Long-Term Space Flight Simulation Reveals Infradian Rhythmicity in Human Na+ Balance
Long-Term Space Flight Simulation Reveals Infradian Rhythmicity in Human Na+ Balance
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DOI：
10.1016/j.cmet.2012.11.013
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发表时间：
2013-01-08
期刊：
影响因子：
29
通讯作者：
Titze, Jens
中科院分区：
文献类型：
--
作者：
Rakova, Natalia;Juettner, Kathrin;Titze, Jens
基于对高盐摄入反应的短期调查，Na+稳态的概念认为，饮食中的Na+被迅速排除到尿液中，从而达到恒定的全身Na+和水分含量。我们引入了反向实验方法，将参加太空飞行模拟的男性的盐摄入量固定在12克、9克和6克/天，持续数月，并测试尿排泄和全身Na+含量的预测稳定性。在恒定的盐摄入量下，每日Na+排泄表现出醛固酮依赖性，每周（circaseptan）节律，导致周期性Na+储存。全身Na+ (+/- 200-400 mmol)的变化表现出更长的次周期（大约每月和更长的周期长度），而体重和细胞外水没有平行变化，与尿醛固酮排泄直接相关，与尿皮质醇排泄成反比，提示有节奏的激素控制。我们的研究结果定义了独立于血压或身体水分的有节奏的Na+排泄和保留模式，这与盐的摄入无关。
The steady-state concept of Na+ homeostasis, based on short-term investigations of responses to high salt intake, maintains that dietary Na+ is rapidly eliminated into urine, thereby achieving constant total-body Na+ and water content. We introduced the reverse experimental approach by fixing salt intake of men participating in space flight simulations at 12 g, 9 g, and 6 g/day for months and tested for the predicted constancy in urinary excretion and total-body Na+ content. At constant salt intake, daily Na+ excretion exhibited aldosterone-dependent, weekly (circaseptan) rhythms, resulting in periodic Na+ storage. Changes in total-body Na+ (+/- 200-400 mmol) exhibited longer infradian rhythm periods (about monthly and longer period lengths) without parallel changes in body weight and extracellular water and were directly related to urinary aldosterone excretion and inversely to urinary cortisol, suggesting rhythmic hormonal control. Our findings define rhythmic Na+ excretory and retention patterns independent of blood pressure or body water, which occur independent of salt intake.