Ca2+ Acting At The External Side Of The Inner Mitochondrial Membrane Can Stimulate Mitochondrial Permeability Transition Induced By Phenylarsine Oxide.

dc.creatorKowaltowski, A J
dc.creatorCastilho, R F
dc.date1997-Dec
dc.date2015-11-27T12:19:04Z
dc.date2015-11-27T12:19:04Z
dc.date.accessioned2018-03-29T00:52:26Z
dc.date.available2018-03-29T00:52:26Z
dc.identifierBiochimica Et Biophysica Acta. v. 1322, n. 2-3, p. 221-9, 1997-Dec.
dc.identifier0006-3002
dc.identifier
dc.identifierhttp://www.ncbi.nlm.nih.gov/pubmed/9452768
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/194084
dc.identifier9452768
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1294317
dc.descriptionMitochondrial permeability transition (MPT) induced by the thiol cross-linker phenylarsine oxide (PhAsO) in Ca(2+)-depleted mitochondria incubated in the presence of ruthenium red, an inhibitor of the Ca2+ uniporter, is stimulated by the addition of extramitochondrial Ca2+. The presence of extramitochondrial Ca2+ stimulates the reaction of mitochondrial membrane protein thiol groups with PhAsO. Both Ca(2+)-induced increase in mitochondrial membrane permeabilization and protein thiol group reaction with PhAsO are dependent on time (5-10 min to be complete) and the concentration of Ca2+ (1-25 microM). Mitochondrial permeabilization induced by PhAsO (15 microM) and extramitochondrial Ca2+ is inhibited by ADP, cyclosporin A, dibucaine and Mg2+, while mitochondrial permeabilization induced by high concentrations of PhAsO (60 microM) in the absence of Ca2+ is inhibited only by ADP and cyclosporin A. These results suggest that dibucaine and Mg2+ can inhibit mitochondrial permeabilization by antagonizing the effect of Ca2+ on the mitochondrial membrane. Once mitochondrial permeabilization induced by 15 microM PhAsO and extramitochondrial Ca2+ has already occurred, the addition of the Ca2+ chelator EGTA restores mitochondrial membrane potential (MPT pore closure), suggesting that the presence of Ca2+ is essential for the maintenance of the permeability of the mitochondrial membrane to protons (MPT pore opening). In conclusion, the results presented indicate that low Ca2+ concentrations acting at the external side of the inner mitochondrial membrane can stimulate mitochondrial permeability transition induced by PhAsO, due to increased accessibility of protein thiol groups to the reaction with PhAsO and increased probability of MPT pore opening.
dc.description1322
dc.description221-9
dc.languageeng
dc.relationBiochimica Et Biophysica Acta
dc.relationBiochim. Biophys. Acta
dc.rightsfechado
dc.rights
dc.sourcePubMed
dc.subjectAnimals
dc.subjectArsenicals
dc.subjectCalcium
dc.subjectCalcium Channels
dc.subjectCalcium-binding Proteins
dc.subjectChelating Agents
dc.subjectCross-linking Reagents
dc.subjectEgtazic Acid
dc.subjectIntracellular Membranes
dc.subjectMembrane Potentials
dc.subjectMembrane Proteins
dc.subjectMitochondria, Liver
dc.subjectOsmolar Concentration
dc.subjectPermeability
dc.subjectRats
dc.subjectRats, Wistar
dc.subjectRuthenium Red
dc.subjectSulfhydryl Compounds
dc.titleCa2+ Acting At The External Side Of The Inner Mitochondrial Membrane Can Stimulate Mitochondrial Permeability Transition Induced By Phenylarsine Oxide.
dc.typeArtículos de revistas


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