[Characteristics of reversible and irreversible Ca2+-induced efflux of Ca2+ from mitochondria in permeabilized Ehrlich ascites carcinoma cells].

The Cyclosporin A-sensitive mitochondrial permeability transition in Ehrlich ascites tumour cells has been investigated. It was shown that Ca2+ ions induce both the self-reversible and irreversible mitochondrial permeability transition. ADP effectively inhibits the reversible but has no effect on the irreversible permeability transition. Bromophenacyl bromide, a potent inhibitor of phospholipase A2, effectively inhibits both the reversible and irreversible permeability transition. Accumulation of phosphatidylcholine and phosphatidylethanolamine lysoforms in mitochondria during Ca(2+)-induced Ca2+ release from mitochondria was found. The role of lysophospholipids in the formation of the non-selective pore in inner mitochondrial membranes during the mitochondrial permeability transition was postulated.