Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5 Pt 1
|
pubmed:dateCreated |
1990-12-11
|
pubmed:abstractText |
The presence of Na(+)-H+ exchange activity is demonstrated on both the brush-border membrane (BBM) and the basolateral membrane (BLM) of villus cells from rabbit ileum. The possibility that the Na(+)-H+ exchange activity on the BLM represents HCO3- cotransport is excluded. The two Na(+)-H+ exchangers are then compared in terms of kinetics and substrate and inhibitor specificity. The most striking difference between the two exchangers was sensitivity to amiloride and K+. The IC50 for amiloride on the BLM was 10-fold lower than the BBM (11.2 +/- 2.1 vs. 103 +/- 20.9 microM; P less than 0.02). External K+, in concentrations as low as 10 mM, inhibited Na(+)-H+ exchange on the BBM but not on the BLM. The Na+ Km and proton Km were twice as high on the BLM exchanger (46.3 +/- 3.4 vs. 28.8 +/- 2.3 mM and 468 +/- 9 vs. 232 +/- 45 nM, respectively). Proton Vmax was similar, whereas Na+ Vmax was higher on the BLM. Inhibition by Li+ was similar on both membranes. These results indicate distinct differences between the two Na(+)-H+ exchangers. Whether these differences are due to the two different gene products or are the result of posttranslational modification of a single gene product remains to be determined.
|
pubmed:grant | |
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Lithium,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium-Hydrogen Antiporter
|
pubmed:status |
MEDLINE
|
pubmed:month |
Nov
|
pubmed:issn |
0002-9513
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
259
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
G802-6
|
pubmed:dateRevised |
2007-11-14
|
pubmed:meshHeading |
pubmed-meshheading:2173416-Animals,
pubmed-meshheading:2173416-Carrier Proteins,
pubmed-meshheading:2173416-Hydrogen-Ion Concentration,
pubmed-meshheading:2173416-Ileum,
pubmed-meshheading:2173416-Intestinal Mucosa,
pubmed-meshheading:2173416-Jejunum,
pubmed-meshheading:2173416-Kinetics,
pubmed-meshheading:2173416-Lithium,
pubmed-meshheading:2173416-Membrane Potentials,
pubmed-meshheading:2173416-Microvilli,
pubmed-meshheading:2173416-Muscle, Smooth,
pubmed-meshheading:2173416-Potassium,
pubmed-meshheading:2173416-Rabbits,
pubmed-meshheading:2173416-Sodium,
pubmed-meshheading:2173416-Sodium-Hydrogen Antiporter
|
pubmed:year |
1990
|
pubmed:articleTitle |
Characterization of Na(+)-H+ exchangers on villus cells in rabbit ileum.
|
pubmed:affiliation |
Department of Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|