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In vitro measurement and adaptive response of Fe 3+ uptake by mouse intestine
Author(s) -
Raja Kishor B.,
Bjarnason Ingvar,
Simpson Robert J.,
Peters Timothy J.
Publication year - 1987
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.290050109
Subject(s) - nitrilotriacetic acid , incubation , in vitro , kinetics , chemistry , brush border , chelation , metabolism , biochemistry , biology , medicine , inorganic chemistry , physics , vesicle , quantum mechanics , membrane
In order to define the importance of the mucosal uptake step in the intestinal regulation of iron absorption, unidirectional uptake rates of Fe 3+ from a nitrilotriacetic acid chelate were measured in duodenal fragments from mice using an in vitro technique. [ 57 Co]‐Cyanocobalamin was used as a marker of adherent incubation medium. Uptake showed saturation kinetics over the concentration range 18–450 μM. Uptake was increased in fragments from hypoxic, dietary iron‐deficient and pregnant mice. The enhanced uptake was due to an increase in V app max . However, the modest increase in uptake rates in pregnancy and the gross changes observed in iron‐deficiency make the hypoxic model the most convenient. The increase in uptake in hypoxic animals was located to the duodenal region and was not associated with changes in either total mucosal iron content or epithelial cell turnover. The rate of uptake of iron via the serosa did not change with hypoxia. This study implies that flux of Fe 3+ across the brush border is subject to adaptive regulation. The hypoxic model is suitable for investigation into the regulation of iron homestasis.