Linked Life Data

9211809

Source:http://linkedlifedata.com/resource/pubmed/id/9211809

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1997-9-3
pubmed:abstractText
Intracellular pH (pHi) was measured in enzymically isolated, neonatal rat carotid body type-1 cells, using the fluorophore carboxy-SNARF-1 (AM-loaded), and using the nigericin technique for in situ fluorescence calibration (nigericin is a membrane-soluble K+-H+ exchanger). In CO2/HCO3--free media, inhibiting Na+-H+ exchange produced a prompt fall of pHi (background acid-loading), the rate of which was reduced by raising the extracellular K+ concentration, [K+]o. pHi recovery from an intracellular acid or alkali load was also sensitive to changes of [K+]o. These results are similar to those of Wilding et al. (J Gen Physiol 100:593-608, 1992), who proposed the existence of an acid-loading, K+-H+ exchanger (KHE) in the type-1 cell. However, when nigericin was not used for post-experimental calibration, and the superfusion system was flushed exhaustively with strong detergent, alcohol and distilled water, then background acid-loading was attenuated, and the K+o sensitivity of pHi insignificant. Background loading was increased again, and K+o sensitivity restored, when cells were monitored in a superfusion system which had previously been exposed to a single nigericin-calibration protocol (followed by a short system wash with strong detergent and distilled water). We conclude that the previously reported expression of KHE in carotid body type-1 cells is an artefact caused by nigericin contamination. We have therefore quantified the pHi dependence of background loading in uncontaminated type-1 cells. We consider the possible implications of our work for reports of KHE in other cell types.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
434
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
429-37
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Assessment of evidence for K+-H+ exchange in isolated type-1 cells of neonatal rat carotid body.
pubmed:affiliation
University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't