Protection by recombinant human erythropoietin (rhEPO) of compressive spinal cord injury in the rat. rhEPO ameliorates spinal cord injury with a wide therapeutic window. Spinal cord injury was initiated in rats (six per group) by application of an aneurysm clip for 1 min, as previously described . Saline or rhEPO was administered once at the indicated times (1000 U/kg body weight intravenously) following injury. Animals were serially evaluated for motor function; a score of 0 is paraplegic and 21 is normal.