Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 2
pubmed:dateCreated
1998-11-5
pubmed:abstractText
We show by confocal immunofluorescence microscopy that the water channel protein aquaporin-1, not previously identified within cardiomyocytes, localizes at 20 and 37 degrees C to rat cardiomyocyte sarcolemmal caveolar membrane and subsarcolemmal cytoplasm of primary atrial myocyte cultures, dissociated atrial and ventricular myocytes, and in situ cardiomyocytes of atrial and ventricular frozen sections. Confocal immunofluorescence microscopy shows that the normal in situ colocalization of the quasi-muscle-specific caveolar coating protein caveolin-3 with aquaporin-1 is reversibly disrupted by exposing in situ atrial or ventricular myocytes to physiological saline made hypertonic by adding 150 mM sucrose or 75 mM NaCl to isotonic physiological saline. This causes caveolae to close off from the interstitium and swell, while aquaporin-1 is internalized reversibly. At 4 degrees C aquaporin-1 does not colocalize with caveolin-3. We suggest that 1) in vivo, under near-isotonic conditions, caveolae may alternate frequently between brief open and closed-off states; 2) aquaporin-1-caveolin-3 colocalization may be energy dependent; and 3) while closed off from the interstitium, each caveola transiently functions as an osmometer that experiences, monitors, and reacts to net water flow from or into the subcaveolar cytosol of the myocyte.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1988-2000
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Water channel proteins in rat cardiac myocyte caveolae: osmolarity-dependent reversible internalization.
pubmed:affiliation
Departments of Medicine, University of Chicago, Chicago, Illinois 60637, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.