Background: Erythropoietin (Epo) has been shown to have important cytoprotective properties against ischemic damage of the myocardium besides its important hematopoietic effect.
Aim: This study was designed to find out the possible effects of treatment with recombinant human erythropoietin in rat model of myocardial infarction induced by isoproterenol.
Materials and Methods: Adult male albino rats weighing 200 – 220 gm were divided into 4 groups: group I (Control group) Received no medications and given free access to food and water. Group II (ISO group): Injected intraperitoneal "i.p." with a single dose of isoprenaline in a dose of 75 mg/kg body weight for induction of myocardial infarction. Group III (ISO + rhEPO): Injected i.p. by single dose recombinant human EPO (rhEPO) in a dose of 5000 I.U/kg body weight, 2 hours after induction of myocardial infarction with isoprotrenol. Group IV (rhEPO 10 days + ISO): Injected i.p. with rhEPO in a dose of 5000 I.U/kg body weight/day for 10 days before induction of myocardial infarction with isoprenaline
Results: A significant reduction in the infarction size, serum cardiac enzymes (CPK and LDH), significant increases in plasma NO and non-significant change in both mean systemic arterial blood pressure (MSABP) and hematocrit (Hct) value were observed in rats injected with a single dose of rhEPO (5000 I.U/ kg body weight), 2 hours after induction of myocardial infarction when compared with rat model of myocardial infarction (ISO group). Pretreatment of rats with rhEPO (5000 I.U/ kg body weight/day) for 10 days before induction of myocardial infarction causes significant decrease in cardiac enzymes and infarction size, non-significant change in plasma NO, significant increase in Hct value and MSABP when compared with rat model of myocardial infarction. While on comparing these results with those rats treated with single dose of rhEPO, 2 hours after induction of myocardial infarction, there was significant decrease in cardiac enzyme, plasma NO, Significant increase in MSABP, Hct value and non- significant change in the infarction size.
Conclusion: rhEPO has a Cardioprotective effect and this effect conferred by rhEPO has many mechanisms. One of them is by modulating the hemodynamic functions through increasing the plasma NO concentration. Although, treatment with rhEPO for longer periods may result in increased hematocrit associated side effects such as hypertension or thromboembolism.
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