Linked Life Data

9808712

Source:http://linkedlifedata.com/resource/pubmed/id/9808712

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-12-7
pubmed:abstractText
We have isolated a kidney-specific organic cation transporter, rat OCT2, which is distinct from rat OCT1 (Okuda M, Saito H, Urakami Y, Takano M and Inui K (1996) Biochem Biophys Res Commun 224:500-507). In our study, the functional characteristics and membrane localization of OCT1 and OCT2 were investigated by uptake studies using MDCK cells transfected with rat OCT1 or OCT2 cDNA (MDCK-OCT1 or MDCK-OCT2) and immunological studies. Tetraethylammonium (TEA) uptake by both MDCK-OCT1 and MDCK-OCT2 cells was markedly elevated when TEA was added to the basolateral medium, but not to the apical medium. Efflux of TEA from MDCK-OCT1 and MDCK-OCT2 cells was not changed by extracellular pH from 5.4 to 8.4, whereas TEA uptake by both transfectants was decreased by acidification of extracellular medium. Apparent Km values for TEA uptake by MDCK-OCT1 and MDCK-OCT2 cells were 38 and 45 microM, respectively. Although various hydrophilic organic cations such as 1-methyl-4-phenylpyridinium, cimetidine, quinidine, nicotine, N1-methylnicotinamide and guanidine markedly inhibited TEA uptake by both MDCK-OCT1 and MDCK-OCT2 cells, there were no significant differences in the apparent inhibition constants (Ki) against these organic cations between both transfectants. Furthermore, immunological studies using a polyclonal antibody against OCT1 revealed that OCT1 was expressed in the basolateral membranes but not in the brush-border membranes of the rat kidney. These results suggested that both OCT1 and OCT2 are basolateral-type organic cation transporters with broad substrate specificities, mediating tubular secretion of cationic drugs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
287
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
800-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Functional characteristics and membrane localization of rat multispecific organic cation transporters, OCT1 and OCT2, mediating tubular secretion of cationic drugs.
pubmed:affiliation
Department of Pharmacy, Kyoto University Hospital, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't