title: Effects of cryopreservation on human sperm deoxyribonucleic acid integrity.
abstract: OBJECTIVE
  To evaluate the effect of cryopreservation on sperm motility and viability and to assess sperm DNA fragmentation and oxidation in men undergoing infertility investigation before and after cryopreservation in liquid nitrogen.
  
  
  METHODS
  Analysis of cryopreservation effects on sperm DNA integrity.
  
  
  METHODS
  Laboratory of Histology-Embryology of medicine faculty, Sfax, Tunisia.
  
  
  METHODS
  Fifteen semen samples from men undergoing infertility investigation.
  
  
  METHODS
  Neat semen samples were cryopreserved in liquid nitrogen using a commercial freezing medium (SpermFreeze, Fertipro, Belgium) according to the manufacturer's instructions. Samples were thawed at room temperature.
  
  
  METHODS
  Sperm DNA fragmentation was assessed using terminal deoxynucleotidyl transferase (Tdt) mediated dUTP nick end labeling and sperm DNA oxidation was determined using a fluorescent assay (OxyDNA test) for the detection of 8-oxoguanine. Evaluation of DNA fragmentation and oxidation rates was carried out before and after cryopreservation using flow cytometry.
  
  
  RESULTS
  A significant decrease in sperm motility and viability was observed after cryostorage. In addition, sperm DNA fragmentation and DNA oxidative damage increased significantly after cryopreservation/thaw.
  
  
  CONCLUSIONS
  Cryopreservation has deleterious effects on sperm DNA by inducing DNA fragmentation and oxidation but the mechanisms underlying such damages need to be elucidated by further investigations.
authors.affiliation: Laboratory of Histology-Embryology, Medicine Faculty of Sfax, Sfax, Tunisia. nacira.zribi@gmail.com
authors.forename: Nassira
authors.initials: N
authors.lastname: Zribi
authors.forename: Nozha
authors.initials: N
authors.lastname: Feki Chakroun
authors.forename: Henda
authors.initials: H
authors.lastname: El Euch
authors.forename: Jalel
authors.initials: J
authors.lastname: Gargouri
authors.forename: Ali
authors.initials: A
authors.lastname: Bahloul
authors.forename: Leila
authors.initials: L
authors.lastname: Ammar Keskes
mesh_terms: D000328:Adult; D015925:Cryopreservation; D053938:DNA Fragmentation; D005434:Flow Cytometry; D006147:Guanine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism / Q000473:pathology*; D014416:Tunisia
chemical_list: C024829:8-hydroxyguanine; D006147:Guanine