SUMMARY
1. Four men and three women ascended by télépherique and helicopter from 1000 to 4333 m. where they remained for 23 days.
2. Measurements of urinary 17-hydroxycorticosteroids, 17-oxosteroids, pregnanediol and pregnanetriol and circulating eosinophils were made at sea level and at high altitude.
3. An attempt was also made to measure changes in emotional activity by means of the palmar sweat index (PSI). This index was assessed at intervals throughout the day at sea level and at high altitude, and in response to adrenocorticotrophic hormone (ACTH) and a self-imposed stress.
4. Within 24 hr. of acute exposure to high altitude urinary 17-hydroxycorticosteroids increased whilst circulating eosinophils decreased; by the 5th day both were returning to sea-level values. The output of 17-oxosteroids was lower by the 5th day at high altitude and subsequently increased; pregnanediol and pregnanetriol levels remained unchanged.
5. PSIs throughout the day become progressively lower as the length of stay at altitude increased. The response to ACTH at sea level and high altitude appeared to be similar but the response to a self-imposed stress was longer in duration at high altitude than at sea level.
Structural and Functional Changes of the Human Macula during Acute Exposure to High Altitude
