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Updated: Aug 15, 2026

Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess
Published on: June 1, 2022
Role of alpha-tocopherol in the regulation of mitochondrial permeability transition
Masae Yorimitsu1, Shikibu Muranaka, Eisuke F Sato
1Institute of Medical Science, Kurashiki Medical Center, Kurashiki, Japan.
Abstract:
We previously showed that Ca2+-induced cyclosporin A-sensitive membrane permeability transition (MPT) of mitochondria occurred with concomitant generation of reactive oxygen species (ROS) and release of cytochrome c (Free Rad. Res.38, 29-35, 2004). To elucidate the role of alpha-tocopherol in MPT, we investigated the effect of alpha-tocopherol on mitochondrial ROS generation, swelling and cytochrome c release induced by Ca2+ or hydroxyl radicals. Biochemical analysis revealed that alpha-tocopherol suppressed Ca2+-induced ROS generation and oxidation of critical thiol groups of mitochondrial adenine nucleotide translocase (ANT) but not swelling and cytochrome c release. Hydroxyl radicals also induced cyclosporin A-sensitive MPT of mitochondria. alpha-Tocopherol suppressed the hydroxyl radical-induced lipid peroxidation, swelling and cytochrome c release from mitochondria. These results indicate that alpha-tocopherol inhibits ROS generation, ANT oxidation, lipid peroxidation and the opening of MPT, thereby playing important roles in the prevention of oxidative cell death.
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