Linked Life Data

15693272

Source:http://linkedlifedata.com/resource/pubmed/id/15693272

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-2-7
pubmed:abstractText
Mitochondria are an active source of the free radical superoxide (O2-) and nitric oxide (NO), whose production accounts for about 2% and 0.5% respectively, of mitochondrial O2 uptake under physiological conditions. Superoxide is produced by the auto-oxidation of the semiquinones of ubiquinol and the NADH dehydrogenase flavin and NO by the enzymatic action of the nitric oxide synthase of the inner mitochondrial membrane (mtNOS). Nitric oxide reversibly inhibits cytochrome oxidase activity in competition with O2. The balance between NO production and its utilization results in a NO intramitochondrial steady-state concentration of 20-50 nM, which regulates mitochondrial O2 uptake and energy supply. The regulation of cellular respiration and energy production by NO and its ability to switch the pathway of cell death from apoptosis to necrosis in physiological and pathological conditions could take place primarily through the inhibition of mitochondrial ATP production. Nitric oxide reacts with O2- in a termination reaction in the mitochondrial matrix, yielding peroxynitrite (ONOO-), which is a strong oxidizing and nitrating species. This reaction accounts for approximately 85% of the rate of mitochondrial NO utilization in aerobic conditions. Mitochondrial aging by oxyradical- and peroxynitrite-induced damage would occur through selective mtDNA damage and protein inactivation, leading to dysfunctional mitochondria unable to keep membrane potential and ATP synthesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0716-9760
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
65-70
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Free radical chemistry in biological systems.
pubmed:affiliation
Laboratory of Free Radical Biology, School of Pharmacy and Biochemistry, University of Buenos Aires, Argentina. lbvaldez@ffyb.uba.ar
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't