Studies in Iron Metabolism. IV. Iron Absorption in Experimental Iron Deficiency

I RON ABSORPTION is enhanced by iron deficiency in human subjects ( see J osephs, ’ Calbender,2 and Moore3) , and in experimental animals ( e.g., Bothwell, Pirzio-Birobi and Finch4). The mechanism by which iron deficiency and other factors influence iron absorption by the small intestine has not yet been satisfactorily explained. The attractive hypothesis of “mucosab bbock,”58 which might provide an explanation of the effect of iron deficiency, has been seriously criticized ( see Moore3) but no alternative hypothesis is available. The experiments described here were undertaken to study the absorption of Fe59-tagged iron salts by rats maintained on semisynthetic diets which produce an apparently uncomplicated state of iron deficiency.9”#{176} Results confirm the remarkable increase in absorption produced by iron deficiency and enable some suggestions to be made about mechanisms of absorption. MATERIALS AND METHODS Female Wistar-strain albino rats were caged and fed as described previously.941 Weights and hemoglobin and hematocrit values were measured regularly.9 The iron-deficient group