Physiological changes induced by pre-adaptation to high altitude.

摘要: To study the physiological effects of pre-adaptation to high altitude, seven subjects were submitted acclimatization at 4350 m followed by intermittent acclimation in a low barometric pressure chamber (5000 8500 m). The then spent 25 days Himalayas. Ventilatory and cardiac responses studied during hypobaric poikilocapnic hypoxic test performed both rest exercise (100 W) normoxia hypoxia (barometric pressure: 589 hPa, altitude: 4500 Haemoglobin, erythrocytes, reticulocytes, packed cell volume, 2,3-diphosphoglycerate (2,3-DPG) erythropoietin (EPO) measured. All variables before altitude (A), after period (B), (C) expedition (D). ventilatory characterized an increased tidal volume (+ 33% B,P < 0.05; + 100% C,P 0.05) without any change respiratory frequency, whereas systolic blood was only observed C [+23 mmHg (3.07 kPa),P<0.01]. Arterial O2 saturation higher D, (+8.2% +4.7%,P<0.01, respectively), (+6.3% +6.3%,P<0.01, respectively). Erythrocytes, haemoglobin did not vary significantly. number reticulocytes B (+172%,P<0.05) (+249%,P<0.05). EPO 2,3-DPG 770%,P<0.01 +23%,P<0.05, These results showed that combination continuous pre-acclimatization on Mont Blanc triggered efficient mechanisms allowing climbers save 1 2 weeks mountain clinical inconvenience.