ENDOCRINE HOMEOSTASIS IN DOGS UNDER NONHYPOXIC-HYPOBARIC CONDITIONS.
Abstract
Plasma insulin concentration, 17-hydroxycorticosteroid (17-OHCS) secretion rate, and norepinephrine (NE) secretion were studied in dogs anesthetized with sodium pentobaribital and exposed to 100% oxygen at 259 torr. The 17-OHCS secretion rate was also studied in dogs breathing 100% oxygen at 760 torr. The secretion rates of NE and 17-OHCS were estimated by direct measurements on blood collected from a cannula inserted into the left lumboadrenal vein of each dog. No change was detected in plasma insulin concentration. Slight increases in NE secretion were noted in 2 of 3 dogs exposed to the low pressure. The secretion rate of 17-OHCS increased to about 25% of maximum values during exposure to 100% oxygen at 760 torr and at 259 torr. However, the values over time were different for the two pressures. Peak 17-OHCS secretion occurred after 15 minutes at 259 torr (90 minutes on 100% oxygen), but not until 135 minutes on oxygen at 760 torr. This indicates that dogs may be mildly stressed by breathing 100% oxygen and that there is a stress associated with hypobarism that cannot be attributed to hypoxia. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1969
- Accession Number
- AD0702156
Entities
People
- Gordon L. Coppoc
- Shelton J. Leger
Organizations
- United States Air Force School of Aerospace Medicine