Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/59353
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, RF
KOWALTOWSKI, AJ
MEINICKE, AR
BECHARA, EJH
VERCESI, AE
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: RAT LIVER MITOCHONDRIA
CALCIUM ION
REACTIVE OXYGEN SPECIES
THIOL CROSS-LINKING
IRON
T-BUTYL HYDROPEROXIDE
FREE RADICALS
Country: Inglaterra
Editor: Pergamon-elsevier Science Ltd
Rights: fechado
Identifier DOI: 10.1016/0891-5849(94)00166-H
Date Issue: 1995
Appears in Collections:Unicamp - Artigos e Outros Documentos

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