Abstract
Objective. To answer the question if plasma hormone concentrations (plasma renin activity PRA, vasopressin - pAVP, and aldosterone concentration) due to antiorthostatic immobilization (8 days -6° head-down tilt bed rest - HDBR) are altered by oral salt load, we provided constant sodium supply during 4 days ambulatory conditions followed by 8 days HDBR in 10 normotensive men. Methods. A,low' (LS: 143±10 mM) and,high' (HS: 434±17 mM Na+-/d excreted) sodium treatment were provided in randomized order, separated ≥1 mo. Before and at the end of HDBR, hemodynamic variables and thoracic impedance were determined, and blood was taken for aldosterone and PRA, venous hematocrit, and plasma mass density. Extracellular fluid volume and pAVP were determined every second day. Whole body electrical impedance spectroscopy was employed to assess changes in extracellular volume, hormone determinations were done with radioimmunoassay, mass density measurements with the mechanical oscillator technique. Results. Extracellular volume decreased with HDBR (LS: -4.0%, p=0.002; HS: -5.8%, p=0.018) without significant difference between salt treatments. Resting hormone levels were not altered by HDBR, but pAVP was lower (5.5±0.1 pg/ml) in HS than in LS (7.2±0.3 pg/ml) as was plasma aldosterone (HS: 69±7 pg/ml, LS: 180±24 pg/ml). On the other hand, HDBR reduced extracellular volume by ?5% irrespective of dietary sodium supply. Conclusions. Our data support the hypothesis that hormonal activities are more affected by oral salt load than by simulated short-term space flight, and suggest that the reduction of extracellular fluid volume due to head down bed rest is not influenced by moderate changes of dietary sodium supply.
| Original language | English |
|---|---|
| Pages (from-to) | 151-159 |
| Number of pages | 9 |
| Journal | Endocrine Regulations |
| Volume | 36 |
| Issue number | 4 |
| Publication status | Published - Nov 2002 |
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Keywords
- Aldosterone
- Bed rest
- Bioelectrical impedance spectroscopy
- Cardiovascular
- Extracellular fluid volume
- Extracellular volume
- Immobilization
- Plasma renin activity
- Renal function
- Salt intake
- Sodium excretion
- Vasopressin
ASJC Scopus subject areas
- Endocrinology
Cite this
Bed rest immobilization with various oral sodium supply : Plasma hormones and body fluids. / Hinghofer-Szalakay, Helmut G.; László, Z.; Jezova, Daniela; Rössler, Andreas; Haditsch, Bernd; Pilz, Karl; Passath, Herfried; Scharfetter, Herman.
In: Endocrine Regulations, Vol. 36, No. 4, 11.2002, p. 151-159.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Bed rest immobilization with various oral sodium supply
T2 - Plasma hormones and body fluids
AU - Hinghofer-Szalakay, Helmut G.
AU - László, Z.
AU - Jezova, Daniela
AU - Rössler, Andreas
AU - Haditsch, Bernd
AU - Pilz, Karl
AU - Passath, Herfried
AU - Scharfetter, Herman
PY - 2002/11
Y1 - 2002/11
N2 - Objective. To answer the question if plasma hormone concentrations (plasma renin activity PRA, vasopressin - pAVP, and aldosterone concentration) due to antiorthostatic immobilization (8 days -6° head-down tilt bed rest - HDBR) are altered by oral salt load, we provided constant sodium supply during 4 days ambulatory conditions followed by 8 days HDBR in 10 normotensive men. Methods. A,low' (LS: 143±10 mM) and,high' (HS: 434±17 mM Na+-/d excreted) sodium treatment were provided in randomized order, separated ≥1 mo. Before and at the end of HDBR, hemodynamic variables and thoracic impedance were determined, and blood was taken for aldosterone and PRA, venous hematocrit, and plasma mass density. Extracellular fluid volume and pAVP were determined every second day. Whole body electrical impedance spectroscopy was employed to assess changes in extracellular volume, hormone determinations were done with radioimmunoassay, mass density measurements with the mechanical oscillator technique. Results. Extracellular volume decreased with HDBR (LS: -4.0%, p=0.002; HS: -5.8%, p=0.018) without significant difference between salt treatments. Resting hormone levels were not altered by HDBR, but pAVP was lower (5.5±0.1 pg/ml) in HS than in LS (7.2±0.3 pg/ml) as was plasma aldosterone (HS: 69±7 pg/ml, LS: 180±24 pg/ml). On the other hand, HDBR reduced extracellular volume by ?5% irrespective of dietary sodium supply. Conclusions. Our data support the hypothesis that hormonal activities are more affected by oral salt load than by simulated short-term space flight, and suggest that the reduction of extracellular fluid volume due to head down bed rest is not influenced by moderate changes of dietary sodium supply.
AB - Objective. To answer the question if plasma hormone concentrations (plasma renin activity PRA, vasopressin - pAVP, and aldosterone concentration) due to antiorthostatic immobilization (8 days -6° head-down tilt bed rest - HDBR) are altered by oral salt load, we provided constant sodium supply during 4 days ambulatory conditions followed by 8 days HDBR in 10 normotensive men. Methods. A,low' (LS: 143±10 mM) and,high' (HS: 434±17 mM Na+-/d excreted) sodium treatment were provided in randomized order, separated ≥1 mo. Before and at the end of HDBR, hemodynamic variables and thoracic impedance were determined, and blood was taken for aldosterone and PRA, venous hematocrit, and plasma mass density. Extracellular fluid volume and pAVP were determined every second day. Whole body electrical impedance spectroscopy was employed to assess changes in extracellular volume, hormone determinations were done with radioimmunoassay, mass density measurements with the mechanical oscillator technique. Results. Extracellular volume decreased with HDBR (LS: -4.0%, p=0.002; HS: -5.8%, p=0.018) without significant difference between salt treatments. Resting hormone levels were not altered by HDBR, but pAVP was lower (5.5±0.1 pg/ml) in HS than in LS (7.2±0.3 pg/ml) as was plasma aldosterone (HS: 69±7 pg/ml, LS: 180±24 pg/ml). On the other hand, HDBR reduced extracellular volume by ?5% irrespective of dietary sodium supply. Conclusions. Our data support the hypothesis that hormonal activities are more affected by oral salt load than by simulated short-term space flight, and suggest that the reduction of extracellular fluid volume due to head down bed rest is not influenced by moderate changes of dietary sodium supply.
KW - Aldosterone
KW - Bed rest
KW - Bioelectrical impedance spectroscopy
KW - Cardiovascular
KW - Extracellular fluid volume
KW - Extracellular volume
KW - Immobilization
KW - Plasma renin activity
KW - Renal function
KW - Salt intake
KW - Sodium excretion
KW - Vasopressin
UR - http://www.scopus.com/inward/record.url?scp=0038298859&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0038298859&partnerID=8YFLogxK
M3 - Article
VL - 36
SP - 151
EP - 159
JO - Endocrine Regulations
JF - Endocrine Regulations
SN - 1210-0668
IS - 4
ER -