Abstract:Aim To investigate the beneficial effects of amlodipine on neovascularization and cardiac function in rats after acute myocardial infarction (AMI), and explore the potential underlying mechanism for these effects. Methods Left anterior descending coronary artery ligation was performed to induce AMI. Rats post-AMI were randomly assigned into amlodipine group and control group after surgery (n20 in each group). Capillary density in the peripheral area of infarction and small artery density in myocardium were determined by CD31 and α-SMA staining separately. The percentage of CD45-/low+CD133+KDR+ EPC in peripheral blood mononuclear cells was measured by flow cytometry pre-operation and on day 7 post-operation. The expression and phosphorylation of protein associated with neovascularization in the border zone of infarction were determined by Western blot analysis. Echocardiagraphy was performed to evaluate cardiac function. Results Amlodipine treatment could notably increase the density of capillary vessels (81.3±4.0 vs 69.0±5.6, P<0.05) around infarction and small arteries (11.5±3.5 vs 6.2±2.3, P<0.05) in myocardium. At the same time, elevated circulating EPC count (120.3±18.3/106 vs 42.5±6.3/106, P<0.01) as well as increased expression of VEGF, phosphor-Akt, phosphor-eNOS and NO in the border zone of infarction (all P<0.05) were observed.