Intermittent hypoxia improves behavioral and adrenal gland dysfunction induced by post-traumatic stress disorder in rats

Non-pharmacological treatments of stress-induced disorders are promising, since they enhance endogenous stress defense systems and have few contraindications and side effects.

This study, published at Journal of Applied Physiology, tested a hypothesis that intermittent hypoxia conditioning (IHC) ameliorates behavioral, biochemical, and morphological signs of experimental PTSD induced in rats using a model of predator stress (10-day exposure to cat urine scent, 15 min daily followed by 14 days of stress-free rest). After the last day of stress exposure, rats were conditioned in an altitude chamber for 14 days at a 1,000 m simulated altitude for 30 min on day 1 with progressively increasing the altitude and duration to 4,000 m for 4 hours on day 5.

PTSD was associated with decreased time spent in open arms and increased time spent in closed arms of the elevated X-maze, increased anxiety index, and increased rate of freezing responses. Functional and structural signs of adrenal cortex degeneration were also observed, including decreased plasma corticosterone and weight of adrenal glands, reduced thickness of the fasciculate zone, and hydropic degeneration of adrenal gland cells. The thickness of the adrenal fasciculate zone negatively correlated with the anxiety index. IHC alleviated both behavioral signs of PTSD and morphological evidence of adrenal cortex dystrophy. Also, IHC alone exerted an anti-stress effect, which was evident from the increased time spent in open arms of the elevated x-maze, and a fewer number of rats displaying freezing responses.

Therefore, IHC of rats with experimental PTSD reduced behavioral signs of the condition and damage to the adrenal glands.

Follow NEWS.am Medicine on Facebook and Twitter