title: Canine model of infertility after spinal cord injury: time course of acute changes in semen quality and spermatogenesis.
abstract: OBJECTIVE
  We established a canine model of subfertility after spinal cord injury and examined the time course of acute changes in semen quality and spermatogenesis after spinal cord injury.
  
  
  METHODS
  Seven dogs underwent surgical T7 spinal cord injury. Six dogs were used as controls. Electroejaculation and testicular fine needle aspiration were performed at baseline and twice weekly for 3 weeks after spinal cord injury. Semen quality change was examined by standard semen analysis. Spermatogenesis was assessed by flow cytometry of testicular fine needle aspiration in all dogs as well as by testicular histology at study conclusion in 4 controls and 4 spinal cord injured dogs.
  
  
  RESULTS
  No significant changes in spinal cord injured dogs were noted before 3 weeks after injury. From baseline to 3 weeks after injury certain changes were evident in spinal cord injured dogs. Mean antegrade sperm motility decreased from 62.9% to 20.1% (p = 0.008), mean total sperm (antegrade plus retrograde total sperm) decreased from 423 to 294 x 106 which was not statistically significant, and the incidence of testicular haploid cells decreased from 75.6% to 48.3% (p = 0.028). No significant change in any parameter was present in control dogs. The mean number of mature spermatids per cross-sectional tubule on final testicular histology was significantly decreased in spinal cord injured dogs compared with controls (13.6 versus 43.9, p = 0.02).
  
  
  CONCLUSIONS
  In the canine model tested the dogs readily survived spinal cord injury, electroejaculation was effective for obtaining ejaculate and fine needle aspiration allowed serial examination of spermatogenesis. Three weeks after spinal cord injury but not before 3 weeks sperm motility and spermatogenesis were significantly decreased. However, at the same point this decrease in spermatogenesis was not yet reflected in the total ejaculated sperm count.
authors.affiliation: Department of Surgery (Urology and Neurosurgery), University of Michigan, 1500 East Medical Center Dr., Ann Arbor, MI, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Ohl
authors.forename: J
authors.initials: J
authors.lastname: Sønksen
authors.forename: G
authors.initials: G
authors.lastname: Wedemeyer
authors.forename: M C
authors.initials: MC
authors.lastname: Zaborniak
authors.forename: T N
authors.initials: TN
authors.lastname: Dam
authors.forename: A C
authors.initials: AC
authors.lastname: Menge
authors.forename: M J
authors.initials: MJ
authors.lastname: Putzi
authors.forename: S M
authors.initials: SM
authors.lastname: Papadopoulos
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D007248:Infertility, Male / Q000209:etiology*; D008297:Male; D013076:Sperm Count; D013081:Sperm Motility; D013091:Spermatogenesis; D013119:Spinal Cord Injuries / Q000150:complications*; D013997:Time Factors