Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-9-26
pubmed:abstractText
Astrocytes actively maintain their intracellular pH (pHi) more alkaline than expected by passive distribution of H+. Acid extruding transporters such as the amiloride-sensitive Na+/H+ exchanger (NHE) are necessary for pH regulation. Currently, four mammalian NHEs (NHE1-NHE4) have been cloned, with a fifth (NHE5) partially cloned. We attempted to determine which isoform(s) of NHE was present in cultured hippocampal astrocytes using amiloride sensitivity and immunospecificity as criteria. In the absence of HCO3-, amiloride blocked pHi recovery after an acid load with an IC50 of approximately 3.18 microM, similar to values reported for the amiloride-sensitive isoforms NHE1 and NHE2. Immunoblotting with a highly specific antibody for NHE1 identified a 100 kDa protein, indicating the presence of NHE1 in whole brain, hippocampus, and cultured hippocampal astrocytes. Further probing for an additional amiloride-sensitive NHE failed to detect evidence of the presence of NHE4. Surprisingly, application of the potent analog of amiloride, ethylisopropylamiloride (EIPA), caused a reversible alkalinization of pHi, suggesting the presence of an additional acid/base transport mechanism that is EIPA-sensitive.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0360-4012
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
191-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Characterization of Na+/H+ exchange activity in cultured rat hippocampal astrocytes.
pubmed:affiliation
Department of Surgery (Neurosurgery), Yale University School of Medicine, New Haven, Connecticut 06510, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't