Department of Aerospace Biodynamics, Fourth Military Medical University, Xi'an 710032, China.
Cytokine. 2011 Dec;56(3):648-55. doi: 10.1016/j.cyto.2011.09.004. Epub 2011 Oct 1.
Cardiovascular and musculoskeletal deconditioning occurring in long-term spaceflight requires new strategies to counteract these adverse effects. We previously reported that a short-arm centrifuge produced artificial gravity (AG), together with ergometer, has an approving effect on promoting cardiovascular function. The current study sought to investigate whether the cardiac and cerebrovascular functions were maintained and improved using a strategy of AG combined with exercise training on cardiovascular function during 4-day head-down bed rest (HDBR). Twelve healthy male subjects were assigned to a control group (CONT, n=6) and an AG combined with ergometric exercise training group (CM, n=6). Simultaneously, cardiac pumping and systolic functions, cerebral blood flow were measured before, during, and after HDBR. The results showed that AG combined with ergometric exercise caused an increase trend of number of tolerance, however, there was no significant difference between the two groups. After 4-day HDBR in the CONT group, heart rate increased significantly (59±6 vs 66±7 beats/min), while stroke volume (98±12 vs 68±13 mL) and cardiac output (6±1 vs 4±1 L/min) decreased significantly (p<0.05). All subjects had similar drops on cerebral vascular function. Volume regulating hormone aldosterone increased in both groups (by 119.9% in CONT group and 112.8% in the CM group), but only in the CONT group there were a significant changes (p<0.05). Angiotensin II was significantly increased by 140.5% after 4-day HDBR in the CONT group (p<0.05), while no significant changes were observed in the CM group. These results indicated that artificial gravity with ergometric exercise successfully eliminated changes induced by simulated weightlessness in heart rate, volume regulating hormones, and cardiac pumping function and partially maintained cardiac systolic function. Hence, a daily 1h alternating +1.0 and +2.0 Gz with 40 W exercise training appear to be an effective countermeasure against cardiac deconditioning.
心血管和肌肉骨骼去适应在长期太空飞行中发生，需要新的策略来对抗这些不利影响。我们之前报道过，短臂离心机产生人工重力（AG），再加上测力计，对促进心血管功能有积极作用。本研究旨在探讨在 4 天的头低位卧床休息（HDBR）期间，使用 AG 结合运动训练来维持和改善心血管功能时，心脏和脑血管功能是否得到维持和改善。12 名健康男性受试者被分为对照组（CONT，n=6）和 AG 结合测力计运动训练组（CM，n=6）。同时，在 HDBR 前后测量了心脏泵血和收缩功能、脑血流。结果表明，AG 结合测力计运动引起了耐受次数的增加趋势，但两组之间没有显著差异。在 CONT 组的 4 天 HDBR 后，心率显著增加（59±6 比 66±7 次/分钟），而每搏量（98±12 比 68±13 毫升）和心输出量（6±1 比 4±1 升/分钟）显著降低（p<0.05）。所有受试者的脑血管功能都有类似的下降。两组的容量调节激素醛固酮均增加（CONT 组增加 119.9%，CM 组增加 112.8%），但仅 CONT 组有显著变化（p<0.05）。CONT 组在 4 天 HDBR 后血管紧张素 II 显著增加 140.5%（p<0.05），而 CM 组无明显变化。这些结果表明，人工重力结合测力计运动成功消除了模拟失重引起的心率、容量调节激素和心脏泵血功能的变化，并部分维持了心脏收缩功能。因此，每天 1 小时交替+1.0 和+2.0 Gz 与 40 W 运动训练似乎是对抗心脏去适应的有效对策。
