Accession Number : AD0702156

Title :   ENDOCRINE HOMEOSTASIS IN DOGS UNDER NONHYPOXIC-HYPOBARIC CONDITIONS.

Descriptive Note : Final rept. Feb-Oct 69,

Corporate Author : SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX

Personal Author(s) : Coppoc,Gordon L. ; Leger,Shelton J.

Report Date : DEC 1969

Pagination or Media Count : 12

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)

Descriptors :   (*HORMONES, LOW PRESSURE), (*SECRETION, LOW PRESSURE), ALTITUDE, ENDOCRINE GLANDS, INSULIN, LEVARTERENOL, OXYGEN, BIOCHEMISTRY, DOGS

Subject Categories : Biochemistry
      Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE