title: [Effects of insulin and transforming growth factor-beta on alkaline phosphatase activity and total protein content in human periodontal ligament cells].
abstract: OBJECTIVE
  The aim of this study is to evaluate the biological effects of insulin and/or transforming growth factor (TGF-beta) on alkaline phosphatase (ALPase) activity and protein synthesis of periodontal ligament (PDL) cells in vitro.
  
  
  METHODS
  The fifth passage of PDL cells were cultured in a 5% humid CO2 environment at 37 degrees C by using Dulbecco minimum essential medium (DMEM) supplemented with 10% fetal bovine serum (FBS) for 24 hours, and then insulin, TGF-beta, and insulin and TGF-beta were added respectively in a medium of 1% FBS. After 5 days, their ALPase activities were measured by using a kinetic method, and the total protein content was measured by using Coomassie brilliant blue staining.
  
  
  RESULTS
  Both insulin and TGF-beta significantly increased the ALPase activity and the total protein content of PDL cells at the concentrations from 1.0 to 100 U/L, and of 0.1-100 micrograms/L. The most optimal concentrations of insulin and TGF-beta were respectively 10 U/L and 1 microgram/L. The synergistic effect of insulin (10 U/L) and TGF-beta (1 microgram/L) was observed (P < 0.01).
  
  
  CONCLUSIONS
  The results suggest that insulin and/or TGF-beta may promote the differentiation and protein synthesis of PDL cells. The combination of them may be valuable in the regeneration of periodontal tissue.
authors.affiliation: Department of Periodontology, College of Stomatology, Fourth Military Medical University.
authors.forename: G
authors.initials: G
authors.lastname: Dong
authors.forename: Z
authors.initials: Z
authors.lastname: Wu
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000187:drug effects* / Q000378:metabolism; D002648:Child; D004357:Drug Synergism; D006801:Humans; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology*; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects*; D011506:Proteins / Q000032:analysis / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: D007328:Insulin; D011506:Proteins; D016212:Transforming Growth Factor beta; D000469:Alkaline Phosphatase