Intestinal iron transfer after ileojejunal transposition

Little is known on how longitudinal differences in intestinal iron absorption develop and to what extent distal segments can adapt to a more proximal location after surgical intervention. Therefore, 3 weeks after ileojejunal transposition in rats adaptational changes of intestinal iron transfer were measured together with those of glucose and water transfer, intestinal dry weight and villus surface. In vitro iron transfer (Fisher-Parsons technique) was significantly increased in transposed segments as compared to ileal controls, when related to intestinal length. Jejunal values were not reached, though, which was confirmed by corresponding in vivo results. Increases in intestinal mass which are known to be caused by villus hyperplasia were closely correlated to increases in iron transfer after ileojejunal transposition. Thus, the increased iron transfer might partly be due to an increased number of enterocytes. In addition, transposed enterocytes took up jejunal characteristics regarding the ratio between transferred iron and water quantities which significantly increased the serosal 59Fe concentration as compared to ileal segments. Similar changes were also observed for glucose. Therefore, the adaptation of intestinal 59Fe transfer after ileojejunal transposition seems to be part of a more general adaptation process, essential parts of which are likely to be located in the brush border.