Sufentanil postconditioning protects the myocardium from ischemia-reperfusion via PI3K/Akt-GSK-3β pathway

Background: Previous studies have shown that opioid postconditioning reduces apoptosis through antiapoptotic signaling. The present study evaluated whether sufentanil could induce cardioprotection after ischemia-reperfusion (I/R) and whether the PI3K/Akt-GSK-3 beta pathway modulates antiapoptotic proteins in sufentanil postconditioning. Methods: We subjected male Sprague-Dawley rats to 30 min of myocardial ischemia and 2 h of reperfusion. We randomized rats into seven groups: sham, I/R, sufentanil postconditioning (I/R+sufen), sham plus sufentanil (sham+sufen), sham plus 15 mu g.kg(-1) intravenous wortmannin (PI3K inhibitor), I/R plus wortmannin, and sufentanil plus wortmannin. We induced sufentanil postconditioning with 3 mu g.kg(-1) sufentanil for 3 min in the beginning of reperfusion after 30 min ischemia. We assessed hemodynamics, myocardial infarct size, number of apoptotic cardiomyocytes, total Akt and GSK-3 beta, phosphorylated Akt and GSK-3 beta, caspase-3, Bax, and Bcl-2 protein expression. Results: The I/R+sufen group had significantly reduced infarct size compared with the I/R group (23.3% +/- 9.0% versus 50.1% +/- 7.4%; P < 0.05). The apoptotic index of cardiomyocytes was significantly reduced with sufentanil treatment (20.0% +/- 3.5%) compared with the I/R group (47.0% +/- 6.3%; P < 0.05). The I/R+sufen group reduced the expression of protein-cleaved caspase-3 and Bax, and increased Bcl-2, phosphorylated Akt, and GSK3 beta compared with the I/R group. Wortmannin eliminated the cardioprotection produced with sufentanil treatment. Conclusions: Sufentanil postconditioning can induce myocardial protection by activating the PI3K/Akt-GSK-3 beta pathway and modulating Bax and Bcl-2 expression. (C) 2012 Elsevier Inc. All rights reserved.