title: [The effect of serum concentration and culture time on the biologic activity of human periodontal ligament cells].
abstract: OBJECTIVE
  To investigate the effect of serum concentration and culture time on the biologic activity of human periodontal ligament cells (HPDLCs).
  
  
  METHODS
  The proliferation (1,4,7,10,14,21d), the protein synthesis, the ALP activity, the collagen synthesis, the calcium intake and the osteocalcin secretion (4,7d) of the fourth passage (P4) HPDLCs treated with 10 mL/L or 50 mL/L neonatal bovine serum (NBS) were examined using MTT method, BCA protein concentration, ALP activity,hydroxyproline and Roche Diagnostics cobas calcium content reagent kits and radio-immunity assay. The data were subjected to two-way analysis of variance and t test using SPSS13.0 software package.
  
  
  RESULTS
  50 mL/L NBS could significantly increase the proliferation (1,4,7,10,14,21d) and the protein synthesis (4,7d) of the P4 HPDLCs. 50 mL/L NBS could significantly inhibit their ALP activity, the calcium intake (4,7d) and the osteocalcin secretion (7d). But it had no effect on the collagen synthesis. During cell culture, the two serum concentrations and the culture time only had interaction on the proliferation, ALP activity and osteocalcin secretion of the P4 HPDLCs.
  
  
  CONCLUSIONS
  The serum concentration and culture time could affect the biologic activity of HPDLCs.
authors.affiliation: Institute of Stomatology, General Hospital of Chinese PLA, Beijing 100853, China. elingling@sohu.com
authors.forename: Ling-ling
authors.initials: LL
authors.lastname: E
authors.forename: Hong-chen
authors.initials: HC
authors.lastname: Liu
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Xia
authors.initials: X
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Lv
authors.forename: Dong-sheng
authors.initials: DS
authors.lastname: Wang
mesh_terms: D000818:Animals; D001688:Biological Products; D002417:Cattle; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D010513:Periodontal Ligament
chemical_list: D001688:Biological Products