[Cation permeability of liver mitochondrial membranes during Ca+-dependent anoxic damage in vitro]

Ca2+ ions are responsible for impairment of oxidative phosphorylation in rat liver mitochondria under anoxia in vitro. The decrease in this function is due to inhibition of electron transport over respiratory chain and to uncoupling. The increase in membrane permeability for H+, K+ and Na+ was observed on incubation of mitochondria under anoxic condition together with Ca2+. Uncoupling of phosphorylation depends on the increased permeability of the membranes for H+. The increased permeability of membranes for Na+ and K+ under energy liberation and in presence of penetrating anions led to active swelling of organelles and to secondary (osmotic) impairment. Ca2+-activated mitochondrial phospholipase A2 appears to participate in the organelle impairment under anoxia.