title: The establishment of a mechanobiology model of bone and functional adaptation in response to mechanical loading.
abstract: BACKGROUND
  Mechanical stimuli affected bone adaptation, however, the mechanism on a dose-response relationship between mechanical stimuli and bone response is unclear. Therefore, we established a mechanobiology model to evaluated the adaptive response of bone to strain deformation at high-frequencies (5-15 Hz) of externally applied strain.
  
  
  METHODS
  The ulnae of adult female rats were subjected to dynamic axial loading in vivo using Instron materials-testing machine. The applied loading at frequencies of 5 Hz, 10 Hz, and 15 Hz for 10 min with a haversine, low-magnitude waveform for a 2 weeks period, the peak strains is 2000 muepsilon and 3000 muepsilon. Strain was recorded using strain gauge conditioner and compared to physiological values obtained after testing.
  
  
  RESULTS
  At frequencies of 10 Hz, 15 Hz groups, loading promoted obviously secreted of osteocalcin and collagen; a relative benefit in Bone Mineral Density (BMD) was found compare to the control (P < 0.05) followed the decline of material mechanical properties (modulus of elasticity, ultimate stress) (P < 0.01).
  
  
  CONCLUSIONS
  These data show that a mechanobiology model of the axial ulna loading technique had been established successfully in rat. A short daily period of low-magnitude, high-frequency mechanical stimuli results in an osteogenic response related to peak strain magnitude, which do not result in significant differences in mechanical properties between the groups.
authors.affiliation: Medical College of Chinese People's Army Police Force, Tianjin 300161, China.
authors.forename: Xu-Yi
authors.initials: XY
authors.lastname: Chen
authors.forename: Xi-Zheng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Guo
authors.forename: Rui-Xin
authors.initials: RX
authors.lastname: Li
authors.forename: Jin-Jin
authors.initials: JJ
authors.lastname: Lin
authors.forename: Yan
authors.initials: Y
authors.lastname: Wei
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D019245:Compressive Strength; D003198:Computer Simulation; D004548:Elasticity; D005260:Female; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D008954:Models, Biological; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D013718:Tensile Strength; D014457:Ulna / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*