Influence of initial semen quality on the integrity of human sperm DNA following semen processing.
OBJECTIVE
To examine and compare the effects of density-gradient centrifugation on the integrity of sperm DNA from the semen of both fertile and infertile men.


METHODS
Prospective, observational study.


METHODS
University infertility clinic.


METHODS
Forty-four nonazoospermic, infertile men and nine fertile controls.


METHODS
Semen samples were processed by density-gradient centrifugation. Sperm motility and sperm chromatin structure (evaluated by flow cytometry analysis of acridine orange-treated spermatozoa) were monitored before and after semen was processed.


METHODS
Sperm motility and DNA integrity.


RESULTS
Following density-gradient centrifugation, mean sperm motility (+/-SEM) improved significantly compared to whole semen in samples from fertile and infertile men, respectively (71 +/- 6 vs. 49 +/- 7% and 56 +/- 3 vs. 44 +/- 3%, P<0.05). However, the percentage of sperm with denatured DNA increased compared to whole semen after processing of samples from infertile (25 +/- 3 vs. 15 +/- 2%, P<0. 01) but not fertile men (9 +/- 3 vs. 8 +/- 2%, P>0.05).


CONCLUSIONS
Our data indicate that the potential detrimental effect of density-gradient centrifugation on sperm DNA integrity is related to the initial semen quality. These data urge us to examine our current sperm-processing techniques to minimize sperm DNA damage.
Zini
A
A
Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada. azini@mtsinai.on.ca
Nam
R K
RK
Mak
V
V
Phang
D
D
Jarvi
K
K
D000165:Acridine Orange; D000328:Adult; D002499:Centrifugation, Density Gradient; D004247:DNA / Q000737:chemistry*; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D019370:Observation; D011446:Prospective Studies; D012661:Semen / Q000502:physiology*; D012662:Semen Preservation / Q000592:standards*; D013081:Sperm Motility
D004247:DNA; D000165:Acridine Orange