Histological studies on tibial bone of rats in the 1975 COSMOS-782 flight. Part 1: Endochondral osteogenesis; medullary bone turnover

摘要

Tibia lengths, histological appearance of the proximaltibial epiphysis and metaphysis, and measurements of the bony spongiosa are reported for six rats subjected to weightlessness in earth-orbit for 19 days, and are compared with similar studies conducted on vivarium controls and on synchronous controls. Bone formation was slightly impaired in synchronous controls, and to an appreciably greater extent in flight animals. Bone resorption was moderately accelerated in synchronous controls, markedly more so in flight animals, to an extent under which virtually all pre-flight medullary bone was removed.