S. D. Melnychuk, S. V. Khyzhnyak, V. S. Morozova, V. M. Voitsitsky
National University of Life and Environmental Sciences of Ukraine, Kyiv;
The modification particularities of the structural and functional state of the inner mitochondrial membrane of the rat liver and myocardium were observed in conditions of artificial hypobiosis, which was created using hypoxic and hypercapnic gas medium with a body temperature reduction. Under the artificial hypobiosis the activity of NAD·H-generating enzymes of the Krebs cycle of the liver mitochondria decreases. The established changes of the enzymes activity and cytochromes content of the inner mitochondrial membrane indicate the decrease of the oxidative activity of a respiratory chain, that can be limited on a terminal (cytochrome c oxidase) site and leads to the decrease (by 49% at an average) of the H+-ATPase activity of the liver mitochondria. Under the artificial hypobiosis the detected increase of the succinate-KoQ-oxidoreductase activity (by 65% at average) causes the maintaining of the functional activity of a mitochondrial respiratory chain, considering the high (relative to control) cytochrome c oxidase and H+-ATPase activities of the mitochondria of the rats’ myocardium. The structural changes of the inner mitochondrial membrane of the liver and myocardium in experimental conditions are accompanied by the increase of hydrophobicity of tryptophan residues microenvironment and the intramolecular modifications of protein molecules.
Key words: artificial hypobiosis, liver, myocardium, mitochondria, membranes, respiratory chain complexes, cytochromes, fluorescence.
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