Title
Dietary iron lowers the intestinal uptake of cadmium-metallothionein in rats
Author
Instituut CIVO-Toxicologie en Voeding TNO
Groten, J.P.
Luten, J.B.
van Bladeren, P.J.
Publication year
1992
Abstract
It has been shown that addition of extra calcium/phosphorus (Ca/P), zinc (Zn) and iron (Fe2+) to the diet results in a significant protection against cadmium (Cd) accumulation and toxicity in rats fed inorganic Cd salt. However, it is not clear whether the presence of these mineral supplements in the diet also protects against the Cd uptake from cadmium-metallothionein. The present study examines the influence of Ca/P, Zn and Fe2+ on the Cd disposition in rats fed diets containing either 1.5 and 8 mg Cd/kg diet as cadmium-metallothionein (CdMt) or as cadmium chloride (CdCl2) for 4 weeks. The feeding of Cd resulted in a dose-dependent increase of Cd in intestine, liver and kidneys. The total Cd uptake in liver and kidneys after exposure to CdMt was lower than after exposure to CdCl2. At the low dietary Cd level and after addition of the mineral supplement, the kidney/liver concentration ratio increased. However, this ratio was always higher with CdMt than with CdCl2, suggesting a selective renal disposition of dietary CdMt. The uptake of Cd from CdCl2 as well as from CdMt was significantly decreased by the presence of a combined mineral supplement of Ca/P, Zn and Fe2+. The protection which could be achieved was 72 and 75% for CdMt and 85 and 92% for CdCl2 after doses of 1.5 mg/kg and 8 mg/kg respectively. In a following experiment it was shown that the protective effect of the mineral mixture against CdMt was mainly due to the presence of Fe2+. It seems clear that Cd speciation and the mineral status of the diet have a considerable impact on the extent of Cd uptake in rats. Chemicals/CAS: Cadmium Chloride, 10108-64-2; Cadmium, 7440-43-9; cadmium-binding protein; Calcium, Dietary; Chlorides; Ferric Compounds; Metallothionein, 9038-94-2; Phosphorus, Dietary
Subject
Medicine
Geneeskunde
Physiology
Fysiologie
Analysis of Variance
Animal
Cadmium
Cadmium Chloride
Calcium, Dietary
Chlorides
Diet
Dose-Response Relationship, Drug
Ferric Compounds
Intestines
Kidney
Liver
Male
Metallothionein
Phosphorus, Dietary
Rats
Rats, Wistar
Support, Non-U.S. Gov't
Animalia
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DOI
https://doi.org/10.1016/0926-6917(92)90007-y
TNO identifier
78741
ISSN
0926-6917
Source
European Journal of Pharmacology - Environmental Toxicology and Pharmacology Section, 228 (228), 23-28
Document type
article