Calcium induced release of mitochondrial cytochrome c by different mechanisms selective for brain versus liver
Calcium induced release of mitochondrial cytochrome c by different mechanisms selective for brain versus liver
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DOI:
10.1038/sj.cdd.4400565
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发表时间:
1999-09-01
影响因子:
12.4
通讯作者:
Fiskum, G
中科院分区:
文献类型:
--
作者:
Andreyev, A;Fiskum, G
Increased mitochondrial Ca2+ accumulation is a trigger for the release of cytochrome c from the mitochondrial intermembrane space into the cytosol where it can activate caspases and lead to apoptosis, This study tested the hypothesis that Ca2+-induced release of cytochrome c in vitro can occur by membrane permeability transition (MPT)-dependent and independent mechanisms, depending on the tissue from which mitochondria are isolated, Mitochondria were isolated from rat liver and brain and suspended at 37 degrees C in a K+-based medium containing oxidizable substrates, ATP, and Mg2+. Measurements of changes in mitochondrial volume (via light scattering and electron microscopy), membrane potential and the medium free [Ca2+] indicated that the addition of 0.3-3.2 mu mol Ca2+ mg(-1) protein induced the MPT in liver but not brain mitochondria, Under these conditions, a Ca2+ dose-dependent release of cytochrome c was observed with both types of mitochondria; however, the MPT inhibitor cyclosporin A was only capable of inhibiting this release from liver mitochondria. Therefore, the MPT is responsible for cytochrome c release from liver mitochondria, whereas an MPT-independent mechanism is responsible for release from brain mitochondria.