Erythropoietic agents as neurotherapeutic agents: what barriers exist?

Erythropoietin is the primary physiological regulator of erythropoiesis, and it exerts its effect by binding to cell surface receptors. It has recently been shown that both erythropoietin and its receptor are found in the human cerebral cortex, and that, in vitro, the cytokine is synthesized by astrocytes and neurons, has neuroprotective activity, and is up-regulated following hypoxic stimuli. In animal models, exogenous recombinant human erythropoietin has been reported to be beneficial in treating experimental global and focal cerebral ischemia and reducing nervous system inflammation.