Linked Life Data

9452449

Source:http://linkedlifedata.com/resource/pubmed/id/9452449

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1998-3-5
pubmed:abstractText
During myocardial hibernation, decreases in coronary perfusion elicit inhibition of contraction, suggesting that energy demand is attenuated. We previously found an inhibition of contraction and O2 consumption during hypoxia (3% O2; PO2 = 20 torr for >2 h) in cardiomyocytes, which was reversible after reoxygenation. This study sought to determine whether mitochondria function as cellular O2 sensors mediating this response. Embryonic cardiomyocytes were studied under controlled O2 conditions. Hypoxia produced no acute decrease in mitochondrial potential as assessed using tetramethylrhodamine ethylester (TMRE). Cellular [ATP] was preserved throughout hypoxia, as assessed using the probe Magnesium Green. Thus, ATP synthesis and utilization remained closely coupled. Cells adapted to hypoxia for >2 h exhibited a 4% increase in mitochondrial potential upon reoxygenation, suggesting that a partial inhibition of cytochrome c oxidase had existed. To test whether the oxidase serves as an O2 sensor, azide was administered (1 mM) to simulate the effects of hypoxia by lowering the Vmax of the oxidase. The effects of azide on contraction and mitochondrial potential mimicked the response to hypoxia. We conclude that partial inhibition of cytochrome oxidase during hypoxia allows mitochondria to function as the O2 sensor mediating the decreases in ATP utilization and O2 consumption during hypoxia.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3320-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Hibernation during hypoxia in cardiomyocytes. Role of mitochondria as the O2 sensor.
pubmed:affiliation
Pulmonary and Critical Care Medicine, The University of Chicago, Chicago, Illinois 60637, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't