RESUMO
<p><b>AIM</b>To observe change of binding activity of HIF-1 with erythropoietin (EPO) hypoxia response element (HRE) in the hippocampus of mice preconditioned to hypoxia and explore relationship between the changes and the preconditioning.</p><p><b>METHODS</b>The hippocampus was removed from mice exposed to hypoxia for 0 run (control group), 1 run (H1 group) and 4 runs(H4 group). Electrophoretic mobility shift assays (EMSA), chromatin immunoprecipitation (ChIP)and real time PCR were used to detect the change of activity of HIF-1 on HRE of EPO.</p><p><b>RESULTS</b>Both in vitro and in vivo binding tests showed that the HIF-1 DNA-binding activities were increased in group H1 and markedly increased in group H4.</p><p><b>CONCLUSION</b>The increase of HIF-1 and HRE of EPO binding activities is thought be involved in hypoxic preconditioning.</p>