The purpose of this study was to investigate the effect of ovariectomy
on osteoinductive activity in the bone in rat. Homograft implantation
of decalcified humeral diaphysis from ovariectomized or sham-operated
rats was performed and harvested after several time periods. A signif
icant decrease in bone induction was found in terms of soft X-ray phot
ography, alkaline phosphatase activity, mineral content and expression
of osteocalcin (BGP; bone gla-protein) in the implants from the ovari
ectomized group in comparison to those from the sham-operated animals.
This result suggested that the level of osteoinductive activity, prob
ably due to bone morphogenetic protein, decreased in ovariectomized an
imals.