[Disturbances of oxygen-dependent processes in periodontal tissues under prolonged immobilization stress and ways of their pharmacological correction].

Influence of prolonged immobilization (6 h strict horizontal position of rats in the tight containers daily for 2 weeks) on oxygen tension, oxygen consumption, pro-/antioxidant balance, and energetic metabolism of soft and hard periodontal tissues has been investigated. It was established that prolonged immobilization stress resulted in marked decrease in the gum tissue PO2 (36%) and in the bone tissue oxygen consumption rate (46%) compared to control. It was also determined that prolonged stress led to a reduction in the gum mitochondrial respiration rate. The latter was more expressed in case of the NAD-dependent substrate oxidation than of the FAD- dependent one. It was determined that the prolonged stress results in intensification of peroxide processes and depletion of antioxidant protection of soft tissues of periodontum. It was found that Thiotriazolin and Actovegin have modified and diminished stress-induced disorders in the soft and hard periodontal tissues oxygen homeostasis under prolonged immobilization stress.

[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. The next oxidation substrates were used: 1 mmol/l succinate and 1 mmol/l alpha-ketoglutarate as well as the next inhibitor succinate dehydrogenase 2 mmol/l malonate. It was shown that physical work combined with intermittent hypoxic training led to the increase of mitochondrial respiration effectiveness in muscle energy supply under alpha-ketoglutarate oxidation in comparison with succinate oxidation as well as to the decrease of succinate dehydrogenase activity and lipid peroxidation. The study suggested that these changes may correct mitochondrial dysfunction under intensive muscular work.

[Effect of intermittent hypoxic training on indices of adaptation to hypoxia in rats during physical exertion]. / Vplyv interval'noho hipoksychnoho trenuvannia na pokaznyky adaptatsiï shchuriv do hipoksiï navantazhennia.

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. The latter led to the lesser shifts in metabolic parameters in the muscle of rats adapted both to IHT and endurance training than in rats adapted to endurance training only. The combined effects of IHT and adaptation to load hypoxia resulted in an increase of the role of NADH - oxidation pathway in the mitochondrial energy production.