Mucosal uptake and whole-body retention of dietary manganese are not altered in beta2-microglobulin knockout mice

To further examine the interrelationships between manganese and iron absorption, the mucosal uptake, initial rate of loss, wholebody retention, and tissue distribution of an orally administered ⁵⁴Mn radiotracer were compared between normal and β₂-microglobulin knockout [β₂m(-/-)] mice. These mutant mice are commonly used as a model for the study of human hemochromatosis, a hereditary ironoverload disease. Initial uptake of ⁵⁴Mn by the intestinal mucosa, the liver, and the brain was not different between the two strains. The mutant mice had much higher concentrations of nonheme and total iron in the liver, but hepatic manganese, copper, magnesium, and zinc concentrations were similar between the two strains. In summary, the mucosal uptake and whole-body retention of manganese and tissue manganese concentrations were not altered in β₂m(-/-) mice; this suggests that normal homeostasis of manganese is not affected by the altered HFE protein-β₂m complex in these mice. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable. The US Department of Agriculture, Agricultural Research Service, Northern Plains Area, is an equal opportunity/affirmative action employer and all agency services are available without discrimination.