title: Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats.
abstract: OBJECTIVE
  To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS).
  
  
  METHODS
  The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographies of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05%.
  
  
  RESULTS
  Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness.
  
  
  CONCLUSIONS
  Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head.
authors.affiliation: Postgraduate Program in Pathology, UFF, Niteroi, RJ, Brazil. carolberg12@hotmail.com
authors.forename: Ana Carolina Bergmann de
authors.initials: AC
authors.lastname: Carvalho
authors.forename: Gustavo Vieira Oliveira
authors.initials: GV
authors.lastname: Fernandes
authors.forename: Inayá
authors.initials: I
authors.lastname: Lima
authors.forename: Davi Ferreira de
authors.initials: DF
authors.lastname: Oliveira
authors.forename: Helene Nara
authors.initials: HN
authors.lastname: Henriques
authors.forename: José Augusto Soares
authors.initials: JA
authors.lastname: Pantaleão
authors.forename: José Mauro
authors.initials: JM
authors.lastname: Granjeiro
authors.forename: Ricardo Tadeu
authors.initials: RT
authors.lastname: Lopes
authors.forename: Maria Angélica
authors.initials: MA
authors.lastname: Guzmán-Silva
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D004195:Disease Models, Animal; D004812:Epidemiologic Methods; D020847:Estrogen Receptor Modulators / Q000008:administration & dosage / Q000009:adverse effects*; D004967:Estrogens / Q000172:deficiency*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D009652:Norpregnenes / Q000008:administration & dosage / Q000009:adverse effects*; D010052:Ovariectomy / Q000009:adverse effects*; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000473:pathology
chemical_list: D020847:Estrogen Receptor Modulators; D004967:Estrogens; D009652:Norpregnenes; C027385:tibolone