title: Effect of tamoxifen on ovarian reserve: A randomized controlled assessor-blind trial in a mouse model.
abstract: OBJECTIVE
  To determine whether tamoxifen (TMX) exposure causes a permanent decrease in ovarian reserve.
  
  
  METHODS
  A randomized controlled assessor-blind trial including 30 adult female inbred BALB/C mice. Fifteen mice in the TMX group were given a single 0.1-mg dose of TMX intraperitoneally. Fifteen mice in the control group were given a single dose of the vehicle at the same volume intraperitoneally. Two cycles later, blood samples were collected for determination of anti-Müllerian hormone (AMH) levels, and the mice were sacrificed. After gonadectomy, ovarian size was measured, and follicles were counted under light microscopy.
  
  
  RESULTS
  Median serum AMH levels were 6.53 and 6.14 ng/ml in the control and TMX groups, respectively (p=0.03). Ovarian size was significantly decreased in the TMX group. While the number of primordial (9 vs 8), primary (6 vs 3), and secondary (4.5 vs 5) follicles were similar, there were significantly fewer preantral (11.5 vs 6, p<0.01) and antral (2 vs 1, p: 0.03) follicles, as well as corpora lutea (6 vs 3, p: 0.04), in the TMX group than in the control group. The number of atretic (2.5 vs 5, p: 0.048) follicles was increased in the TMX group.
  
  
  CONCLUSIONS
  Tamoxifen administration leads to arrested growth of gonadotropin-sensitive follicles, while insensitive follicles can remain unaffected. TMX is merely an endocrine disruptor, and it does not cause a decrease in primordial follicle pool.
authors.affiliation: Department of Obstetrics and Gynecology, Uludağ University Faculty of Medicine, Bursa, Turkey.
authors.forename: Ayşe Topçu
authors.initials: AT
authors.lastname: Akduman
authors.affiliation: Department of Obstetrics and Gynecology, Uludağ University Faculty of Medicine, Bursa, Turkey.
authors.forename: Kemal
authors.initials: K
authors.lastname: Özerkan
authors.affiliation: Department of Histology and Embryology, Uludağ University Faculty of Veterinary Medicine, Bursa, Turkey.
authors.forename: Berrin
authors.initials: B
authors.lastname: Zik
authors.affiliation: Department of Histology and Embryology, Uludağ University Faculty of Veterinary Medicine, Bursa, Turkey.
authors.forename: Sabire
authors.initials: S
authors.lastname: Peker
authors.affiliation: Department of Obstetrics and Gynecology, Uludağ University Faculty of Medicine, Bursa, Turkey ; Department of Histology and Embryology, Uludağ University Faculty of Medicine, Bursa, Turkey.
authors.forename: Berrin
authors.initials: B
authors.lastname: Avcı
authors.affiliation: Department of Obstetrics and Gynecology, Uludağ University Faculty of Medicine, Bursa, Turkey ; Department of Obstetrics and Gynecology, Koç University Faculty of Medicine, İstanbul, Turkey.
authors.forename: Barış
authors.initials: B
authors.lastname: Ata
keywords: Tamoxifen; anti-Müllerian hormone; antral follicle count; folliculogenesis; ovarian reserve