Abstract
Erythroblast ferritin (EF), isolated from phenylhydrazine-anemic rabbit marrow, interacts with components of normal plasma and forms a complex separable by starch granule electrophoresis and by dialysis techniques. The binding is facilitated at low ionic strength. The plasma factors responsible for binding EF are present in autologous, as well as homologous, plasma of normal nonimmune rabbits, although binding activities are quite variable in different plasmas. The binding activity for rabbit EF is also present in heterologous plasma of mouse, guinea pig, and man. The active principles in plasma were identified as two heat-stable components which fractionate as immunoglobulins, one as IgG and the other as IgM. The results support the hypothesis that natural antiferritin antibodies of low titer are present in normal plasma.
