title: Alendronate (ALN) combined with osteoprotegerin (OPG) significantly improves mechanical properties of long bone than the single use of ALN or OPG in the ovariectomized rats.
abstract: BACKGROUND
  Alendronate (ALN) is the most common form of bisphosphonates used for the treatment of osteoporosis. Osteoprotegerin (OPG) has also been shown to reduce osteoporotic changes in both humans and experimental animals after systemic administration. The aim of this current study was to test if the anti-resorption effects of ALN may be enhanced when used in combination with OPG.
  
  
  OBJECTIVE
  To investigate the effects of ALN, OPG or combined on bone mass and bone mechanical properties in ovariectomized (OVX) rats.
  
  
  METHODS
  OVX rats were treated with ALN, OPG-Fc, or OPG-Fc and ALN. Biochemical markers, trabecular bone mass, biomechanics, histomorphometry and RANKL expression in the bone tissues were examined following the treatments.
  
  
  RESULTS
  The treatment of ALN, OPG-Fc and ALN+OPG-Fc all prevented bone loss in the OVX-rats, there was no statistical difference among the three treatment groups in terms of vertebrae BMD, mineralizing surfaces, mineral apposition rate, BFR/BS. The ALN+OPG-Fc treatment group had significantly increased the mechanical strength of lumber vertebral bodies and femoral shafts when compared to the ALN and OPG-Fc treatment groups. The RANKL protein expression in the vertebral bones was significantly decreased in the ALN and ALN+OPG-Fc treatment groups, suggesting the combined use of OPG-Fc and ALN might have amplified inhibition of bone resorption through inhibiting RANKL-dependent osteoclastogenesis.
  
  
  CONCLUSIONS
  The combined use of OPG-Fc and ALN may be a new treatment strategy for reversing bone loss and restoring bone quality in osteoprotic disorders.
authors.affiliation: Department of Orthopaedic Surgery, The General Hospital of People's Liberation Army, Beijing, PR China. yanwang301@yahoo.com
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Huang
authors.forename: Pei-Fu
authors.initials: PF
authors.lastname: Tang
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chan
authors.forename: Gang
authors.initials: G
authors.lastname: Li
mesh_terms: D019386:Alendronate / Q000494:pharmacology*; D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D001862:Bone Resorption / Q000378:metabolism / Q000517:prevention & control; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D004359:Drug Therapy, Combination; D005260:Female; D023421:Models, Animal; D053244:Osteoprotegerin / Q000494:pharmacology*; D010052:Ovariectomy; D053245:RANK Ligand / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D050071:Bone Density Conservation Agents; D053244:Osteoprotegerin; D053245:RANK Ligand; D002118:Calcium; D019386:Alendronate