Objective:To investigate the effect of preconditioning with isoproterenol(ISO)on myocardial ischemia/reperfusion(I/R)injury in rats and elaborate the possible mechanism.Methods:32 male SD rats were divided into sham group,I/R injury group,ISO group,and selective β2-adrenergic recepter(β2-AR)antagonist ICI118551+ISO-I/R group(ICI group)based on random number table(8 in each group).Myocardial HE staining was used to observe cardiomyocyte morphology,Western blot analysis was used to detect the expression level...