NT-ProBNP levels, water and sodium homeostasis in healthy men: effects of 7 days of dry immersion

作者：Navasiolava Nastassia M^*; Pajot Aurelie; Gallois Yves; Pastushkova Ludmila Kh; Kulchitsky Vladimir A; Gauquelin Koch Guillemette; Kozlovskaya Inesa B; Heer Martina; Hand Olga; Larina Irina M; Custaud Marc Antoine

来源：European Journal of Applied Physiology, 2011, 111(9): 2229-2237.

DOI：10.1007/s00421-011-1858-7

• Plasma volume
• Simulated weightlessness
• Natriuretic peptides
• Water immersion
• Body fluid regulation
• Deconditioning

Immersion is a useful tool for studying fluid-volume homeostasis. Natriuretic peptides play a vital role in renal, humoral, and cardiovascular regulation under changing environmental conditions. We hypothesized that dry immersion would rapidly induce a new steady state for water and sodium metabolism, and that serum NT-proBNP levels, a proxy measure for brain natriuretic peptide (BNP), would decrease during long-term dry immersion and increase during recovery. Eight healthy young men were studied before, during, and after 7 days of dry immersion. Body weight, water balance, and plasma volume changes were evaluated. Plasma and serum samples were analyzed for active renin, NT-proBNP, aldosterone, electrolytes, osmolality, total protein, and creatinine. Urine samples were analyzed to determine levels of electrolytes, osmolality, creatinine, and free cortisol. A stand test was performed before and after dry immersion to evaluate cardiovascular deconditioning. Long-term dry immersion induced acute changes in water and sodium homeostasis on day 1, followed by a new steady state. Plasma volume decreased significantly during dry immersion. The serum levels of NT-proBNP increased significantly in recovery (10 +/- 3 ng/L before dry immersion vs. 26 +/- 5 ng/L on the fourth recovery day). Heart rate in the standing position was significantly greater after immersion. Results suggest that chronic dry immersion rapidly induced a new level of water-electrolyte homeostasis. The increase in NT-proBNP levels during the recovery period may be related to greater cardiac work and might reflect the degree of cardiovascular deconditioning.

• 出版日期2011-9