Effects of spaceflight (sls-2) and recovery on rat humeri and
vertebrae : histological and cell culture studies .
Zerath, Erik, Danielle Godet, Xavier Holy, Catherine Andre, Sylvie
Renault, Monique Hott, and Pierre J. Marie.
IMASSA-CERMA, D[acute]epartement de Physiologie Analytique, Base
d'Essais en Vol, 91220 Br[acute]etigny-sur-Orge ; and INSERM
Unit[acute]e 349, Cell and Molecular Biology of Bone and Cartilage,
Lariboisi[grave]ere Hospital, 75010 Paris, France
APStracts 3:0085A, 1996.
Skeletal changes associated with spaceflight in the rat have been well
documented, but few data are available on bone tissue and bone cell
metabolism after subsequent on-Earth recovery. We therefore
investigated the effects of microgravity and subsequent recovery on
trabecular bone morphology and cellular activities in rat humeri and
thoracic vertebrae, and compared histomorphometric parameters in
caudal vertebrae with the behavior of vertebral osteoblastic cells in
culture. We report here that humeral weight showed normal growth
during the experiment, but was unaffected by spaceflight or recovery
from spaceflight. However the 14-day spaceflight resulted in
inhibition of static indices of bone formation in humeral proximal
metaphyses and thoracic vertebral bodies. This was associated with a
decrease in bone volume in humeral metaphyses. After 14 days of on
-Earth recovery, osteoblastic and osteoid surfaces returned toward
normal, and bone volume was normalized in humeri, whereas the static
bone formation parameters were not restored in thoracic vertebrae. In
addition, histological indices of bone formation and osteoblastic
cell growth in vitro were not affected by spaceflight in caudal
vertebrae. This study shows that rat humeri, thoracic and caudal
vertebrae exhibit different patterns of response to spaceflight and
subsequent on-Earth recovery, which could be due, at least in part,
to the different loading pattern of these bones, and also to
difference in bone turnover rate.
Received 3 August 1995; accepted in final form 29 January 1996.
APS Manuscript Number A854-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 14 February 96