Document Detail


Ontogeny of NHE8 in the rat proximal tubule.
MedLine Citation:
PMID:  17429030     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Proximal tubule bicarbonate reabsorption is primarily mediated via the Na(+)/H(+) exchanger, identified as NHE3 in adults. Previous studies have demonstrated a maturational increase in rat proximal tubule NHE3 expression, with a paucity of NHE3 expression in neonates, despite significant Na(+)-dependent proton secretion. Recently, a novel Na(+)/H(+) antiporter (NHE8) was identified and found to be expressed on the apical membrane of the proximal tubule. To determine whether NHE8 may be the antiporter responsible for proton secretion in neonates, the present study characterized the developmental expression of NHE8 in rat proximal tubules. RNA blots and real-time RT-PCR demonstrated no developmental difference in the mRNA of renal NHE8. Immunoblots, however, demonstrated peak protein abundance of NHE8 in brush border membrane vesicles of 7- and 14-day-old compared with adult rats. In contrast, the level of NHE8 expression in total cortical membrane protein was higher in adults than in neonates. Immunohistochemistry confirmed the presence of NHE8 on the apical membrane of the proximal tubules of neonatal and adult rats. These data demonstrate that NHE8 does undergo maturational changes on the apical membrane of the rat proximal tubule and may account for the Na(+)-dependent proton flux in neonatal proximal tubules.
Authors:
Amy M Becker; Jianning Zhang; Sunita Goyal; Vangipuram Dwarakanath; Peter S Aronson; Orson W Moe; Michel Baum
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2007-04-11
Journal Detail:
Title:  American journal of physiology. Renal physiology     Volume:  293     ISSN:  1931-857X     ISO Abbreviation:  Am. J. Physiol. Renal Physiol.     Publication Date:  2007 Jul 
Date Detail:
Created Date:  2007-07-09     Completed Date:  2007-08-17     Revised Date:  2013-03-14    
Medline Journal Info:
Nlm Unique ID:  100901990     Medline TA:  Am J Physiol Renal Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  F255-61     Citation Subset:  IM    
Affiliation:
Dept. of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9063, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blotting, Western
DNA, Complementary / biosynthesis,  genetics
Electrophoresis, Polyacrylamide Gel
Female
Immunohistochemistry
Kidney Tubules, Proximal / embryology,  growth & development*,  metabolism*
Microscopy, Fluorescence
Microvilli / metabolism
Pregnancy
Proteins / metabolism
RNA / biosynthesis,  isolation & purification
Rats
Rats, Sprague-Dawley
Reverse Transcriptase Polymerase Chain Reaction
Sodium-Hydrogen Antiporter / metabolism*
Grant Support
ID/Acronym/Agency:
P01 DK017433/DK/NIDDK NIH HHS; P01-DK-20543/DK/NIDDK NIH HHS; R01 DK033793/DK/NIDDK NIH HHS; R01-DK-41612/DK/NIDDK NIH HHS; R01-DK-48482/DK/NIDDK NIH HHS
Chemical
Reg. No./Substance:
0/DNA, Complementary; 0/NHE8 protein, rat; 0/Proteins; 0/Sodium-Hydrogen Antiporter; 0/sodium-hydrogen exchanger 3; 63231-63-0/RNA

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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