Effects of 6 hours hypoxic and cold exposure on urinary electrolyte and catecholamine excretion

Eleven young male Indian volunteers fasted overnight and were exposed to 6 h to cold at 8 degrees C (I), hypoxia at 4267 m at 28 degrees C (II), and cold plus hypoxia of 4267 m at , degrees C (III), in a walk-in climatic chamber, and excretion of some urinary constituents was measured. Urine output was significantly decreased in (II) and increased in (I) and (III). Urine pH significantly increased only in (II). Catecholamine excretion significantly increased only in (I). Ca++ excretion was significantly raised in (I) and (III) and lowered in (II). Na+ excretion was significantly decreased and K+ excretion remained unchanged in all three stress conditions. Cold seemed to be a greater stressor than hypoxia, under stated experimental conditions.