HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 288/5/G1007    most recent 00210.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Bauerly, K. A. Articles by Lönnerdal, B. Search for Related Content PubMed PubMed Citation Articles by Bauerly, K. A. Articles by Lönnerdal, B.

MUCOSAL BIOLOGY

Effects of copper supplementation on copper absorption, tissue distribution, and copper transporter expression in an infant rat model

Department of Nutrition, University of California, Davis, California

Submitted 7 May 2004 ; accepted in final form 7 December 2004

Infants are exposed to variable copper (Cu) intake; Cu in breast milk is low, whereas infant formulas vary in Cu content as well as the water used for their preparation. Little is known about the regulation of Cu absorption during infancy. The objectives of this study were to determine effects of Cu supplementation on Cu absorption and tissue distribution and the expression of Cu transporters in an infant rat model. Suckling rat pups were orally dosed with 0, 10, or 25 µg Cu/day. Intestine and liver were collected at days 10 and 20, and Cu concentration, Cu transporter-1 (Ctr1), Atp7A, Atp7B, and metallothionein (MT) mRNA and protein levels were measured. ⁶⁷Cu absorption was measured at days 10 and 20. Total ⁶⁷Cu absorption decreased, and intestinal ⁶⁷Cu retention increased with increased Cu intake. At day 10, intestine Cu concentration, MT mRNA, and Ctr1 protein levels increased with supplementation, but no changes in Atp7A or Atp7B levels were observed. At day 20, intestine Cu concentration was unaffected by Cu supplementation, but Ctr1 protein and Atp7A mRNA and protein levels were higher than in controls. In liver, Cu level reflected Cu intake at days 10 and 20. There was a significant increase in Ctr1, Atp7B, and MT mRNA expression in liver at both ages with Cu supplementation. In conclusion, the ability of suckling rat pups to tolerate varying amounts of dietary Cu may be due to changes in Cu transporters, facilitated by transcriptional and posttranslational mechanisms. Despite these adaptive changes, Cu supplementation resulted in elevated alanine aminotransferase levels, suggesting a risk of Cu toxicity with supplementation during infancy.

copper transport; infancy; intestine; liver; copper transporter-1; Atp7A; Atp7B

This article has been cited by other articles:

				S. Lutsenko, N. L. Barnes, M. Y. Bartee, and O. Y. Dmitriev Function and Regulation of Human Copper-Transporting ATPases Physiol Rev, July 1, 2007; 87(3): 1011 - 1046. [Abstract] [Full Text] [PDF]

				L. Nyasae, R. Bustos, L. Braiterman, B. Eipper, and A. Hubbard Dynamics of endogenous ATP7A (Menkes protein) in intestinal epithelial cells: copper-dependent redistribution between two intracellular sites Am J Physiol Gastrointest Liver Physiol, April 1, 2007; 292(4): G1181 - G1194. [Abstract] [Full Text] [PDF]

				Y.-M. Kuo, A. A. Gybina, J. W. Pyatskowit, J. Gitschier, and J. R. Prohaska Copper Transport Protein (Ctr1) Levels in Mice Are Tissue Specific and Dependent on Copper Status J. Nutr., January 1, 2006; 136(1): 21 - 26. [Abstract] [Full Text] [PDF]