title: Follicular viability and histological assessment after cryopreservation of whole sheep ovaries with vascular pedicle by vitrification.
abstract: OBJECTIVE
  To evaluate a cryopreservation technique by vitrification of whole ovaries with their vascular pedicle in sheep, by using two cryoprotectant solutions.
  
  
  METHODS
  Animal study.
  
  
  METHODS
  Fertility clinic in a university teaching hospital.
  
  
  METHODS
  Five to 6-month-old ewes.
  
  
  METHODS
  Whole sheep ovaries with their vascular pedicles were collected at the slaughterhouse and prepared for cryoprotectant toxicity tests and freezing procedures.
  
  
  METHODS
  Follicle viability assessment by trypan blue test and histological examination of ovary and vessel structure.
  
  
  RESULTS
  No statistically significant difference in follicle viability or normal primordial follicle rates were observed between ovaries exposed or nonexposed to cryoprotectant solutions. Nor was any statistically significant difference observed before and after vitrification with the two cryoprotectant solutions. The decrease in the number of primordial follicles was smaller when frozen-thawed ovaries were treated with VS4 solution containing dimethyl sulfoxide, formamide, and propylene glycol. There were fewer nuclear anomalies and general follicular anomalies with the VS4 solution. Pedicle fractures occurred in most ovaries during thawing (11/15).
  
  
  CONCLUSIONS
  Cryopreservation of whole ovary by vitrification appears a promising technique in reproductive medicine. The best histologic results were obtained with the VS4 cryoprotectant. Further studies are required to overcome vitrified ovarian vessel fracture.
authors.affiliation: Unité INSERM 418, Hôpital Debrousse, Lyon, France.
authors.forename: Blandine
authors.initials: B
authors.lastname: Courbiere
authors.forename: Jérôme
authors.initials: J
authors.lastname: Massardier
authors.forename: Bruno
authors.initials: B
authors.lastname: Salle
authors.forename: Claire
authors.initials: C
authors.lastname: Mazoyer
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Guerin
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Lornage
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D005260:Female; D006080:Ovarian Follicle / Q000098:blood supply* / Q000166:cytology* / Q000187:drug effects; D010053:Ovary / Q000098:blood supply* / Q000166:cytology / Q000187:drug effects; D012756:Sheep
chemical_list: D003451:Cryoprotective Agents