title: Cryopreservation of human spermatozoa within human or mouse empty zona pellucidae.
abstract: OBJECTIVE
  To compare the empty zona pellucidae (ZP) of different species for use in the cryopreservation of spermatozoa.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  An IVF unit of a medical center.
  
  
  METHODS
  Patients with azoospermia, oligoasthenozoospermia, or normal spermatozoa.
  
  
  METHODS
  Human and mouse ZP were prepared by evacuating the cytoplasm of oocytes or embryos. The evacuated ZP were injected with spermatozoa from patients with severe oligoasthenozoospermia and from healthy, fertile men. After the freezing and thawing procedure, the spermatozoa were aspirated outside the ZP.
  
  
  METHODS
  The number of spermatozoa per ZP, the number of motile sperm before freezing and after thawing, the number of sperm lost per ZP after freezing, and the sperm recovery rate were compared according to the different origins of the ZP and the sperm.
  
  
  RESULTS
  The number of spermatozoa, number of motile sperm before freezing and after thawing, number of sperm lost per ZP, and sperm recovery rate were comparable in all groups. The total mean number of motile sperm before freezing and after thawing, the mean number of nonmotile sperm after thawing, the mean number of sperm lost after thawing, and the sperm recovery rate were 14.5%, 11. 8%, 1.0%, 1.5%, and 82%, respectively.
  
  
  CONCLUSIONS
  Zona pellucidae are an ideal vehicle for the cryopreservation of sperm collected by testicular sperm extraction or microsurgical epididymal sperm aspiration or from patients with severe oligoasthenozoospermia. There were no differences when human and mouse ZP were used for sperm storage.
authors.affiliation: Department of Obstetrics, China Medical College Hospital, Taichung, Taiwan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hsieh
authors.forename: H
authors.initials: H
authors.lastname: Tsai
authors.forename: C
authors.initials: C
authors.lastname: Chang
authors.forename: H
authors.initials: H
authors.lastname: Lo
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D004622:Embryo, Mammalian / Q000166:cytology; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009845:Oligospermia / Q000473:pathology; D012099:Reproductive Techniques; D013094:Spermatozoa / Q000502:physiology*; D015044:Zona Pellucida / Q000737:chemistry / Q000502:physiology*