[Comparative study of the effects of alpha-tocopherol and a synthetic antioxidant on respiration and oxidative phosphorylation in rat liver mitochondria].
In order to decide whether vitamin E action on ubiquinone-dependent enzymatic systems of mitochondria and on ubiquinone metabolism consisting in its antioxidative function, the effects of alpha-tocopherol and the most effective synthetic antioxidant, chlorohydrate 2-ethyl-6-methyl-3-hydroxypyridine, were compared. It was shown that the contents of vitamin E and ubiquinone as well as the activities of succinate- and NADH-ubiquinone reductase, succinate- and NADH-dehydrogenases in liver mitochondria are increased and the levels of ATP, adenine nucleotides and phosphate potential in the livers of vitamin E-deficient rats are elevated 3 hours after alpha-tocopherol injection (5 micrograms per 1 g of body weight). The synthetic antioxidant injected under identical conditions at a dose of 50 micrograms per 1 g of body weight did not change the ubiquinone content or the enzymatic activities, but considerably enhanced the ATP level. The same antioxidant when injected at a dose of 105 micrograms per 1 g of body weight did not significantly affect the parameters under study but decreased the activity of succinate-ubiquinone reductase. Thus, the role of vitamin E in oxidative phosphorylation may not only consist in its antioxidant action and is largely due to the regulation of metabolism and functioning of ubiquinone.
D000227:Adenine Nucleotides / Q000378:metabolism; D000818:Animals; D007700:Kinetics; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010085:Oxidative Phosphorylation / Q000187:drug effects*; D010101:Oxygen Consumption / Q000187:drug effects*; D010847:Picolines / Q000494:pharmacology*; D051381:Rats; D014810:Vitamin E / Q000494:pharmacology*; D014811:Vitamin E Deficiency / Q000378:metabolism
D000227:Adenine Nucleotides; D010847:Picolines; D014810:Vitamin E; C009820:6-methyl-2-ethyl-3-hydroxypyridine
Sravnitel'noe izuchenie vozdeĭstviia al'fa-tokoferola i sinteticheskogo antioksidanta na protsessy dykhaniia i okislitel'nogo fosforilirovaniia v mitokhondriiakh pecheni krys.