Adaptative processes in the albino rat raised under hypoxia at simulated altitude.

Albino rats of the Wistar family were raised from the time of birth in a simulated altitude of about 6000 meters (barometric pressure 370 mm Hg) for a period of about 50 days. Part of these were killed after losing consciousness upon exposure to acute hypoxia. The other groups were killed without being first subjected to acute hypoxia. Control groups of the some stock were raised for a corresponding period of time in a normal atmosphere at sea level and killed like the preceding. We were not able to demonstrate significant variations in tolerance to acute hypoxia in the various groups studied. Instead the animals raised in a simulated altitude displayed an increase in the 2,3-DPG content in the red blood cells, Hb concentration and the number of erythrocytes for mm3 of blood. The animals raised in a simulated altitude also displayed a displacement of the acid-base balance of blood towards the acid side. This was even more accentuated in the group subjected to acute hypoxia. Finally, it was observed, via the weight curve, that the animals raised in a simulated altitude presented a slower body growth in comparison to the control group.