Intracardiac erythropoietin injection reveals antiinflammatory potential and improved cardiac functions detected by forced swim test

Systemic administration of erythropoietin (Epo) protects the myocardium from an ischemic insult and promotes beneficial remodeling. We hypothesized that intracardiac injection of Epo may exhibit cardioprotective potential with reduced systemic toxicity. Following myocardial infarction (MI), Epo was injected directly into the border of the infarction. Six weeks after an MI, we evaluated infarction size, angiogenesis, and pathologic effects of the treatment. Myocardial performance was assessed with a Forced Swim Test adapted to the study. Anti-inflammatory and cellular proliferative effects of Epo were analyzed by measuring expression of integrin-beta and CdK4 by reverse transcriptase-polymerase chain reaction (RT-PCR). The findings indicated improved cardiac status with direct Epo administration. Exercise capacity detected by the Forced Swim Test was significantly increased. There was radical reduction of absolute infarction size, ventricular dilatation, and hypertrophy in the Epo group. Integrin-beta was down-regulated and CdK4 expression was increased significantly with Epo. In conclusion, the study demonstrated that intramyocardial Epo injection, following MI, reduced inflammation, enhanced angiogenesis and proliferation, improved myocardial functions, and did not lead to intramural thrombus formation.