title: [Protective effect of Annexin 5 on human sperm membrane and DNA integrity].
abstract: OBJECTIVE
  To investigate the role of Annexin 5 in protecting human sperm membrane and DNA integrity.
  
  
  METHODS
  We collected 53 semen samples based on the criteria of sperm density > 20 x 10(6)/ml and motility > 60%, and divided them into an experimental group (2.5 microl 10(-6) mol/L Annexin 5 added to 47.5 microl semen), a negative control group (2.5 microl 1 mol/L Tris-HCl [pH 8.0, 25 degrees C] added to 47.5 microl semen), and a blank control group (2.5 microl 0.01 mol/L PBS [pH 7.4] added to 47.5 microl semen). After 20 minutes of incubation, we evaluated the sperm membrane integrity using the hypoosmotic swelling test and, after another 60 minutes of treatment with H2O2 at 2.5 microl 10.02 mol/L, measured the sperm nuclear DNA integrity by acridine orange fluorescent staining.
  
  
  RESULTS
  After 20 minutes of treatment with Annexin 5, the experimental group showed extremely significant difference in the percentage of hypoosmotic swelling sperm ([66.17 +/- 12.02] %) from the blank control ([58.13 +/- 13.08]%, P < 0.01) and the negative control group ([59.94 +/- 11.91]%, P < 0.01), but there was no significant difference between the latter two. Treatment with H2O2 remarkably increased DFI in the experimental group (6.39 +/- 1.07) as compared with the blank control (11.16 +/- 1.16) and the negative control group (10.86 +/- 1.05, P < 0.01), but no significant difference was observed between the latter two.
  
  
  CONCLUSIONS
  Annexin 5 can increase the percentage of hypoosmotic swelling sperm in vitro and protect sperm membrane integrity, and it can also protect sperm DNA from H2O2 damage.
authors.affiliation: PLA Research Institute of Clinical Laboratory Medicine, Nanjing University School of Medicine/Nanjing General Hospital of Nanjing Military Region, Nanjing, Jiangsu 210002, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Lu
authors.forename: Cui
authors.initials: C
authors.lastname: Guo
authors.forename: Xiao-qian
authors.initials: XQ
authors.lastname: Tao
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Liu
authors.forename: Shan-shan
authors.initials: SS
authors.lastname: Shi
authors.forename: Chai-ying
authors.initials: CY
authors.lastname: Lin
authors.forename: Bing
authors.initials: B
authors.lastname: Yao
mesh_terms: D017304:Annexin A5 / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects*; D004247:DNA; D053938:DNA Fragmentation; D006801:Humans; D008297:Male; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000187:drug effects*
chemical_list: D017304:Annexin A5; D004247:DNA