Identification of Transferrin as the Principal Plutonium-binding Protein in the Blood Serum and Liver Cytosol of Rats: Immunological and Chromatographic Studies

Summary

An analysis of ²³⁹Pu-labelled protein complexes in serum and liver cytosol fractions prepared from rats injected intravenously with ²³⁹Pu-citrate indicated that among the possible metal-binding proteins, ferritin, transferrin and metallothionein, ²³⁹Pu was bound almost exclusively to transferrin. The method employed for the quantitative determination of ²³⁹Pu-transferrin was chromatography on immobilized rabbit anti-rat apo-transferrin. There was no evidence that transferrins from serum and liver cytosol are serologically different. The residual blood content of perfused and non-perfused liver was measured using ⁵¹Cr-labelled red blood cells and the amounts of blood-derived ²³⁹Pu and ²³⁹Pu-transferrin in the liver cytosol were calculated.

The results are discussed with respect to the possible role of transferrin in the uptake of Pu into cells.

• transferrin
• plutonium-binding protein
• serum and liver cytosol of rats