title: Nitric Oxide Synthase is Necessary for Normal Urogenital Development.
abstract: BACKGROUND
  Neuronal nitric oxide synthase (NOS-I) is significantly decreased with Cavernous Nerve (CN) injury in Erectile Dysfunction (ED) models. Increased apoptosis and collagen deposition accompany decreased NOS/CN injury, however these changes are typically attributed to the altered signaling of other factors, and a contribution of NOS in maintenance of urogenital structures has not previously been examined. Morphological changes in the corpora cavernosa occur at the same time as decreased NOS, suggesting a potential connection between decreased/inhibited NOS and morphological changes associated with ED. In this study we propose that NOS impacts urogenital morphology during development and will examine this hypothesis by NOS inhibition with L-NAME.
  
  
  METHODS
  Primary outcomes were H&E, western and TUNEL to determine if penis, prostate and bladder morphology were altered with L-NAME treatment of Postnatal day 4 (P4) Sprague Dawley rats for 8 days. Tissue weight and immunohistochemical analysis for NOS were performed. Secondary evaluation of NOS-I regulation by Sonic Hedgehog (SHH) was examined by SHH inhibition in the pelvic ganglia (PG) and NOS-I protein was quantified by western in the PG/CN and penis. Nos abundance was quantified by RT-PCR during urogenital development and after CN injury.
  
  
  RESULTS
  Apoptosis increased and penis, prostate and bladder morphology were altered with L-NAME. NOS inhibition decreased bladder weight 25%. SHH inhibition decreased NOS-I 35% in the PG/CN and 47% in the penis. Nos-III expression spiked within the first two weeks after birth in the penis but remained abundant in the adult. In the prostate, Nos-III was abundant immediately after birth and declined steadily with age. Nos-I expression in the PG/CN decreased sharply with CN injury and returned to baseline by 7 days.
  
  
  CONCLUSIONS
  NOS is required for normal urogenital development. Since NOS is decreased with ED, it may contribute to the abnormal morphology observed in ED patients and animal models.
authors.affiliation: Department of Urology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bond
authors.affiliation: Department of Urology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Omer Onur
authors.initials: OO
authors.lastname: Cakir
authors.affiliation: Division of Urology, Southern Illinois University School of Medicine, Springfield, IL, USA.
authors.forename: Kevin T
authors.initials: KT
authors.lastname: McVary
authors.affiliation: Department of Urology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Carol A
authors.initials: CA
authors.lastname: Podlasek
keywords: Bladder; Development; NOS; Penis; Prostate; Urogenital