Background After myocardial infarction,specific growth factors promote cardiac angiogenisis,leading to a therapeuticeffect.Although this effect is mediated by specific receptors in the endothelium of the cardiac microvasculature,fewstudies have investigated dynamic changes in their expression.We explored this phenomenon in a murine model.Methods We observed the mRNA expression of receptors by specific angiogenesis gene microarray at day 3 and day 7after infarction.The vascular endothelial growth factor (VEGF) receptor FIk-1 was observed at the protein level at day 3and day 7 by immunohistochemistry.The dynamic expression of fibroblast growth factor receptor-1 (FGFR-1) mRNA inthe border zone and the noninfarcted zone at day 3,day 7,day 14,and day 42 was investigated by real-time PCR.Statistical significance was analyzed with SPSS 10.0 software using one-way analysis of variance (ANOVA).Results Three days after infarction,9 receptors in the border zone and 7 receptors in the noninfarcted zone weredown-regulated.Two receptors in the infarct edge and 5 receptors in the distant myocardium were up-regulated.Howeverat day 7,11 receptors in the border zone were up-regulated,and only one was down-regulated.In the border zone,FIk-1levels decreased at day 3 but increased significantly at day 7.Real-time PCR showed that FGFR-1 mRNA decreasedmarkedly in the border zone at day 3 but increased afterward for at least 6 weeks.In the early stage (3 days) afterinfarction,the expression of receptors had decreased to some extent.However,at day 7,receptor expression was activeand had moved from the distant noninfarcted zone to the border zone as a part of the acute repair process.Conclusion Selecting the proper growth factors to target receptors with protective activity,and determining appropriatetherapeutic timing may be important to the success of therapeutic angiogenesis. Background After myocardial infarction, specific growth factors promote cardiac angiogenisis, leading to a therapeuticeffect. Although this effect is mediated by specific receptors in the endothelium of the cardiac microvasculature, fewstudies have investigated dynamic changes in their expression. We explored this phenomenon in a murine model . Methods We observed the mRNA expression of receptors by specific angiogenesis gene microarray at day 3 and day 7 after infarction. The vascular endothelial growth factor (VEGF) receptor FIk-1 was observed at the protein level at day 3 and day 7 by immunohistochemistry. Dynamic expression of fibroblast growth factor receptor-1 (FGFR-1) mRNA inthe border zone and the noninfarcted zone at day 3, day 7, day 14, and day 42 was investigated by real-time PCR. Statistical significance was analyzed with SPSS 10.0 software using one-way analysis of variance (ANOVA). Results Three days after infarction, 9 receptors in the border zone and 7 receptors in the noninfarcted zone weredown-regulated. Two receptors in the infarct edge and 5 receptors in the distant myocardium were up-regulated. Howerat 7, 11 receptors in the border zone were up-regulated, and only one was down- regulated. in the border zone , FIk-1levels decreased at day 3 but increased significantly at day 7. Real-time PCR showed that FGFR-1 mRNA decreasedmarkedly in the border zone at day 3 but increased afterward for at least 6 weeks.In the early stage (3 days) afterinfarction, the expression of receptors had decreased to some extent. Despite, at day 7, receptor expression was active and had moved from the distant noninfarcted zone to the border zone as a part of the acute repair process. Conlusion Selecting the proper growth factors to target receptors with protective activity, and determine appropriate therapeutic timing may be important to the success of therapeutic angiogenesis.