EFFECTS OF IRON ON ABSORPTION AND RETENTION OF LEAD

  • 1 January 1978
    • journal article
    • research article
    • Vol. 92  (4) , 536-547
Abstract
In rats, the state of body Fe repletion had significant effects on the absorption of Pb but no effect on P excretion. Intraluminal Fe decreased the absorption of test doses of Pb from the small intestine in a dose-related manner. This apparently occurred because the 2 metals competed for similar binding sites on intestinal mucosal proteins which were important in the absorptive process. In vivo, both Pb and Fe bound to 2 heat-stable intestinal mucosal fractions, particularly the higher-MW fraction. Addition of Fe to test doses of Pb markedly diminished the amount of Pb bound by the high-MW fraction. This fraction, with a MW of approximately 370,000, bound both Pb and Fe. Shared binding sites on this protein may explain why dietary Fe decreased Pb absorption and Fe deficiency increased it.