Metabolic and osmoregulatory function at low and high (3800 m) altitude
Article first published online: 10 JUN 2010
© 2002 EVJ Ltd
Equine Veterinary Journal
Volume 34, Issue S34, pages 545–550, September 2002
How to Cite
GREENE, H. M., COGGER, E. A., MILTENBERGER, T. L., KOCH, A. K., BRAY, R. E. and WICKLER, S. J. (2002), Metabolic and osmoregulatory function at low and high (3800 m) altitude. Equine Veterinary Journal, 34: 545–550. doi: 10.1111/j.2042-3306.2002.tb05480.x
- Issue published online: 10 JUN 2010
- Article first published online: 10 JUN 2010
Altitude evokes physiological adjustments that include not only respiratory and cardiovascular properties, but also metabolic function, renal and endocrine responses. The purpose of the present study was designed to expand our understanding of the physiological process involved with acclimatisation to high altitude in equids. The study examined temporal effects on metabolic and osmoregulatory function in horses (n = 6) at rest and postexercise at 3800 m. Animals were studied at 225 m (Pb = 743 mmHg) and during a 10 day stay at altitude (Pb = 487 mmHg). Rest samples were taken 90 min postprandial at 0830 h and immediately after the gallop phase of a standard exercise test. Changes in glucose, insulin, cortisol, thyroxine, sodium, potassium, chloride and total protein were assessed at both altitudes. Exercise stimulated increases in cortisol, thyroxine, potassium, and chloride; while the concentrations of glucose, insulin, sodium and total protein (regardless of altitude) decreased. Acute (Day 2) altitude exposure (following transport stress) produced significant increases in glucose, cortisol, thyroxine, chloride and protein at rest and exercise. All variables (except cortisol) appeared to stabilise by Day 4 of altitude exposure.
Observations from these data (coupled with haematological and blood gases data) indicate that equids acutely acclimate within 2–3 days to this altitude.