TUMOR OXYGENATION IN ANEMIC RATS - EFFECTS OF ERYTHROPOIETIN TREATMENT VERSUS RED-BLOOD-CELL TRANSFUSION

Anemia was induced in rats by the development of a hemorrhagic ascites . These animals also bore solid tumors (DS-sarcomas) on the hind foot dorsum, The effects of two methods for anemia correction on oxygenatio n in the solid tumors were compared in this study. Anemia was correcte d either chronically by erythropoietin administration (1000 IU/kg) ove r 14 days (EPO) or acutely by transfusion with red blood cells (TR). N on-anemic and untreated anemic animals served as controls, Tumor oxyge nation was determined in anesthetized animals using polarographic need le electrodes and pO(2) histography. The reduction in hematocrit and h emoglobin content found in anemic animals could successfully be correc ted either by EPO or by TR. Anemia resulted in a worsening of tumor ox ygenation which could partially be reversed by EPO or TR in small tumo rs (<1.4 ml), In larger tumors (greater than or equal to 1.4 ml), neit her method of anemia correction resulted in significant changes in tum or oxygenation.