OBJECTIVETo observe the role of activation of aldehyde dehydrogenase 2 (ALDH2) on myocardial ischemia/reperfusion (I/ R) injury in diabetic rats.

METHODSDiabetic rat model was simulated by intraperitoneal injection 55 mg/kg streptozotocin (STZ) and divided into diabetes and ethanol + diabetes groups (n = 8). After 8 weeks, myocardial ischemia/reperfusion model was mimicked in vitro. The ventricular dynamical parameters and lactate dehydrogenase (LDH) content in coronary flow were determined. The fasting blood glucose and glycosylated hemoglobin (HbA1c) level were determined by automatic biochemistry analyzer. The ALDH2 mRNA and protein expressions of left anterior myocardium were evaluated by RT-PCR and Western blot.

RESULTSIn contrast to I/R in normal rat, in diabetic rat, left ventricular development pressure (LVDP), maximal rise/fall rate of left ventricular pressure (+/- dp/dtmax) and left ventricular work (RPP) were decreased, left ventricular end diastolic pressure (LVEDP) and LDH release were increased, and ALDH2 mRNA and protein expressions were decreased; compared with I/R in diabetic rat, ALDH2 agonist ethanol significantly promoted the recovery of LVDP, +/- dp/dtmax, RPP, reduced HbA1c level, LVEDP and LDH released, ALDH2 mRNA and protein expressions were increased.

CONCLUSIONIn diabetic rat, the expression of ALDH2 was decreased when heart was subjected to I/R. Enhanced mitochondrial ALDH2 expression in diabetic rat could play cardiac protective role.