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

The development of ways to increase the adaptive reservesof the body and resistance to negative factors continues to be anurgent problem for physiology, which has a significant translationalpotential in the fields of healthcare, sports, cosmonautics andthe national economy. Long-term studies of the authors have provedthe promise in this respect of hypoxic hypobaric conditioning ina pressure chamber. In the present study, the principles of hypobaricconditioning were transferred to the model of normobaric intermittenthypoxia/normoxia caused by the inhalation of gas mixtures, whichis widely used in practice for human interval hypoxic training.A comparative experimental analysis of molecular and cellular changesin the blood of rats in response to three-day interval hypoxic trainingat 9, 12, or 16% O₂ in the mixture was carriedout using an automated setup. It was shown that the most intenseand effective 3 × 9% O₂ regimen, in termsof duration and amplitude, had the greatest effect on the parametersof the clinical blood test of rats, initiating an increase in thenumber of erythrocytes and a decrease in the variability of theirvolumes, and causing a shift in the balance of lymphokine and monokineeffects towards a calm activation reaction. On the first day aftertraining at 9 and 12% oxygen, the total antioxidant capacity ofserum significantly decreased, followed by rapid normalization,which fits into the dynamics of the reaction of pro- and antioxidantsystems to non-damaging hypoxia. The stimulating effect of all thestudied regimens of interval training on the basal and stress activityof the hypothalamic-pituitary-adrenocortical system, characteristicof conditioning, was revealed. All detected post-training changescan be attributed to the basic adaptive mechanisms that increaseresistance to adverse factors.