title: Androgen receptors are expressed in a variety of human fetal extragenital tissues: an immunohistochemical study.
abstract: OBJECTIVE
  To investigate the expression of androgen receptors in the extragenital tissues of developing human embryo.
  
  
  METHODS
  Using immunohistochemistry, we investigated the distribution of androgen receptor (AR) in the extragenital tissues of paraffin-embedded tissue sections of first trimester (8-12 weeks gestation) human embryos. Gender was determined by polymerized chain reaction.
  
  
  RESULTS
  There were no differences in the expression and distribution of AR in male and female embryos at any stage of gestation. AR expression was seen in the thymus gland. The bronchial epithelium of the lungs showed intense positive staining with surrounding stroma negative. Furthermore, positive staining for androgen receptor was exhibited in the spinal cord with a few positive cells in the surrounding tissues. Cardiac valves also showed strong positive staining but with faint reactivity of the surrounding cardiac muscle. There was no staining in kidney, adrenal, liver or bowel.
  
  
  CONCLUSIONS
  This study demonstrates that immunoreactive AR protein is present in a wide variety of human first trimester fetal tissues and shows the potential for androgen affecting tissues, which are mostly not considered to be androgen dependent. Moreover, it implies that androgen might act as a trophic factor and affect the early development of these organs rather than simply sexual differentiation.
authors.affiliation: Reproductive Medicine Unit, Liverpool Women's Hospital, Crown Street, Liverpool L8 7SS, UK. y.sajjad@btinternet.com
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Sajjad
authors.forename: Siobhan
authors.initials: S
authors.lastname: Quenby
authors.forename: Paul
authors.initials: P
authors.lastname: Nickson
authors.forename: David Iwan
authors.initials: DI
authors.lastname: Lewis-Jones
authors.forename: Gill
authors.initials: G
authors.lastname: Vince
mesh_terms: D001980:Bronchi / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D005260:Female; D005333:Fetus / Q000166:cytology / Q000378:metabolism*; D006321:Heart / Q000196:embryology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology / Q000378:metabolism*
chemical_list: D011944:Receptors, Androgen