title: [Effects of orthodontic tooth movements on insulin-like growth factors expression in periodontal tissues].
abstract: OBJECTIVE
  To elucidate the regulatory bio-mechanism of estrogen and local stress on the bone remodeling activities in vivo.
  
  
  METHODS
  A Wistar rat experimental model was established to apply orthodontic activation during different stages of estrous cycle. In situ hybridization was used to detect the variation of the insulin-like growth factors (IGF) mRNA expression in the periodontal tissues. The data of each group was analyzed with SPSS 11.0 software package for Student-Newman-Keuls (S-N-K) test and one way ANOVA test.
  
  
  RESULTS
  Both IGF-I mRNA and IGF-II mRNA level expressed in the periodontal tissues were increased by orthodontic activation during various stages of the estrous cycle. But a similar pattern emerged that the IGF-I mRNA level was the lowest in the estrous stage, whereas its level was the highest in the proestrus stage (P < 0.05). No rhythm of IGF-II mRNA expression found during the estrous cycle.
  
  
  CONCLUSIONS
  It was concluded that local mechanical stimulation directly enhanced the IGF expression. In contrast to the IGF-II, IGF-I was also influenced by the sex hormone rhythm during the estrous cycle.
authors.affiliation: Dept. of Orthodontics, School of Stomatology, Shandong University, Jinan 250012, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Guo
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhao
authors.forename: Yang-xi
authors.initials: YX
authors.lastname: Chen
mesh_terms: D000818:Animals; D030762:Estrous Cycle; D004971:Estrus; D005260:Female; D017403:In Situ Hybridization; D007334:Insulin-Like Growth Factor I; D012333:RNA, Messenger; D051381:Rats; D017208:Rats, Wistar; D013002:Somatomedins; D014087:Tooth Movement Techniques
chemical_list: D012333:RNA, Messenger; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I