Objective: We studied expression of Vascular endothelial growth factor (VEGF) and angiogenesis in ischemic myocardium from a group of rats with acute myocardial infarction (AMI) after taking metoprolol---- a beta-receptor blocker

in order to determine if beta-receptor blocker can promote myocardial angiogenesis in rat s with AMI and reveal the mechanism. Methods: The infarcted rats received last metoprolol administration for 1-3 weeks. Vascular endothelial cells and VEGF protein in ischemic myocardium were detected by immunohisto-chemical technique. Capillary density and heart rate were detected too. Results: Capillary density and expression of VEGF protein were higher in ischemic myocardium of rats with metoprolol treatment than in ischemic myocardium of rats in control group. Capillary density and expression of VEGF significantly increased in ischemic myocardium with reduction of heart rate in comparison with no reduction of heart rate in rats with metoprolol treatment. Conclusion: Beta-receptor blocker may promote capillary angiogenesis in ischemic myocardium of rats. It suggests that VEGF plays a key role in the angiogenic response that occurs with chronic bradycardia.