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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6 Pt 2
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pubmed:dateCreated |
1993-8-5
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pubmed:abstractText |
Previous studies have demonstrated that systemic administration of glucocorticoids stimulates proximal tubule acidification in part by increasing Na+/H+ antiporter activity; however, these studies could not exclude the possibility that changes in Na+/H+ antiporter activity were secondary to glucocorticoid-induced hemodynamic changes. The present study examined the effect of dexamethasone on Na+/H+ antiporter activity in quiescent OKP cells. Na+/H+ antiporter activity was assayed as the initial rate of Na(+)-dependent pH recovery from an acid load. Intracellular pH was measured using the pH-sensitive dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF). Dexamethasone produced a dose- and time-dependent stimulation of Na+/H+ antiporter activity in OKP cells. Dexamethasone produced a 24% stimulation in Na+/H+ antiporter activity at 10(-9) M and an approximately 40% stimulation of Na+/H+ antiporter activity at both 10(-8) and 10(-6) M. The effect of 10(-6) M dexamethasone was seen within 4 h of incubation and was due to an increase in maximal velocity (Vmax, 3.03 vs. 1.79 pH units/min) with no change in the affinity constant for sodium (KNa, 47.2 vs. 42.0 mM). The stimulatory effect of dexamethasone on Na+/H+ antiporter activity was blocked by cycloheximide and was not observed with 10(-8) M aldosterone. These data demonstrate a direct effect of glucocorticoids to stimulate Na+/H+ antiporter activity in OKP cells.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Amiloride,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Cycloheximide,
http://linkedlifedata.com/resource/pubmed/chemical/Dexamethasone,
http://linkedlifedata.com/resource/pubmed/chemical/Glucocorticoids,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium-Hydrogen Antiporter,
http://linkedlifedata.com/resource/pubmed/chemical/ethylisopropylamiloride
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0002-9513
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
264
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
F1027-31
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:8391752-Amiloride,
pubmed-meshheading:8391752-Animals,
pubmed-meshheading:8391752-Carrier Proteins,
pubmed-meshheading:8391752-Cell Line,
pubmed-meshheading:8391752-Cycloheximide,
pubmed-meshheading:8391752-Dexamethasone,
pubmed-meshheading:8391752-Drug Resistance,
pubmed-meshheading:8391752-Glucocorticoids,
pubmed-meshheading:8391752-Hydrogen-Ion Concentration,
pubmed-meshheading:8391752-Kidney,
pubmed-meshheading:8391752-Sodium-Hydrogen Antiporter
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pubmed:year |
1993
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pubmed:articleTitle |
Glucocorticoids stimulate Na+/H+ antiporter in OKP cells.
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pubmed:affiliation |
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas 75235-9063.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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