Effect of ascorbic acid and iron on binding and uptake of copper by caco-2 cells

H. M. Meltzer, S. L. Norenberg, B. Lonnerdal

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Abstract

It is widely assumed that ascorbic acid (Asc) has a negative effect on copper (Cu) absorption in animals and humans, mainly through reducing the element to its cuprous form, which is believed to be poorly absorbed. The use of iron (Fe) fortification has also raised the possibility of excess Fe impairing the absorption of Cu. The aim of the present study was to investigate the effect of varying concentrations of Asc and Fe on Cu binding and uptake in the human colon carcinoma cell line Caco-2. Within physiological ranges, Asc enhanced both binding and uptake of Cu in the Caco-2 cells. Increasing ratios of Asc to Cu resulted in an increased Cu uptake. At 1 ppm Cu, a 100:1 molar ratio increased the uptake 4-fold after 2 and 6 h. At 5 ppm Cu, the enhancing effect of Asc became pronounced only after 6 h. Fe did not seem to influence Cu binding or uptake at Fe/Cu ratios below 12:1. Our results support studies showing that Asc (or reducing equivalent) increases the accessibility of Cu to cells, while moderately high Fe/Cu ratios do not affect binding and uptake of Cu.

Original languageEnglish (US)
JournalFASEB Journal
Volume10
Issue number3
StatePublished - 1996

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ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Cell Biology

Cite this

Meltzer, H. M., Norenberg, S. L., & Lonnerdal, B. (1996). Effect of ascorbic acid and iron on binding and uptake of copper by caco-2 cells. FASEB Journal, 10(3).