title: Fetal distribution of 5alpha-reductase 1 and 5alpha-reductase 2, and their input on human prostate development.
abstract: OBJECTIVE
  Human prostate development starts in the tenth week of gestation. Initial interactions between the epithelium and mesenchyma are stimulated by androgens. The transformation of circulating testosterone to 5alpha-dihydrotestosterone by tissue linked 5alpha-reductase is a key event in androgen metabolism. The 5alpha-dihydrotestosterone mediates androgen effects in the urogenital sinus and external genitalia, leading to the formation of a male phenotype and androgen mediated prostate growth. Supposedly 5alpha-reductase 2 is the predominant isoenzyme in human accessory sex tissue, whereas the function of 5alpha-reductase 1 remains unclear. We focused on the detection, distribution and effects of the 2 isoenzymes during gestation and infancy.
  
  
  METHODS
  Serial sections from fetuses and infants were immunostained using antibodies directed against 5alpha-reductase 1 and 2. Additionally, to detect the downstream products of androgen synthesis reverse transcriptase-polymerase chain reaction analyses were done for 17 beta-hydroxysteroid dehydrogenase types 2, 3 and 7.
  
  
  RESULTS
  Immunohistochemistry revealed positive staining for each isoenzyme throughout fetal development. Moreover, reverse transcriptase-polymerase chain reaction for 5alpha-reductase 1 and 2 confirmed these findings on the transcription level. Additionally, the most relevant enzymatic downstream products of cellular androgen synthesis (17 beta-hydroxysteroid dehydrogenase 2, 3 and 7) were also detected by reverse transcriptase-polymerase chain reaction.
  
  
  CONCLUSIONS
  To our knowledge this is the first study revealing the expression and distribution of each 5alpha-reductase isoenzyme as well as the potential contribution of 5alpha-reductase 1 during fetal human prostate development.
authors.affiliation: Department of Urology, Hanuschkrankenhaus, Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Lunacek
authors.forename: C
authors.initials: C
authors.lastname: Schwentner
authors.forename: J
authors.initials: J
authors.lastname: Oswald
authors.forename: H
authors.initials: H
authors.lastname: Fritsch
authors.forename: C
authors.initials: C
authors.lastname: Sergi
authors.forename: L N
authors.initials: LN
authors.lastname: Thomas
authors.forename: R S
authors.initials: RS
authors.lastname: Rittmaster
authors.forename: H
authors.initials: H
authors.lastname: Klocker
authors.forename: H
authors.initials: H
authors.lastname: Neuwirt
authors.forename: G
authors.initials: G
authors.lastname: Bartsch
authors.forename: C
authors.initials: C
authors.lastname: Radmayr
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000235:genetics; D042944:Cholestenone 5 alpha-Reductase / Q000235:genetics*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007124:Immunoenzyme Techniques; D007231:Infant, Newborn; D007527:Isoenzymes / Q000235:genetics*; D008297:Male; D011247:Pregnancy; D011467:Prostate / Q000196:embryology* / Q000254:growth & development; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D007527:Isoenzymes; D015067:17-Hydroxysteroid Dehydrogenases; D042944:Cholestenone 5 alpha-Reductase