title: The effect of hyperbaric oxygen therapy on erectile function recovery in a rat cavernous nerve injury model.
abstract: BACKGROUND
  Cavernosal oxygenation appears to be important for preservation of erectile tissue health. Hyperbaric oxygen therapy (HBOT) has been shown to improve tissue oxygenation and has neuromodulatory effects.
  
  
  OBJECTIVE
  This study was designed to define the effects of HBOT on erectile function (EF) and cavernosal tissue in the rat cavernous nerve (CN) injury model.
  
  
  METHODS
  Four groups of Sprague-Dawley rats were studied: rats with bilateral CN crush, HBOT treated (Crush+/HBOT+); bilateral CN-crush/no HBOT (C+/H-); no crush/no HBOT (C-/H-); and no crush/HBOT (C-/H+). HBOT was delivered daily for 90 minutes at three atmospheres for 10 days commencing the day of CN crush.
  
  
  METHODS
  Ten days after CN injury, the animals underwent CN stimulation measuring the maximal intracavernosal pressure/mean arterial pressure (ICP/MAP) ratios. Corporal tissue was harvested pre-sacrifice, and immunohistochemically stained for nerve growth factor (NGF), endothelial nitric oxide synthase (eNOS), and cluster of differentiation molecule (CD31). Histologic analysis was performed for Masson's trichrome to assess the smooth muscle-collagen ratio. Terminal deoxynucleotidyl transferase Biotin-dUTP Nick End Labeling assay was used to define apoptotic indices (AIs).
  
  
  RESULTS
  The C+/H- group had significantly lower ICP/MAP ratios compared with C-/H- rats, (31% vs. 70%, P < 0.001). C+/H+ rats had significantly higher ICP/MAP ratio recovery compared with the C+/H- group (55% vs. 31%, P = 0.005). NGF and eNOS staining densities were higher in C+/H+ rats compared with C+/H- rats (P < 0.05 and P < 0.001, respectively). No difference was seen in CD31 expression. Staining density for MT displayed a trend toward higher smooth muscle preservation after HBOT. AIs were significantly increased by HBOT (P < 0.05).
  
  
  CONCLUSIONS
  HBOT following a CN injury improved EF preservation in this model, supporting the cavernosal oxygenation concept as protective mechanism for EF. The effects appear to be mediated via preservation of neurotrophic and endothelial factor expression.
authors.affiliation: Department of Urology, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Müller
authors.forename: Raanan
authors.initials: R
authors.lastname: Tal
authors.forename: John F
authors.initials: JF
authors.lastname: Donohue
authors.forename: Yemi
authors.initials: Y
authors.lastname: Akin-Olugbade
authors.forename: Keith
authors.initials: K
authors.lastname: Kobylarz
authors.forename: Darius
authors.initials: D
authors.lastname: Paduch
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Cutter
authors.forename: Babak J
authors.initials: BJ
authors.lastname: Mehrara
authors.forename: Peter T
authors.initials: PT
authors.lastname: Scardino
authors.forename: John P
authors.initials: JP
authors.lastname: Mulhall
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D007172:Erectile Dysfunction / Q000473:pathology / Q000628:therapy*; D006931:Hyperbaric Oxygenation; D007150:Immunohistochemistry; D008297:Male; D009409:Nerve Crush; D020932:Nerve Growth Factor / Q000378:metabolism; D009416:Nerve Regeneration; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D010413:Penis / Q000293:injuries / Q000294:innervation* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D020932:Nerve Growth Factor; D052250:Nitric Oxide Synthase Type III