Effects of spaceflight on bone mineralization in the rhesus monkey. Zerath, Erik, Valery Novikov, Adrian Leblanc, Alexei Bakulin, Victor Oganov, and Marc Grynpas. D[acute]epartement de Physiologie Analytique, Centre d'Etudes et de Recherches de M[acute]edecine A[acute]erospatiale (CERMA), 91223 Br[acute]etigny-sur-Orge, France, The Methodist Hospital, 6550 Fannin, Suite 577, Houston, Texas, 77030, USA, Department of Pathology, University of Toronto, and Samuel Lunenfeld Research Institute of Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada and Institute of Biomedical Problems, Ministry of Health, Moscow, Russia.
APStracts 2:0168A, 1995.
We combined dual photon absorptiometry (DPA), iliac crest histomorphometry and back-scattered electrons (BSE) analyses to characterize bone mineralization effects of a spaceflight on young monkeys. Two 4-5 kg male rhesus monkeys (Macaca mulatta) were flown during a 11.5 day spaceflight which took place onboard Cosmos 2229 biosatellite (Bion 10). Vivarium (n=4) and on-Earth chaired (n=4) control situations were studied for comparison. Flight monkeys exhibited lower values of iliac cancellous bone volume, associated with non-significantly thinner trabeculae. Bone mineralization rate and the proportion of trabecular bone surface involved in mineralization processes were found markedly reduced after spaceflight. Analysis of embedded sections by BSE imaging showed a non significant shift to lower mineralization in the flight biopsies versus postflight mock-up biopsies. These results were in accordance with DPA evaluations showing a tendency for decreased bone mineral content (BMC) during flight and recovery thereafter. The ground simulation experiment performed more than one month after landing on the same monkeys suggests that the observed effects were specifically related to spaceflight, and that the animals had only partially recovered. Additional animals on future flights would be required to confirm these findings.

Received 28 December 1994; accepted in final form 18 April 1995.
APS Manuscript Number A1371-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on  2 May 1995.