Biological & pharmaceutical bulletin
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We evaluated the cardioprotection against myocardial ischemia-reperfusion injury induced by sevoflurane postconditioning (SpostC) in chronically-infarcted rat hearts, and investigated the roles of phosphoinositide 3-kinase (PI3K)-protein kinase B/Akt (PKB/Akt), mitogen-activated extracellular regulated kinase 1/2 (MEK 1/2)-extracellular regulated kinase 1/2 (ERK 1/2), and mitochondrial permeability transition pore (mPTP). Left anterior descending (LAD) coronary artery was ligated to induce myocardial infarction in rats. Six weeks later, chronically-infarcted hearts were isolated and subjected to 30 min of global ischemia, followed by 1 h of reperfusion with Krebs-Henseleit (K-H) buffer. ⋯ We found that exposure of 3% sevoflurane during early reperfusion significantly improved functional recovery (improved left ventricular developed pressure (LVDP), +/-dp/dt, CF, HR and reduced left ventricular end-diastolic pressure (LVEDP)), decreased myocardial infarct size and reduced LDH and CK-MB release, when compared with unprotected hearts. However, these protective effects were abolished in the presence of either LY294002 or PD98059, which was accompanied by the prevention of PKB/Akt and ERK 1/2 phosphorylation, and reduction of myocardial nicotinamide adenine dinucleotide (NAD+) content. These findings suggest that sevoflurane postconditioning protects chronically-infarcted rat hearts against ischemia-reperfusion injury by inhibiting mPTP opening via recruitment of PKB/Akt and ERK 1/2.