Reduced sperm yield from testicular biopsies of vasectomized men is due to increased apoptosis.
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.
O'Neill
Deirdre A
DA
Obstetrics and Gynaecology, School of Medicine, Queen's University Belfast, Institute of Clinical Science, Belfast, United Kingdom.
McVicar
Carmel M
CM
McClure
Neil
N
Maxwell
Perry
P
Cooke
Inez
I
Pogue
Katherine M
KM
Lewis
Sheena E M
SE
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
D053222:Fas Ligand Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D019014:fas Receptor