Male -- mice have a significant reduction in bone mass and administration of a peptide that contains the insulin-like growth factor binding protein-2(IGFBP-2) receptor-binding domain stimulates bone formation in these animals. Female -/- mice do not have this phenotype but following ovariectomy (OVX) lose more bone than OVX wild-type mice. This suggests that in the absence of estrogen， IGFBP-2 is required to maintain bone mass. Therefore these studies were undertaken to determine if this peptide could stimulate bone acquisition in OVX rats. OVX rats were divided into seven treatment groups: sham animals， OVX animals， OVX animals receiving a control scrambled peptide， or one of three doses of the active peptide termed PEG-HBD-1 (0.7， 2， and 6?mg·kg) and an OVX group receiving parathyroid hormone (PTH) (50?μg·kg?per?day). The peptides were administered for 8 weeks. DXA revealed a significant reduction in femoral and tibial areal bone mineral density (aBMD) after OVX， whereas treatment with the high-dose peptide increased aBMD by 6.2%?±?2.4% (?