title: Increased osteoblast and osteoclast activity in female senescence-accelerated, osteoporotic SAMP6 mice during fracture healing.
abstract: BACKGROUND
  Previous studies have shown that fracture healing depends on gender and that in females, ovariectomy-induced osteoporosis impairs the healing process. There is no information, however, whether the alteration of fracture healing in osteoporosis also depends on gender.
  
  
  METHODS
  Therefore, we herein studied fracture healing in female and male senescence-accelerated osteoporotic mice, strain P6 (SAMP6), including biomechanical, histomorphometric, and protein biochemical analysis.
  
  
  RESULTS
  Bending stiffness was reduced in male and female SAMP6 mice compared with senescence-resistant strain 1 (SAMR1) controls. This was associated with elevated serum concentrations of tartrate-resistent acid phosphatase form 5b (TRAP) in both female and male SAMP6 mice. Callus size, however, was significantly larger in female SAMP6 mice compared with male SAMP6 mice and female SAMR1 controls. This indicates a delayed remodeling process in female SAMP6 mice. The delay of callus remodeling in female SAMP6 mice was associated with a significantly higher osteoprotegerin (OPG) callus tissue expression and increased serum concentrations of osteocalcin (OC) and deoxypyridinoline (DPD), indicating elevated osteoblast and osteoclast activities.
  
  
  CONCLUSIONS
  The present study shows that remodeling during fracture healing in female, but not in male, SAMP6 mice is delayed, most probably due to an increased osteoblast and osteoclast activity.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University of Saarland, Homburg/Saar, Germany. tina.histing@uks.eu
authors.forename: Tina
authors.initials: T
authors.lastname: Histing
authors.forename: David
authors.initials: D
authors.lastname: Stenger
authors.forename: Swantje
authors.initials: S
authors.lastname: Kuntz
authors.forename: Claudia
authors.initials: C
authors.lastname: Scheuer
authors.forename: Andrea
authors.initials: A
authors.lastname: Tami
authors.forename: Patric
authors.initials: P
authors.lastname: Garcia
authors.forename: Joerg H
authors.initials: JH
authors.lastname: Holstein
authors.forename: Moritz
authors.initials: M
authors.lastname: Klein
authors.forename: Tim
authors.initials: T
authors.lastname: Pohlemann
authors.forename: Michael D
authors.initials: MD
authors.lastname: Menger
mesh_terms: D000135:Acid Phosphatase / Q000097:blood; D000375:Aging / Q000378:metabolism / Q000473:pathology*; D000596:Amino Acids / Q000097:blood; D000818:Animals; D001696:Biomechanical Phenomena; D016723:Bone Remodeling / Q000502:physiology; D002146:Bony Callus / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D017102:Fracture Healing / Q000502:physiology*; D007527:Isoenzymes / Q000097:blood; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D010006:Osteoblasts / Q000378:metabolism / Q000473:pathology*; D015675:Osteocalcin / Q000097:blood; D010010:Osteoclasts / Q000378:metabolism / Q000473:pathology*; D010024:Osteoporosis / Q000378:metabolism / Q000473:pathology*; D053244:Osteoprotegerin / Q000378:metabolism; D012727:Sex Characteristics; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D000596:Amino Acids; D007527:Isoenzymes; D053244:Osteoprotegerin; D015675:Osteocalcin; C036020:deoxypyridinoline; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase