Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-3-14
pubmed:abstractText
We used the pH-sensitive fluorescent dye BCECF to study intracellular pH (pHi) regulation in primary cultures of rat astrocytes and C6 glioma cells. Both cell types contain three pH-regulating transporters: 1) alkalinizing Na+/H+ exchange; 2) alkalinizing Na+ + HCO3-/Cl- exchange; and 3) acidifying Cl-/HCO3- exchange. Na+/H+ exchange was most evident in the absence of CO2; recovery from acidification was Na+ dependent and amiloride sensitive. Exposure to CO2 caused a cell alkalinization that was inhibited by DIDS, dependent on external Na+, and inhibited 75% in the absence of Cl- (thus mediated by Na+ + HCO3-/Cl- exchange). When pHi was increased above the normal steady-state pHi, a DIDS-inhibitable and Na(+)-independent acidifying recovery was evident, indicating the presence of Cl-/HCO3- exchange. Astrocytes, but not C6 cells, contain a fourth pH-regulating transporter, Na(+)-HCO3- cotransport; in the presence of CO2, depolarization caused an alkalinization of 0.12 +/- 0.01 (n = 8) and increased the rate of CO2-induced alkalinization from 0.23 +/- 0.02 to 0.42 +/- 0.03 pH unit/min. Since C6 cells lack the Na(+)-HCO3- cotransporter, they are an inferior model of pHi regulation in glia. Our results differ from previous observations in glia in that: 1) Na+/H+ exchange was entirely inhibited by amiloride; 2) Na+ + HCO3-/Cl- exchange was present and largely responsible for CO2-induced alkalinization; 3) Cl-/HCO3- exchange was only active at pHi values above steady state; and 4) depolarization-induced alkalinization of astrocytes was seen only in the presence of CO2.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0894-1491
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
196-210
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Intracellular pH regulation in primary rat astrocytes and C6 glioma cells.
pubmed:affiliation
Department of Physiology and Biophysics, Wright State University School of Medicine, Dayton, Ohio 45435.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't