Influence of microsurgical varicocelectomy on human sperm mitochondrial DNA copy number: a pilot study
There is good evidence to show that varicocele repair can improve conventional sperm parameters, as well as, sperm DNA integrity, in infertile men with a clinical varicocele.
To examine the effect of varicocelectomy on sperm quality, specifically, sperm nuclear chromatin integrity and sperm mitochondrial DNA (mtDNA) copy number.
Design, Setting, and Participants
A prospective study done between March 2007 and January 2008. We evaluated a consecutive series of infertile men (n = 14) presenting to Ovo clinic with one year or more history of infertility, a clinically palpable varicocele and poor motility (<25 % rapid progressive and <50 % progressive).
Microsurgical sub-inguinal varicocelectomy.
Outcome Measurements and Statistical Analysis
Conventional sperm parameters, sperm mtDNA copy number (by real time PCR) and sperm chromatin structure assay (SCSA) parameters (%DFI,% HDS) before and 4 months after microsurgical varicocelectomy.
Results and Limitations
Sperm concentration and SCSA parameters (%DFI and %HDS) improved significantly after surgery (P < 0.05). Sperm mitochondrial DNA copy number decreased significantly after surgery (27 ± 30 to 9 ± 6 copies per sperm, respectively, P = 0.032). There was a significant negative correlation between mitochondrial DNA copy number and sperm motility (r = − 0.71, P = 0.002).
These findings support the concept that correction of a varicocele can improve spermatogenesis and sperm function, as mitochondrial DNA copy number has been suggested to reflect the efficiency of spermatogenesis and has been inversely related to sperm motility.
KeywordsSperm DNA mitochondrial DNA sperm motility male infertility varicocele
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