Prostaglandin E sub(2) restores cancellous bone to immobilized limb and adds bone to overloaded limb in right hindlimb immobilization rats

The purpose of this study was to determine whether prostaglandin E sub(2) (PGE sub(2)) can restore cancellous bone mass and architecture to osteopenic, continuously immobilized (IM), proximal tibial metaphysis (PTM) in female rats. The right hindlimb of three and one-half-month-old Sprague-Dawley female rats were immobilized by right hindlimb immobilization (RHLI) in which the right hindlimb was underloaded and the contralateral left limb was overloaded during ambulation. After 4 or 12 weeks of RHLI, the rats were treated with PGE sub(2) and RHLI for 8 or 16 weeks. Our findings indicate that daily 3 or 6 mg PGE sub(2)/kg/d treatment restores and maintains PTM cancellous bone mass in continuously immobilized (right) tibiae, and adds and maintains extra bone to slightly overloaded PTM cancellous bone in female rats.