Møller Kirsten, Paulson Olaf B, Hornbein Tom F, Colier Wil N J M, Paulson Anna S, Roach Robert C, Holm Søren, Knudsen Gitte Moos
Department of Infectious Diseases, National University Hospital Rigshospitalet, Copenhagen, Denmark.
J Cereb Blood Flow Metab. 2002 Jan;22(1):118-26. doi: 10.1097/00004647-200201000-00014.
The authors investigated the effect of acclimatization to high altitude on cerebral blood flow and oxidative metabolism at rest and during exercise. Nine healthy, native sea-level residents were studied 3 weeks after arrival at Chacaltaya, Bolivia (5,260 m) and after reacclimatization to sea level. Global cerebral blood flow at rest and during exercise on a bicycle ergometer was measured by the Kety-Schmidt technique. Cerebral metabolic rates of oxygen, glucose, and lactate were calculated by the Fick principle. Cerebral function was assessed by a computer-based measurement of reaction time. At high altitude at rest, arterial carbon dioxide tension, oxygen saturation, and oxygen tension were significantly reduced, and arterial oxygen content was increased because of an increase in hemoglobin concentration. Global cerebral blood flow was similar in the four conditions. Cerebral oxygen delivery and cerebral metabolic rates of oxygen and glucose also remained unchanged, whereas cerebral metabolic rates of lactate increased slightly but nonsignificantly at high altitude during exercise compared with high altitude at rest. Reaction time was unchanged. The data indicate that cerebral blood flow and oxidative metabolism are unaltered after high-altitude acclimatization from sea level, despite marked changes in breathing and other organ functions.
作者研究了从海平面适应高海拔环境对静息及运动时脑血流量和氧化代谢的影响。对9名健康的、来自海平面的本地居民进行了研究，他们抵达玻利维亚查卡尔塔亚（海拔5260米）3周后以及重新适应海平面后接受了研究。采用凯蒂-施密特技术测量静息及在自行车测力计上运动时的全脑血流量。通过菲克原理计算脑氧、葡萄糖和乳酸的代谢率。通过基于计算机的反应时间测量来评估脑功能。在高海拔静息状态下，动脉二氧化碳分压、氧饱和度和氧分压显著降低，由于血红蛋白浓度增加，动脉氧含量升高。在四种情况下，全脑血流量相似。脑氧输送以及脑氧和葡萄糖的代谢率也保持不变，而与高海拔静息时相比，高海拔运动时脑乳酸代谢率略有增加但无显著差异。反应时间未变。数据表明，尽管呼吸和其他器官功能发生了显著变化，但从海平面适应高海拔环境后，脑血流量和氧化代谢并未改变。
