Objective: To investigate the changes of expression of VEGF and angiogenesis in ischemic myocardium of rats in various periods. Methods: 30 male infarcted rats were divided into 24h group

1w group

2w group

3w group and 4w group. The myocardial samples from all groups were taken for detecting the numbers of endothelial cell (EC)

capillary density (CD)

and expression of VEGFmRNA and protein. Results : ⑴ECs and CD increased at 1 week after AMI

and peaked at 2 weeks after AMI

while gradually decreased at 3 weeks after AMI

decreased at 4weeks after AMI to the same level with that at 1 week after AMI.⑵Expression of VEGFmRNA in ischemic myocardium increased at 24 hours after AMI

peaked at 1 week after AMI

gradually decreased at 2 weeks after AMI

and little expression was found at 4 weeks after AMI. Expression of VEGF protein increased at 1 week after AMI

peaked at 2 weeks after AMI

gradually decreased at 3 weeks after AMI

decreased at 4 weeks to the same level with that at 1 weeks after AMI. Conclusion : CD

expression of VEGF increased in ischemic myocardium of infarcted rats

and the changing trend of these two variables is comparable.