Subcellular localization of DMT1 in enterocytes from anemic mk/mk mice.

Sections from proximal duodenum (I1) from either wild-type mice on a low-iron diet [+/+ (−Fe); panels A and B] or mk/mk mice (panels C and D) were analyzed for DMT1 expression with a rabbit polyclonal antiserum directed against the amino terminus of DMT1, and examined under high magnification (600 ×, panels A and C; 1000×, panels B and D). Transverse (A and C) and longitudinal (B and D) sections are shown. In iron-depleted +/+ mice (A and B), DMT1 is concentrated at the brush border (arrow) and also detectable in the apical region (arrowhead) of villus enterocytes. Inmk/mk mice (C and D), DMT1 staining is intracellular (arrowhead) and is not (or weakly) detectable at the brush border. In all sections, mucus-secreting goblet cells remain negative (white arrows).