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Dietary Selenium (Se) and Copper (Cu) Interact to Affect Homocysteine Metabolism in Rats

Permanent URL:
http://handle.nal.usda.gov/10113/37278
File:
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Abstract:
Previously, we reported that both Se deficiency and Cu deficiency decreased plasma homocysteine (pHcys) and increased plasma glutathione (pGSH) in rats. We also showed that the catalytic subunit of glutamate-cysteine ligase (Gclc), which catalyzes the rate-limiting step in glutathione biosynthesis, was upregulated in Se and Cu deficiencies. We suggested that in both deficiencies, Hcys was being shunted through the trans-sulfuration pathway as a result of this up-regulation. Because both Se and Cu deficiencies have similar effects, we hypothesized that a combined deficiency would exacerbate the decrease in pHcys and the increase in pGSH by further up-regulating Gclc. In a 2 x 2 experiment, male weanling Sprague-Dawley rats (n = 8-20/group) were fed an amino-acid-based diet containing either 0 or 0.2 μg Se (as selenite)/g and <1 or 6 μg Cu (as Cu carbonate)/g for 5 weeks. Our findings show that a combined deficiency of both Se and Cu results in lower pHcys and significantly elevated pGSH. However, the up-regulation of liver Gclc alone cannot explain why rats fed with the doubly deficient diet have the lowest pHcys and the highest pGSH.
Author(s):
Uthus, Eric O. , Ross, Sharon
Subject(s):
selenium , copper , dietary minerals , nutrient deficiencies , nutrient-nutrient interactions , homocysteine , amino acid metabolism , blood chemistry , liver , rats
Format:
p. 213-220.
Note:
Includes references
Source:
Biological trace element research 2009 June, v. 129, no. 1-3
Language:
English
Publisher:
New York : Humana Press Inc
Year:
2009
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.