The  -Subunit of the Epithelial Sodium Channel Is an Aldosterone-Induced Transcript in Mammalian Collecting Ducts, and This Transcriptional Response Is Mediated via Distinct cis-Elements in the 5'-Flanking Region of the Gene

2001 ◽  
Vol 15 (4) ◽  
pp. 575-588 ◽  
Author(s):  
V. E. Mick
Keyword(s):  
Sodium Channel ◽  
Transcriptional Response ◽  
Epithelial Sodium Channel ◽  
Cis Elements ◽  
Collecting Ducts ◽  
Flanking Region

scholarly journals Sub-chronic testosterone treatment increases the levels of epithelial sodium channel (ENaC)-α,βandγin the kidney of orchidectomized adult male Sprague–Dawley rats

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2145 ◽  
Author(s):  
Su Yi Loh ◽  
Nelli Giribabu ◽  
Naguib Salleh
Keyword(s):  
Blood Pressure ◽  
Sodium Channel ◽  
Adult Male ◽  
Epithelial Sodium Channel ◽  
Physiological Parameter ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Collecting Ducts ◽  
Distal Tubules ◽  
Epithelial Sodium Channel Enac

Testosterone has been reported to cause blood pressure to increase. However mechanisms that underlie the effect of this hormone on this physiological parameter are currently not well understood. The aims of this study were to investigate effects of testosterone on expression ofα,βandγ-epithelial sodium channel (ENaC) proteins and messenger RNAs (mRNAs) in kidneys, the channel known to be involved in Na+reabsorption, which subsequently can affect the blood pressure.Methods.Adult male Sprague–Dawley (SD) rats were orchidectomized fourteen days prior to receiving seven days treatment with testosterone propionate (125 µg/kg/day or 250 µg/kg/day) with or without flutamide (androgen receptor blocker) or finasteride (5α-reductase inhibitor). Following sacrifice, the kidneys were removed and were subjected forα,βandγ-ENaC protein and mRNA expression analyses by Western blotting and Real-time PCR (qPCR) respectively. The distribution ofα,βandγ-ENaC proteins in kidneys were observed by immunofluorescence.Results.Theα,βandγ-ENaC proteins and mRNA levels in kidneys were enhanced in rats which received testosterone-only treatment. In these rats,α,βandγ-ENaC proteins were distributed in the distal tubules and collecting ducts of the nephrons. Co-treatment with flutamide or finasteride resulted in the levels ofα,βandγ-ENaC proteins and mRNAs in kidneys to decrease. In conclusions, increases inα,βandγ-ENaC protein and mRNA levels in kidneys mainly in the distal tubules and collecting ducts under testosterone influence might lead to enhance Na+reabsorption which subsequently might cause an increase in blood pressure.

scholarly journals 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.

1994 ◽  
Vol 127 (6) ◽  
pp. 1907-1921 ◽  
Author(s):  
C Duc ◽  
N Farman ◽  
C M Canessa ◽  
J P Bonvalet ◽  
B C Rossier
Keyword(s):  
In Situ Hybridization ◽  
Sodium Channel ◽  
Sodium Transport ◽  
Epithelial Sodium Channel ◽  
Rat Colon ◽  
Sodium Reabsorption ◽  
Gamma Subunit ◽  
Collecting Ducts ◽  
Alpha Beta

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

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