[Effects of different regimes of freezing and thawing on chemiluminescence of rat liver mitochondria].

The rate of Fe2+ activated lipid peroxidation was studied as affected by the different freezing-thawing regime. The level of peroxidation was judged by kinetics and superfeeble luminiscence intensity of mitochondria. It was shown that freezing up to -196 degrees C and subsequent thawing of the mitochondria suspended in a salty medium (KCl) results in an increase in the rate of lipid peroxidation. A more distinct response to the introduction of peroxidation activator (Fe2SO4) is observed in mitochondria, especially in the first 1-2 minutes after ion introduction - in the phase of "slow flash". Besides, there is an increase in the level of stationary luminescence (2-10, 12-22 min) of the frozen-thawed mitochondria in comparison with the control. Slow thawing of quickly or slowly frozen mitochondria results in a more considerable increase in the luminescence light sum, than in the case of rapid thawing. The least-luminescence intensity after freezing and thawing of mitochondria suspension was observed after the rapid freezing and rapid thawing. In case of slow thawing the rate of mitochondria freezing does not considerably affect the degree of chemiluminescence.