Normobaric intermittent postconditioning corrects development of anxiety-depressive state in the experimental model of post-traumatic stress disorder

BACKGROUND: Despite the rapid increase in the prevalence of post-traumatic stress disorder, there are still no effective drugs for its treatment, therefore, the development of non-drug approaches is an extremely urgent task, which this study is aimed at solving. AIM: To estimate experimentally the therapeutic effects of hypoxic postconditioning using intermittent normobaric hypoxia in a model of post-traumatic stress disorder-like pathology in rats. MATERIALS AND METHODS: In the rat model of post-traumatic stress disorder “stress–restress”, the effects of three postconditioning regimes were investigated: three 5-min episodes of hypoxia with 9% oxygen interspaced with 15-min intervals of normoxia (reoxygenation) per day for 3 days after pathogenic stress (hypoxia/normoxia mode); three 5-min episodes of 9% hypoxia interspaced with 3-min intervals of hyperoxia with 30% oxygen in the mixture, per day for 3 days (hypoxia/hyperoxia mode); five 5-min episodes of 12% hypoxia and 3-min 30% O2 hyperoxia per day for 9 days (hypoxia/hyperoxia mode, prolonged). Animal behavior, hypothalamic-pituitary-adrenal axis function and indices of general blood analysis were analysed. RESULTS: All the modes of normobaric postconditioning to a greater or lesser extent had a corrective effect on the manifestation of pathological symptomatology; however, triple hypoxia/hyperoxia postconditioning was more effective than other modes in terms of the totality of protective and absence of side effects. CONCLUSIONS: The results suggest that postconditioning using intermittent normobaric hypoxia/hyperoxia for the treatment of anxiety-depressive disorders in humans, including post-traumatic stress disorder, may be a promising approach.