| Autor: |
Grishina, E., Khaustova, Ya., Vasilieva, A., Mayevsky, E. |
| Zdroj: |
Biophysics; Jul2015, Vol. 60 Issue 4, p581-587, 7p |
| Abstrakt: |
The antioxidant effect of succinate and 3-hydroxybutyrate oxidation on the kinetics of lipid peroxidation induced by ATP-Fe complex in isolated rat liver mitochondria of old (1-1.5 years) and young (3 months) male rats was investigated. Rate of induced lipid peroxidation V in rat liver mitochondria was recorded polarographically by oxygen consumption and the half-time of maximum oxygen consumption Δ t, which includes a lag period and the lipid peroxidation initiation phase, was determined. Without exogenous oxidative substrates V is slightly higher in mitochondria of old animals, but the onset of lipid peroxidation cascade is significantly earlier than in mitochondria of young animals. Incubation of intact mitochondria with 5 mM succinate for 1 min inhibited V by 15 and 35% in young and old animals respectively, however only in mitochondria of old animals Δ t increased by 19%. Oxidation of 3-hydroxybutyrate in mitochondria of young animals did not significantly change the rate of lipid peroxidation, while in mitochondria of old animals it was reduced by 19% with a slight increase of Δ t. To simulate age-dependent dysfunction we damaged isolated mitochondria by a session of freeze-thaw cycles, which caused a significant increase of V in mitochondria of both age groups. Succinate oxidation inhibited V in damaged mitochondria in all cases by 56%, as compared to V without oxidative substrates, and extended Δ t twofold in mitochondria of young animals. Oxidation of 3-hydroxybutyrate had no effect on V in damaged mitochondria regardless of animal age and extended Δ t by 48% in mitochondria of young animals. Thus, the antioxidant effect of succinate oxidation can prevent lipid peroxidation damage and may exhibit geroprotective action on aging mitochondria. Addition of either substrate had no effect on lipid peroxidation parameters in phospholipid emulsion. Therefore, the antioxidant effect is a result of the process of substrate oxidation in the respiratory chain and not an interaction of their structures with membrane lipids per se. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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