Iron Deficiency Anemia Alters Lead Distribution in Rats † 682

Abstract

Background: Lead is bound mainly to intracellular protein. Iron deficiency anemia (IDA) may alter red cell protein content and affect blood lead levels. Objective: To determine the effect of IDA on whole blood lead (WBL) levels for an equivalent body burden of lead. Methods: 12 weanling rats were divided into 2 groups receiving either a normal diet (50 PPM iron) or a low iron diet (<5 PPM) otherwise equivalent. After 4 weeks, rats were weighed, jugular veins accessed, and baseline spun hematocrit (Hct) and WBL measured by stable isotope dilution-inductively coupled plasma mass spectrometry. Lead acetate (5 mg/kg body weight) was administered intravenously, and rats continued on their respective diets for 7 days to allow for lead tissue distribution, then sacrificed for tissue lead measurement. Results: Hct's were different: iron replete 47± 5% SD; iron deficient 29± 3% (p= 0.0001). Baseline WBL's were not different: iron replete 0.23 ± 0.18μg/dl SD; iron deficient 0.11 ± 0.07 μg/dl (p=0.2). WBL and tissue lead levels 7 days after lead injection are provided below.Table Conclusion: Although tissue levels were not different, IDA altered lead distribution such that increased lead was found in blood. Blood levels in IDA may represent different tissue burdens than in iron repletion. Possible explanations include increased RBC lead binding protein or changes in RBC membrane transport of lead.