title: Reduced sperm yield from testicular biopsies of vasectomized men is due to increased apoptosis.
abstract: OBJECTIVE
  To compare sperm yields, apoptotic indices, and sperm DNA fragmentation from vasectomized men and fertile men undergoing vasectomy.
  
  
  METHODS
  Testicular biopsies from vasectomized (n = 26) and fertile men (n = 46), were milked to calculate sperm/gram and also formalin-fixed to determine the numbers of developing sperm and incidence and intensities of testicular FasL, Fas, Bax, and Bcl-2. Testicular sperm DNA fragmentation was assessed using the alkaline Comet assay.
  
  
  METHODS
  An ART unit.
  
  
  METHODS
  Twenty-six men attending for intracytoplasmic sperm injection (ICSI) and 46 men attending for vasectomies.
  
  
  METHODS
  Spermatocyte, spermatid and sperm yields, Fas, FasL, and Bax staining.
  
  
  RESULTS
  Sperm yields from men vasectomized >5 years previously were markedly reduced compared to fertile men. Increased intensities of FasL and Bax staining were observed in the seminiferous tubules of vasectomy men. FasL positivity (percentage) also increased in Sertoli cells, and both FasL and Fas positivity (percentage) increased in primary spermatocytes and round spermatids of vasectomized men. Sperm DNA fragmentation, an end point marker of apoptosis, increased significantly in vasectomized men compared to fertile men.
  
  
  CONCLUSIONS
  Reduced sperm yields after vasectomy are associated with increased apoptosis through the Fas-FasL and Bax pathways. Sperm after vasectomy displayed increased DNA fragmentation.
authors.affiliation: Obstetrics and Gynaecology, School of Medicine, Queen's University Belfast, Institute of Clinical Science, Belfast, United Kingdom.
authors.forename: Deirdre A
authors.initials: DA
authors.lastname: O'Neill
authors.forename: Carmel M
authors.initials: CM
authors.lastname: McVicar
authors.forename: Neil
authors.initials: N
authors.lastname: McClure
authors.forename: Perry
authors.initials: P
authors.lastname: Maxwell
authors.forename: Inez
authors.initials: I
authors.lastname: Cooke
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Pogue
authors.forename: Sheena E M
authors.initials: SE
authors.lastname: Lewis
mesh_terms: D000328:Adult; D017209:Apoptosis; D001706:Biopsy; D053938:DNA Fragmentation; D053222:Fas Ligand Protein / Q000032:analysis / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012708:Sertoli Cells / Q000166:cytology; D013076:Sperm Count; D013737:Testis; D014659:Vasectomy; D051028:bcl-2-Associated X Protein / Q000032:analysis / Q000502:physiology; D019014:fas Receptor / Q000032:analysis / Q000502:physiology
chemical_list: D053222:Fas Ligand Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D019014:fas Receptor