title: TRPV1 expression on peritoneal endometriosis foci is associated with chronic pelvic pain.
abstract: OBJECTIVE
  To investigate the expression of capsaicin receptor (transient receptor potential vanilloid type 1 [TRPV1]) in the peritoneal endometriosis foci of women with and without chronic pelvic pain (CPP).
  
  
  METHODS
  A case-control study was conducted on 49 women with endometriosis who underwent laparoscopy, 28 of whom had CPP and 21 without CPP. Samples from peritoneum of the rectouterine excavation (2 cm2) were obtained by laparoscopy, fixed in 4% formaldehyde, and underwent immunohistochemistry analysis using rabbit anti-TRPV1 (1:400) polyclonal antibody.
  
  
  RESULTS
  Image analysis revealed that the immunoreactivity for TRPV1 was more frequent in specimens (endometriosis foci) from women with CPP (n = 15 of 28, 53.6%), compared to samples from the endometriosis foci of women without CPP (n = 6 of 21, 28.6%; P = .04). There was no correlation with duration, intensity of pain, or stage of the disease (endometriosis).
  
  
  CONCLUSIONS
  The present study shows that TRPV1 expression in peritoneal endometriosis foci is related to CPP in women. However, this association is not related to the endometriosis stage. In view of the immunoreactivity for TRPV1 observed here, we believe that some endometriotic lesions may provide a scenario for TRPV1 to be tonically active and this activity may contribute to the underlying pathology of CPP.
authors.affiliation: Department of Obstetrics and Gynecology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Marcelo Gondim
authors.initials: MG
authors.lastname: Rocha
authors.forename: Júlio César Rosa
authors.initials: JC
authors.lastname: e Silva
authors.forename: Alfredo
authors.initials: A
authors.lastname: Ribeiro da Silva
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: Candido Dos Reis
authors.forename: Antonio Alberto
authors.initials: AA
authors.lastname: Nogueira
authors.forename: Omero Benedicto
authors.initials: OB
authors.lastname: Poli-Neto
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002908:Chronic Disease; D004715:Endometriosis / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D010535:Laparoscopy; D017699:Pelvic Pain / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D010537:Peritoneum / Q000378:metabolism*; D012720:Severity of Illness Index; D050916:TRPV Cation Channels / Q000378:metabolism*
chemical_list: D050916:TRPV Cation Channels; C494482:TRPV1 protein, human