title: Effects of combined insulin-like growth factor 1 and macrophage colony-stimulating factor on the skeletal properties of mice.
abstract: OBJECTIVE
  Insulin-like growth factor-1 (IGF-1) and macrophage colony-stimulating factor (MCSF) are critical to skeletal homeostasis. We investigated the effects of combined IGF-1 plus MCSF on mice.
  
  
  METHODS
  C57BL/6J mice, aged 7 weeks, were assigned to baseline, vehicle, IGF-1, MCSF, or combined IGF-1 plus MCSF (1 mg/kg/day each, n=12-13/group, 28-day duration).
  
  
  RESULTS
  IGF-1 or MCSF had no effect on bone formation rate; however, IGF-1 plus MCSF produced a 169% increase in periosteal bone formation rate. Combined therapy increased femoral mechanical properties (+25% elastic force), while IGF-1, and MCSF alone did not. Combined therapy affected trabecular bone volume fraction (+40%), number (+13%), and spacing (-13%). MCSF produced similar trabecular changes, while IGF-1 had no effect. Combined therapy and MCSF alone increased bone mineral content.
  
  
  CONCLUSIONS
  We have demonstrated the superior effects of combined IGF-1 and MCSF. Together, these agents may promote bone modeling to a greater extent than either therapy alone.
authors.affiliation: Department of Orthopaedics, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
authors.forename: Shane A
authors.initials: SA
authors.lastname: Lloyd
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Simske
authors.forename: Lori K
authors.initials: LK
authors.lastname: Bogren
authors.forename: Sara E
authors.initials: SE
authors.lastname: Olesiak
authors.forename: Ted A
authors.initials: TA
authors.lastname: Bateman
authors.forename: Virginia L
authors.initials: VL
authors.lastname: Ferguson
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011859:Radiography
chemical_list: D007334:Insulin-Like Growth Factor I; D016173:Macrophage Colony-Stimulating Factor