EPO administration increased angiogenesis in diabetic rats and was dependent on VEGF and EPOR up-regulation. (A) Representative micrographs of heart sections stained with antibodies against CD31, EPOR and VEGF (400x magnification). (B) Capillary density in number of capillaries per mm2. Quantitative data showed EPOR and VEGF staining. (C) Representative western blots of myocardial VEGF and EPOR levels. (D) Real-time PCR analysis of VEGF and EPOR mRNA levels. Data are expressed as the mean ± SEM (n = 5). *P < 0.05 vs control, #P <0.01 vs control, ▴P <0.05 vs diabetes, ▵P <0.01 vs diabetes.