[Effects of weightlessness on phospho-calcium metabolism and its hormonal regulation in man during the 51 G Franco-American space flight].
During the 51 G franco-american mission in weightlessness, calcium metabolism and hormonal regulation were analyzed in two astronauts (a male, a female) before (30,7 and 4 days) and after (0,2 and 5 days) the 7-day spaceflight. Calcium, phosphate, alkaline phosphatase, GLA protein, 25 hydro-vitamin D, 1-25 dihydroxyvitamin D, parathyroid hormone, 24 h urinary calcium, total, dialysable and nondialysable hydroxyproline and glycosaminoglycans (GAG) were measured in blood and urine. Only urinary parameters are increased after space flight. Blood parameters, in particular hormone measurements, are unchanged. The data indicate stimulation of resorptive activity which could result in bone matrix atrophy and demineralisation. On the contrary, no bone formation impairment is noted since alkaline phosphatase and GLA protein are unchanged. These changes are not dependent on hormonal variations. They could only reflect the mechanical bone adaptation to weightlessness.
Alexandre
C
C
Université de Saint-Etienne, Faculté de Médecine, France.
Vico
L
L
Pilonchery
G
G
Chapuy
M C
MC
Delmas
P D
PD
Chappard
D
D
D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000097:blood; D005260:Female; D006025:Glycosaminoglycans / Q000652:urine; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood; D006909:Hydroxyproline / Q000652:urine; D008297:Male; D015675:Osteocalcin; D010281:Parathyroid Hormone / Q000097:blood*; D010758:Phosphorus / Q000097:blood*; D013026:Space Flight; D014893:Weightlessness / Q000009:adverse effects*
D002135:Calcium-Binding Proteins; D006025:Glycosaminoglycans; D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D015675:Osteocalcin; D010758:Phosphorus; D000469:Alkaline Phosphatase; D002117:Calcitriol; D006909:Hydroxyproline; D002118:Calcium
Effects de l'apesanteur sur le métabolisme phospho-calcique et sa régulation hormonale chez l'homme au cours du vol spatial Franco-Américain 51 G.