Ischemic postconditioning decreases matrix metalloproteinase-2 expression during ischemia-reperfusion of myocardium in a rabbit model: A preliminary report.

Objective: To investigate the effect of ischemic postconditioning on the expression of matrix metalloproteinase (MMP)-2 during ischemia-reperfusion of myocardium in a rabbit model.

Methods: Thirty-six male New Zealand white rabbits were randomly divided into sham, ischemia-reperfusion and ischemic postconditioning groups. Myocardial ischemia-reperfusion was created by ligating the left anterior descending coronary artery for 30 min followed by 3 h of reperfusion. Myocardial infarction sizes were determined by dual staining with triphenyltetrazolium chloride and trypan blue. Plasma levels of MMP-2 were measured using ELISA. Myocardial MMP-2 messenger RNA was analyzed by reverse transcription polymerase chain reaction.

Results: The mean (± SD) infarct size in the ischemic postconditioning group was significantly smaller compared with the ischemia-reperfusion group (37.1±3.8% versus 57.5±1.9%; P=0.02). The incidence of ventricular tachycardia in the ischemic postconditioning group was also lower than in the ischemia-reperfusion group (8.5% versus 75%; P=0.003). MMP-2 messenger RNA expression in the ischemic postconditioning group was significantly lower compared with the ischemia-reperfusion group (0.4944±0.0476 versus 0.6989±0.0694; P=0.02).

Conclusion: Ischemic postconditioning reduces myocardial ischemia-reperfusion injury, possibly by inhibiting the expression of MMP-2.