Tag Archives: cytochrome oxidase

Activity of respiratory chain cytochrome complexes and cytochromes content in the rat kidney mitochondria under different nutrients content in a diet

H. P. Kopylchuk, O. M. Voloshchuk*

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

Received: 07 February 2023; Revised: 17 March 2023;
Accepted: 13 April 2023; Available on-line: 27 April 2023

An important role in ensuring the functioning of the respiratory chain belongs to the cytochrome part, which includes complexes III (ubiquinol-cytochrome c oxidoreductase) and IV (cytochrome c oxidase). The key components of these enzymatic complexes are heme-containing cytochromes, the number of which depends on the balance of heme synthesis and catabolism. δ-Aminolevulinate synthase catalyzes the first step of the heme biosynthetic pathway, while heme oxygenase is the key enzyme of heme degradation. It is known that nutritional imbalances drive many risk factors for chronic kidney disease. That is why our research aimed to study the activity of ubiquinol-cytochrome c oxidoreductase and cytochrome oxidase complexes, the level of cytochromes a+a3, b, c, and c1, and the activity of key enzymes of heme metabolism in the mitochondria of rat kidneys under conditions of different content of protein and sucrose in animal diet. The obtained results showed a decreased activity of ubiquinol-cytochrome c oxidoreductase and cytochrome oxidase complexes and reduced levels of mitochondria cytochromes a+a3, b, c, and c1 in the kidney mitochondria under the conditions of nutrient imbalance, with the most pronounced changes found in animals kept on a low-protein/high-sucrose diet. A decrease in δ-aminolevulinate synthase activity with a simultaneous 2-fold increase in heme oxygenase activity was found in kidney mitochondria of animals kept on a low-protein/high-sucrose diet compared to those kept on full-value diet indicating an intensification of heme catabolism along with inhibition of its synthesis. The obtained results testify the energy imbalance under the conditions of low-protein/high-sucrose which in turn can lead to the progression of kidney injury.

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.