The role of Ca2+ in the process of mithocondrial damage associated with oxidative stress

摘要: Mitochondria from a wide range of sources have the ability to accumulate Ca “down their electro-chemical gradient mediated by a uniport mechanism and to release the cation via two different pathways: an Na ‘-dependent and an Na*-independent mechanism. The kinetic characteristics of these calcium influx-efflux pathways appear to be incompatible with an important role for mitochondria as cytosolic Ca2+ buffers, under resting normal physiological conditions. However under conditions in which a high cytosolic Ca2+ concentration is sustained the uniport becomes operative and the matrix Ca2+ concentration may attain levels that lead to impairment of mitochondrial functions such as inhibition of oxidative phosphorylation and increase in inner membrane permeability. Accumulation of Ca “by mitochondria under conditions of oxidative stress induces an increase in inner membrane permeability by a mechanism …