title: Effect of cryopreservation on sperm apoptotic deoxyribonucleic acid fragmentation in patients with oligozoospermia.
abstract: OBJECTIVE
  To verify if the increase in sperm apoptotic DNA fragmentation during cryopreservation is greater in oligozoospermic patients than in normozoospermic controls.
  
  
  METHODS
  Controlled prospective study.
  
  
  METHODS
  Patients in an academic research environment.
  
  
  METHODS
  Forty-seven patients with oligozoospermia (concentration <10 x 10(6) sperm/mL) and 30 normozoospermic men.
  
  
  METHODS
  Sperm cryopreservation using a standard protocol with a test-yolk buffer, glycerol as the cryoprotectant.
  
  
  METHODS
  Rate of apoptotic sperm DNA fragmentation as assessed by the terminal deoxynucleotidyl-mediated deoxyuridine triphosphate nickend labeling (TUNEL) assay, graded in apoptotic or nonapoptotic, before and after cryopreservation.
  
  
  RESULTS
  An increase in apoptotic DNA fragmentation was observed in all the groups, regardless of sperm concentration. Normozoospermic men presented a smaller rate of apoptotic DNA fragmentation than oligozoospermic patients, both in pre- and postcryopreservation samples. The increase in DNA fragmentation was similar in both groups.
  
  
  CONCLUSIONS
  Cryopreservation induces apoptotic sperm DNA fragmentation in men, regardless of sperm concentration. Men with oligozoospermia present with higher precryopreservation and postcryopreservation apoptotic sperm DNA fragmentation. The increase in DNA fragmentation is similar in both groups.
authors.affiliation: Department of Surgery, Division of Urology, São Paulo Federal University, São Paulo, Brazil.
authors.forename: Thais Serzedello
authors.initials: TS
authors.lastname: de Paula
authors.forename: Ricardo Pimenta
authors.initials: RP
authors.lastname: Bertolla
authors.forename: Deborah Montagnini
authors.initials: DM
authors.lastname: Spaine
authors.forename: Maria Adelaide
authors.initials: MA
authors.lastname: Cunha
authors.forename: Nestor
authors.initials: N
authors.lastname: Schor
authors.forename: Agnaldo Pereira
authors.initials: AP
authors.lastname: Cedenho
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000235:genetics; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D053938:DNA Fragmentation; D006801:Humans; D008297:Male; D009845:Oligospermia / Q000235:genetics* / Q000473:pathology*; D013076:Sperm Count; D013094:Spermatozoa / Q000473:pathology*