title: The expression of activins, their type II receptors and follistatin in human Fallopian tube during the menstrual cycle and in pseudo-pregnancy.
abstract: BACKGROUND
  The Fallopian tube (FT) is the site of fertilization and early embryonic development. We have previously reported the expression of activins, their receptors and follistatin by the FT. Here, our aim was to study the expression of tubal activins, their type II receptors and follistatin during the menstrual cycle and following exposure to hCG in vivo.
  
  
  METHODS
  A set of 30 FTs were collected from cycling women (n = 12) at different stages of the cycle (n = 4 in each stage) and pseudo-pregnant women (n = 3) at the time of hysterectomy for benign disease. The pseudo-pregnant women were injected with hCG in the days leading up to hysterectomy, and pseudo-pregnancy was confirmed by the persistence of amenorrhea, the presence of corpus luteum and decidualization of the endometrium. FT specimens were examined using immunohistochemistry and quantitative RT-PCR.
  
  
  RESULTS
  The expression of activin βA- and βB-subunits, activin type IIA and IIB receptors, and follistatin varied throughout the menstrual cycle, being lowest in the follicular phase and highest in the luteal phase. These results were demonstrated at the mRNA and protein level by quantitative RT-PCR and immunohistochemistry (P< 0.05). HCG injection rescued the expression of the candidate molecules from falling to the follicular stage levels but the expression remained lower than in the luteal phase.
  
  
  CONCLUSIONS
  We suggest that activins play a role in tubal physiology and early embryonic development. Additionally, exposure of the tubal epithelium to hCG modulates the expression of tubal activins.
authors: Laboratory Medicine Department, College of Applied Medical Sciences,  Umm Al-Qura University, Mecca,  Kingdom of Saudi Arabia.
authors: Bassem
authors: B
authors: Refaat
authors: William
authors: W
authors: Ledger
mesh_terms: D030301:Activin Receptors, Type II / Q000378:metabolism* / Q000502:physiology; D028341:Activins / Q000378:metabolism* / Q000502:physiology; D000328:Adult; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D008597:Menstrual Cycle / Q000378:metabolism*; D011555:Pseudopregnancy / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D006063:Chorionic Gonadotropin; D028341:Activins; D030301:Activin Receptors, Type II