title: Effect of testosterone administration on serum and urine kallikrein concentrations in female-to-male transsexuals.
abstract: BACKGROUND
  Concentrations of human tissue kallikreins (hKs), a group of 15 secreted serine proteases found in many tissues, are modulated by steroid hormones in cancer cell lines. To gain insight into in vivo kallikrein regulation we measured kallikrein concentrations in serum and urinary tissue in female-to-male transsexuals before and after testosterone administration.
  
  
  METHODS
  We collected blood and urine samples before treatment and after 4 and 12 months from 28 female-to-male transsexuals who received 250 mg of testosterone esters intramuscularly every 2 weeks. We used ELISA assays to measure multiple kallikreins in serum and urine.
  
  
  RESULTS
  After testosterone administration, serum testosterone concentrations increased by approximately 15-fold. Serum kallikrein concentrations increased dramatically for hK3 (prostate-specific antigen) and increased moderately for hK2, hK5, hK6, hK7, hK8, hK10, and hK11. In urine, we noted major increases for hK3 and hK2 only. For all other kallikrein concentrations, we observed no considerable changes.
  
  
  CONCLUSIONS
  We conclude that, in serum and urine of female-to-male transsexuals after testosterone administration, hK3 (prostate-specific antigen) and to a lesser extent hK2 concentrations increase dramatically, but concentration of other kallikreins increase either moderately in serum (hK5, hK6, hK7, hK8, hK10, and hK11) or not at all in either serum (hK4, hK13, hK14) or urine (hK4, hK5, hK6, hK7, hK8, hK10, hK11, hK13, hK14).
authors.affiliation: Department of Endocrinology, Vrije Universiteit University Medical Centre, Amsterdam, The Netherlands, and Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada.
authors.forename: Margrita H
authors.initials: MH
authors.lastname: Slagter
authors.forename: Andreas
authors.initials: A
authors.lastname: Scorilas
authors.forename: Louis J G
authors.initials: LJ
authors.lastname: Gooren
authors.forename: Willem
authors.initials: W
authors.lastname: de Ronde
authors.forename: Antoninus
authors.initials: A
authors.lastname: Soosaipillai
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Giltay
authors.forename: Miltiadis
authors.initials: M
authors.lastname: Paliouras
authors.forename: Eleftherios P
authors.initials: EP
authors.lastname: Diamandis
mesh_terms: D000293:Adolescent; D000328:Adult; D000728:Androgens / Q000627:therapeutic use*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007610:Kallikreins / Q000097:blood* / Q000652:urine*; D008297:Male; D013739:Testosterone / Q000494:pharmacology*; D014189:Transsexualism / Q000378:metabolism*
chemical_list: D000728:Androgens; D013739:Testosterone; D007610:Kallikreins