Immunocytochemical and immunoelectron microscopic localization of α-, β-, and γ-ENaC in rat kidney

Henrik Hager, Tae Hwan Kwon, Anna K. Vinnikova, Shyama Masilamani, Heddwen L Brooks, Jørgen Frøkiaer, Mark A. Knepper, Søren Nielsen

Research output: Contribution to journalArticle

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Abstract

Epithelial sodium channel (ENaC) subunit (α, β, and γ) mRNA and protein have been localized to the principal cells of the connecting tubule (CNT), cortical collecting duct (CCD), and outer medullary collecting duct (OMCD) in rat kidney. However, the subcellular localization of ENaC subunits in the principal cells of these cells is undefined. The cellular and subcellular localization of ENaC subunits in rat kidney was therefore examined. Immunocytochemistry demonstrated the presence of all three subunits in principal cells of the CNT, CCD, OMCD, and IMCD. In cortex and outer medulla, confocal microscopy demonstrated a difference in the subcellular localization of subunits. α-ENaC was localized mainly in a zone in the apical domains, whereas β- and γ-ENaC were found throughout the cytoplasm. Immunoelectron microscopy confirmed the presence of ENaC subunits in both the apical plasma membrane and intracellular vesicles. In contrast to the labeling pattern seen in cortex, α-ENaC labeling in IMCD cells was distributed throughout the cytoplasm. In the urothelium covering pelvis, ureters, and bladder, immunoperoxidase and confocal microscopy revealed differences the presence of all ENaC subunits. As seen in CCD, α-ENaC was present in a narrow zone near the apical plasma membrane, whereas β-and γ-ENaC were dispersed throughout the cytoplasm. In conclusion, all three subunits of ENaC are expressed throughout the collecting duct (CD), including the IMCD as well as in the urothelium. The intracellular vesicular pool in CD principal cells suggests ENaC trafficking as a potential mechanism for the regulation of Na+ reabsorption.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Renal Physiology
Volume280
Issue number6 49-6
StatePublished - 2001
Externally publishedYes

Fingerprint

Kidney
Urothelium
Cytoplasm
Confocal Microscopy
Cell Membrane
Epithelial Sodium Channels
Immunoelectron Microscopy
Protein Subunits
Ureter
Pelvis
Urinary Bladder
Immunohistochemistry
Messenger RNA

Keywords

  • Aldosterone
  • Collecting duct
  • Epithelial sodium channel
  • Intracellular trafficking
  • Sodium transport
  • Urothelium

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Hager, H., Kwon, T. H., Vinnikova, A. K., Masilamani, S., Brooks, H. L., Frøkiaer, J., ... Nielsen, S. (2001). Immunocytochemical and immunoelectron microscopic localization of α-, β-, and γ-ENaC in rat kidney. American Journal of Physiology - Renal Physiology, 280(6 49-6).

Immunocytochemical and immunoelectron microscopic localization of α-, β-, and γ-ENaC in rat kidney. / Hager, Henrik; Kwon, Tae Hwan; Vinnikova, Anna K.; Masilamani, Shyama; Brooks, Heddwen L; Frøkiaer, Jørgen; Knepper, Mark A.; Nielsen, Søren.

In: American Journal of Physiology - Renal Physiology, Vol. 280, No. 6 49-6, 2001.

Research output: Contribution to journalArticle

Hager, H, Kwon, TH, Vinnikova, AK, Masilamani, S, Brooks, HL, Frøkiaer, J, Knepper, MA & Nielsen, S 2001, 'Immunocytochemical and immunoelectron microscopic localization of α-, β-, and γ-ENaC in rat kidney', American Journal of Physiology - Renal Physiology, vol. 280, no. 6 49-6.
Hager, Henrik ; Kwon, Tae Hwan ; Vinnikova, Anna K. ; Masilamani, Shyama ; Brooks, Heddwen L ; Frøkiaer, Jørgen ; Knepper, Mark A. ; Nielsen, Søren. / Immunocytochemical and immunoelectron microscopic localization of α-, β-, and γ-ENaC in rat kidney. In: American Journal of Physiology - Renal Physiology. 2001 ; Vol. 280, No. 6 49-6.
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AU - Hager, Henrik

AU - Kwon, Tae Hwan

AU - Vinnikova, Anna K.

AU - Masilamani, Shyama

AU - Brooks, Heddwen L

AU - Frøkiaer, Jørgen

AU - Knepper, Mark A.

AU - Nielsen, Søren

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