Mucosal uptake and whole-body retention of dietary manganese are not altered in [beta]2-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 ^sup 54^Mn radiotracer were compared between normal and β^sub 2^-microglobulin knockout [β^sub 2^m(-/-)] mice. These mutant mice are commonly used as a model for the study of human hemochromatosis, a hereditary ironoverload disease. Initial uptake of ^sup 54^Mn 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 β^sub 2^m(-/-) mice; this suggests that normal homeostasis of manganese is not affected by the altered HFE protein-β^sub 2^m complex in these mice.[PUBLICATION ABSTRACT]