ABSTRACT
Aim To investigate the role of mitochondrial aldehyde dehydrogenase 2 ( ALDH2) in the cardio-protection of ischemic postconditioning in isolated rat hearts. Methods Hearts isolated from male Sprague-Dawley rats were perfused on a langendorff apparatus and subjected to 30 min of regional ischemia( occlusion of left anterior descending artery) followed by 120 min reperfusion. Ischemic postconditioning was achieved by 6 cycles of 10 s reperfusion/10 s global ischemia starting at the beginning of reperfusion. The ventricular hemodynamic parameters and lactate dehydrogenase ( LDH) release during reperfusion were measured. The infarct size was measured by TTC staining method. The expressions of ALDH2,Bcl-2 and Bax at mRNA level of left anterior myocardium were detected by RT-PCR analysis. Results In contrast to ischemia and reperfusion,ischemic postconditioning improved the recovery of left ventricular developed pressure,rate pressure product during reperfusion,and reduced LDH release and infarct size. The expressions of ALDH2 mRNA level and the ratio of Bcl-2 /Bax were increased. Adminis-tration of ALDH2 antagonist cyanamide at the beginning of reperfusion attentuated the role of ischemic postconditioning. Conclusion Ischemic postconditioning plays a role in the cardioprotection partially through increasing mitochondrial ALDH2 mRNA expression.