Linked Life Data

11875267

Source:http://linkedlifedata.com/resource/pubmed/id/11875267

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Suppl
pubmed:dateCreated
2002-3-4
pubmed:abstractText
In a search for the HCO(3)(-) supply mechanisms to the enterocyte we cloned and sequenced an intestinal subtype of the Na(+)HCO(3)(-) cotransporter isoform I (dNBC1), which turned out to be identical to the pancreatic NBC1 subtype (pNBC1). Within the intestine, we found particularly high NBC1 expression levels in the duodenum and proximal colon. Experiments with stripped rabbit duodenum in Ussing-chambers revealed that Na(+)HCO(3)(-) cotransport (NBC) and CO(2) hydration/Na(+)/H(+) exchange were equally important duodenal HCO(3)(-) supply pathways and were both upregulated during cAMP-mediated secretion. In the proximal colon, however, HCO(3)(-) secretion was low but NBC1 expression even higher than in the duodenum. Ussing-chamber experiments with an NBC-specific inhibitor revealed that NBC, coupled to basolateral Cl(-)/HCO(3)(-) exchange, was an important alternative Cl(-) supply pathway to Na(+)K(+)2Cl(-) cotransport (NKCC) during cAMP-stimulated colonic Cl(-) secretion. To investigate the functional integrity of anion uptake pathways in the absence of cystic fibrosis transmembrane conductance regulator (CFTR), we fluorometrically assessed NBC and NKCC transport rates and cell volume before and during forskolin-stimulation in isolated colonic crypts from normal and CFTR (-/-) mice. Although forskolin stimulation decreased cell volume only in normal, not in CFTR (-/-) crypts, it activated NBC and NKCC to a similar degree in both normal and CFTR (-/-) crypts. We conclude that, depending on the intestinal segment, NBC1 plays an important role in basolateral HCO(3)(-) or Cl(-) uptake. Expression and activation by cAMP is preserved in CFTR (-/-) intestine.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1590-8577
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
247-56
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Na+/HCO3- cotransport in normal and cystic fibrosis intestine.
pubmed:affiliation
1st Department of Medicine, University of Tübingen, Tübingen, Germany. ursula.seidler@uni-tuebingen.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't