Gizatullina 2005 Biochim Biophys Acta
|Gizatullina ZZ, Chen Y, Zierz S, Gellerich FN (2005) Effects of extramitochondrial ADP on permeability transition of mouse liver mitochondria. Biochim Biophys Acta 1706:98-104.
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 μM CAT and 75 μM 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 μM 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 μM 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. • Keywords: Mitochondria, Permeability transition pore, Adenine nucleotide translocator, Carboxyatractyloside, Bongkrekic acid
• O2k-Network Lab: DE Magdeburg Gellerich FN
Organism: Mouse Tissue;cell: Liver Preparation: Isolated mitochondria