Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1980-10-27
pubmed:abstractText
Rat and pigeon heart mitochondria supplemented with antimycin produce 0.3-1.0nmol of H(2)O(2)/min per mg of protein. These rates are stimulated up to 13-fold by addition of protophores (carbonyl cyanide p-trifluoromethoxyphenylhydrazone, carbonyl cyanide m-chloromethoxyphenylhydrazone and pentachlorophenol). Ionophores, such as valinomycin and gramicidin, and Ca(2+) also markedly stimulated H(2)O(2) production by rat heart mitochondria. The enhancement of H(2)O(2) generation in antimycin-supplemented mitochondria and the increased O(2) uptake of the State 4-to-State 3 transition showed similar protophore, ionophore and Ca(2+) concentration dependencies. Thenoyltrifluoroacetone and N-bromosuccinimide, which inhibit succinate-ubiquinone reductase activity, also decreased mitochondrial H(2)O(2) production. Addition of cyanide to antimycin-supplemented beef heart submitochondrial particles inhibited the generation of O(2) (-), the precursor of mitochondrial H(2)O(2). This effect was parallel to the increase in cytochrome c reduction and it is interpreted as indicating the necessity of cytochrome c(1) (3+) to oxidize ubiquinol to ubisemiquinone, whose autoxidation yields O(2) (-). The effect of protophores, ionophores and Ca(2+) is analysed in relation to the propositions of a cyclic mechanism for the interaction of ubiquinone with succinate dehydrogenase and cytochromes b and c(1) [Wikstrom & Berden (1972) Biochim. Biophys. Acta283, 403-420; Mitchell (1976) J. Theor. Biol.62, 337-367]. A collapse in membrane potential, increasing the rate of ubisemiquinone formation and O(2) (-) production, is proposed as the molecular mechanism for the enhancement of H(2)O(2) formation rates observed on addition of protophores, ionophores and Ca(2+).
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-11748, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-13319342, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-14003, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-165977, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-16742541, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-182149, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-186667, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-195520, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-196591, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-197811, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-198250, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-202279, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-220256, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-236930, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-241399, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-4295832, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-4346389, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-4401581, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-4404507, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-4623845, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-4749271, http://linkedlifedata.com/resource/pubmed/commentcorrection/7406888-5016537
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0264-6021
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
188
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31-7
pubmed:dateRevised
2010-9-10
pubmed:meshHeading
pubmed:year
1980
pubmed:articleTitle
Enhancement of hydrogen peroxide formation by protophores and ionophores in antimycin-supplemented mitochondria.
pubmed:publicationType
Journal Article, In Vitro