RESUMO
Correcting action of vitamin E and it's short chain derivative on the activity of some mitochondria electron transport chain enzymes were investigated on models of acute and chronic toxic hepatitis. Inhibition of NADH- and succinate-cytochrome c oxidoreductase complexes activity was established in short term action of xenobiotics. Treatment of rats with CCl4 during 60 days lowered activity of NADH-cytochrome c oxidoreductase complex and significantly increased activity of succinate-cytochrome c oxidoreductase complex and succinate dehydrogenase. Obviously, as a result of long term influence of hepatotoxic agents switching over in rat mitochondria electron transport from NAD-dependent way of substrate oxidation to succinate-dependent way took place. This event could be a part of the body adaptation mechanisms. Vitamin E and its short chain analogue corrected activities of investigated enzymes of mitochondria liver in the animals with acute and chronic hepatitis.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Mitocôndrias Hepáticas/efeitos dos fármacos , NADH Desidrogenase/metabolismo , Succinato Citocromo c Oxirredutase/metabolismo , Succinato Desidrogenase/metabolismo , Vitamina E/análogos & derivados , alfa-Tocoferol/análogos & derivados , Animais , Tetracloreto de Carbono/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Transporte de Elétrons , Ativação Enzimática , Masculino , Mitocôndrias Hepáticas/enzimologia , Ratos , Tocoferóis , Vitamina E/química , Vitamina E/farmacologiaRESUMO
The quaternary structure of the Mo-Fe-protein from Azotobacter vinelandii has been studied by electron microscopy. A model of the molecule of the Mo-Fe-protein has been proposed: two alpha subunits are displaced relative to two beta subunits along a twofold axis, so the molecule can be characterized by the point-group pseudosymmetry 222. Computer averaging of the images showed that one of the projections of the molecule could be characterized by twofold rotational symmetry. Micrographs of nitrogenase recombined complex (Mo-Fe-protein + Fe-protein) have been obtained. They showed particles close in size and form to the Mo-Fe-protein molecule. Therefore, it has been proposed that the Fe-protein could be situated in the central cavity of Mo-Fe-protein.