title: Spontaneous recovery of cavernous nerve crush injury.
abstract: OBJECTIVE
  To investigate pathophysiological consequences and spontaneous recovery after cavernous nerve crush injury (CNCI) in a rat model.
  
  
  METHODS
  Twenty 4-week-old male Sprague-Dawley rats were divided into the following groups: sham-operated group (n=10) and bilateral CNCI groups (n=10) for two different durations (12 and 24 weeks). At both time points, CN electrical stimulation was used to assess erectile function by measuring the intracavernous pressure. The expression of hypoxia inducible factor (HIF)-1α and sonic hedgehog (SHH) was examined in penile tissue. Immunohistochemical staining was performed for nerve growth factor (NGF), endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), and smooth muscle α-actin.
  
  
  RESULTS
  CNCI significantly decreased erectile function at 12 weeks (51.7% vs. 71.9%, mean ICP/BP ratio, p<0.05) and increased the expression of HIF-1α and decreased the expression of eNOS, nNOS, and SHH. At 24 weeks, erectile function in the CNCI group was improved with no significant difference versus the sham group (70.5% vs. 63.3%, mean ICP/BP ratio, p<0.05) or the CN group at 12 weeks (51.7% vs. 63.3%, mean ICP/BP ratio, p<0.05). By RT-PCR, the increase in HIF-1α and decrease in SHH mRNA was restored at 24 weeks. By immunohistochemistry, the expression of eNOS and nNOS was increased at 24 weeks.
  
  
  CONCLUSIONS
  CN injury induces significantly impaired erectile function and altered gene and protein expression, which suggests that local hypoxic and inflammatory processes may contribute to this change. Significant spontaneous recovery of erectile function was observed at 6 months after CN crush injury.
authors.affiliation: Department of Urology, College of Medicine, Hallym University, Seoul, Korea.
authors.forename: Hyo Jong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Ha Young
authors.initials: HY
authors.lastname: Kim
authors.forename: Sung Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Won Ki
authors.initials: WK
authors.lastname: Lee
authors.forename: Dae Yul
authors.initials: DY
authors.lastname: Yang