title: [Expression and significance of nitric oxide synthase in mandibular distraction osteogenesis of canine].
abstract: OBJECTIVE
  To investigate the expression and significance of nitric oxide synthase (NOS) during mandibular distraction osteogenesis and bone trauma healing, to futher study the mechanism of distraction osteogenesis.
  
  
  METHODS
  Twenty-eight adult dogs were randomly divided into DO group (12 dogs), acutely lengthening group (12 dogs) and control group (4 dogs). Immunohistochemical examination were carried out to test the expression of NOS during the sixth day in distraction period, the second and eighth week of consolidation.
  
  
  RESULTS
  In DO group infiltration of inflammatory cell was found in the distraction gap, more red blood cells (RBC) leak out around vascellum and matrix in the sixth day in distraction period. The expression of local iNOS (inducible NOS) and eNOS (endothelinal NOS) in DO gruoup and acutely lengthening group was higher than that in the control group (P < 0.05), the expression of local iNOS and eNOS in acutely lengthening group was lower than that in DO group (P < 0.05) in the early of distraction period and the consolidation. The expression of local iNOS and eNOS was no statistic difference between three groups (P > 0.05) in the eighth week of consolidation.
  
  
  CONCLUSIONS
  NOS as a sensitive index of tissue trauma are highly expressed, and RBC was found leaking out in the early of distraction, indicating that micro-trauma to some extent may occurr during DO procedure, the micro-trauma may be one of the significant factors which increasing regeneration of bone during DO.
authors.affiliation: Dept. of Oral and Maxillofacial Surgery, School of Stomatology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Nuo
authors.initials: N
authors.lastname: Zhou
authors.forename: Ni
authors.initials: N
authors.lastname: Liao
authors.forename: Shan-Liang
authors.initials: SL
authors.lastname: Wei
authors.forename: Fei-Xin
authors.initials: FX
authors.lastname: Liang
mesh_terms: D000818:Animals; D001842:Bone and Bones; D004285:Dogs; D008334:Mandible; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D019857:Osteogenesis, Distraction
chemical_list: C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II