STUDY QUESTION<\/p>\n
Can selection of spermatozoa by density gradient centrifugation prior to cryopreservation and\/or hypotaurine supplementation improve the post-thaw quality of sperm from infertile men with oligoasthenoteratozoospermia?<\/p>\n
SUMMARY ANSWER<\/p>\n
Sperm selection by density gradient centrifugation before freezing and supplementation of the media by hypotaurine is beneficial for the cryopreservation of semen samples of patients with oligoasthenoteratozoospermia.<\/p>\n
WHAT IS KNOWN ALREADY<\/p>\n
Sperm from men with oligoasthenoteratozoospermia are more susceptible than normal to cryoinjury. Density gradient centrifugation before sperm freezing may allow the selection of a subpopulation of spermatozoa more resistant to cryopreservation. Hypotaurine is an antioxidant with a protective effect on sperm functions.<\/p>\n
STUDY DESIGN, SIZE, DURATION<\/p>\n
The experiment was carried out according to a factorial design involving two binary factors resulting in four treatment combinations which were randomly allocated in oligoasthenoteratozoospermia sperm samples from 64 patients recruited between January 2009 and June 2010.<\/p>\n
PARTICIPANTS\/MATERIALS, SETTING, METHODS<\/p>\n
Semen was provided by 64 men undergoing evaluation for infertility at the Centre for Reproductive Medicine of the University Hospital in Clermont-Ferrand, France, between January 2009 and June 2010. Four treatment combinations were tested: sperm freezing before selection without (F-S\/H–; n<\/I> = 16) and with hypotaurine supplementation (F-S\/H+; n<\/I> = 16); sperm selection before freezing without (S-F\/H–; n<\/I> = 16) and with hypotaurine supplementation (S-F\/H+; n<\/I> = 16). Measurements of sperm recovery rates and markers of apoptosis (externalization of phosphatidylserine (PS), mitochondrial membrane potential and DNA fragmentation) were compared in recovered spermatozoa after each procedure.<\/p>\n
MAIN RESULTS AND THE ROLE OF CHANCE<\/p>\n
Higher recovery rates of progressive and total motile spermatozoa were observed when sperm selection was performed before freezing (P<\/I> < 0.05). The protective effect of hypotaurine was only observed on the percentage of live spermatozoa with PS externalization among total live spermatozoa (AN+ PI–\/((AN+ PI–) + (AN– PI–)) when the sperm selection by density gradient centrifugation was performed before freezing (S-F\/H+ versus S-F\/H–: 6.8 ± 1.09 versus 11.8 ± 2.03%, P<\/I> = 0.04). The percentage of mitochondrial membrane potential (DiOC6<\/SUB>(3) high<\/sup>) spermatozoa was higher (P<\/I> = 0.001) when sperm selection was done before freezing compared with procedures in which sperm selection was done after sperm freezing with (S-F\/H+ versus F-S\/H+: 58.1 ± 3.50 versus 46.7 ± 5.48%) or without (S-F\/H– versus F-S\/H–: 57.0 ± 5.18 versus 35.4 ± 4.99%) hypotaurine supplementation. The percentages of TUNEL+ spermatozoa were significantly lower (P<\/I> = 0.001) when sperm selection was done before sperm freezing compared with procedures in which sperm selection was done after sperm freezing with (S-F\/H+ versus F-S\/H+: 38.6 ± 9.59 versus 55.7 ± 5.88%) or without hypotaurine supplementation (S-F\/H– versus F-S\/H–: 37.2 ± 7.91 versus 71.0 ± 5.66%).<\/p>\n LIMITATIONS, REASONS FOR CAUTION<\/p>\n The ICSI outcomes were not assessed and the fertility of the spermatozoa remains unknown.<\/p>\n WIDER IMPLICATIONS OF THE FINDINGS<\/p>\n Sperm selection by density gradient centrifugation before freezing and hypotaurine supplementation could improve the cryopreservation of sperm from oligoasthenoteratozoospermic men and make a larger number of functional spermatozoa available for ICSI.<\/p>\n STUDY FUNDING\/COMPETING INTERETS(S)<\/p>\n This work was supported by a hospital grant (Projet Hospitalier Recherche Clinique, CHU Clermont Ferrand, France). None of the authors has any conflict of interest to declare.<\/p>\n Source: STUDY QUESTION Can selection of spermatozoa by density gradient centrifugation prior to cryopreservation and\/or hypotaurine supplementation improve the post-thaw quality of sperm from infertile men with oligoasthenoteratozoospermia? SUMMARY ANSWER Sperm selection by density gradient centrifugation before freezing and supplementation of … Continue reading
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