title: Changes of osteocalcin and IGF-I during bone lengthening.
abstract: OBJECTIVE
  To examine the changes of osteocalcin and insulin-like growth factor I (IGF-I) during bone lengthening, and to clarify the mechanism of bone healing.
  
  
  METHODS
  Thirty-two shepherd dogs were divided into five groups randomly. Their tibiae were lengthened by Ilvzarov's external fixator at the rate of 1 mm/day. The lengthening area was the experimental side and the opposite side was the control. Samples were obtained on the 2nd, 4th, 6th, 8th, 12th weekend respectively. The samples were defatted, dried, powdered, centrifuged and measured by radioimmunoassay.
  
  
  RESULTS
  The osteocalcin concentration increased at the subsequent periods, but it was significantly lower in the experimental side than that of the control side, P<0.05 and the IGF-I concentration was not significantly lowered.
  
  
  CONCLUSIONS
  Different noncollagenous bone growth factors may be different at different stage.
authors.affiliation: Department of Orthopedics, 12th Hospital of Guangzhou, Guangdong 510620, China. wbing222@163.com
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: Yi-yun
authors.initials: YY
authors.lastname: Liu
authors.forename: Jie-bai
authors.initials: JB
authors.lastname: Zheng
authors.forename: Shi-xiang
authors.initials: SX
authors.lastname: Yuan
authors.forename: Guo-xun
authors.initials: GX
authors.lastname: Chen
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001852:Bone Lengthening / Q000379:methods*; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000378:metabolism*; D008297:Male; D015675:Osteocalcin / Q000032:analysis / Q000378:metabolism*; D011336:Probability; D011863:Radioimmunoassay; D011897:Random Allocation; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013977:Tibia / Q000601:surgery*
chemical_list: D015415:Biomarkers; D015675:Osteocalcin; D007334:Insulin-Like Growth Factor I