MicroRNA Expression in Rat Myocardial Infarction intervened by propranolol

We established a rat model of myocardial Infarction by performing a surgical operation of left anterior descending coronary artery occlusion under sterie conditions. Wistar rats were previously randomly divided into 4 groups: control, ischemia, ischemia-propranolol, and non-ischemia-propranolol. Our data suggested that propranolol could reverse many microRNAs with too high or too low expression in the ischemia group versus control group. Wistar rats were initially anesthetized with pentobarbital (40 mg/kg, i.v.), which were previously randomly divided into 4 groups: control, ischemia (MI), ischemia-propranolol (MI-PRO), and non-ischemia-propranolol (NMI-PRO). The rat model of MI was established by performing a surgical operation of left anterior descending coronary artery occlusion under sterie conditions. Successful occlusion was confirmed by an increase in the amplitude of R wave of lead I during the first few seconds of each occlusion and elevation of S-T segment of lead II, and a 20-30% decline in the arterial blood pressure compared to the pre-ischemic values mesured by a previously installed ECG recorder (BL 420, ChengDu TME Technology Co, Ltd, ChengDu, China). Propranolol was administrated 2 months before the experiment with daily oral doses of 50 mg/kg. Hearts were quickly isolated after the rats were sacrificed and the ischemic zone of the left ventricle was prepared for the miRNA microarray experiment. Control and NMI-PRO animals underwent open chest procedures without coronary artery occlusion.