Effect of dietary salt intake on epithelial Na+ channels (ENaCs) in the hypothalamus of Dahl salt-sensitive rats.
Physiol Rep
; 6(16): e13838, 2018 08.
Article
em En
| MEDLINE
| ID: mdl-30156045
ABSTRACT
All three epithelial Na+ channel (ENaC) subunits (α, ß, and γ) and the mineralocorticoid receptor (MR), a known regulator of ENaC, are located in vasopressin (VP) synthesizing magnocellular neurons in the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei. Our previous study showed that ENaC mediates a Na+ leak current that affects the steady-state membrane potential of VP neurons. This study was conducted in Dahl salt-sensitive (Dahl-SS) rats to determine if any abnormal responses in the expression of ENaC subunits and MR occur in the hypothalamus and kidney in response to a high dietary salt intake. After 21 days of high salt consumption, Dahl-SS rat resulted in a significant increase in γENaC expression and exhibited proteolytic cleavage of this subunit compared to Sprague-Dawley (SD) rats. Additionally, Dahl-SS rats had dense somato-dendritic γENaC immunoreactivity in VP neurons, which was absent in SD rats. In contrast, SD rats fed a high salt diet had significantly decreased αENaC subunit expression in the kidney and MR expression in the hypothalamus. Plasma osmolality measured daily for 22 days demonstrated that Dahl-SS rats fed a high salt diet had a steady increase in plasma osmolality, whereas SD rats had an initial increase that decreased to baseline levels. Findings from this study demonstrate that Dahl-SS rats lack a compensatory mechanism to down regulate ENaC during high dietary salt consumption, which may contribute to the development of hypertension.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Cloreto de Sódio na Dieta
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Canais Epiteliais de Sódio
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Hipotálamo
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article