Studies of Plasma Fe59 Disappearance--A Manifestation of Ineffective Erythropoiesis and of Hemolysis

1. Studies of the plasma radioiron disappearance data have revealed arelative "elevation" of plasma radioactivity after the second day in normalsubjects, and after the first day in patients with hemolytic anemia, megaloblastic anemia and thalassemia. This elevation in plasma radioactivity in normal subjects may be interpreted as due to the return to plasma of radioironfrom those cells that are "ineffectively" produced and are hemolyzed in themarrow. Other interpretations are also presented.

2. Dyspoieses involving ineffective red cell economy, but not detectably affecting iron economy are contrasted with disorders involving ineffectiveutilization of iron and of pigment alone.

3. After the first day plasma radioiron activity shows a diurnal variationsimilar to the diurnal variation in plasma iron concentration.

Submitted on July 17, 1964 Accepted on September 29, 1964