title: Immunohistochemical characterization of endometriosis-associated smooth muscle cells in human peritoneal endometriotic lesions.
abstract: BACKGROUND
  Smooth muscle cells (SMC) are common components of endometriotic lesions. SMC have been characterized previously in peritoneal, ovarian and deep infiltrating endometriotic lesions and adenomyosis. The aim of this retrospective study was to investigate the extent of differentiation in endometriosis-associated SMC (EMaSMC) in peritoneal endometriotic lesions.
  
  
  METHODS
  We obtained biopsies from peritoneal endometriotic lesions (n = 60) and peritoneal sites distant from the endometriotic lesion (n = 60), as well as healthy peritoneum from patients without endometriosis (control tissue, n = 10). These controls were hysterectomy specimens from patients without endometriosis or adenomyosis. Histopathological examination of peritoneal specimens using antibodies against oxytocin receptor (OTR), vasopressin receptor (VPR), smooth muscle myosin heavy chain (SM-MHC), estrogen receptor (ER) or progesterone receptor (PR) was performed. To identify SMC and their level of differentiation, antibodies for smooth muscle actin desmin and caldesmon were used.
  
  
  RESULTS
  SMC were detected in all endometriotic lesions. SMC were more abundant in unaffected peritoneum of women with endometriosis (38%) compared with women without endometriosis (6%; P < 0.0001). Depending on the level of differentiation, SMC stained for SM-MHC, OTR, VPR, ER and PR. OTR was only detected in fully differentiated SMC.
  
  
  CONCLUSIONS
  Identification of OTR, VPR, ER and PR leads to the hypothesis that the EMaSMC might be functionally active and possibly involved in the generation of pain associated with endometriosis.
authors.affiliation: Endometriosis Research Center Berlin, Department of Gynecology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Barcena de Arellano
authors.forename: Jessica
authors.initials: J
authors.lastname: Gericke
authors.forename: Uta
authors.initials: U
authors.lastname: Reichelt
authors.forename: Ali Fuat
authors.initials: AF
authors.lastname: Okuducu
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Ebert
authors.forename: Vito
authors.initials: V
authors.lastname: Chiantera
authors.forename: Achim
authors.initials: A
authors.lastname: Schneider
authors.forename: Sylvia
authors.initials: S
authors.lastname: Mechsner
mesh_terms: D000328:Adult; D001706:Biopsy / Q000379:methods; D002454:Cell Differentiation; D004715:Endometriosis / Q000473:pathology*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008875:Middle Aged; D009130:Muscle, Smooth / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000378:metabolism; D010537:Peritoneum / Q000473:pathology*; D017697:Premenopause; D011960:Receptors, Estrogen / Q000378:metabolism; D018045:Receptors, Oxytocin / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies
chemical_list: D011960:Receptors, Estrogen; D018045:Receptors, Oxytocin; D011980:Receptors, Progesterone; D018995:Myosin Heavy Chains