Open AccessInvolvement of the ADP/ATP carrier in permeabilization processes of the inner mitochondrial membrane
Author(s) -
MACEDO Denise,
NEPOMUCENO Maria de Fátima,
PEREIRADASILVA Lucia
Publication year - 1993
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1993.tb18070.x
Subject(s) - atp–adp translocase , inner mitochondrial membrane , mitochondrion , inner membrane , dithiothreitol , biophysics , mitochondrial permeability transition pore , chemistry , membrane potential , biochemistry , chemiosmosis , adenosine triphosphate , atp synthase , adenosine diphosphate , biology , enzyme , platelet , apoptosis , programmed cell death , platelet aggregation , immunology
The effect of different agents on inner‐mitochondrial‐membrane permeabilization and lipoperoxidation induced by Ca 2+ and the pyridine‐nucleotide oxidant t ‐butylhydroperoxide or inorganic phosphate was investigated. Comparing the protection conferred by ADP, a substrate of the ADP/ATP carrier, dithiothreitol, a disulfide reductant and butylhydroxytoluene, a radical scavenger, it was found that ADP was always the most effective against mitochondrial damage, when present in the incubation medium from the beginning. Moreover, carboxyatractyloside, a specific inhibitor of the ADP/ATP carrier, abolished completely the protective effect of ADP on both the lipoperoxidation and mitochondrial swelling processes. Experiments where deenergized mitochondria were previously incubated with Ca 2+ showed a decrease in the content of active ADP/ATP carrier, indicating a direct involvement of this protein in the formation of a non‐specific Ca 2+ ‐dependent pore. Our results also eliminate the possibility of an attack of oxygen radicals on lipids or proteins of the mitochondrial membrane as the primary event triggering the permeability transition of the inner mitochondrial membrane.