Measurement of erythropoietin in chloroleukemic rats.

Erythropoietin (Ep) levels were measured in Shay chloroleukemic rats at various stages of anemia. Serum Ep was shown to increase logarithmically as the anemia became more severe. This increase in Ep levels was similar to that observed in normal rats subjected to acute blood loss. Significant levels of Ep were also demonstrated in ascitic fluid extracted from the peritoneal cavity of leukemic rats. These results indicate that the anemia of this disease is not due to a diminished production of Ep.