Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/193886
Type: Artigo de periódico
Title: Permeabilization Of The Inner Mitochondrial Membrane By Ca2+ Ions Is Stimulated By T-butyl Hydroperoxide And Mediated By Reactive Oxygen Species Generated By Mitochondria.
Author: Castilho, R F
Kowaltowski, A J
Meinicke, A R
Bechara, E J
Vercesi, A E
Abstract: The extent of swelling undergone by deenergized mitochondria incubated in KCl/sucrose medium in the presence of Ca2+ alone or Ca2+ and t-butyl hydroperoxide decreases by decreasing molecular oxygen concentration in the reaction medium; under anaerobiosis no swelling occurs. This swelling is also inhibited by the presence of exogenous catalase or by the Fe2+ chelator o-phenanthroline in a time-dependent manner. The production of protein thiol cross-linking that leads to the formation of protein aggregates induced by Ca2+ and t-butyl hydroperoxide does not occur when mitochondria are incubated in anaerobic medium or in the presence of o-phenanthroline. In addition, it is also shown that the yield of stable methyl radical adducts, obtained from rat liver mitochondria treated with t-butyl hydroperoxide and the spin trap DMPO, is reduced by addition of EGTA and increases by addition of Ca2+ ions. These data support the hypothesis that Ca2+ ions stimulate electron leakage from the respiratory chain, increasing the mitochondrial production of reactive oxygen species.
Subject: 4,4'-diisothiocyanostilbene-2,2'-disulfonic Acid
Anaerobiosis
Animals
Calcium
Catalase
Cross-linking Reagents
Free Radicals
In Vitro Techniques
Intracellular Membranes
Membrane Proteins
Mitochondria, Liver
Mitochondrial Swelling
Models, Biological
Oxidative Stress
Oxygen
Permeability
Peroxides
Phenanthrolines
Rats
Rats, Wistar
Reactive Oxygen Species
Tert-butylhydroperoxide
Citation: Free Radical Biology & Medicine. v. 18, n. 3, p. 479-86, 1995-Mar.
Rights: fechado
Address: http://www.ncbi.nlm.nih.gov/pubmed/9101238
Date Issue: 1995
Appears in Collections:Unicamp - Artigos e Outros Documentos

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