拉萨世居藏族青年的最大氧摄取和氧转运功能

MAXIMAL OXYGEN UPTAKE AND OXYGEN TRANSPORT SYSTEM IN TIBETAN NATIVES

对拉萨市(海拔3658m)16名世居藏族和20名已习服的移居汉族健康青年男性的最大氧摄取、最大运动负荷及其影响因素进行了对此研究。结果发现在最大努力作功时,藏族的最大氧摄取量、最大运动负荷量、潮气量、肺通气量以及氧脉搏等均大于移居汉族。说明西藏高原世居藏族具有更佳的氧转运功能,对高原低氧已获得了良好的生理适应。

16 Tibetan lifelong residents of Lasha, Tibet (3658 m), and 20 Han residents (8± 1 years of residence) of the same altitude were studied. They were matched for age, height, weight and lack of exercise training. At maximal effort, the Tibetans had greater O2 uptake (51 ± 1 vs 46 ± 1 ml STPDmin-1 · kg-1, P<0.05), maximal exercise workload (177± 5 vs 155± 6 W, P<0.05), minute ventilation (149± 6 vs 126± 4 L BTPS/min, P<0.01) and O2 pulse (15.2± 0.4 vs 13.3± 0.5 ml/ beat, P<0.05) as compared with the Hans. Equally high heart rates were present at maximal effort (191 ± 3 vs 187 ± 3 beats/min), supporting that true maximal work load was achieved in both groups. The greater minute ventilation in the Tibetans resulted from greater tidal volume and greater maximal tidal volume correlated positively with greater resting vital capacity. It is concluded that the Tibetans achieve a higher maximal O2 uptake than the Hans, implying an increased capacity for O2 transport to the working muscle.