Influence of Interval Hypoxic Training in Different Regimes on the Blood Parameters of Rats

The development of ways to increase the adaptive reserves of the body and resistance to negative factors continues to be an urgent problem for physiology, which has a significant translational potential in the fields of healthcare, sports, cosmonautics and the national economy. Long-term authors studies have proved the promise in this respect of hypoxic hypobaric conditioning in a pressure chamber. In the present study, the principles of hypobaric conditioning were transferred to the model of normobaric intermittent hypoxia/normoxia caused by the inhalation of gas mixtures, which is widely used in practice for human interval hypoxic training. A comparative experimental analysis of molecular and cellular changes in the blood of rats in response to three-day interval hypoxic training at 9, 12, or 16% O2 in the mixture was carried out using an automated setup. It was shown that the most intense and effective 3 × 9% O2 regimen, in terms of duration and amplitude, had the greatest effect on the parameters of the clinical blood test of rats, initiating an increase in the number of erythrocytes and a decrease in the variability of their volumes, and causing a shift in the balance of lymphokine and monokine effects towards a calm activation reaction. On the first day after training at 9 and 12% oxygen, the total antioxidant capacity of serum significantly decreased, followed by rapid normalization, which fits into the dynamics of the reaction of pro- and antioxidant systems to non-damaging hypoxia. The stimulating effect of all the studied regimens of interval training on the basal and stress activity of the hypothalamic-pituitary-adrenocortical system, characteristic of conditioning, was revealed. All detected post-training changes can be attributed to the basic adaptive mechanisms that increase resistance to adverse factors.