人工重力联合运动锻炼对4d头低位卧床期间心血管功能的影响

Effects of Artificial Gravity Combined with Ergometric Exercise on Cardiovascular Function during 4 d Head-down Bed Rest

目的利用头低位卧床模拟失重模型，观察人工重力联合运动锻炼对抗短期模拟失重致心血管功能失调的作用效果。方法12名男性受试者随机平均分为两组：对照组和对抗组。对照组仅进行4d头低位卧床，对抗组利用SAC—Ⅱ型短臂离心机在卧床期间每天进行1h梯度（1～2G）人工重力联合40w运动锻炼。所有受试者卧床前后进行立位耐力、心脏泵血与收缩功能、最大工作负荷（PWC170）、胭静脉顺应性测试。结果与卧床前相比，对照组卧床后立位耐力、心脏泵血与收缩功能、PWC170显著降低（P〈0．05），胭静脉横截面积及顺应性显著升高（P〈0．05）。对抗组上述参数在卧床前后无明显变化。结论4d头低位卧床可导致心脏泵血和收缩功能降低，运动耐力下降以及下肢静脉顺应性明显升高。每天1h梯度（1～2G）人工重力联合40w运动锻炼能够有效维持头低位卧床期间心脏泵血和收缩功能、运动耐力以及静脉顺应性。

Objective Using head-down best rest model, to explore the changes of cardiovascular function dur- ing short-term simulated weightlessness after artificial gravity training combined with ergometric exercise. Methods Twelve male subjects were randomly divided into two groups： control group and countermeasure group. The subjects in control group executed head-down bed rest （HDBR） for 4 d. The countermeasure group trained with daily 1 h gradient （ 1 - 2 G） artificial gravity combined with 40 W ergometric exercise during HDBR using SAC- Ⅱ type of short-arm centrifuge. Orthostatie tolerance, cardiac pump and systolic func- tion, PWC170, and popliteal vein compliance were measured after HDBR. Results Compared with pre-HDBR, orthostatic tolerance, cardiac pump and systolic function, PWC170 in control group significantly decreased after HDBR（P 〈0.05）, while popliteal vein cross-sectional area and venous compliance increased significantly（P 〈 0.05 ）. There were no significant changes in countermeasure group after HDBR. Conclusion HDBR for 4 d can lead a significant decrease in cardiac pump and systolic function, aerobic exercise tolerance and increase in venous compliance, while these parameters remain unchanged due to daily 1 h gradient （1 -2 G） artificial gravity combined with 40 W ergometric exercise.