Organ retention and excretion of radiolead administered intravenously in rats: A Comparison of erythrocyte- and plasma-associated lead

Abstract

Organ retention and excretion of lead transported by erythrocytes may differ from plasma. To evaluate this, we administered inorganic radiolabeled lead to adult male rats intravenously after its incorporation into erythrocytes or incubation with plasma. The percentage of remaining whole‐body radiolead lead retained in major organs was similar in animals dosed with erythrocyte‐ and plasma‐associated radiolead, but less erythrocyte‐associated radiolead was excreted in urine and stool. Calcium disodium EDTA significantly decreased the whole‐body retention of plasma‐associated radiolead in comparison with erythrocyte‐associated radiolead; dimercaprol and penicillamine did not affect whole‐body radiolead retention. However, the percentages of erythrocyte‐ and plasma‐associated radiolead in major organs were similar in rats that received calcium disodium EDTA, dimercaprol, or penicillamine and in normal controls. The whole‐body retention of radiolead was similar in rats with acetylphenylhydrazine (APH)‐induced anemia and in normal control rats. However, the percentages of radiolead retained in the livers and spleens of APH‐treated rats were significantly greater. We conclude that the percentages of erythrocyte‐ and plasma‐associated lead retained in the major organs of normal rats are similar. However, erythrocyte‐associated lead may be deposited preferentially in the liver and spleen when hemolytic anemia is present. Erythrocyte‐associated lead is excreted less readily than lead in plasma. J. Trace Elem. Exp. Med. 14:89–98, 2001. © 2001 Wiley‐Liss, Inc.