Abstract
Abstract
An increased and more effective microvascular perfusion is postulated to play a key role in the physiological adaptation of Sherpa highlanders to the hypobaric hypoxia encountered at high altitude. To investigate this, we used Lempel-Ziv complexity (LZC) analysis to explore the spatiotemporal dynamics of the variability of the skin microvascular blood flux (BF) signals measured at the forearm and finger, in 32 lowlanders (LL) and 46 Sherpa highlanders (SH) during the Xtreme Everest 2 expedition. Measurements were made at baseline (BL) (LL: London 35 m; SH: Kathmandu 1300 m) and at Everest base camp (LL and SH: EBC 5,300 m). We found that BF signal content increased with ascent to EBC in both SH and LL. At both altitudes, LZC of the BF signals was significantly higher in SH, and was related to local slow-wave flow-motion activity over multiple spatial and temporal scales. In SH, BF LZC was also positively associated with LZC of the simultaneously measured tissue oxygenation signals. These data provide robust mechanistic information of microvascular network functionality and flexibility during hypoxic exposure on ascent to high altitude. They demonstrate the importance of a sustained heterogeneity of network perfusion, associated with local vaso-control mechanisms, to effective tissue oxygenation during hypobaric hypoxia.
Publisher
Springer Science and Business Media LLC
Reference53 articles.
1. Gilbert-Kawai, E. T., Milledge, J. S., Grocott, M. P. & Martin, D. S. King of the mountains: Tibetan and Sherpa physiological adaptations for life at high altitude. Physiology (Bethesda). 29(6), 388–402 (2014).
2. Beall, C. M. et al. Hemoglobin concentration of high-altitude Tibetans and Bolivian Aymara. Am. J. Phys. Anthropol. 106(3), 385–400 (1998).
3. Samaja, M., Veicsteinas, A. & Cerretelli, P. Oxygen affinity of blood in altitude Sherpas. J Appl. Physiol.Respir. Environ. Exerc. Physiol. 47(2), 337–341 (1979).
4. Wu, T. & Kayser, B. High altitude adaptation in Tibetans. High. Alt. Med. Biol. 7(3), 193–208 (2006).
5. Martin, D. S. et al. Changes in sublingual microcirculatory flow index and vessel density on ascent to altitude. Exp. Physiol. 95, 880–891 (2010).
Cited by
7 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献