1. [An antioxidant prevents and reverses calcium-induced uncoupling of rat liver mitochondria].
- Author
-
Novgorodov SA, Gogvadze VG, Medvedev BI, and Zinchenko VP
- Subjects
- Animals, Butylated Hydroxytoluene pharmacology, Calcium pharmacology, In Vitro Techniques, Membrane Potentials drug effects, Mitochondria, Liver drug effects, Oxidation-Reduction, Phosphates pharmacology, Rats, Antioxidants pharmacology, Calcium metabolism, Mitochondria, Liver metabolism, Uncoupling Agents antagonists & inhibitors
- Abstract
Accumulation of Ca2+ by rat liver mitochondria in the presence of inorganic phosphate results in spontaneous activation of respiration accompanied by a progressive loss of the accumulated cation. The lipid peroxidation inhibitor, ionol, completely prevents and reverses the Ca2+/phosphate-induced loss of accumulated Ca2+ and restores the respiration to state 4 level without having any effect on the rate of Ca2+ accumulation and respiration in the presence of an uncoupler. No correlation between the ionol-dependent loss of Ca2+ and the formation of malonic dialdehyde in mitochondria was found. The measurements of delta psi across the inner mitochondrial membrane during a progressive loss of Ca2+ suggest that the Ca2+/phosphate-induced "uncoupling" is mainly due to the appearance of electrogenic fluxes (but not Ca2+ cycling) which is under control of some products of initial steps of lipid peroxidation.
- Published
- 1987