Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2001-1-8
pubmed:abstractText
The distinguishing feature of the mammalian outer hair cells (OHCs) is to elongate and shorten at acoustic frequencies, when their intracellular potential is changed. This "electromotility" or "electromechanics" depends critically on positive intracellular pressure (turgor), maintained by the inflow of water through yet uncharacterized water pathways. We measured the water volume flow, J(v), across the plasma membrane of isolated guinea pig and rat OHCs after osmotic challenges and estimated the osmotic water permeability coefficient, P(f), to be approximately 10(-2) cm/sec. This value is within the range reported for osmotic flow mediated by the water channel proteins, aquaporins. J(v) was inhibited by HgCl(2), which is known to block aquaporin-mediated water transport. P(f) values that were estimated for OHCs from neonatal rats were of the order of approximately 2 x 10(-3) cm/sec, equivalent to that of membranes lacking water channel proteins. In an immunofluorescence assay we showed that an anti-peptide antibody specific for aquaporins labels the lateral plasma membrane of the OHC in the region in which electromotility is generated. Using patch-clamp recording, we found that water influx into the OHC is regulated by intracellular voltage. We also found that the most pronounced increases of the electromotility-associated charge movement and of the expression of OHC water channels occur between postnatal days 8 and 12, preceding the onset of hearing function in the rat. Our data indicate that electromotility and water transport in OHCs may influence each other structurally and functionally.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8996-9003
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:11124975-Aging, pubmed-meshheading:11124975-Animals, pubmed-meshheading:11124975-Antibodies, pubmed-meshheading:11124975-Aquaporins, pubmed-meshheading:11124975-Biological Transport, pubmed-meshheading:11124975-Blotting, Western, pubmed-meshheading:11124975-Cell Membrane, pubmed-meshheading:11124975-Cell Membrane Permeability, pubmed-meshheading:11124975-Cell Size, pubmed-meshheading:11124975-Cells, Cultured, pubmed-meshheading:11124975-Cochlea, pubmed-meshheading:11124975-Dose-Response Relationship, Drug, pubmed-meshheading:11124975-Electrophysiology, pubmed-meshheading:11124975-Fluorescent Antibody Technique, pubmed-meshheading:11124975-Guinea Pigs, pubmed-meshheading:11124975-Hair Cells, Auditory, Outer, pubmed-meshheading:11124975-Hypotonic Solutions, pubmed-meshheading:11124975-Immunohistochemistry, pubmed-meshheading:11124975-Mercuric Chloride, pubmed-meshheading:11124975-Osmolar Concentration, pubmed-meshheading:11124975-Patch-Clamp Techniques, pubmed-meshheading:11124975-Rats, pubmed-meshheading:11124975-Water
pubmed:year
2000
pubmed:articleTitle
Water permeability of cochlear outer hair cells: characterization and relationship to electromotility.
pubmed:affiliation
Section on Structural Cell Biology, National Institute on Deafness and other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't