[Ca2+ release from rat liver mitochondria subjected to deep freezing].

Freezing-thawing of rat liver mitochondria evokes a release of Ca2+ into the incubation medium containing oxidation substrates: succinate and phosphate. The release is accompanied by a decrease in the membrane potential value. ATPase and NADH-dehydrogenase inhibitors when introduced into the medium simultaneously with mitochondria prevent the both processes, but only till Ca2+ release. ADP added during Ca2+ release, initiates its uptake. When succinate is replaced by NAD-dependent substrates (malate in combination with glutamate) and in the presence of the antioxidant (ionol) Ca2+ is not released from mitochondria. It is supposed that Ca2+ release from mitochondria due to freezing-thawing is evoked by activation of lipid peroxidation and is controlled by the degree of pyridine nucleotide reduction.