Water and Electrolyte Exchange during Exposure to Cold, Altitude and Combined Cold and Altitude
Final rept. 1975-1981
FLORIDA UNIV GAINESVILLE DEPT OF PHYSIOLOGY
Pagination or Media Count:
Exposure of rats to air at 5 C for 1 to 12 days is accompanied by a relative dehydration in spite of the continued presence of water. Dehydration was manifested by a a reduction in the ration of waterfood ingested b an increase in the ratio of urine excretedwater ingested c an increased evaporative water loss d an increased serum osmolality and chloride concentration and c a striking thirst and ingestion of water following transfer from cold to air at 26 C. Drinking began within 15 minutes and lasted approximately 1 hour. Thermogenic drinking persisted for at least 120 days of exposure to cold. It was not thwarted by preventing access to water for either 1 or 2 hours following transfer to warm air, but either intragastric or intraperitoneal administration of a water load equal to 3 of body weight inhibited water intake following transfer. Rats exposed chronically to hypoxia 12 oxygen in nitrogen became dehydrated. They decreased their water intake below prehypoxic control levels during the first 2 weeks of exposure but gradually returned water intake to control level by the 4th week of exposure. In contrast, daily urinary output was uninfluenced by hypoxia.
- Stress Physiology