Tag Archives: succinate dehydrogenase

The NADH-ubiquinone reductase and succinate dehydrogenase activity in the rat kidney mitochondria under the conditions of different protein and sucrose content in the diet

O. M. Voloshchuk*, М. S. Ursatyy, G. P. Kopylchuk

Yuriy Fedkovych Chernivtsi National University, Institute of Biology, Chemistry and Natural Resources, Ukraine;
*e-mail: o.voloschuk@chnu.edu.ua

Received: 11 November 2021; Accepted: 21 January 2022

The NADH-ubiquinone reductase (EC 7.1.1.2) and succinate dehydrogenase (EC 1.3.5.1) activity, the levels of total ubiquinone and its redox forms, and the degree of oxidative modification of mitochondrial proteins in the rat kidney were investigated. It was found that when consuming a low-protein diet there is a decrease in NADH-ubiquinone reductase and succinate dehydrogenase activity by 1.4-1.7 times, a 20% decrease in total ubiquinone and a quantitative redistribution of its oxidized and reduced form with a predominance of oxidized form. Under the studied conditions, there is no accumulation of carbonyl derivatives, but the level of free SH-groups is significantly reduced compared with control. At the same time, in animals consuming a high-sucrose diet there is an increase in NADH-ubiquinone reductase and succinate dehydrogenase activity by 1.5-2 times and maintenance of the total ubiquinone at the control level against the background of redistribution of its redox forms, namely a decrease in reduced ubiquinone and an increase in oxidized ubiquinone on average by 1.5 times. In addition, there is an intensification of the reactions of free radical damage of mitochondrial proteins in kidney cells, as evidenced by an increase in the level of carbonyl derivatives and a significant decrease in the level of free protein SH-groups by approximately 1.4-1.5 times. The most pronounced changes in the studied indicators are found in animals that consumed a low-protein/high-sucrose diet. In particular, an excessive consumption of sucrose on the background of protein deficiency is accompanied by a reduction of NADH-ubiquinone reductase and succinate dehydrogenase activity by 1.7-2 times, a decrease in total ubiquinone level by approximately 1.4 times, and a two-fold decrease in reduced ubiquinone against the background of intensification of the free radical oxidation of mitochondrial proteins, which can be considered as a prerequisite for the impairment of the renal function under the conditions of carbohydrate-protein imbalance.

Glutathione influence on energy metabolism in rat liver mitochondria under experimental nephropathy

Ye. O. Ferenchuk, I. V. Gerush

Higher State Educational Establishment of Ukraine “Bukovinian State Medical University”, Chernivtsi;
e-mail: yelena_f@ukr.net

Received: 17 October 2018; Accepted: 14 March 2019

Mitochondrial oxidative damage and disorders of energy metabolism contribute to a wide range of pathologies and disease progression. In our work, the effect of glutathione on the activity of respiratory chain enzymes and the content of free SH-groups in rat liver mitochondria was examined with the use of folic acid-induced nephropathy model. Mitochondria were isolated by differential centrifugation, NADH-dehydrogenase, succinate dehydrogenase, cytochrome oxidase and H+-ATPase activity were determined. The activity of these enzymes and the content of the free SH-groups in the liver were shown to be decreased under conditions of nephropathy, evidently due to the intensification of the free radical processes. The introduction of glutathione increased the content of SH-groups and the activity of the Complexes II and V enzymes of mitochondrial respiratory chain but did not change the activity of cytochrome oxidase in mitochondria isolated from the liver of rats under experimental nephropathy. The results obtained demonstrate a positive effect of glutathione on mitochondrial succinate dehydrogenase and H+-ATPase activity normalization in the liver of rats with nephropathy. These findings may help to extend the understanding of mitochondrial energy metabolism under development of kidney diseases.

NADH:ubiquinone reductase and succinate dehydrogenase activity in the liver of rats with acetaminophen-induced toxic hepatitis on the background of alimentary protein deficiency

G. P. Kopylchuk, O. M. Voloshchuk

Yuriy Fedkovych Chernivtsi National University,
Institute of Biology, Chemistry and Life, Ukraine;
e-mail: kopilchuk@gmail.com

The ratio between the redox forms of the nicotinamide coenzymes and key enzymatic activity of the I and II respiratory chain complexes in the liver cells mitochondria of rats with acetaminophen-induced hepatitis under the conditions of alimentary deprivation of protein was studied. It was estimated, that under the conditions of acute acetaminophen-induced hepatitis of rats kept on a low-protein diet during 4 weeks a significant decrease of the NADH:ubiquinone reductase and succinate dehydrogenase activity with simultaneous increase of the ratio between redox forms of the nicotinamide coenzymes (NAD+/NADН) is observed compared to the same indices in the liver cells of animals with experimental hepatitis kept on the ration balanced by all nutrients. Results of research may become basic ones for the biochemical rationale for the approaches directed to the correction and elimination of the consequences­ of energy exchange in the toxic hepatitis, induced on the background of protein deficiency.