| Increased renal alpha-epithelial sodium channel (ENAC) protein and increased ENAC activity in normal pregnancy. | |
| | |
MedLine Citation:
|
PMID: 20686170 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Pregnancy-mediated sodium (Na) retention is required to provide an increase in plasma volume for the growing fetus. The mechanisms responsible for this Na retention are not clear. We first used a targeted proteomics approach and found that there were no changes in the protein abundance compared with virgin rats of the β or γ ENaC, type 3 Na(+)/H(+) exchanger (NHE3), bumetanide-sensitive cotransporter (NKCC2), or NaCl cotransporter (NCC) in mid- or late pregnancy. In contrast, we observed marked increases in the abundance of the α-ENaC subunit. The plasma volume increased progressively during pregnancy with the greatest plasma volume being evident in late pregnancy. ENaC inhibition abolished the difference in plasma volume status between virgin and pregnant rats. To determine the in vivo activity of ENaC, we conducted in vivo studies of rats in late pregnancy (days 18-20) and virgin rats to measure the natriuretic response to ENaC blockade (with benzamil). The in vivo activity of ENaC (U(Na)V postbenzamil-U(Na)V postvehicle) was markedly increased in late pregnancy, and this difference was abolished by pretreatment with the mineralocorticoid receptor antagonist, eplerenone. These findings demonstrate that the increased α-ENaC subunit of pregnancy is associated with an mineralocorticoid-dependent increase in ENaC activity. Further, we show that ENaC activity is a major contributor of plasma volume status in late pregnancy. These changes are likely to contribute to the renal sodium retention and plasma volume expansion required for an optimal pregnancy. |
| | |
Authors:
|
Crystal West; Zheng Zhang; Geoffrey Ecker; Shyama M E Masilamani |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural Date: 2010-08-04 |
Journal Detail:
|
Title: American journal of physiology. Regulatory, integrative and comparative physiology Volume: 299 ISSN: 1522-1490 ISO Abbreviation: Am. J. Physiol. Regul. Integr. Comp. Physiol. Publication Date: 2010 Nov |
Date Detail:
|
Created Date: 2010-11-03 Completed Date: 2010-12-01 Revised Date: 2011-11-01 |
Medline Journal Info:
|
Nlm Unique ID: 100901230 Medline TA: Am J Physiol Regul Integr Comp Physiol Country: United States |
Other Details:
|
Languages: eng Pagination: R1326-32 Citation Subset: IM |
Affiliation:
|
Department of Internal Medicine/Division of Nephrology, Virginia Commonwealth University Medical Center, Richmond, Virginia 23298-0160, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Aldosterone Antagonists
/
pharmacology Amiloride / analogs & derivatives, pharmacology Animals Epithelial Sodium Channel / antagonists & inhibitors, metabolism* Female Immunoblotting Kidney / drug effects, metabolism* Mineralocorticoids / metabolism Natriuresis Plasma Volume Pregnancy Proteomics Rats Rats, Sprague-Dawley Sodium / metabolism* Sodium Channel Blockers / pharmacology Spironolactone / analogs & derivatives, pharmacology Up-Regulation |
| Grant Support | |
ID/Acronym/Agency:
|
K22HL66994/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Aldosterone Antagonists; 0/Epithelial Sodium Channel; 0/Mineralocorticoids; 0/Scnn1a protein, rat; 0/Sodium Channel Blockers; 0/eplerenone; 2609-46-3/Amiloride; 2898-76-2/benzamil; 52-01-7/Spironolactone; 7440-23-5/Sodium |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Gas exchange kinetics in obese adolescents. Inferences on exercise tolerance and prescription.
Next Document: Physiological characteristics of gastric contractions and circadian gastric motility in the free-mov...