title: Ultrastructure of epithelial plaque formation and stromal cell transformation by post-ovulatory chorionic gonadotrophin treatment in the baboon (Papio anubis).
abstract: BACKGROUND
  To understand factors controlling endometrial responses to pregnancy, we have established a model using the baboon and examined the effects of infused human chorionic gonadotrophin (HCG) on the preparation of the luminal epithelium and stromal cell differentiation for the establishment of pregnancy.
  
  
  METHODS
  The ultrastructure of endometrium from normal day 10 post-ovulation animals, cycling females treated with either HCG or FSH (control), and a day 15 pregnant animal has been compared.
  
  
  RESULTS
  In the control endometrium, the luminal epithelium was smooth and regular, with underlying spindle shaped stromal cells. In pregnancy, the luminal epithelium underwent a plaque reaction, while stromal cells enlarged and developed filament-rich cell processes. Infusion of HCG produced changes similar to those seen in pregnancy, with generalized plaque formation and stromal decidualization, while in the animal treated with FSH there was no response.
  
  
  CONCLUSIONS
  This study indicates that infusion of HCG into the uterus can duplicate many of the responses of the endometrium to pregnancy, although in this case the plaque reaction involved the whole of the luminal epithelium, rather than only the implantation site as in pregnancy.
authors.affiliation: Academic Unit of Obstetrics and Gynaecology, University of Manchester, St Mary's Hospital, Whitworth Park, Manchester M13 0JH, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Jones
authors.forename: A T
authors.initials: AT
authors.lastname: Fazleabas
mesh_terms: D000199:Actins / Q000032:analysis; D000818:Animals; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000494:pharmacology*; D003656:Decidua / Q000648:ultrastructure; D010064:Embryo Implantation; D004717:Endometrium / Q000187:drug effects* / Q000648:ultrastructure*; D004848:Epithelium / Q000648:ultrastructure; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006358:Hot Temperature; D006984:Hypertrophy; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D008854:Microscopy, Electron; D010060:Ovulation; D010215:Papio; D011247:Pregnancy; D011994:Recombinant Proteins / Q000494:pharmacology; D017154:Stromal Cells / Q000648:ultrastructure*; D013997:Time Factors
chemical_list: D000199:Actins; D006063:Chorionic Gonadotropin; D011994:Recombinant Proteins; D007633:Keratins; D005640:Follicle Stimulating Hormone