Original Investigations: Pathogenesis and Treatment of Kidney Disease and HypertensionLong-term sodium balance in humans in a terrestrial space station simulation study*,**,★,★★
Section snippets
Subjects and environmental conditions
During HUBES, three male subjects were isolated over a period of 135 days. Two subjects (no. 002 and 003) were trained cosmonauts, and successful participation in the isolation study would qualify them for a space flight. According to body mass index, subject 004 was marginally underweight, whereas subjects 002 and 003 were of normal body mass index (Table 1).
The isolation study was conducted at the Institute for Biomedical Problems in Moscow and approved by several ethical boards of the
BW and body composition
Figure 1 shows changes in BW over the entire isolation period. Descriptives are listed in Table 1. BW increased substantially in all subjects, at least initially, but eventually tended to remain stable in all subjects. Figure 2 shows changes in body composition.
Discussion
We determined long-term sodium balances to investigate whether infradian oscillations in TBS content exist in humans. In addition to such hypothetical oscillations, subjects showed an unexpected excessive sodium accumulation. TBS content in humans is estimated at 55 to 60 mmol/kg BW.14, 15 If this held true, sodium accumulation in subject 004 almost tripled his TBS content from presumed normal values to far beyond the norm. Excessive positive sodium balances toward the end of isolation give
Acknowledgements
The authors thank the three confined crew members for their cooperation during confinement, training, and control periods; R. Ziegler, for curve fitting; J. Nurrish-Weiß, for help with the text; and F.C. Luft, for advice and comments on the manuscript.
References (29)
- et al.
Exaggerated natriuresis in essential hypertension
Am J Med
(1958) Phenomenological analysis of renal regulation of sodium and potassium balance
Kidney Int
(1985)- et al.
Food intake and nutritional status during EXEMSI
- et al.
Body weight and body composition during sixty days of isolation
- et al.
Anatomy of body water and electrolytes
Am J Med
(1959) Veränderlichkeit der Chloridausscheidung mit der Zufuhr
- et al.
Surfeit and deficit of sodium: A kinetic concept of sodium excretion
Arch Intern Med
(1958) - et al.
The response to the administration of an isotonic sodium chloride-lactate solution in patients with essential hypertension
J Clin Invest
(1960) - et al.
Aldosterone excretion. Physiological variations in man measured by radioimmunoassay or double-isotope dilution
Circ Res
(1972) Evidence for a splanchnic sodium input monitor regulating renal sodium excretion in man: Lack of dependence upon aldosterone
Circ Res
(1978)
The significance of the secretion of aldosterone during dietary sodium deprivation in normal subjects
J Clin Endocrinol Metab
Evidence that renal sodium excretion by normal human subjects is regulated by adrenal cortical activity
J Clin Invest
Failure of renal dopamine response to salt loading in chronic renal disease
BMJ
Exchangeable sodium and blood volume in normotensive and hypertensive humans on high and low sodium intake
Circulation
Cited by (121)
Effect of sodium administration on fluid balance and sodium balance in health and the perioperative setting. Extended summary with additional insights from the MIHMoSA and TOPMAST studies
2022, Journal of Critical CareCitation Excerpt :This ingenious mechanism is still being elucidated but seems to assist mammals in limiting unrestrained fluid accumulation in conditions of extreme sodium loading. Indeed, several experiments suggest that significant amounts of sodium can be stored in an osmotically inactive form, which does not contribute to body fluid retention (Fig. 5) [25,26]. Depending on conditions that are not fully unraveled, the excess sodium is stored in the interstitial matrix of the skin, muscle and the endothelial surface layer, presumably bound to negatively charged glycosaminoglycans, as demonstrated in animal experiments and experiments in humans using magnetic resonance imaging of sodium (Na-MRI). [27-29]
Perturbed body fluid distribution and osmoregulation in response to high salt intake in patients with hereditary multiple exostoses
2021, Molecular Genetics and Metabolism ReportsInfluence of Dialysate Sodium Prescription on Skin and Muscle Sodium Concentration
2021, American Journal of Kidney DiseasesAdvances in magnetic resonance tomography
2021, Magnetic Materials and Technologies for Medical ApplicationsTangram of Sodium and Fluid Balance
2024, Hypertension
- *
This experiment was performed in the MIR simulator of the Institute for Biomedical Problems, Moscow, Russia.
- **
Supported in part by the European Space Agency-Long Term Program Office; and Else Kröner-Fresenius-Stiftung (J.T.). The Institute of Physiology, Free University of Berlin, receives financial support from DLR Germany, grant no. 50WB9622; and the Laboratory of Environmental Physiology (Lyon, France) receives financial support from CNES and GIP Exercise for its space-related research.
- ★
Address reprint requests to Jens Titze, MD, Department of Nephrology, Friedrich-Alexander-University Erlangen-Nürnberg, Loschgestraße 8, 91054 Erlangen, Germany. E-mail: [email protected]
- ★★
0272-6386/02/4003-0010$35.00/0