Cardiovascular response to submaximal exercise in sustained microgravity.
Cardiovascular response to submaximal exercise in sustained microgravity.
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DOI：
10.1152/jappl.1996.81.1.26
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发表时间：
1996-07
影响因子：
3.3
通讯作者：
B. Shykoff;L. Farhi;A. Olszowka;D. Pendergast;M. Rokitka;C. Eisenhardt;R. Morin
中科院分区：
文献类型：
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作者：
B. Shykoff;L. Farhi;A. Olszowka;D. Pendergast;M. Rokitka;C. Eisenhardt;R. Morin
在微重力暴露期间，对六名受试者在休息和两种运动水平下重复测量心输出量 (Q)、心率 (HR)、血压和耗氧量 (VO2)。锻炼量为工作负荷的 30% 和 60%，产生 1 G 的最大摄氧量。其中三名受试者参加了为期 9 天的飞行，Spacelab Life Sciences-1，三名受试者参加了为期 15 天的飞行，Spacelab Life Sciences-2。我们在飞行过程中没有发现时间差异。因此，我们结合了所有微重力测量值，将飞行中的值与直立或仰卧的控制值进行比较。休息时，飞行中的 Q 为直立 Q 的 126%（P < 0.01），但与仰卧 Q 没有差异，飞行中的 HR 为直立 HR 的 81%（P < 0.01）和仰卧 HR 的 91%（P < 0.05）。因此，飞行中的静息每搏输出量 (SV) 为直立 SV 的 155%（P < 0.01）和仰卧 SV 的 109%（P < 0.05）。飞行时的静息平均动脉压和舒张压低于直立时的平均动脉压和舒张压（P < 0.05）。运动值被认为是摄氧量的函数。飞行中 VO2 导致的 Q 值增加小于 1 G 时的值（斜率 3.5 与 6.1 x min-1.l-1.min-1）。飞行时的 SV 随着摄氧量的增加而下降，而直立时的 SV 上升，仰卧时的 SV 保持不变。飞行时、直立或仰卧时，血压对运动的反应没有什么不同。我们得出的结论是，真正的微重力引起的心血管反应不同于任何假定模拟中所看到的反应。
Cardiac output (Q), heart rate (HR), blood pressure, and oxygen consumption (VO2) were measured repeatedly both at rest and at two levels of exercise in six subjects during microgravity exposure. Exercise was at 30 and 60% of the workload producing the individual's maximal VO2 in 1 G. Three of the subjects were on a 9-day flight, Spacelab Life Sciences-1, and three were on a 15-day flight, Spacelab Life Sciences-2. We found no temporal differences during the flights. Thus we have combined all microgravity measurements to compare in-flight values with erect or supine control values. At rest, Q in flight was 126% of Q erect (P < 0.01) but was not different from Q supine, and HR in flight was 81% of HR erect (P < 0.01) and 91% of HR supine (P < 0.05). Thus resting stroke volume (SV) in flight was 155% of SV erect (P < 0.01) and 109% SV supine (P < 0.05). Resting mean arterial blood pressure and diastolic pressure were lower in flight than erect (P < 0.05). Exercise values were considered as functions of VO2. The increase in Q with VO2 in flight was less than that at 1 G (slope 3.5 vs. 6.1 x min-1.l-1.min-1). SV in flight fell with increasing VO2, whereas SV erect rose and SV supine remained constant. The blood pressure response to exercise was not different in flight from erect or supine. We conclude that true microgravity causes a cardiovascular response different from that seen during any of its putative simulations.