title: Testosterone-induced prostate growth is blocked by co- and preadministration of norethisterone enanthate in castrated cynomolgus monkeys.
abstract: BACKGROUND
  Prostate size and function are regulated by testosterone. However, the progesterone receptor is expressed in the primate prostate. Progestins affect the prostate by endocrine suppression, but can also act directly. Examining the role of progestins, we studied the effects of norethisterone (NET) on testosterone undecanoate (TU)-induced prostate growth in castrated macaques.
  
  
  METHODS
  Two groups (n = 6 for each group) received TU every 9 weeks. Using a crossover setting, group I received norethisterone enanthate (NETE) 3 times at 3-week intervals, while group II received placebo. After 9 weeks, placebo was administered to group I, and group II received NETE.
  
  
  RESULTS
  In group II, the prostate grew under TU and placebo over the first period. In group I, coadministered with NETE, the increase was lower. After the crossover, prostates of animals previously treated with NETE did not increase to normal values under placebo. Prostates of animals treated with TU and placebo in the first period shrank following NETE administration after the crossover. The long half-life of NET can explain the lack of a TU effect on animals coadministered with NETE after the crossover.
  
  
  CONCLUSIONS
  Pre- and coadministration of NET reduces testosterone-induced prostate growth with possible implications for the treatment of benign prostate hyperplasia and hormonal male contraception.
authors.affiliation: Centre of Reproductive Medicine and Andrology, University Hospital, Münster, Germany. joachim.wistuba @ ukmuenster.de
authors.forename: Joachim
authors.initials: J
authors.lastname: Wistuba
authors.forename: Eberhard
authors.initials: E
authors.lastname: Nieschlag
authors.forename: Axel
authors.initials: A
authors.lastname: Semjonow
authors.forename: Reinhild
authors.initials: R
authors.lastname: Sandhowe-Klaverkamp
authors.forename: Stephanie
authors.initials: S
authors.lastname: Friderichs-Gromoll
authors.forename: Michael
authors.initials: M
authors.lastname: Zitzmann
authors.forename: Manuela
authors.initials: M
authors.lastname: Simoni
authors.forename: C Marc
authors.initials: CM
authors.lastname: Luetjens
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D001835:Body Weight / Q000187:drug effects; D004334:Drug Administration Schedule; D006400:Hematocrit; D020249:Hormone Replacement Therapy; D008252:Macaca fascicularis; D008297:Male; D009640:Norethindrone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D009919:Orchiectomy; D009929:Organ Size / Q000187:drug effects; D011372:Progestins / Q000008:administration & dosage* / Q000097:blood; D011467:Prostate / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D013997:Time Factors
chemical_list: D015415:Biomarkers; D011372:Progestins; D013739:Testosterone; C010792:testosterone undecanoate; C024319:norethindrone enanthate; D009640:Norethindrone