Effect of spermine on mitochondrial glutathione release

Spermine prevents glutathione release induced in rat liver mitochondria by the combined addition of Ca2+ and phosphate. Spermine also inhibits mitochondrial swelling, membrane potential decrease, oxygen uptake and [14C] sucrose entry stimulated by the above reported agent. Mitochondrial swelling is completely prevented by 25 microM spermine while higher concentrations (100 microM) are required for the full inhibition of glutathione release. Therefore, polyamines decrease the mitochondrial inner membrane permeability and, by preventing mitochondrial glutathione loss, also act as protective agents against oxidative stress.