Calcium elevation in mitochondria is the main Ca2+ requirement for mitochondrial permeability transition pore (mPTP) opening.

ABSTRACT: We have investigated in detail the role of intra-organelle Ca2+ content during induction of apoptosis by the oxidant menadione while changing and monitoring the Ca2+ load of endoplasmic reticulum (ER), mitochondria, and acidic organelles. Menadione causes production of reactive oxygen species, induction of oxidative stress, and subsequently apoptosis. In both pancreatic acinar and pancreatic tumor AR42J cells, menadione was found to induce repetitive cytosolic Ca2+ responses because of the release of Ca2+ from both ER and acidic stores. Ca2+ responses to menadione were accompanied by elevation of Ca2+ in mitochondria, mitochondrial depolarization, and mitochondrial permeability transition pore (mPTP) opening. Emptying of both the ER and acidic Ca2+ stores did not necessarily prevent menadi

SUBMITTER: Baumgartner HK 

PROVIDER: S-EPMC2742844 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature