Linked Life Data

12080082

Source:http://linkedlifedata.com/resource/pubmed/id/12080082

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
35
pubmed:dateCreated
2002-8-30
pubmed:abstractText
Nitric oxide (NO) signal transduction may involve at least two targets: the guanylyl cyclase-coupled NO receptor (NO(GC)R), which catalyzes cGMP formation, and cytochrome c oxidase, which is responsible for mitochondrial O(2) consumption and which is inhibited by NO in competition with O(2). Current evidence indicates that the two targets may be similarly sensitive to NO, but quantitative comparison has been difficult because of an inability to administer NO in known, constant concentrations. We addressed this deficiency and found that purified NO(GC)R was about 100-fold more sensitive to NO than reported previously, 50% of maximal activity requiring only 4 nm NO. Conversely, at physiological O(2) concentrations (20-30 microM), mitochondrial respiration was 2-10-fold less sensitive to NO than estimated beforehand. The two concentration-response curves showed minimal overlap. Accordingly, an NO concentration maximally active on the NO(GC)R (20 nm) inhibited respiration only when the O(2) concentration was pathologically low (50% inhibition at 5 microM O(2)). Studies on brain slices under conditions of maximal stimulation of endogenous NO synthesis suggested that the local NO concentration did not rise above 4 nm. It is concluded that under physiological conditions, at least in brain, NO is constrained to target the NO(GC)R without inhibiting mitochondrial respiration.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31801-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Differential sensitivity of guanylyl cyclase and mitochondrial respiration to nitric oxide measured using clamped concentrations.
pubmed:affiliation
Wolfson Institute for Biomedical Research, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't