Heer M, Elia M, Ritz P
German Aerospace Center (Deutschen Zentrum für Luft und Raumfahrt), Institute of Aerospace Medicine, Cologne, Germany.
Curr Opin Clin Nutr Metab Care. 2001 Jul;4(4):307-11. doi: 10.1097/00075197-200107000-00011.
Astronauts lose body mass when exploring space. The mechanism was considered to be an upward fluid shift inducing diuresis and natriuresis (the Henry-Gauer mechanism) during the first few days in microgravity. However, recent space missions have shown that neither diuresis nor natriuresis occurs in space missions. In contrast, a sodium-retaining status was shown, which led to positive metabolic sodium balances without fluid retention. Energy intake was consistently reduced whereas energy needs were unchanged, resulting in a negative energy balance of 20%. The reasons for this are many, although proper studies on appetite regulation have not been carried out. Despite numerous countermeasures, bone mass is lost in microgravity situations. These are body composition changes that need to be challenged before humans can be sent to space for extra-long missions.
宇航员在探索太空时会体重减轻。该机制曾被认为是在微重力环境下的最初几天，体液向上转移引发利尿和利钠作用（亨利 - 高尔机制）。然而，近期的太空任务表明，太空任务中既不会出现利尿也不会出现利钠现象。相反，出现了钠潴留状态，这导致代谢性钠平衡为正且无液体潴留。能量摄入持续减少，而能量需求不变，导致能量负平衡达20%。尽管尚未对食欲调节进行恰当研究，但造成这种情况的原因有很多。尽管采取了诸多应对措施，在微重力环境下骨质仍会流失。这些身体成分的变化在人类能够被送往太空执行超长任务之前需要加以应对。
