[Phase changes of energy metabolism during adaptation to immobilization stress].

In stress, it was showed the organ and tissue changes associated with damage by lipid peroxides, and the disrupted barrier function. As a consequence, it was to lead to a syndrome of "stress-induced lung" and violation of oxygen delivery to the tissues and hypoxia. Purpose of the study was to investigate the dynamics of changes in gas exchange, blood glucose, body temperature, oxidant and antioxidant system activity, as well as mitochondrial respiration by Chance under the influence of chronic stress (6-hour immobilization daily for 3 weeks).

[Mitochondrial thiol-disulfide system under acute hypoxia and hypoxic-hyperoxic adaptation].

The authors investigated the state of mitochondrial glutathione pool (reduced and oxidized glutathione, protein-GSH mixed disulfides), content of carbonyl groups and free sulfhydryl groups of proteins, protein expression of key mitochondrial antioxidant enzymes such as glutathione peroxidase and thioredoxin reductase as well as activity of glutathione reductase, glutathione peroxidase and glutaredoxin in the liver mitochondria of rats exposed to acute hypoxia after prolonged hypoxic-hyperoxic training (HHT). It was shown that the preliminary HHT reduced the intensity of proteins oxidative modification under acute hypoxia, activated the mitochondrial antioxidant defense as well as affected the thiol-disulfide exchange, redox balance in mitochondria, modulated the S-glutathionylation/deglutathionylation process in mitochondria membranes.

[Continuous adaptation of rats to hypobaric hypoxia prevents stressor hyperglycemia and optimizes mitochondrial respiration under acute hypoxia].

Oxygen consumption, glucose blood level and liver mitochondrial respiration were investigated in male Wistar rats permanently living in middle altitude (2100 m, Elbrus region). The animals were characterized by reduced body oxygen consumption and blood glucose level, as well as by intensified utilization of NAD-dependent substrates in mitochondrial respiratory chain with increasing indices of ADP-stimulated respiration in comparison with plains rats. As a result of adaptive rebuilding of oxidative metabolism in rats--inhabitants of midlands, the nature and severity of metabolic responses to acute hypoxia were also changed.

[Changes in mRNA and protein expression of antioxidant enzymes in children with bronchial asthma after interval hypoxic training].

The effect of 10 days of interval hypoxic training (IHT) on the mRNA expression and protein content of antioxidant enzymes (superoxide dismutase, catalase and glutathione-S-transferase) in leukocytes of children with bronchial asthma (BA) was investigated. It was shown that after sessions of IHT the mRNA expression of superoxide dismutase decreased by 32.5% (P < 0,05), but the level of protein was unchanged.

[Glutathione system adaptation to acute stress in the heart of rats during different regimes of hypoxia training].

The intensity of lipid peroxidation (LPO), reduced and oxidized glutathione (GSH and GSSG) contents, glutathione reductase, glutathione peroxidase, glutathione-S-transferase, glucose-6-phosphate dehydrogenase (G-6-PDH), and NADP-isocitrate dehydrogenase (NADP-IDH) activities were studied in the heart of male rats exposed to two modes of intermittent hypoxic training (IHT): I-breathing in normobaric chamber with 7% O2 gas mixture for 5 min with 15 min normoxic intervals 4 times daily during 3 weeks; II-breathing by 12% O2 gas mixture in the same manner). After adaptation to hypoxia, the rats were subjected to 6h-immobilization stress. It has been shown that stress action after IHT (regime I) caused the increase in LPO and the shift of GSH/GSSG to disulfides.

[Individual characteristics of human adaptation to intermittent hypoxia: possible role of genetic mechanisms].

The majority of the adaptation processes to hypoxia is based on transcriptional regulation by hypoxia-inducible factors--HIFs. Recently the allele polymorphism of oxygen-dependent degradation domain of HIF-lalpha has been described. It consists in the replacement of cytosine for thymine in 1772 location (C1772-->T).

[Genetically determined organ-specific changes of some tissue morphometric characteristics under the various exogenous influences].

