Introduction: Human sperm cryopreservation can be considered as a common procedure in assisted reproduction technologies (ARTs). In spite of extensive use of cryopreservation in ART programs, it is widely reported that freezing and thawing cause serious detrimental changes in structures (nucleus, membrane and mitochondria) and functions (i.e. motility) of ejaculated spermatozoa. Kisspeptin (KP), as an antioxidant, has beneficial effects on the sperm functions. The objectives of this study were to determine the mitigating impact of KP on detrimental effects of the sperm freeze-thawing process.
Methods: Semen samples were collected from 30 healthy subjects, aged 18–35 years, attending cytogenetic clinic in Shiraz, Iran. normal semen samples, prepared by swim-up procedure, were divided into three aliquots: negative control, without any treatment; positive control receiving GSH; and experimental aliquot treated with KP for 30 min. All aliquots were cryopreserved, and then thawed after 48hr. Sperm DNA quality was evaluated by Acridine Orange, Aniline Blue, Chromomycin A3, and TUNEL staining methods. Statistical analyses were performed using ANOVA and LSD.
Results: KP supplementation improved DNA quality compared with both controls. Freeze-thaw procedure damaged DNA integrity severely, and KP pre-treatment significantly reduced the frequency of apoptotic sperms along with those with histone – protamine substitution impairment.
Conclusion: Pre-exposure of the sperms to KP can protect the sperm quality including DNA integrity against the detrimental influence of freezing and thawing. Therefore, it can be considered as a good pre-additive substance to control the sperm quality during freezing and thawing procedure.
Keywords: Kisspeptin, DNA integrity, Cryopreservation