1 Ecotechnology and Sustainable Building, Mid Sweden University , Östersund, Sweden .
High Alt Med Biol. 2014 Apr;15(1):52-7. doi: 10.1089/ham.2013.1061.
Release of stored red blood cells resulting from spleen contraction improves human performance in various hypoxic situations. This study determined spleen volume resulting from two contraction-evoking stimuli: breath holding and exercise before and after altitude acclimatization during a Mount Everest ascent (8848 m). Eight climbers performed the following protocol before and after the climb: 5 min ambient air respiration at 1370 m during rest, 20 min oxygen respiration, 20 min ambient air respiration at 1370 m, three maximal-effort breath holds spaced by 2 min, 10 min ambient air respiration, 5 min of cycling at 100 W, and finally 10 min ambient air respiration. We measured spleen volume by ultrasound and capillary hemoglobin (HB) concentration after each exposure, and heart rate (HR) and arterial oxygen saturation (Sao2) continuously. Mean (SD) baseline spleen volume was unchanged at 213 (101) mL before and 206 (52) mL after the climb. Before the climb, spleen volume was reduced to 184 (83) mL after three breath holds, and after the climb three breath holds resulted in a spleen volume of 132 (26) mL (p=0.032). After exercise, the preclimb spleen volume was 186 (89) mL vs. 112 (389) mL) after the climb (p=0.003). Breath hold duration and cardiovascular responses were unchanged after the climb. We concluded that spleen contraction may be enhanced by altitude acclimatization, probably reflecting both the acclimatization to chronic hypoxic exposure and acute hypoxia during physical work.
储存的红细胞从脾脏收缩中释放出来，可以改善人体在各种缺氧情况下的表现。本研究确定了两种引起收缩的刺激导致的脾脏体积：登珠穆朗玛峰（8848 米）期间的高空适应前和后的屏息和运动。在攀登前后，8 名登山者进行了以下方案：在海拔 1370 米的环境空气中休息 5 分钟，在海拔 1370 米的环境空气中呼吸 20 分钟，在海拔 1370 米的环境空气中呼吸 20 分钟，3 次最大努力的屏气，每次屏气间隔 2 分钟，10 分钟的环境空气呼吸，10 分钟的 100W 自行车骑行，最后是 10 分钟的环境空气呼吸。我们在每次暴露后通过超声和毛细血管血红蛋白（HB）浓度测量脾脏体积，并连续测量心率（HR）和动脉血氧饱和度（Sao2）。平均（SD）基线脾脏体积在攀登前后分别为 213（101）mL 和 206（52）mL 不变。在攀登前，三次屏气后脾脏体积减少到 184（83）mL，而在攀登后，三次屏气后脾脏体积减少到 132（26）mL（p=0.032）。运动后，攀登前的脾脏体积为 186（89）mL，而攀登后的脾脏体积为 112（38）mL（p=0.003）。攀登后屏气持续时间和心血管反应没有变化。我们得出结论，脾脏收缩可能通过高空适应增强，可能反映了慢性低氧暴露和体力工作期间急性缺氧的适应。
