Increased Formation of Early-Labeled Bilirubin in Rats with Iron Deficiency Anemia: Evidence for Ineffective Erythropoiesis

The production of early-labeled bilirubin and erythrocyte hemoglobin hemewas measured in rats with iron deficiency anemia, using glycine-2-¹⁴C asprecursor. The erythropoietic component of the early pigment fraction wassignificantly augmented and the formation of labeled hemoglobin depressed inthe anemic animals, findings characteristic of ineffective erythropoiesis. Bycontrast, the hepatic component of early-labeled bilirubin was substantiallyenlarged during the acute response to iron therapy. These experiments illustrate that overproduction of bilirubin may originate from both erythropoieticand hepatic sources of the early-labeled fraction of bile pigment, as well asfrom hemolysis of circulating red blood cells.

Submitted on November 14, 1968 Accepted on January 21, 1969