Organ-specific alterations of ultrastructure and morphofunctional condition in different organism's tissues, which could evidence of the genetic factors inclusion under the development of different hypoxic condition in organism, were investigated. The dates obtained indicated the marked organ-specific "structure" reaction of tissues, cells and organelles under various exogenous influences. Such reactions confirm the presence of different genes expression which account for ultrastructure alterations; its activity is determined by a type, intensity, duration of influence as well as organ belonging.

[Effect of intermitent hypoxia on ultrastructure and prooxidant-antioxidant balance in the soft tissue of the periodontium in acute immobilization stress].

The changes of prooxidant-antioxidant balance and morphofunctional state of soft tissue of paradontum under the acute immobilization stress, intermittent hypoxia and its complex influence were investigated. It was shown, that intermittent hypoxia can stimulate own endogenous mechanisms of nonspecific resistance, such as antioxidant protection in soft tissue of paradontum. Normalization of the prooxidant-antioxidant balance under immobilization stress after intermittent hypoxia essentially improved the morphofunctional state of tissue investigated with decrease of edema and improvement of mitochondria apparatus ultrastructure.

[Effect of intermittent hypoxic hypoxia on energy supply of rat skeletal muscle during adaptation to physical load].

The experiment, on Wistar male rats was carried out to investigate influence of endurance training (swimming with load 7.0 +/- 1.3% body weight, 30 min a day, during 4 weeks) and additional intermittent hypoxic training (12% O2 in N2 - 15 min, 21% O2 - 15 min, 5 sessions a day, during the first 2 weeks) on the following parameters: ADF-stimulated mitochondrial respiration, lactate/pyruvate ratio, succinate dehydrogenase activity, and lipid peroxidation in skeletal muscle.

[Characteristics of changes in respiratory function of humans after a long stay in Antarctic region].

Fifteen participants of the Antarctic expedition (men, 27-51 years old) have been investigated after their return from a one-year stay there. All subjects have signs of latent hypoxia. Compensation of hypoxic reactions depended on the initial state of organism oxygen regimen as well as on the features of a genotype.

[Effect of intermittent hypoxic training on indices of adaptation to hypoxia in rats during physical exertion].

The aim of this study was to investigate physical endurance, maximal oxygen uptake, oxygen partial pressure, and pH in blood and skeletal muscle as well as the muscle metabolic parameters (lactate and pyruvate concentration, lactate/pyruvate and NAD/NADH ratios, succinate dehydrogenase activity, ADP-stimulated mitochondrial respiration) under various regimen of combination of endurance training with intermittent hypoxic training (IHT) in adult Wistar rats. It was shown that physical endurance, maximal oxygen uptake, and muscle PO2 (PmO2) were maximally increased in those animals who simultaneously underwent endurance training and IHT. The same animals demonstrated the minimal decrease in PmO2, blood and muscle pH under testing intensive physical workload.

[Oxygen transport in skeletal muscles working with its maximum consumption during hypoxemia].

The influence of acute hypoxia (35 < or = PaO2 < or = 100 mmHg) on the values of VO2max and parameters of oxygen transport in muscle working at VO2max was studied under different values of muscle blood flow F (80 < or = F < or = 120 ml/(min 100g), blood pH (7.0-7.6), and different diffusion conditions.

[The role of oxygen radicals in the physiology and pathology of human sperm].

Reactive oxygen species in low doses are necessary compound of sperm capacitation and hyperactivation. Superoxide anion, hydroxyl radical and hydrogen peroxide initiate sperm capacitation. The edding of antioxidant enzymes inhibits the spontaneous and induced sperm hyperactivation.

[The antioxidant action of taurine in acute hypoxic hypoxia].

It was found that preliminary treatment by amino acid taurine protected rats from lipid peroxidation intensification (expressed in terms of malondialdehyde and conjugated dienes contents) in the liver, brain and heart under acute severe normobaric hypoxic hypoxia. The mechanisms of the antioxidant action of taurine are connected to the prevention of lactate accumulation in tissues and cell membrane structure disorders (expressed in a decrease of membrane Na+, K(+)-ATPase activity). It was also shown that taurine reduced significantly a decrease of glutathione antioxidant system activity protecting tissues against reduced glutathione pool depletion and preventing a decrease of glutathione reductase and glutathione peroxidase activities in acute severe hypoxia.