Cardioplegia solution plus metformin protects isolated rat hearts / 中华胸心血管外科杂志

ABSTRACT

Objective To evaluate the protective value of cardioplegia solution plus metformin in different cardiac arrest time and concentration of metformin in isolated rat hearts .Methods There were 36 male Sprague–Dawley rats divided into six groups randomly, according to the duration of cardioplegic arrest(30 min or 60min) and the concentrations of metformin(50μmol/L or 100 μmol/L) .Langendorff-perfused Sprague-Dawley rat hearts were perfused for 20 minutes with Krebs-Henseleit buffer followed by 30 or 60 minutes of crystalloid cardioplegia or plus metformin (50 or 100 μmol/L) and 60 minutes of reperfu-sion.The left ventricular performance was recorded at 5 time points.The expressions of AMPKαand phosphorylation of AMPKαwere detected by western Blot.The changes of myocardial mitochondria were observed under transmission electron mi-croscope.Results There were no significant differences in Con(A), 50(A) and 100(A) groups in LVDP, ±dp/dtmax and HR.Compared with Con(B) group subjected to 60 minutes of ischemia followed by 60 minutes of reperfusion, the 100(B) group significantly improved myocardial performance , and the ratio of p-AMPKα/AMPKαwas the highest in all 6 groups.The structure of myocardial mitochondria in 100(B) group was better protected than that of Con(B) group.Conclusion These findings suggested that the left ventricular performance was protected in rat heart perfused by cardioplegia plus 100 μmol/L after 60 minutes cardioplegic arrest .The mechanism may be the activation of AMPK and the protection of structures of myocardial mitochondria.