title: Aromatase inhibitor treatment limits progression of peritoneal endometriosis in baboons.
abstract: OBJECTIVE
  To determine the effect of inhibiting aromatase activity on endometrial lesion growth and aromatase expression in a baboon model of induced endometriosis.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Primate research institute.
  
  
  METHODS
  Sixteen olive baboons.
  
  
  METHODS
  Sixteen olive baboons with induced endometriosis were examined with laparoscopy 10 months after disease inoculation. Animals in group 1 (n = 10) were treated with 1.25 mg/d of the aromatase inhibitor (AI) letrozole, and animals in group 2 (n = 6) were given a placebo for a total of 6 months.
  
  
  METHODS
  Total number of endometriotic lesions, morphology, and volume of lesions, as well as semiquantitative reverse transcription-polymerase chain reaction and quantitative polymerase chain reaction for levels of aromatase cytochrome messenger RNA were measured. Ovarian volumes were evaluated before treatment initiation and every 2 months during the study.
  
  
  RESULTS
  Treatment of group 1 animals with an AI significantly decreased lesion volume from baseline measurements, whereas the placebo-treated animals showed an increase in lesion volume. Aromatase messenger RNA levels in lesions in the AI-treated animals were significantly lower compared with the placebo-treated animals. Ovarian volumes were significantly increased at 6 months of AI treatment compared with pretreatment volumes.
  
  
  CONCLUSIONS
  These findings suggest that suppression of aromatase cytochrome P450 may inhibit the in vivo growth of endometriotic lesions in baboons.
authors.affiliation: Institute for Primate Research, Nairobi, Kenya.
authors.forename: David
authors.initials: D
authors.lastname: Langoi
authors.forename: Mary Ellen
authors.initials: ME
authors.lastname: Pavone
authors.forename: Bilgin
authors.initials: B
authors.lastname: Gurates
authors.forename: Daniel
authors.initials: D
authors.lastname: Chai
authors.forename: Asgerally
authors.initials: A
authors.lastname: Fazleabas
authors.forename: Serdar E
authors.initials: SE
authors.lastname: Bulun
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics / Q000378:metabolism; D047072:Aromatase Inhibitors / Q000494:pharmacology*; D004195:Disease Models, Animal; D018450:Disease Progression; D004715:Endometriosis / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D010535:Laparoscopy; D000077289:Letrozole; D008598:Menstruation / Q000187:drug effects; D009570:Nitriles / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000187:drug effects* / Q000473:pathology; D048530:Papio anubis; D010537:Peritoneum / Q000187:drug effects / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D016896:Treatment Outcome; D014230:Triazoles / Q000494:pharmacology*
chemical_list: D047072:Aromatase Inhibitors; D009570:Nitriles; D012333:RNA, Messenger; D014230:Triazoles; D000077289:Letrozole; D001141:Aromatase