Linked Life Data

15601755

Source:http://linkedlifedata.com/resource/pubmed/id/15601755

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-3-11
pubmed:abstractText
Resting or basal intracellular pH (pHi) measured in cultured human syncytiotrophoblast cells was 7.26+/-0.04 (without HCO3-) or 7.24+/-0.03 (with HCO3-). Ion substitution and inhibitor experiments were performed to determine whether common H+-transporting species were operating to maintain basal pHi. Removal of extracellular Na+ or Cl- or addition of amiloride or dihydro-4,4'-diisothiocyanatostilbene-2,2'-disulfonate (H2DIDS) had no effect. Acidification with the K+/H+ exchanger nigericin reduced pHi to 6.25+/-0.15 (without HCO3-) or 6.53+/-0.10 (with HCO3-). In the presence of extracellular Na+, recovery to basal pHi was prompt and occurred at similar rates in the absence and presence of HCO3-. Ion substitution and inhibition experiments were also used to identify the species mediating the return to basal pHi after acidification. Recovery was inhibited by removal of Na+ or addition of amiloride, whereas removal of Cl- and addition of H2DIDS were ineffective. Addition of the Na+/H+ exchanger monensin to cells that had returned to basal pHi elicited a further increase in pHi to 7.48+/-0.07. Analysis of recovery data showed that there was a progressive decrease in DeltapH per minute as pHi approached the basal level, despite the continued presence of a driving force for H+ extrusion. These data show that in cultured syncytial cells, in the absence of perturbation, basal pHi is preserved despite the absence of active, mediated pH maintenance. They also demonstrate that an Na+/H+ antiporter acts to defend the cells against acidification and that it is the sole transporter necessary for recovery from an intracellular acid load.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0363-6143
pubmed:author
pubmed:issnType
Print
pubmed:volume
288
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C891-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Intracellular pH homeostasis in cultured human placental syncytiotrophoblast cells: recovery from acidification.
pubmed:affiliation
Dept. of Obstetrics, Gynecology, and Women's Health, Medical Sciences Bldg., E506, New Jersey Medical School, 185 South Orange Ave., Newark, NJ 07103-2714, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.