title: Effects of melatonin on histomorphology and on the expression of steroid receptors, VEGF, and PCNA in ovaries of pinealectomized female rats.
abstract: OBJECTIVE
  To evaluate the effect of melatonin both on the ovaries of pinealectomized female rats through histomorphometric analysis and on steroid receptors, proliferating cell nuclear antigen (PCNA), and vascular endothelial growth factor (VEGF) expression.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Federal University of São Paulo, Brazil.
  
  
  METHODS
  Forty female rats.
  
  
  METHODS
  Forty rats were divided equally into four groups: GI-vehicle without surgery; GII--surgery without removal of the pineal gland (sham); GIII--pinealectomized with vehicle; and GIV--pinealectomized with melatonin treatment. After treatment for 3 consecutive months, the animals were killed and their ovaries removed for analysis.
  
  
  METHODS
  Estrogen and progesterone receptors, histologic and immunohistochemical analysis.
  
  
  RESULTS
  The GIII samples presented signals of proliferation on ovarian surface epithelium and interstitial cells as well as high expressions of PCNA and VEGF in those structures compared with GI, GII, and GIV. Also, the levels of progesterone receptor (fmol/g) in ovaries of GIII (250.6 ± 32.4) were significantly lower than in those of GI (429.0 ± 23,8), GII (442.3 ± 30.2), and GIV (564.1 ± 78.7). The levels of progesterone in GIII were superior to those in GI, GII, and GIV.
  
  
  CONCLUSIONS
  Our findings suggest that melatonin may attenuate proliferation in ovarian structures and increase the number of luteal bodies as well as the levels of progesterone receptor.
authors.affiliation: Gynecology Department, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Lucrecia Regina G
authors.initials: LR
authors.lastname: Romeu
authors.forename: Eduardo Leme A
authors.initials: EL
authors.lastname: da Motta
authors.forename: Carla C
authors.initials: CC
authors.lastname: Maganhin
authors.forename: Celina T F
authors.initials: CT
authors.lastname: Oshima
authors.forename: Marcelle C
authors.initials: MC
authors.lastname: Fonseca
authors.forename: Karina F
authors.initials: KF
authors.lastname: Barrueco
authors.forename: Ricardo S
authors.initials: RS
authors.lastname: Simões
authors.forename: Renata
authors.initials: R
authors.lastname: Pellegrino
authors.forename: Edmund C
authors.initials: EC
authors.lastname: Baracat
authors.forename: José M
authors.initials: JM
authors.lastname: Soares-Junior
mesh_terms: D000818:Animals; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D008550:Melatonin / Q000502:physiology*; D010053:Ovary / Q000166:cytology / Q000378:metabolism*; D010870:Pineal Gland / Q000378:metabolism / Q000601:surgery*; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis*; D011485:Protein Binding / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D011987:Receptors, Steroid / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D011987:Receptors, Steroid; D042461:Vascular Endothelial Growth Factor A; D008550:Melatonin