A Comparative Study of Lead Nephrotoxicity and Tissue Deposition Between Rats, Mice, and Pigeons Exposed to Drinking Water Containing 2, 20, or 200 ppm Lead

Abstract

White Carnaew pigeons were exposed to drinking water containing various concentrations of lead to study the relationship between exposure and tissue deposition and the relationship between the concentrations of lead in kidney and morphologic alterations. The concentration of lead in the blood was the only tissue which showed a linear increase with respect to the concentration of lead in the drinking water. The concentration of lead in the liver, kidney, brain, heart, aorta, and pancreas increased in response to lead in the drinking water; however, these increases were not linear with respect to lead exposure. Similar results were obtained for rats and mice exposed via the drinking water to 2, 20, or 200 ppm lead; however, the concentration of lead in tissues was substantially greater in pigeons. Kidneys from rats and mice appeared normal following the exposure of 200 ppm lead for 4 months, whereas, in kidneys from pigeons exposed to 200 ppm for a similar period of time there was tubular degeneration, fibrosis, and acid fast intranuclear inclusion bodies. These pathoanatomic alterations may be related to the concentration lead found in the kidney in pigeons. The concentration of lead in the kidney was 3,930 μg gram dry weight for pigeons but only 40 and 6 μg for mice and rats respectively. These studies suggest that the pigeon is more responsive to ingested lead than the rat or mouse. The renal lesions induced by chronic lead exposure are similar in pigeons and man suggesting that the pigeon may be useful animal model to study the yet unanswered questions related to chronic nephritis following lead poisoning.