Dietary sodium induces a redistribution of the tubular metabolic workload.

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Etat: Public
Version: Final published version
Licence: CC BY 4.0
ID Serval
serval:BIB_117A3ADEBC80
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Dietary sodium induces a redistribution of the tubular metabolic workload.
Périodique
The Journal of physiology
Auteur(s)
Udwan K., Abed A., Roth I., Dizin E., Maillard M., Bettoni C., Loffing J., Wagner C.A., Edwards A., Feraille E.
ISSN
1469-7793 (Electronic)
ISSN-L
0022-3751
Statut éditorial
Publié
Date de publication
15/11/2017
Peer-reviewed
Oui
Volume
595
Numéro
22
Pages
6905-6922
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
Résumé
Body Na <sup>+</sup> content is tightly controlled by regulated urinary Na <sup>+</sup> excretion. The intrarenal mechanisms mediating adaptation to variations in dietary Na <sup>+</sup> intake are incompletely characterized. We confirmed and expanded observations in mice that variations in dietary Na <sup>+</sup> intake do not alter the glomerular filtration rate but alter the total and cell-surface expression of major Na <sup>+</sup> transporters all along the kidney tubule. Low dietary Na <sup>+</sup> intake increased Na <sup>+</sup> reabsorption in the proximal tubule and decreased it in more distal kidney tubule segments. High dietary Na <sup>+</sup> intake decreased Na <sup>+</sup> reabsorption in the proximal tubule and increased it in distal segments with lower energetic efficiency. The abundance of apical transporters and Na <sup>+</sup> delivery are the main determinants of Na <sup>+</sup> reabsorption along the kidney tubule. Tubular O <sub>2</sub> consumption and the efficiency of sodium reabsorption are dependent on sodium diet.
Na <sup>+</sup> excretion by the kidney varies according to dietary Na <sup>+</sup> intake. We undertook a systematic study of the effects of dietary salt intake on glomerular filtration rate (GFR) and tubular Na <sup>+</sup> reabsorption. We examined the renal adaptive response in mice subjected to 7 days of a low sodium diet (LSD) containing 0.01% Na <sup>+</sup> , a normal sodium diet (NSD) containing 0.18% Na <sup>+</sup> and a moderately high sodium diet (HSD) containing 1.25% Na <sup>+</sup> . As expected, LSD did not alter measured GFR and increased the abundance of total and cell-surface NHE3, NKCC2, NCC, α-ENaC and cleaved γ-ENaC compared to NSD. Mathematical modelling predicted that tubular Na <sup>+</sup> reabsorption increased in the proximal tubule but decreased in the distal nephron because of diminished Na <sup>+</sup> delivery. This prediction was confirmed by the natriuretic response to diuretics targeting the thick ascending limb, the distal convoluted tubule or the collecting system. On the other hand, HSD did not alter measured GFR but decreased the abundance of the aforementioned transporters compared to NSD. Mathematical modelling predicted that tubular Na <sup>+</sup> reabsorption decreased in the proximal tubule but increased in distal segments with lower transport efficiency with respect to O <sub>2</sub> consumption. This prediction was confirmed by the natriuretic response to diuretics. The activity of the metabolic sensor adenosine monophosphate-activated protein kinase (AMPK) was related to the changes in tubular Na <sup>+</sup> reabsorption. Our data show that fractional Na <sup>+</sup> reabsorption is distributed differently according to dietary Na <sup>+</sup> intake and induces changes in tubular O <sub>2</sub> consumption and sodium transport efficiency.
Mots-clé
Adaptation, Physiological, Animals, Glomerular Filtration Rate, Kidney Tubules, Proximal/metabolism, Kidney Tubules, Proximal/physiology, Male, Mice, Mice, Inbred C57BL, Oxygen/metabolism, Renal Elimination, Renal Reabsorption, Sodium, Dietary/metabolism, Sodium, Dietary/pharmacokinetics, Na+ transport, Na+ transporters, dietary salt, diuretics, optimal Na+ diet
Pubmed
Web of science
Open Access
Oui
Création de la notice
09/10/2017 9:50
Dernière modification de la notice
20/08/2019 13:39
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