Changes of serum erythropoietin during Cisplatin- or 5-Fluorouracil-induced anemia in rats.

The aim of the present work was to investigate changes of serum erythropoietin (Epo) during cisplatin (DDP)-or 5-Fluorouracil (5-Fu)-induced anemia in rats. Anemia was induced with single intravenous (IV) injection of DDP of 8 mg/kg body weight or 5-Fu of 150 mg/kg body weight. Serum Epo, hemoglobin (Hb), blood urea nitrogen (BUN) concentration, and reticulocyte (Ret) counts were measured 7, 21, 35, and 49 days after administration of the anticancer drugs. The changes of renal tissue were examined by light microscope. A single injection of 5-Fu decreased Ret counts and Hb concentration and increased serum Epo levels. No evident morphological abnormalities were found by light microscopy in 5-Fu-treated rats. A single injection of DDP decreased Ret counts and Hb concentration and increased BUN. Serum Epo was decreased 7 days but was increased 21 days after DDP treatment; however, serum Epo elevation was modest. Pathological examination revealed that DDP caused significant renal damage in rats. These results suggest that in 5-Fu-induced anemia, the elevated serum Epo level was due to the feedback response to anemia. In DDP-induced anemia, the elevated serum Epo level was low in relation to the level of anemia, and DDP-induced nephrotoxicity might be the main cause of changes of serum Epo.