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Gut Transport of a Molybdenum/Ascorbic Acid Complex

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Abstract

Background: Relatively little work has been done on the absorption of trace elements in the mammalian small intestine. Recently, studies have demonstrated that a molybdenum/ascorbic acid complex has shown some promise as a potentially orally administered insulin-mimetic agent. However, the transport mechanism of the molybdenum/ascorbic acid complex is unknown. In this study we examine some aspects of the movement of the complex across the intestinal wall using measurements of elemental molybdenum as an indicator because it is not possible to measure the complex directly.

Methods: Everted rat small intestine sacs were used to determine some aspects of the transport of the complex across the intestine. Intestinal sacs from five rats were incubated in a medium containing 1 g/L of the molybdenum complex. Sacs from a further five rats had 1 mmol/L of 2,4-dinitrophenol, a known inhibitor of oxidative phosphorylation, added to the incubation medium. In a second experiment, everted sacs from five rats were also incubated in media containing one of six concentrations of the molybdenum complex (0.5, 1, 2, 4, 8 or 10 g/L).

Results: There was no significant difference between transport rates of groups with or without 2,4-dinitrophenol in the incubation medium, suggesting that the predominant mechanism of molybdenum transport is energy-independent. There was a significant positive, linear increase in the transport rate with increasing concentration of the molybdenum complex.

Conclusion: These data suggest that the predominant mechanism of this molybdenum/ascorbic acid complex transport in the small intestine is non-saturable and therefore not protein-mediated.

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Acknowledgements

The authors would like to thank Ms Kelly Crossman for her ability to maintain a rat colony in excellent health. Funding for this study was provided by the New Brunswick Heart and Stroke Foundation, the Natural Sciences and Engineering Research Council of Canada, the Canadian Foundation for Innovation and a research grant from Mount Allison University.

The authors have no financial interests or other conflicts of interest relevant to the content of this study.

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Authors and Affiliations

  1. Department of Biology and Department of Chemistry, Mount Allison University, Sackville, New Brunswick, Canada

    M. S. Russell,  J. Bailey, S. J. Duffy, C. M. Vogels & S. A. Westcott

  2. Department of Physiology, Midwestern University, Glendale, Arizona, USA

    T. L. Broderick

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  1. M. S. Russell
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  2. J. Bailey
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  3. S. J. Duffy
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  4. C. M. Vogels
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  5. T. L. Broderick
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  6. S. A. Westcott
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Correspondence to J. Bailey.

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Russell, M.S., Bailey, J., Duffy, S.J. et al. Gut Transport of a Molybdenum/Ascorbic Acid Complex. Drugs R D 7, 111–117 (2006). https://doi.org/10.2165/00126839-200607020-00005

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  • DOI: https://doi.org/10.2165/00126839-200607020-00005

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