title: Expression of angiopoietin 1 and 2 in ectopic endometrium on the chicken chorioallantoic membrane.
abstract: OBJECTIVE
  To investigate the role of angiopoietin 1 and 2 (ANGPT1/ANGPT2) in angiogenesis of the ectopic endometrium as a crucial step in the development of an endometriotic lesion, we analyzed their expression patterns in an experimental model of endometriosis.
  
  
  METHODS
  Experimental prospective study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Endometrium samples obtained from healthy, ovulating women undergoing hysterectomy for benign gynecologic conditions.
  
  
  METHODS
  Endometrial fragments were transplanted to the chicken chorioallantoic membrane (CAM) and cultivated for 0, 24, 48, and 72 hours.
  
  
  METHODS
  Expression of ANGPT1 and ANGPT2 mRNA was quantified by competitive reverse transcriptase polymerase chain reaction (RT-PCR) and normalized to expression of the housekeeping gene human glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA. The expression of ANGPT1 and ANGPT2 protein was analyzed by immunohistochemical staining.
  
  
  RESULTS
  All grafts expressed ANGPT1 and ANGPT2 mRNA. The mRNA concentration of both factors decreased after cultivation, but the ANGPT2/ANGPT1 ratio increased considerably during the first 24 hours of cultivation. The immunohistochemical investigation for ANGPT1 and ANGPT2 revealed presence of both proteins at all the times but no obvious correlation with the duration of cultivation.
  
  
  CONCLUSIONS
  The ratio of ANGPT2/ANGPT1 mRNA in endometrial grafts increased after 24 hours of cultivation on the chicken chorioallantoic membrane and shows a shift toward a more dominant role of ANGPT2. This agrees with the current model of angiopoietin action in angiogenesis and might indicate angiogenic activity in the endometrial graft. The angiopoietins are likely to play an important role in the pathogenesis of endometriosis.
authors.affiliation: Institute of Physiology, Medical University of Luebeck, Luebeck, Germany.
authors.forename: Merle
authors.initials: M
authors.lastname: Drenkhahn
authors.forename: Dorothee Maria
authors.initials: DM
authors.lastname: Gescher
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Wolber
authors.forename: Annette
authors.initials: A
authors.lastname: Meyhoefer-Malik
authors.forename: Eduard
authors.initials: E
authors.lastname: Malik
mesh_terms: D000482:Allantois / Q000378:metabolism*; D042683:Angiopoietin-1 / Q000235:genetics / Q000378:metabolism*; D042702:Angiopoietin-2 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002645:Chickens; D002823:Chorion / Q000378:metabolism*; D004715:Endometriosis / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors
chemical_list: D042683:Angiopoietin-1; D042702:Angiopoietin-2; D012333:RNA, Messenger