditioning (PR) or ischemic postconditioning (PT) could protect isolated perfused hearts from hydrogen peroxide(H2O2)-induced damage. Methods:Male SD rats were used. Langendroff-perfused rat hearts were subjected to 1) Control(CT) group: 30 min 100 μM H2O2 perfusion followed by 30 min washout. 2) PR group: 3 times ischemic preconditioning (3 min ischemia and 5 min reperfusion), followed by 30 min 100 μM H2O2 perfusion and 30 min washout. 3)PT group: 30 min 100 μM H2O2 perfusion followed by 3 times ischemic postconditioning (30 sec ischemia and 30 sec reperfusion) and 30 min washout. Results:After 30 min perfusion with H2O2, left ventricular developed pressure (LVDP) of CT, PR and PT groups decreased to 29.5±2.8%, 40.8±5.1% and 35.0±5.1%, respectively. The decrease of LVDP in PR group was significantly (P<0.05) lower than those of CT and PT groups. AT the end of washout period , LVDP of PR and PT groups recovered to 95.2±6.6% and 96.3±2.3% respectively which were significantly better than that of CT group (75.7±7.5%,P<0.05). Recovery of LVDP was quickest in PT group indicating protective mechanism different from that of PR. Conclusions:The results of this study indicate that ischemic preconditioning and postconditioning rapidly promote LVDP recovery and attenuate H2O2-induced ventricular dysfunction. [Jpn J Physiol 54 Suppl:S96 (2004)]
