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Effect of salt and water intake on epithelial sodium channel mRNA abundance in the kidney of salt‐sensitive Sabra rats
Author(s) -
Nicco Carole,
Bankir Lise,
Bouby Nadine
Publication year - 2003
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.2003.03941.x
Subject(s) - vasopressin , epithelial sodium channel , endocrinology , medicine , sodium , aldosterone , chemistry , kidney , messenger rna , biology , biochemistry , gene , organic chemistry
Summary 1. The level of mRNA expression of epithelial sodium channel (ENaC) subunits was studied in a salt‐dependent hypertensive rat strain (Sabra). These rats exhibit high vasopressin levels compared with their normotensive counterparts. We also investigated whether this expression is influenced by changes in the sodium intake/aldosterone axis or in the fluid intake/vasopressin axis. 2. A higher expression of β‐ and γ‐subunit mRNA was found in salt‐sensitive compared with salt‐resistant rats on a normal salt diet. A high‐sodium diet did not alter mRNA abundance in either substrain. In contrast, water supplementation in salt‐sensitive rats fed the high‐sodium diet induced a marked reduction in mRNA abundance of β‐ and γ‐subunits. 3. The present study provides evidence that β‐ and γ‐subunits of ENaC are differently expressed in the kidney of salt‐sensitive and salt‐resistant Sabra rats and that their abundance is regulated by vasopressin, not by sodium intake. These results are consistent with the hypothesis that increased vasopressin‐dependent ENaC expression and activity may contribute to the pathogenesis of hypertension in salt‐sensitive Sabra rats.