title: The effect of oral contraceptive pills on markers of endometrial receptivity.
abstract: OBJECTIVE
  To determine if oral contraceptive (OC) usage alters expression of integrins associated with endometrial receptivity.
  
  
  METHODS
  Immunohistochemical staining intensity for integrins was compared in frozen sections of endometrial tissue specimens obtained from women with normal ovulatory cycles (n = 23; cycle days 20 to 24 based on LH surge) and from those taking oral contraceptives pills (n = 23; cycle days 5 to 27).
  
  
  METHODS
  University-based outpatient infertility clinic.
  
  
  RESULTS
  Constitutive integrin expression in the endometrium (alpha 2 beta 1, alpha 3 beta 1, alpha 5 beta 1, alpha 6 beta 1, and alpha 6 beta 4) was similar in OC users and normally cycling individuals, except for an increase in epithelial alpha 3 beta 1 in OC users. Oral contraceptive use was associated with significant alterations in cycle-dependent integrin expression (alpha 1 beta 1, alpha 4 beta 1, and alpha v beta 3). Specifically, we observed increased glandular alpha 4 beta 1, and decreased alpha v beta 3 expression. The P-regulated alpha 1 subunit was present in both groups. Increased stromal alpha v and beta 3 and decreased alpha 3 beta 1 and alpha 6 beta 1 staining was observed in OC users.
  
  
  CONCLUSIONS
  Expression of those integrins most closely associated with endometrial receptivity, alpha v beta 3 and alpha 4 beta 1, is altered in the glandular epithelium of women taking OCs. Stromal integrin expression in OC users also differs from that in cycling women. These alterations in epithelial and stromal integrin expression suggest that impaired uterine receptivity is one mechanism whereby OCs exert their contraceptive actions.
authors.affiliation: Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill 27599-7570, USA.
authors.forename: S G
authors.initials: SG
authors.lastname: Somkuti
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: C W
authors.initials: CW
authors.lastname: Yowell
authors.forename: M A
authors.initials: MA
authors.lastname: Fritz
authors.forename: B A
authors.initials: BA
authors.lastname: Lessey
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal; D003276:Contraceptives, Oral / Q000494:pharmacology*; D004717:Endometrium / Q000166:cytology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D039041:Integrin alpha4beta1; D016023:Integrins / Q000378:metabolism*; D038981:Receptors, Collagen; D016201:Receptors, Lymphocyte Homing / Q000378:metabolism*; D019030:Receptors, Vitronectin / Q000378:metabolism*; D013194:Staining and Labeling; D017154:Stromal Cells / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D003276:Contraceptives, Oral; D039041:Integrin alpha4beta1; D016023:Integrins; D038981:Receptors, Collagen; D016201:Receptors, Lymphocyte Homing; D019030:Receptors, Vitronectin