Effect of recombinant human erythropoietin on cerebral ischemia following experimental subarachnoid hemorrhage.
Erythropoietin exerts a neuroprotective effect during cerebral ischemia. We investigated the effect of systemic administration of recombinant human erythropoietin in a rabbit model of subarachnoid hemorrhage-induced acute cerebral ischemia. The animals were divided into three groups: group 1, subarachnoid hemorrhage; group 2, subarachnoid hemorrhage plus placebo; group 3, subarachnoid hemorrhage plus recombinant human erythropoietin (each group, n=8). Experimental subarachnoid hemorrhage was produced by injecting autologous blood into the cisterna magna. Treatment with recombinant human erythropoietin and placebo was started 5 min after subarachnoid hemorrhage and was continued every 8 h for 24 h. Before the animals were killed, erythropoietin concentration was measured in the cerebrospinal fluid. The rabbits were killed 24 h after subarachnoid hemorrhage and ischemic brain injury was histologically evaluated. In group 3, the concentration of erythropoietin in the cerebrospinal fluid was significantly increased and a significant reduction in cortical necrotic neuron count was also observed. These findings may encourage the use of erythropoietin in the treatment of cerebral ischemia that often occurs in the early stage of subarachnoid hemorrhage.