Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Tao-Yuan, TAIWAN.
Heart Failure Center, Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Keelung, TAIWAN.
Med Sci Sports Exerc. 2019 Jul;51(7):1404-1412. doi: 10.1249/MSS.0000000000001923.
Physical exercise or hypoxic exposure influences erythrocyte susceptibility to osmotic stress, and the aquaporin 1 (AQP1) facilitates the transport of water in erythrocytes. This study investigated whether high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) affect erythrocyte osmotic deformability by modulating AQP1 function under hypoxic stress.
Forty-five healthy sedentary males were randomized to engage in either HIIT (3-min intervals at 40% and 80% V˙O2 reserve, n = 15) or MICT (sustained 60% V˙O2 reserve, n = 15) on a bicycle ergometer for 30 min·d, 5 d·wk for 6 wk, or to a control group that did not perform any exercise (n = 15). All subjects were analyzed with osmotic gradient ektacytometry for assessing erythrocyte membrane stability and osmotic deformability after hypoxic exercise (HE) (100 W under 12%O2 for 30 min).
Before the intervention, HE increased the shear stress at 50% of maximal elongation (SS1/2) and the ratio of SS1/2 to maximal elongation index (SS1/2/EImax) on erythrocytes pretreated with 50 Pa of shear stress for 30 min and diminished HgCl2-depressed osmolality at 50%EImax (Ohyper). However, both HIIT and MICT for 6 wk diminished the elevations of erythrocyte SS1/2 and SS1/2/EImax caused by HE. Moreover, HIIT also increased contents of erythrocyte AQP1 proteins while enhancing HgCl2-depressed Ohyper and area under elongation index-osmolarity curve after HE. Additionally, changes in erythrocyte AQP1 contents were associated with changes in HgCl2-depressed erythrocyte Ohyper and area under elongation index-osmolarity curve.
Acute HE reduces erythrocyte membrane stability, whereas either HIIT or MICT attenuates the depression of erythrocyte membrane stability by HE. Moreover, HIIT increases the AQP1 content and facilitates the HgCl2-mediated osmotic deformability of erythrocytes after HE.
体育锻炼或低氧暴露会影响红细胞对渗透胁迫的敏感性，水通道蛋白 1（AQP1）促进红细胞内水的转运。本研究旨在探讨高强度间歇训练（HIIT）和中等强度持续训练（MICT）是否通过调节低氧应激下 AQP1 的功能来影响红细胞的渗透变形能力。
将 45 名健康的久坐男性随机分为 HIIT 组（3 分钟间隔，40%和 80%的最大摄氧量储备，n=15）、MICT 组（持续 60%的最大摄氧量储备，n=15）或对照组（不进行任何运动，n=15）。所有受试者均采用渗透梯度 ektacytometry 评估低氧运动（HE）（12%O2 下 100 W 运动 30 min）后红细胞膜稳定性和渗透变形能力。
在干预前，HE 增加了经 50 Pa 剪切力预处理 30 min 的红细胞的最大伸长率的 50%处的剪切应力（SS1/2）和 SS1/2 与最大伸长指数的比值（SS1/2/EImax），并降低了 HgCl2 抑制的 50%EImax 时的渗透压（Ohyper）。然而，6 周的 HIIT 和 MICT 均可降低 HE 引起的红细胞 SS1/2 和 SS1/2/EImax 的升高。此外，HIIT 还增加了红细胞 AQP1 蛋白的含量，同时增强了 HE 后 HgCl2 抑制的 Ohyper 和伸长指数-渗透压曲线下面积。此外，红细胞 AQP1 含量的变化与 HgCl2 抑制的红细胞 Ohyper 和伸长指数-渗透压曲线下面积的变化相关。
急性 HE 降低了红细胞膜的稳定性，而 HIIT 或 MICT 均可减轻 HE 引起的红细胞膜稳定性的降低。此外，HIIT 增加了 AQP1 的含量，并促进了 HE 后 HgCl2 介导的红细胞渗透变形能力。
