Objective:To investigate the influence of rhEPO on myocardial function in rats with myocardial ischemia/Reperfusion and PI3K/Akt pathway.Methods:42 rats were randomly divided into①Sham operation group(Sham grou)

②Ischemia/Reperfusion group(I/R group)

③Ischemia-Postconditioning group(I-postC group)

④I-postC+Wortmannin group(I-postC+Wort group)

⑤rhErythropoietin group(rhEPO group)

⑥rhEPO+Wort group

⑦rhEPO+I-postC group.ECG changes were monitored during the procedure.Ischemic and infarct areas were measured by Evans blue and TTC staining respectively.The mRNA and protein expression of Akt and p70S6K in myocardium were tested by RT-PCR and immunohistochemistry.Results:(1)Areas of myocardial infarction:I-PostC group

rhEPO group and rhEPO+I-PostC group had smaller areas of myocardial infarction compared with I/R group(P<0.05)

while I-PostC+Wort group and rhEPO+Wort group had bigger areas of myocardial infarction than I-PostC group and rhEPO group(P<0.05).There were no significant differences among I-PostC group

rhEPO group and rhEPO+I-Post group.(2)The expressions of Akt mRNA

p70s6k mRNA

Akt

p70s6k protein in myocardium:Akt mRNA

p70s6k mRNA and Akt

p70s6k protein expressed in myocardium in each group

with the lowest expression in Sham group.I-PostC group

rhEPO group and rhEPO + I-PostC group had higher expression than I/R group(P<0.05);the expressions in I-PostC+Wort group and rhEPO+Wort ground were lower than rhEPO group the expressions in rhEPO group

I-PostC group and rhEPO+I-PostC group(P<0.05).There were no significant differences among I-PostC group

rhEPO group and rhEPO+I-Post group.Conclusion:rhEPO can significantly protect the myocardial tissues

and exert similar protective effects on myocardial tissues to I-Post.the protective effects of rhEPO on myocardial tissues may be related to the activation of PI3-Akt signaling pathways and its downstream target p70s6k.