title: Effects of low dose of tibolone on steroid receptors and Bcl-2 on the postmenopausal endometrium.
abstract: OBJECTIVE
  A prospective randomized controlled trial was conducted to evaluate the effect of low dose of tibolone on the histology, expression of estrogen (ER) and progesterone receptors (PR) and Bcl-2 protein, in endometrium of postmenopausal women.
  
  
  METHODS
  Forty postmenopausal women consented to treatment and were allocated into two groups of 20 women: Group 1 (Control) without hormone replacement therapy (HRT); Group 2 (Tibolone) treatment at the dose of 1.25 mg/day of oral tibolone administered for a 24-week period. The effect on the endometrium was assessed by histology and the apoptosis marker Bcl-2. The immunoexpression of ER and PR were also measured.
  
  
  RESULTS
  Tibolone group showed higher expression of ER, PR and Bcl-2 protein in glandular epithelium and stroma compared to control group.
  
  
  CONCLUSIONS
  Tibolone in a daily dose of 1.25 mg during 24 weeks demonstrated endometrial action that resulted in low proliferation and was shown to lead to atrophic endometrium. It had favorable effects on the postmenopausal endometrium due to its higher immunoexpression of PR and Bcl-2 protein in endometrial glandular epithelium, thereby creating a balance between pro-apoptotic and anti-apoptotic actions.
authors.affiliation: Department of Gynecology and Obstetrics, Santa Casa of Sao Paulo Medical School, Sao Paulo and Department of Gynecology and Obstetrics, Vale do Sapucaí University, Pouso Alegre, Minas Gerais, Brazil. benefabiano@uol.com.br.
authors.forename: Benedito Fabiano
authors.initials: BF
authors.lastname: Reis
authors.affiliation: Department of Gynecology and Obstetrics, Santa Casa of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Sonia Maria Rolim R
authors.initials: SM
authors.lastname: Lima
authors.affiliation: Department of Gynecology and Obstetrics, Santa Casa of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Gustavo Maximiliano D
authors.initials: GM
authors.lastname: Silva
authors.affiliation: Department of Gynecology and Obstetrics, Vale do Sapucaí University, Pouso Alegre, Minas Gerais, Brazil.
authors.forename: Antonio Marcos C
authors.initials: AM
authors.lastname: Francisco
authors.affiliation: Department of Gynecology and Obstetrics, Vale do Sapucaí University, Pouso Alegre, Minas Gerais, Brazil.
authors.forename: Lyliana Coutinho R
authors.initials: LC
authors.lastname: Barbosa
authors.affiliation: Department of Gynecology and Obstetrics, Vale do Sapucaí University, Pouso Alegre, Minas Gerais, Brazil.
authors.forename: Silvania C Vieira
authors.initials: SC
authors.lastname: Archangelo
authors.affiliation: Department of Pathology, Vale do Sapucaí University, Pouso Alegre, Minas Gerais, Brazil.
authors.forename: Rogerio M
authors.initials: RM
authors.lastname: Grande
mesh_terms: D004311:Double-Blind Method; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism; D020847:Estrogen Receptor Modulators / Q000008:administration & dosage / Q000627:therapeutic use*; D015914:Estrogen Replacement Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009652:Norpregnenes / Q000008:administration & dosage / Q000627:therapeutic use*; D017698:Postmenopause; D011446:Prospective Studies; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000187:drug effects; D011960:Receptors, Estrogen / Q000096:biosynthesis / Q000187:drug effects; D011980:Receptors, Progesterone / Q000096:biosynthesis / Q000187:drug effects
chemical_list: D020847:Estrogen Receptor Modulators; D009652:Norpregnenes; D019253:Proto-Oncogene Proteins c-bcl-2; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C027385:tibolone