Maleate induced change in the kidney binding of mercury in rats pretreated with cadmium

Webb, M.; Magós, L.

doi:10.1016/0009-2797(78)90020-0

Cited by 12 publications

(2 citation statements)

References 22 publications

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“…administration, more Hg 2+ was bound to the metallothionein than to the high molecular weight components (Table 3). In agreement with previous observations (e.g., Webb and Magos 1978) the renal metallothionein of the adult Hg2+-treated rat contained Hg 2+ and copper, but only small amounts of Zn 2 § (Fig. ld).…”

Section: Resultssupporting

confidence: 90%

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Endogenous metal binding proteins in relation to the differences in absorption and distribution of mercury in newborn and adult rats

Webb

Holt

1982

Arch Toxicol

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Abstract. Both in the ilatestinal copper complex and hepatic zinc-thionein of the newborn rat provide immediately available, high-affinity binding sites for Hg 2+. Retention of orally administered Hg 2+ in the gastrointestinal tract is much greater in the 5-day old rat than in the weanling and accounts for most (70-90%) of the body burden at 18 h. At a dose level of 790 ~tg Hg2+/kg body weight, 41% of the Hg 2 § retained in the gastrointestinal tract of the newborn animal is located in the soluble fraction of the mucosa and 48% of this is bound by the copper-complex. This complex, therefore, seems to limit the transfer of Hg 2+ from the mucosa to the serosa. It does not appear, however, to be a primary acceptor of Hg 2+ in the neonatal intestine since, after administration of 100 ~tg Hg2+/kg body weight, its binding of Hg 2+ is less (33% of the soluble Hg 2 § than that (67% of the soluble Hg 2 § of the high molecular weight protein fraction.At 18 h after the intraperitoneal administration of Hg 2+ (790 ~tg Hg2+/kg body weight), whole body retention is greater in the adult (80% of the dose) than in the suckling or weanling animal (63-68% of the dose). In the suckling animal the inter-and intra-organ distributions of the retained Hg 2+ also differ from those in the weanling and/or adult rat. Thus the ratio of the renal:hepatic Hg 2+ contents, after either intragastric or intraperitoneal doses of Hg 2+, increases with age. Also most (approximately 90%) of the Hg 2+ retained in the liver of the newborn animal after an intragastric dose is bound by the metallothionein whereas, in the adult liver, only 4% of the total Hg 2 § is in this form. The presence of the metallothionein, however, is not the cause of the increased Hg > uptake in the former, since induction of hepatic zinc-thionein in the adult by pretreatment with Zn 2+ does not affect the distribution of Hg 2 § between the liver and kidneys.These findings are discussed in relation to the known differences in intestinal absorption and tissue distribution of Cd 2+ and Hg 2+ in newborn

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Section: Resultssupporting

confidence: 90%

“…were measured with a counting efficiency of 12% by the method of Webb and Magos (1978). Contents and concentrations of 2~ in whole organs and in solutions were determined in a well-shaped NaI crystal (13 cm diam, 11 cm deep; counting-efficiency 43%) and a Packard Auto-Gamma 5330 Spectrophotometer, respectively.…”

Section: Methodsmentioning

confidence: 99%