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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1995-3-23
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pubmed:abstractText |
Only indirect observations suggest that gastric surface cells secrete HCOH3-, which, if the case, should result in an alteration of intracellular pH. This study attempts to determine if HCO3- transport is notable in intracellular pH regulation by isolated surface cells. Maintenance of cellular pH during perfusion with HCO3(-)-free Ringer's solution is unaffected by either the absence of Cl- or the presence of an inhibitor of HCO3- transport, 4,4'-diisothiocyanostilbene-2-2'-disulfonate (DIDS). This implies the absence of Cl-/HCO3- exchange and HCO3- transport related to Na+. Addition of HCO3-/CO2 to the perfusate results in acidification due to CO2. The pH then drifts upward, which is prevented by amiloride, an inhibitor of Na+/H+ exchange. Calculated H+ efflux is not significantly affected by HCO3-/CO2. Removal of HCO3-/CO2 results in alkalinization, which is unaffected by the absence of Cl-. Alkalinization following HCO3-/CO2 removal is significantly impaired by acetazolamide. Once alkalinization occurs, the pH declines slowly and is unaffected by a Cl(-)-free perfusate or amiloride or conductance but is markedly accelerated by a Na(+)-free perfusate. The latter is prevented by amiloride but not by DIDS. Thus, under isolated conditions, gastric mucosal surface cells do not appear to be a major source of HCO3- secretion. Alkalinization of the cells can occur as a result of carbonic anhydrase activity, but the alkalinization is maintained by an extracellular Na+ gradient that prevents exchange of intracellular Na+ with extracellular H+.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0022-4804
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
58
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
211-7
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:7861775-Amiloride,
pubmed-meshheading:7861775-Animals,
pubmed-meshheading:7861775-Bicarbonates,
pubmed-meshheading:7861775-Carbon Dioxide,
pubmed-meshheading:7861775-Gastric Acidity Determination,
pubmed-meshheading:7861775-Gastric Mucosa,
pubmed-meshheading:7861775-Male,
pubmed-meshheading:7861775-Perfusion,
pubmed-meshheading:7861775-Rabbits,
pubmed-meshheading:7861775-Sodium
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pubmed:year |
1995
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pubmed:articleTitle |
Do isolated gastric mucosal surface cells from rabbits secrete HCO3-?
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pubmed:affiliation |
Department of Surgery, Wayne State University, Detroit, Michigan 48201.
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pubmed:publicationType |
Journal Article
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