Non-hematogenic activity of erythropoietin.

The cytokine erythropoietin is the main hemopoietic factor synthesized mainly by the kidney. However, erythro-poietin and its receptors are expressed in several tissues and exert pleiotropic activities also in nonhemopoietic tissues. Erythropoietin has an antiapoptotic activity and plays a potential neuroprotective, nefroprotective and cardioprotective role against ischemia and other type of injury. Erythropoietin is also involved in angiogenesis, neurogenesis, and the immune response. It can prevent metabolic alterations, vascular and neuronal degeneration, and inflammatory cell activation. Erythropoietin reduces hyperglycaemia and retards proliferative retinopathy in diabetic patients. Consequently, erythropoietin may be of therapeutic value for a variety of disorders. This short review provides an insight into the nonhemopoietic role of erythropoietin and its mechanisms of action. For elimination of polycythaemia after erythropoietin administration analogues without haematopoietic activity were prepared and tested in animals and in some cases also evaluated in clinical trials.