Background and Objective: One of the major side effects of cerebral ischemia is the water content enhancement in brain tissues which leads to mortality enhancement. Recently, therapeutic strategies have been focusing on preconditioning mechanisms. Erythropoietin as a glycoprotein hormone with anti-inflammatory and antioxidant effects on brain may be effective on brain edema reduction.

Materials and Methods: Male wistar rats were assigned to 5 groups of 6 in each: sham, control and three pretreatments. The pretreatment groups including single-dose (0.5 h before stroke induction), double-dose (0.5 and 48 h before stroke induction) and triple-dose (0.5, 48 and 98 h before stroke induction) received 1,000 IU/kg EPO intraperitoneally. 0.5 hour after the last injection, the animals were exposed to brain ischemia with the MCAO model for 60 minutes and then were evaluated regarding the brain water content, hemoglobin and hematocrit at 24 hours after reperfusion.

Results: Brain water content in the pretreatment group receiving EPO with a lower dose (1000 U/kg) decreased significantly but in the pretreatment group with a higher dose of the drug a significant enhancement was observed. Also, the amount of hemoglobin and hematocrit increased in the pretreatment groups in comparison with the control group.

Conclusion: Our results showed single-dose of EPO pretreatment decreased brain edema in the brain ischemic stroke model in wistar rats.