Linked Life Data

11677254

Source:http://linkedlifedata.com/resource/pubmed/id/11677254

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-10-25
pubmed:abstractText
Mitochondria are widely believed to be the source of reactive oxygen species (ROS) in a number of neurodegenerative disease states. However, conditions associated with neuronal injury are accompanied by other alterations in mitochondrial physiology, including profound changes in the mitochondrial membrane potential DeltaPsi(m). In this study we have investigated the effects of DeltaPsi(m) on ROS production by rat brain mitochondria using the fluorescent peroxidase substrates scopoletin and Amplex red. The highest rates of mitochondrial ROS generation were observed while mitochondria were respiring on the complex II substrate succinate. Under this condition, the majority of the ROS signal was derived from reverse electron transport to complex I, because it was inhibited by rotenone. This mode of ROS generation is very sensitive to depolarization of DeltaPsi(m), and even the depolarization associated with ATP generation was sufficient to inhibit ROS production. Mitochondria respiring on the complex I substrates, glutamate and malate, produce very little ROS until complex I is inhibited with rotenone, which is also consistent with complex I being the major site of ROS generation. This mode of oxidant production is insensitive to changes in DeltaPsi(m). With both substrates, ubiquinone-derived ROS can be detected, but they represent a more minor component of the overall oxidant signal. These studies demonstrate that rat brain mitochondria can be effective producers of ROS. However, the optimal conditions for ROS generation require either a hyperpolarized membrane potential or a substantial level of complex I inhibition.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
79
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
266-77
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
DeltaPsi(m)-Dependent and -independent production of reactive oxygen species by rat brain mitochondria.
pubmed:affiliation
Department of Pharmacology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.