Compensatory up-regulation of angiotensin II subtype 1 receptors in alpha ENaC knockout heterozygous mice.

Détails

ID Serval
serval:BIB_F0A2E0EC7B39
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Compensatory up-regulation of angiotensin II subtype 1 receptors in alpha ENaC knockout heterozygous mice.
Périodique
Kidney international
Auteur(s)
Wang Q., Hummler E., Maillard M., Nussberger J., Rossier B.C., Brunner H.R., Burnier M.
ISSN
0085-2538
Statut éditorial
Publié
Date de publication
2001
Peer-reviewed
Oui
Volume
59
Numéro
6
Pages
2216-21
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't - Publication Status: ppublish
Résumé
BACKGROUND: In mice, a partial loss of function of the epithelial sodium channel (ENaC), which regulates sodium excretion in the distal nephron, causes pseudohypoaldosteronism, a salt-wasting syndrome. The purpose of the present experiments was to examine how alpha ENaC knockout heterozygous (+/-) mice, which have only one allele of the gene encoding for the alpha subunit of ENaC, control their blood pressure (BP) and sodium balance. METHODS: BP, urinary electrolyte excretion, plasma renin activity, and urinary adosterone were measured in wild-type (+/+) and heterozygous (+/-) mice on a low, regular, or high sodium diet. In addition, the BP response to angiotensin II (Ang II) and to Ang II receptor blockade, and the number and affinity of Ang II subtype 1 (AT1) receptors in renal tissue were analyzed in both mouse strains on the three diets. RESULTS: In comparison with wild-type mice (+/+), alpha ENaC heterozygous mutant mice (+/-) showed an intact capacity to maintain BP and sodium balance when studied on different sodium diets. However, no change in plasma renin activity was found in response to changes in sodium intake in alpha ENaC +/- mice. On a normal salt diet, heterozygous mice had an increased vascular responsiveness to exogenous Ang II (P < 0.01). Moreover, on a normal and low sodium intake, these mice exhibited an increase in the number of AT1 receptors in renal tissues; their BP lowered markedly during the Ang II receptor blockade (P < 0.01) and there was a clear tendency for an increase in urinary aldosterone excretion. CONCLUSIONS: alpha ENaC heterozygous mice have developed an unusual mechanism of compensation leading to an activation of the renin-angiotensin system, that is, the up-regulation of AT1 receptors. This up-regulation may be due to an increase in aldosterone production.
Mots-clé
Adaptation, Physiological, Angiotensin II, Animals, Blood Pressure, Body Weight, Epithelial Sodium Channel, Genotype, Heart Rate, Heterozygote, Hypertension, Renal, Mice, Mice, Inbred C57BL, Mice, Knockout, Receptor, Angiotensin, Type 1, Receptor, Angiotensin, Type 2, Receptors, Angiotensin, Renin, Renin-Angiotensin System, Sodium Channels, Vasoconstrictor Agents
Pubmed
Web of science
Création de la notice
05/03/2008 17:40
Dernière modification de la notice
03/03/2018 22:37
Données d'usage