In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 96, No. 4 ( 1999-02-16), p. 1732-1737
Abstract:
The amiloride-sensitive epithelial sodium channel (ENaC) is a
heteromultimer of three homologous subunits (α-, β-, and γ-subunits). To study the role of the β-subunit in
vivo , we analyzed mice in which the βENaC gene locus was
disrupted. These mice showed low levels of βENaC mRNA expression in kidney (≈1%), lung (≈1%), and colon (≈4%). In homozygous
mutant βENaC mice, no βENaC protein could be detected with immunofluorescent staining. At birth, there was a small delay in
lung-liquid clearance that paralleled diminished amiloride-sensitive Na + absorption in tracheal explants. With normal salt
intake, these mice showed a normal growth rate. However, in
vivo , adult βENaC m/m mice exhibited a significantly
reduced ENaC activity in colon and elevated plasma aldosterone levels, suggesting hypovolemia and pseudohypoaldosteronism type 1. This
phenotype was clinically silent, as βENaC m/m mice showed no weight loss, normal plasma Na + and K + concentrations,
normal blood pressure, and a compensated metabolic acidosis. On low-salt diets, βENaC-mutant mice developed clinical symptoms of an
acute pseudohypoaldosteronism type 1 (weight loss, hyperkalemia, and decreased blood pressure), indicating that βENaC is required for
Na + conservation during salt deprivation.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.96.4.1732
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
1999
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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