Effects of cumene hydroperoxide on the Ca(2+)-induced Ca2+ efflux from mitochondria and on the viability of hepatoma cells.

Effects of cumene hydroperoxide on the Ca(2+)-induced Ca2+ efflux from mitochondria isolated from rat liver and Zaidelja hepatoma were compared. Cumene hydroperoxide at micromolar concentrations (0.3-10 microM) prevented the closing of the permeability transition pore in the inner mitochondrial membrane and, therefore, potentiated the Ca(2+)-induced Ca2+ efflux. This response was 10-100 times greater in hepatoma mitochondria than in rat liver mitochondria. Micromolar concentrations of cumene hydroperoxide induced the death of the hepatoma cells in vitro.