[The effect of intermittent deep hypoxia on the adrenal gland cortex]

Wister laboratory rats were subjected to decreased atmospheric pressure occurring at the height of 23000 feet every day during 4 days and every second day during 11 days. The effect of hypoxia on the adrenal cortex and biochemical blood factors in rats, sacrificed at different times after the completion of exposure to hypoxic conditions was investigated. The hypoxic stress elicited alkalosis when Pa O2 and Pa CO2 were decreased, while the saturation oh hemoglobin by oxygen was enhanced. The animals, which were exposed to hypoxia for 4 consecutive days, better endured the whole course of the experiment than those ones exposed every second day. The histological changes in the adrenal cortex were stronger in the animals exposed to the experimental conditions with two-day breaks. The intensity, character and reversibility of the changes depended much more on the rhythm of exposure than on the rhythm of sacrifice.