The validity of extrinsic stable isotopic labeling for mineral absorption studies in rats

Boza, J J, Fox, T E, Eagles, J, Wilson, P D and Fairweather-Tait, S J ORCID: (1995) The validity of extrinsic stable isotopic labeling for mineral absorption studies in rats. Journal of Nutrition, 125 (6). pp. 1611-1616. ISSN 0022-3166

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The use of extrinsic stable and radioisotopic labels (Fe, Zn, Cu and Se) was compared with the use of intrinsic labels by measuring label retention in rats. Saccharomyces cerevisiae (Hansen strain CBS 1171) was prepared intrinsically enriched with a stable isotope of iron, zinc, copper or selenium, and unenriched freeze-dried yeast was extrinsically labeled with the appropriate stable and/or radioisotope. Male Wistar rats, weighing 80-100 g and fed a purified diet, were given a test meal of one of the above labeled yeasts. Isotopic retention was determined by fecal monitoring. Retention of the stable isotopes was determined by thermal ionization quadruple mass spectrometry (TIQMS) and retention of the radioisotopes by counting feces in a whole-body counter. The results indicated that the behavior of the labels differed among the minerals, with copper as the only one in which the intrinsic and extrinsic stable isotopes were comparably retained. With zinc, retention of the extrinsic radiolabel and intrinsic label was similar, but retention of the extrinsic stable isotope label was higher. With iron, the intrinsic label had a significantly lower retention than the two extrinsic labels; with selenium, retention of all three labels was different, but these differences were not of a sufficient magnitude to conclude that extrinsic stable isotopic labelling is not valid. These results demonstrate that an extrinsic stable isotope label can be used for copper, selenium and inorganic iron, but that such a label is not valid for studies on zinc.

Item Type: Article
Uncontrolled Keywords: absorption,animals,copper,diet,iron,iron isotopes,iron radioisotopes,isotope labeling,isotopes,male,mass spectrometry,random allocation,rats,rats, wistar,saccharomyces cerevisiae,selenium,selenium radioisotopes,zinc,zinc isotopes,zinc radioisotopes
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Faculty of Science > School of Chemistry
Faculty of Science > School of Chemical Sciences and Pharmacy
Depositing User: Pure Connector
Date Deposited: 05 Aug 2014 12:30
Last Modified: 24 Oct 2022 06:32

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