Linked Life Data

17762180

Source:http://linkedlifedata.com/resource/pubmed/id/17762180

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2007-8-31
pubmed:abstractText
The present study examined the expression of type 1 L-amino acid transporter (LAT1) and its associated glycoprotein 4F2hc in freshly isolated renal proximal tubules and immortalized renal proximal tubular epithelial (PTE) cells from spontaneously hypertensive (SHR) and normotensive (WKY) rats. The study also examined the inward and outward transport of [(14)C]-L-leucine, the preferred substrate of LAT1. The abundance of LAT1 and 4F2hc was greater in SHR than in WKY, both in freshly isolated renal proximal tubules and immortalized renal proximal tubular cells. In the absence of extracellular Na(+) the BCH (2-aminobicyclo(2,2,1)-heptane-2-carboxylic acid)-sensitive [(14)C]-L-leucine uptake in SHR PTE cells was approximately 50% that observed in WKY PTE cells (77+/-4 vs 164+/-7 pmol/mg protein). In the absence of extracellular Na(+) the affinity of the transporter for the substrate in WKY PTE cells was 7.7-fold that in SHR cells, as evidenced by lower K(0.5) values. Gene silencing with a LAT1 siRNA and a 4F2hc siRNA significantly reduced LAT1 and 4F2hc expression, which was accompanied by a marked reduction in Na(+)-independent [(14)C]-L-leucine uptake in both SHR and WKY PTE cells. The spontaneous and L-leucine-stimulated outward transfer of [(14)C]-L-leucine was Na(+)-independent in both SHR and WKY PTE cells. The spontaneous [(14)C]-L-leucine efflux was higher in WKY than in SHR PTE cells and the potency of L-leucine to stimulate [(14)C]-L-leucine efflux in WKY (EC(50) = 9 microM) was greater than in SHR PTE cells (EC(50) = 41 microM). It is concluded that the SHR kidney overexpress LAT1/4F2hc units which display low affinity for L-leucine transport.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1015-8987
pubmed:author
pubmed:copyrightInfo
Copyright (c) 2007 S. Karger AG, Basel.
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
535-48
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Overexpression of non-functional LAT1/4F2hc in renal proximal tubular epithelial cells from the spontaneous hypertensive rat.
pubmed:affiliation
Institute of Pharmacology and Therapeutics, Faculty of Medicine, Porto, Portugal.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't