Effect of simulated weightlessness and chronic 1,25-dihydroxyvitamin D administration on bone metabolism

Weightlessness, as experienced during space flight, and simulated weightlessness induce osteopenia. Using the suspended rat model to simulate weightlessness, a reduction in total tibia Ca and bone formation rate at the tibiofibular junction as well as an inhibition of Ca-45 and H-3-proline uptake by...

Full description

Saved in:
Bibliographic Details
Published in:The Physiologist 1985-12, Vol.28 (6 Suppl), p.S127-S128
Main Authors: Halloran, B. P., Bikle, D. D., Globus, R. K., Levens, M. J., Wronski, T. J., Morey-Holton, E.
Format: Article
Language:English
Subjects:
Animals
Bone and Bones - metabolism
Calcitriol - pharmacology
Calcium - metabolism
Life Sciences (General)
Rats
Space life sciences
Weightlessness
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Weightlessness, as experienced during space flight, and simulated weightlessness induce osteopenia. Using the suspended rat model to simulate weightlessness, a reduction in total tibia Ca and bone formation rate at the tibiofibular junction as well as an inhibition of Ca-45 and H-3-proline uptake by bone within 5-7 days of skeletal unloading was observed. Between days 7 and 15 of unloading, uptake of Ca-45 and H-3-proline, and bone formation rate return to normal, although total bone Ca remains abnormally low. To examine the relationship between these characteristic changes in bone metabolism induced by skeletal unloading and vitamin D metabolism, the serum concentrations of 25-hydroxyvitamin D (25-OH-D), 24, 25-dihydroxyvitamin D (24,25(OH)2D) and 1,25-dihydroxyvitamin D (1,25(OH)2D) at various times after skeletal unloading were measured. The effect of chronic infusion of 1,25(OH)2D3 on the bone changes associated with unloading was also determined.
ISSN:0031-9376