The Principles of Protective Effects Formation Using Different Hypoxic Preconditioning Modes

The aim of the investigation was to study molecular mechanisms of adaptive reactions formation using short- and long-term hypoxic preconditioning modes. Materials and Methods. We carried out experiments on white outbred male rats. The animals underwent hypoxic preconditioning by 4- and 28-time hypobaric training within 60 min a day in altitude chamber at 310 mm Hg. Hypoxia tolerance test was performed by simulating severe hypobaric hypoxia in preconditioned animals exposed to atmosphere air rarefied to 143 mm Hg, with 30-minute exposure. We determined the intensity of free radical oxidation processes, catalytic activity of lactate dehydrogenase, neuronal enolase, as well as glucose concentration in brain tissue and blood. Results. The comparison of biochemical measurements in animals in 4- and 28-time trainings and in intact group showed no statistically significant changes in brain tissue and blood. Hypoxia tolerance test in both exercise modes revealed the reduction of glucose concentration, total activity of lactate dehydrogenase, and free radical oxidation processes in brain and blood of animals, though in varying degrees. The neuronal enolase level in blood serum of the exercised animals was within normal range. Conclusion. Metabolic adaptation is a controlled process aimed at homeostasis support under hypoxia. The adaptive mechanism is realized through the remodeling of metabolic state depending on adaptation period duration.