Effects of extramitochondrial ADP on permeability transition of mouse liver mitochondria.
Biochim Biophys Acta
; 1706(1-2): 98-104, 2005 Jan 07.
Article
em En
| MEDLINE
| ID: mdl-15620369
ABSTRACT
Carboxyatractylate (CAT) and atractylate inhibit the mitochondrial adenine nucleotide translocator (ANT) and stimulate the opening of permeability transition pore (PTP). Following pretreatment of mouse liver mitochondria with 5 microM CAT and 75 microM Ca2+, the activity of PTP increased, but addition of 2 mM ADP inhibited the swelling of mitochondria. Extramitochondrial Ca2+ concentration measured with Calcium-Green 5N evidenced that 2 mM ADP did not remarkably decrease the free Ca2+ but the release of Ca2+ from loaded mitochondria was stopped effectively after addition of 2 mM ADP. CAT caused a remarkable decrease of the maximum amount of calcium ions, which can be accumulated by mitochondria. Addition of 2 mM ADP after 5 microM CAT did not change the respiration, but increased the mitochondrial capacity for Ca2+ at more than five times. Bongkrekic acid (BA) had a biphasic effect on PT. In the first minutes 5 microM BA increased the stability of mitochondrial membrane followed by a pronounced opening of PTP too. BA abolished the action about of 1 mM ADP, but was not able to induce swelling of mitochondria in the presence of 2 mM ADP. We conclude that the outer side of inner mitochondrial membrane has a low affinity sensor for ADP, modifying the activity of PTP. The pathophysiological importance of this process could be an endogenous prevention of PT at conditions of energetic depression.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Atractilosídeo
/
Difosfato de Adenosina
/
Porinas
/
Membranas Intracelulares
/
Fígado
/
Mitocôndrias
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Alemanha