The epithelial sodium channel (ENaC) controls colonic sodium absorption. So far, investigation of ENaC was limited by an unexplained lack of steroid-dependent ENaC expression in cultured intestinal cells, which we aimed to resolve. HT-29/B6 cells constitutively expressed the alpha-ENaC subunit, while beta- and gamma-ENaC subunits could not be detected due to deficient basal as well as corticosteroid-induced transcription. This was due to a lack of expression of both activating and inhibiting isoforms of glucocorticoid receptor (GR-alpha, -beta) and mineralocorticoid receptor. Stable transfection of GR-alpha restored intestine-specific glucocorticoid upregulation of beta- and gamma-ENaC in HT-29/B6 cells, which was followed by intact targeting of ENaC channels to the apical cell membrane and dose-dependent induction of electrogenic sodium absorption. In conclusion, ENaC deficiency is due to a lack of steroid receptors and not the consequence of a crypt-like phenotype of cultured intestinal cells. By stable GR transfection we obtained a model, in which ENaC regulation can be studied. (c) 2006 Elsevier Inc. All rights reserved.