Interrelationships of lead and iron retention in iron-deficient mice

Abstract

The effect of iron deficiency anemia on lead retention was examined in mice made iron deficient by feeding a low iron diet. Lead retention was measured by incorporation of 203Pb into carrier doses of lead acetate and subsequent whole body counting of the intact animal. Iron deficiency did not influence the whole body retention of ip injections of lead. Iron deficiency did, however, increase the retention of lead administered intragastrically at low doses of 0·01 to 10 nmol. The percentage retention in iron-deficient mice decreased from 10 to 4% with increases in dose. The percentage retained by iron-replete mice was about 2 to 3% and did not differ substantially with dose. Distribution studies indicated a proportionately increased retention of lead in the gastrointestinal tract of iron-deficient mice. Intragastric addition of 1 to 10 μmol of iron as ferric chloride just before lead administration inhibited the 10-day whole body retention of 1 and 10 nmol of lead in iron-deficient mice. Alternately, the addition of high doses of lead (50–200 μmol) reduced the 5-day whole body retention of 0.5 μmol of iron in iron-deficient mice. The results indicate that lead and iron interact at the level of the intestinal iron transport system in iron deficiency and that iron deficiency should be considered in the pathogenesis of lead poisoning.