Influence of Dietary Selenium on Lead Toxicity in the Rat

Abstract

An investigation of the influence of dietary selenium (0.015, 0.05, 0.50, 1.0 ppm) on toxicity of dietary lead (0 and 200 ppm) in the young male rat indicated that selenium was mildly protective against the toxic effects of lead, but only up to 0.50 ppm selenium. At the excess selenium dietary level an exaggeration of lead toxicity was observed. Criteria employed to judge the effects of dietary selenium on lead toxicity included tissue lead concentration and urinary delta-aminolevulinic acid excretion. One exception to the exaggeration effect of excess selenium on lead toxicity was the protective effect of selenium on liver delta-aminolevulinic acid dehydratase activity. Since lead depressed kidney selenium concentration, lead may act as an antagonist to selenium metabolism.

Effects of excess dietary selenite on lead toxicity in sheep

“…Yet, in other cases Se had no effect (5) or increased Pb toxicosis (2), which was also demonstrated in this study. The confusion associated with this interaction of Se with Pb is not readily explained by intake rates of either Pb or Se, nor by the ratio of the two (Table 2).…”

“…Selenium, as the selenite has been shown to protect against Pb toxicosis in some cases (2,3). Yet, in other cases Se had no effect (5) or increased Pb toxicosis (2), which was also demonstrated in this study.…”

“…Selenium, as sodium selenite, was mildly protective against the toxic effects of Pb, as the acetate, but only up to 0.5 ppm Se (2). At higher sodium selenite levels, a synergistic effect of lead acetate toxicity was observed.…”

Factors influencing metabolism and toxicity of metals: a consensus report

“…In studies in which 0.5% Pb was given in the diet, Klauder,Murthy,and Petering (186) showed that lead interfered with copper metabolism. In subsequent reports in which the dietary lead was much lower, namely, 500 gg/g (0.05%), Klauder and Petering (187,188) showed that the toxic effect of lead were accentuated and (189) found that increasing levels of dietary copper (from 1.5 to 20 ppm) resulted in an exaggeration of the toxic effects of lead. Lead concentration was increased in the kidney and a two-to threefold increase in urinary excretion of ALA occurred.…”

Metabolism of /sup 90/Sr and other elements in man, April 1, 1976--March 31, 1977 (extended without additional funding to March 31, 1978) and renewal proposal, April 1, 1978--March 31, 1979

“…Also, selenium provides protection against cadmium and mercury toxicity (114)(115)(116). Excess dietary selenium intake has been reported to aggrevate lead toxicity in rats and resulted in increased lead levels in blood, liver, kidney, and bone (117).…”