Cell-specific expression of epithelial sodium channel alpha, beta, and gamma subunits in aldosterone-responsive epithelia from the rat: localization by in situ hybridization and immunocytochemistry.

• DOI: 10.1083/jcb.127.6.1907
• Publication Date: 2004-05-15T00:22:22Z
• Authors: C Duc; N Farman; C M Canessa; J P Bonvalet; B C Rossier
• Keywords: Amiloride; Epithelial sodium channel; Apical membrane; Renal sodium reabsorption

A highly selective, amiloride-sensitive, epithelial sodium channel from rat colon (rENaC), composed of three homologous subunits termed alpha, beta, and gamma rENaC, has been cloned by functional expression was proposed to mediate electrogenic reabsorption in aldosterone-responsive epithelia. To determine whether rENaC could account for absorption vivo, we studied the cellular localization messenger RNA situ hybridization their subcellular distribution immunocytochemistry kidney, colon, salivary, sweat glands rat. In show that subunit mRNAs are specifically co-expressed renal distal convoluted tubules (DCT), connecting (CNT), cortical collecting ducts (CCD), outer medullary (OMCD), but not inner (IMCD). We demonstrate co-localization proteins apical membrane a majority cells CCD OMCD. Our data indicate nephron (excepting IMCD), correlates with previously described physiological amiloride-sensitive transport. data, however, suggest another transport protein mediates IMCD. also localized surface secretory salivary gland gland, providing further evidence consistent hypothesis is physiologically expressed cells.