Please use this identifier to cite or link to this item:
Title: HCO3−-independent pH Regulation in Astrocytes in Situ Is Dominated by V-ATPase
Authors: Hansen, D. B.
Garrido-Comas, Nestor
Salter, M.
Fern, R.
First Published: 9-Feb-2015
Publisher: American Society for Biochemistry and Molecular Biology
Citation: The Journal of Biological Chemistry, 290, 8039-8047
Abstract: The mechanisms of HCO3−-independent intracellular pH (pHi) regulation were examined in fibrous astrocytes within isolated neonatal rat optic nerve (RON) and in cultured cortical astrocytes. In agreement with previous studies, resting pHi in cultured astrocytes was 6.82 ± 0.06 and inhibition of the V-ATPase H+ pump by Cl− removal or via the selective inhibitor bafilomycin had only a small effect upon resting pHi and recovery following an acid load. In contrast, resting pHi in RON astrocytes was 7.10 ± 0.04, significantly less acidic than that in cultured cells (p < 0.001), and responded to inhibition of V-ATPase with profound acidification to the 6.3–6.5 range. Fluorescent immuno-staining and immuno-gold labeling confirmed the presence V-ATPase in the cell membrane of RON astrocyte processes and somata. Using ammonia pulse recovery, pHi recovery in RON astrocyte was achieved largely via V-ATPase with sodium-proton exchange (NHE) playing a minor role. The findings indicate that astrocytes in a whole-mount preparation such as the optic nerve rely to a greater degree upon V-ATPase for HCO3−-independent pHi regulation than do cultured astrocytes, with important functional consequences for the regulation of pH in the CNS.
DOI Link: 10.1074/jbc.M115.636597
ISSN: 0021-9258
eISSN: 1083-351X
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: © 2015 by The American Society for Biochemistry and Molecular Biology, Inc. Author's Choice—Final version full access. Creative Commons Attribution Unported License applies to Author Choice Articles
Appears in Collections:Published Articles, Dept. of Cell Physiology and Pharmacology

Files in This Item:
File Description SizeFormat 
J. Biol. Chem.-2015-Hansen-8039-47.pdfPublisher version1.89 MBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.