Pretreatment with EPO promotes EPOR activation. Western blot analysis was used to assess EPOR expression and activation by measuring the levels of total EPOR and p-EPOR. (A) Representative result for western blot analysis. (B) Semi-quantitative analysis of the six animals studied in each group. The relative expression levels of EPOR and p-EPOR in each group of rats were normalized against those of β-actin, and presented as a ratio between p-EPOR and EPOR. **P<0.01, IRI-SAL vs. Sham; ###P<0.001, IRI-EPO vs. IRI-SAL. EPO, erythropoietin; IRI, ischemia-reperfusion injury; EPOR, erythropoietin receptor; p-EPOR, phosphorylated EPOR.