Linked Life Data

11447025

Source:http://linkedlifedata.com/resource/pubmed/id/11447025

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-7-11
pubmed:abstractText
Several Na(+)/H(+) exchanger (NHE) isoforms are expressed in the stomach, and NHE1 and NHE2 knockout mice display gastric mucosal atrophy. This study investigated the cellular distribution of the NHE isoforms NHE1, NHE2, NHE3, and NHE4 in rabbit gastric epithelial cells and their regulation by intracellular pH (pH(i)), hyperosmolarity, and an increase in cAMP. Semiquantitative RT-PCR and Northern blot experiments showed high NHE1 and NHE2 mRNA levels in mucous cells and high NHE4 mRNA levels in parietal and chief cells. Fluorescence optical measurements in cultured rabbit parietal and mucous cells using the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein and NHE isoform-specific inhibitors demonstrated that in both cell types, intracellular acidification activates NHE1 and NHE2, whereas hyperosmolarity activates NHE1 and NHE4. The relative contribution of the different isoforms to pH(i)- and hyperosmolarity-activated Na(+)/H(+) exchange in the different cell types paralleled their relative expression levels. cAMP elevation also stimulated NHE4, whereas an increase in osmolarity above a certain threshold further increased NHE1 and not NHE4 activity. We conclude that in rabbit gastric epithelium, NHE1 and NHE4 regulate cell volume and NHE1 and NHE2 regulate pH(i). The high NHE1 and NHE2 expression levels in mucous cells may reflect their special need for pH(i) regulation during high gastric acidity. NHE4 is likely involved in volume regulation during acid secretion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0193-1857
pubmed:author
pubmed:issnType
Print
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
G447-58
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Differential expression and regulation of Na(+)/H(+) exchanger isoforms in rabbit parietal and mucous cells.
pubmed:affiliation
First Department of Medicine, Eberhard-Karls University Tübingen, D-72076 Tübingen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't