title: Increased expression of the leptin receptor in human ovaries affected by endometrioma and detection of high levels of leptin in the ovarian endometriomal fluid.
abstract: BACKGROUND
  This study was designed to investigate leptin levels in the fluid in ovarian endometriomas (OEs) and to compare the expression of leptin and its receptors (OBR) in ovarian tissue affected by endometrioma in infertile women to its expression in the normal ovarian tissue of fertile controls without endometriosis.
  
  
  METHODS
  In this case-control observational study, ovarian tissue, blood samples and peritoneal fluid were obtained from 20 women (10 fertile controls without endometriosis or any ovarian disease, who were undergoing tubal ligation surgery, and 10 infertile women with severe endometriosis and OE). The ovarian endometriomal fluid (EF) was aspirated, and peritoneal-implant (PI) biopsies were performed. The tissues removed during the surgeries were immediately frozen in liquid nitrogen to determine expression levels by western blot and leptin levels by ELISA.
  
  
  RESULTS
  OBR was expressed at higher levels in the ovarian tissue affected by endometrioma than in the normal ovarian tissue (control = 0.38 ± 0.05, study = 0.60 ± 0.09, p = 0.03), but there was no significant difference in leptin levels between these groups (control = 0.57 ± 0.1, study = 0.35 ± 0.1, p = 0.18). Positive and significant correlations were observed between leptin and OBR in the OE (r = 0.85, p = 0.004) and in the PI (r = 0.87, p = 0.001). ELISA results demonstrate a greater leptin concentration within the EF compared with the serum and the PF (serum = 14.25 ± 1.63, PF = 5.98 ± 2.0, EF = 73.8 ± 16.2, p = 0.0001), but there was no correlation between these variables. A positive, significant and strong correlation was observed between PF leptin levels and the expression of leptin and OBR in PI (leptin: r = 0.78, p = 0.007/OBR: r = 0.68, p = 0.04) and between the EF leptin levels and the expression of leptin and OBR in the OE (leptin: r = 0.88, p = 0.008/OBR: r = 0.89, p = 0.005).
  
  
  CONCLUSIONS
  These data suggest that leptin may play an important role in the physiopathology of OE through a modulatory interaction with its active receptor.
authors.affiliation: Department of Gynecology, Rio de Janeiro State University, 20551-030, Rio de Janeiro Brazil. carolzendron@hotmail.com.
authors.forename: Carolina
authors.initials: C
authors.lastname: Zendron
authors.forename: Helder F
authors.initials: HF
authors.lastname: Gonçalves
authors.forename: Fernanda S
authors.initials: FS
authors.lastname: Cavalcante
authors.forename: Thiago R D
authors.initials: TR
authors.lastname: Pereira
authors.forename: Alessandra
authors.initials: A
authors.lastname: Evangelista
authors.forename: Cristiane F
authors.initials: CF
authors.lastname: Ramos
authors.forename: Marco Aurelio P
authors.initials: MA
authors.lastname: Oliveira
mesh_terms: D000328:Adult; D001202:Ascitic Fluid / Q000737:chemistry*; D016022:Case-Control Studies; D004715:Endometriosis / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000209:etiology / Q000378:metabolism; D020738:Leptin / Q000032:analysis* / Q000097:blood; D010049:Ovarian Diseases / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D010053:Ovary / Q000737:chemistry*; D054411:Receptors, Leptin / Q000032:analysis*; D015854:Up-Regulation
chemical_list: C515448:LEPR protein, human; D020738:Leptin; D054411:Receptors, Leptin