Erythropoietin under real and simulated microgravity conditions in humans.
Erythropoietin under real and simulated microgravity conditions in humans.
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人类真实和模拟微重力条件下的促红细胞生成素。
DOI：
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发表时间：
1996
影响因子：
3.3
通讯作者：
L. Röcker
中科院分区：
文献类型：
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作者：
H. Gunga;K. Kirsch;F. Baartz;A. Maillet;C. Gharib;W. Nalishiti;I. Rich;L. Röcker
这项研究的目的是分析在地面微重力模拟过程中促红细胞生成素的时程，如卧床休息、隔离和禁闭、头低位倾斜（HDT; -6度）和浸泡，以评估哪些因素可能导致短期（< 10天）和长期（> 6个月）航天飞行期间和之后在真实的微重力条件下促红细胞生成素的变化。在卧床休息期间（24小时），未观察到EPO的显著变化。受试者被限制在一个潜水室设施60天显示出减少EPO。在恢复期，观察到略微增加，但EPO浓度未达到IC前对照水平。在对照期，HDT前EPO水平正常，HDT第2天EPO水平下降（P < 0.01）。以后EPO水平仍低于对照值，而在HDT后升高（P < 0.05）。浸泡24 h后，EPO浓度明显升高（P < 0.05）。在短期的太空飞行中，宇航员在飞行中（第4天）显示EPO浓度下降和不变。在长期的太空飞行中，恢复后24小时，宇航员显示EPO浓度略有升高，在接下来的几天里明显增加。得出的结论是：1）HDT（-6度）导致人体EPO快速下降，2）IC本身导致EPO浓度降低，3）短期和长期太空飞行期间人体EPO调节可能不同，4）中心血容量的变化，即，中心静脉压似乎参与了模拟和真实的微重力条件下EPO产生和释放的调节，以及5）HDT（-6度）地球模拟主要反映了在人体中真实的微重力条件下观察到的EPO产生和释放的变化。
The aim of this study was to analyze the time course of erythropoietin (EPO) during Earth-bound microgravity simulations such as bed rest, isolation and confinement (IC), head-down tilt (HDT; -6 degrees), and immersion to evaluate which factors could contribute to alterations in EPO under real microgravity conditions during and after short- (< 10 days) and long-term (> 6 mo) spaceflights. During bed rest (24h), no significant changes in EPO could be observed. Subjects confined in a diving chamber facility for 60 days showed a decrease in EPO. In the recovery period a slight increase was observed, but EPO concentrations did not reach the pre-IC control level. In the control period before HDT, subjects showed normal resting values for EPO, but on day 2 of HDT the EPO concentrations were decreased (P < 0.01). Later the EPO levels remained below the control value and were increased after HDT (P < 0.05). After immersion (24 h) increased EPO concentrations could be determined (P < 0.05). During a short-term spaceflight the astronauts showed in-flight (day 4) decreased and unchanged EPO concentrations. During a long-term spaceflight, 24 h after recovery, the cosmonaut showed slightly elevated EPO concentration, which increased markedly during the following days. It is concluded that 1) HDT (-6 degrees) causes a rapid decrease in EPO in humans, 2) IC per se leads to diminished EPO concentrations, 3) EPO regulation in humans during short- and long-term spaceflights might be different, 4) changes in central blood volume, i.e., central venous pressure, seem to be involved in the modulation of EPO production and release under simulated and real microgravity conditions, and 5) the HDT (-6 degrees) Earth-bound simulation reflects mostly the changes in EPO production and release observed under real microgravity conditions in humans.