title: [Effects of mechanical stretching on intercellular free calcium concentration of human periodontal ligament cells].
abstract: OBJECTIVE
  The purpose of this study is to investigate the effects of mechanical stretching on the concentration of free calcium in the human periodontal ligament cells(HPDLCs).
  
  
  METHODS
  HPDLCs were cultured in vitro, and cells which were divided into strain 1%, 10% and 20% group were stretched by dynamic mechanical strain unit for 30,60 and 120 minutes,respectively. Free calcium concentration was examined through flow cytometry and laser scanning confocal microscope.The data was analyzed by one-way ANOVA using SPSS13.0 software package.
  
  
  RESULTS
  The results showed that there was no significant difference of the concentration of the free Ca2+ in cells between each group after 30 minutes of loading ( P>0.05), which was significantly higher than that in the controls by loading stretch for 60 minutes (P<0.01). As the application time of stretch was prolonged, the concentration of free calcium decreased to the level of controls after 120 minutes(P>0.05).
  
  
  CONCLUSIONS
  The free calcium may be a mechanosensor which transduces the mechanical stretching into HPDLCs and regulates the physiology of cells.
authors.affiliation: Department of Prosthodontics, College of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Chun
authors.initials: C
authors.lastname: Xu
authors.forename: Yi
authors.initials: Y
authors.lastname: Hao
authors.forename: Fu-qiang
authors.initials: FQ
authors.lastname: Zhang
mesh_terms: D002118:Calcium / Q000032:analysis*; D002478:Cells, Cultured; D006801:Humans; D010513:Periodontal Ligament / Q000737:chemistry*; D013314:Stress, Mechanical
chemical_list: D002118:Calcium