Behavior of Iron-,Indium-,and Iodine-Labeled Transferrin in the Pregnant Rat 1

Summary

Fetal and placental uptakes after administration of ⁵⁹Fe-, ^113mIn-, and ¹²⁵I-transferrins at various stages of gestation in the rat have been studied. In the latter third of pregnancy ⁵⁰Fe went to the fetus in large amounts, but, in contrast, ^113mIn accumulated in the placenta. Only small quantities of ¹²⁵I-transferrin reached the fetus, and considerably less ¹²⁵I than ^113mIn was found in placenta. It is concluded that transferrin does not carry iron across the placenta and that indium is removed from transferrin by the placenta, but does not cross to the fetus.