Document Detail


Effects of 1-week head-down tilt bed rest on bone formation and the calcium endocrine system.
MedLine Citation:
PMID:  1550528     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
To understand the potential early responses of human bone and the calcium endocrine system to spaceflight, we studied 8 healthy men, aged 35-44 years before, during, and after bed rest in a -6 degrees head-down tilt model for microgravity. Based on a novel single-dose labeling schedule, average rates of bone formation in the iliac crest were reduced in 6, unchanged in 1, and increased in 1 following the bed rest period. The decrease was greatest for subjects whose daily walking miles were highest (r = -0.762, p less than 0.05, n = 7). Before a measurable increase in ionized serum calcium the sixth bed rest day, there was increased excretion of urinary calcium and sodium, evident the first 2 bed-rest days and parallel for the entire week (r = 0.92, p less than 0.001). Reduced excretion of phosphorus and 3', 5' cyclic adenosine monophosphate on the first and second bed rest days was followed by an increase in serum phosphorus by the sixth bed rest day. Depressed serum concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D were manifest by the sixth and seventh bed rest days. The similarity of the response of bone and the calcium endocrine system of healthy men after only 7 days to results of longer term bed rest studies emphasizes the responsiveness of the adult human skeleton to biomechanical stimuli induced by changes in activity and/or position.
Authors:
S B Arnaud; D J Sherrard; N Maloney; R T Whalen; P Fung
Related Documents :
4043238 - Acute effects of ethanol intake on the serum concentrations of parathyroid hormone, cal...
2744038 - Hypercalcaemia in a child with miliary tuberculosis.
22183698 - The effects of increased pressure, variation in inspired gases and the use of a mask du...
10489398 - Serum calcium and cardiovascular risk factors and diseases: the tromsø study.
10207508 - Evidence supporting a direct suppressive effect of growth hormone on serum igfbp-1 leve...
4197748 - Gel filtration studies on immunoreactive gastrin in serum from zollinger-ellison patients.
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Aviation, space, and environmental medicine     Volume:  63     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  1992 Jan 
Date Detail:
Created Date:  1992-04-17     Completed Date:  1992-04-17     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  14-20     Citation Subset:  IM; S    
Affiliation:
Life Science Division, NASA Ames Research Center, Moffett Field, CA 94035-1000.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Bone Resorption / metabolism*
Calcium / metabolism*,  urine
Exercise*
Gravitation
Humans
Male
Parathyroid Hormone / metabolism
Phosphorus / metabolism,  urine
Posture*
Sodium / metabolism,  urine
Space Flight
Chemical
Reg. No./Substance:
0/Parathyroid Hormone; 7440-23-5/Sodium; 7440-70-2/Calcium; 7723-14-0/Phosphorus
Investigator
Investigator/Affiliation:
S B Arnaud / ARC; R T Whalen / ARC

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Massive tumour embolism from primary lung cancer.
Next Document:  Assessment of cardiovascular reflexes is of limited value in predicting maximal +Gz-tolerance.