title: Tributyltin increases the expression of apoptosis- and adipogenesis-related genes in rat ovaries.
abstract: OBJECTIVE
  Tributyltin (TBT), an endocrine disrupting chemical, has been reported to decrease ovarian function by causing apoptosis in the ovary, but the mechanism is not fully understood. Therefore, we examined whether TBT increases the expression of adipogenesis-related genes in the ovary and the increased expression of these genes is associated with apoptosis induction.
  
  
  METHODS
  Three-week-old Sprague-Dawley rats were orally administered TBT (1 or 10 mg/kg body weight) or sesame oil as a control for 7 days. The ovaries were obtained and weighed on day 8, and then they were fixed for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) or frozen for RNA extraction. Using the total RNA of the ovaries, adipogenesis- and apoptosis-related genes were analyzed by real-time polymerase chain reaction (PCR).
  
  
  RESULTS
  The ovarian weight was significantly decreased in rats administered 10 mg/kg TBT compared to that in control rats. As determined by the TUNEL assay, the number of apoptotic follicles in ovary was significantly increased in rats administered 10 mg/kg TBT. The real-time PCR results showed that the expression of adipogenesis-related genes such as PPARγ, aP2, CD36, and PEPCK was increased after TBT administration. In addition, apoptosis-related genes such as TNFα and TNFR1 were expressed more in the TBT-administered rats compared with the control rats.
  
  
  CONCLUSIONS
  The present study demonstrates that TBT induces the expression of adipogenesis- and apoptosis-related genes in the ovary leading to apoptosis in the ovarian follicles. These results suggest that the increased expression of adipogenesis-related genes in the ovary by TBT exposure might induce apoptosis resulting in a loss of ovarian function.
authors.affiliation: Department of Bioenvironmental Technology, College of Natural Sciences, Seoul Women's University, Seoul, Korea.
authors.forename: Hyojin
authors.initials: H
authors.lastname: Lee
authors.forename: Sojeong
authors.initials: S
authors.lastname: Lim
authors.forename: Sujin
authors.initials: S
authors.lastname: Yun
authors.forename: Ayoung
authors.initials: A
authors.lastname: Yoon
authors.forename: Gayoung
authors.initials: G
authors.lastname: Park
authors.forename: Hyunwon
authors.initials: H
authors.lastname: Yang