LIMITING FACTORS TO OXYGEN-TRANSPORT ON MOUNT EVEREST
LIMITING FACTORS TO OXYGEN-TRANSPORT ON MOUNT EVEREST
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DOI：
10.1152/jappl.1976.40.5.658
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发表时间：
1976-01-01
影响因子：
3.3
通讯作者：
CERRETELLI, P
中科院分区：
文献类型：
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作者：
CERRETELLI, P
本文对23名高原适应者（海拔5350-8848 m）在4个月内突然增加吸入氧分压对最大有氧运动能力的影响进行了研究。远征山。珠峰。在390 mmHg下吸入100%O2或通过直升机快速下降（20分钟）至2850 m（PIO 2 = 117 mmHg）将最大O2消耗（≥ VO 2 max）从对照海平面值的平均0.7分别升高至0.92和0.97。在血液Hb浓度增加40%和最大心输出量（≥ Qmax）有限减少的情况下，适应环境的受试者在呼吸O2时未能显著增加或甚至恢复预先存在的海平面≥ VO 2 max，这归因于外周循环的变化。这些可能包括由于红细胞堆积继发于血细胞比容增加（Hct高达70%）而导致的O2扩散障碍，以及来自身体高阻力工作区域的动脉血旁路，旨在减少由血液粘度增加引起的心脏负荷。11.6%以上的正常对照组的Hb浓度增加仍然发现在13名受试者离开海拔25天后，并没有显着增加最大耗氧量。
The effect of a sudden increase of the inspired O2 tension on the maximal aerobic performance was studied on 23 subjects acclimated to high altitude (5350-8848 m above sea level) in the course of a 4 mo. expedition to Mt. Everest. Inhalation of 100% O2 at 390 mmHg or a rapid descent (20 min) by helicopter to 2850 m (PIO2 = 117 mmHg) raised maximal O2 consumption (.ovrhdot.VO2 max) from an average 0.7 of the control sea-level value, respectively, to 0.92 and 0.97. The failure of acclimated subjects to increase markedly or even to resume the preexisting sea-level .ovrhdot.VO2 max while breathing O2 in the presence of a 40% increase of blood Hb concentration and of a limited reduction of maximal cardiac output (.ovrhdot.Qmax), is attributed to changes in the peripheral circulation. These may consist from a hindrance of O2 diffusion due to erythrocytes packing secondary to increase hematocrit (Hct up to 70% and a bypass of arterial blood from the high-resistance working areas of the body aimed at reducing the load on the heart caused by increased blood viscosity. A 11.6% increase above normal controls of Hb concentration still found in 13 subjects 25 days after leaving altitude does not increase significantly maximum O2 consumption.