title: [Cardiomyocytes morphology and collagen quantification in the myocardium of female rats treated with isoflavones or estrogens].
abstract: OBJECTIVE
  To evaluate the histomorphometry of cardiomyocytes and collagen present in the myocardium of rats treated with a concentrated extract of soy or 17β-estradiol (E2).
  
  
  METHODS
  Twenty-eight rats were divided into four groups: GCtrl--estrus phase; GOvx--ovariectomized (Ovx) and receiving vehicle; GIso--Ovx and treated with soy extract (150 mg/kg per day); GE2--Ovx and treated with E2 (10 µg/kg per day). The drugs and vehicle (0.2 mL propylene glycol) were administered for 30 consecutive days after ovariectomy. On the last day the animals were anesthetized, the hearts removed, submerged in 10% formaldehyde and fragments of the ventricles underwent histological procedures, and the sections were stained with hematoxylin and eosin or picrosirius-red. Histomorphometric analysis (number and volume of nuclei and quantification of collagen) was performed under a light microscope with AxioVision Rel. 4.2 software, and collagen fibers were quantified using IMAGELAB-2000 software. Data were submitted to ANOVA followed by the Tukey test (p<0.05).
  
  
  RESULTS
  We observed a higher number of cardiomyocyte nuclei in animals of the Ovx and Iso groups than in GE2 and GCtrl animals (GOvx=121.7±20.2=GIso=92.8±15.4>GE2=70.5±14,8=GCtrl=66.3±9.6; p <0.05), while the nuclear volume was greater in the Ctrl and E2 groups (GE2=35.7±4.8 GCtrl=29.9±3.6=>GIso=26.5±4.5=GOvx=22.4±2.9; p <0.05). Collagen concentration was higher in the Ovx group (GOvx=5.4±0.1>GCtrl=4.0±0.1=GIso=4.4±0.08=GE2=4.3±0.5; p <0.05).
  
  
  CONCLUSIONS
  Estrogen may prevent the reduction of the nuclear volume of cardiomyocytes and collagen deposition between heart muscle fibers, while the administration of isoflavones only prevents the deposition of collagen, which can preserve the mechanical properties of cardiac fibers.
authors.affiliation: Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: Luciana Alécio
authors.initials: LA
authors.lastname: Cabanelas
authors.forename: Adriana Aparecida Ferraz
authors.initials: AA
authors.lastname: Carbonel
authors.forename: Miriam Aparecida
authors.initials: MA
authors.lastname: dos Santos
authors.forename: Ricardo Santos
authors.initials: RS
authors.lastname: Simões
authors.forename: Aroldo Walter
authors.initials: AW
authors.lastname: Liberatori-Filho
authors.forename: Edmund Chada
authors.initials: EC
authors.lastname: Baracat
authors.forename: José Maria
authors.initials: JM
authors.lastname: Soares Júnior
mesh_terms: D000818:Animals; D003094:Collagen / Q000032:analysis*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006321:Heart / Q000187:drug effects*; D007529:Isoflavones / Q000494:pharmacology*; D009206:Myocardium / Q000737:chemistry*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects*; D051381:Rats
chemical_list: D004967:Estrogens; D007529:Isoflavones; D003094:Collagen