Brief communication: magnesium absorption in human ileum.

A novel technique utilizing samples of human distal ileum removed at surgery was used to study magnesium (Mg) absorption. Specimens of isolated absorptive mucosa were obtained by careful dissection of the tissue to remove the muscle layers, and were mounted in flux chambers. Mean tissue Mg concentration in human isolated intestinal mucosa was found to be within the postulated normal range for human tissue. Mucosal to serosal Mg transport was unaffected by ouabain or 2,4-dinitrophenol and sodium fluoride. Overall, the data indicate Mg absorption in distal ileum to be passive in nature, although a minor active transcellular component cannot be excluded.