[Effects of hypoxia on the activity of the sympathetic-adrenal system]

Experiments on rat males (120-150 g b.weight) inhaling air with oxygen concentration 16, 14, 12, 10, 8 and 5.3% for an hour and placed at the altitudes 2000, 3500 and 3200 in above the sea level in the mountains demonstrated that adrenaline and noradrenaline concentrations in the brain tissues, adrenals, blood and urine depend on the intensity and duration of the exposure to low pO2 in the air. Adaptation to hypoxia provokes a significant increase of noradrenaline in the adrenals, cerebral cortex, hypothalamus and biological fluids.