Linked Life Data

2841075

Source:http://linkedlifedata.com/resource/pubmed/id/2841075

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1988-9-13
pubmed:abstractText
Two methods were used to investigate cellular ion transport processes in confluent monolayers of cultured bovine corneal epithelial cells: measurements of membrane voltage (V) using conventional microelectrodes, and intracellular pH (pHi) measurements using the pH sensitive absorbance of intracellularly trapped 5 (and 6)-carboxy-4', 5'dimethyl-fluorescein. (1) V averaged -39.2 +/- 0.9 mV (mean +/- SEM, n = 71) with a range of -30 to -59 mV. Increasing extracellular potassium depolarized the cell membrane with a K+-slope of 43.3 mV/decade [K+] (for [K+] between 20 and 80 mM). Intracellular as well as extracellular acidification reversibly depolarized the cell membrane. Depolarization induced by 40 mM K+-pulses was smaller at extracellular pH (pHo) of 6.9 as compared to pHo = 7.9. These findings are compatible with a pH-sensitive K+ conductance. (2) During steady state pHi was 6.96 +/- 0.05 (mean +/- SEM, n = 7). After intracellular acidification, induced by NH4Cl-prepulse technique, pHi was regulated back towards normal steady state pHi. Application of 1 mM amiloride reversibly inhibited pHi recovery. Furthermore, pHi backregulation was inhibited by removing sodium from the extracellular solution. The effect was reversible after readdition of sodium. These findings suggest that a Na+/H+ exchange is present in corneal epithelial cells and participates in pHi backregulation after an intracellular acid load.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0271-3683
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
619-26
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Evidence for Na+/H+ exchange and pH sensitive membrane voltage in cultured bovine corneal epithelial cells.
pubmed:affiliation
Institut für Klinische Physiologie, Freie Universität Berlin, FRG.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't