抄録
1. A study was made on the physiological rôle of ascorbic acid when a living body is subjected to decompression with or without previous treatment of pure oxygen inhalation.
2. After a non-hypoxic decompression of 200mmHg was loaded on rats for 20 minutes, the animals showed severe symptoms and at the same time the ascorbic acid levels in adrenals, liver, blood and urine showed 81.9, 72.2, 133.8 and 292.6% respectively as compared with that in the control groups. This shows that this form of stress causes a disturbance in the utilization of ascorbic acid in the periphery and gives rise to a mobilization of the vitamin, which in turn causes a stagnation of the vitamin in the blood stream. The excess ascorbic acid is excreted in the urine resulting in the increase of urinary excretion of the vitamin.
3. When the animals had been allowed to inhale pure oxygen under normal pressure for two hours in order to replace nitrogen beforehand, and the similar decompression were loaded, they exhibited practically no abnormal symptoms. Ascorbic acid levels in the adrenals, liver, blood and urine showed 58.3, 62, 31 and 97.5% respectively as compared with that of the control groups, suggesting that the inhalation of pure oxygen prior to decompression not only prevents the formation of nitrogen bubbles and symptoms due to decompression, but also has a favorable influence on the oxidation of ascorbic acid in the peripheral tissues and enhances its utilization, thus increasing tolerance to low pressure.
