Vitrification induced apoptosis in spermatozoa from fertile and subfertile men

Background: Phospholipids are distributed asymmetrically between inner and outer leaflets of the plasma membrane of live cells. Early during apoptosis, this asymmetry is disrupted and phosphatidylserine becomes exposed on the outside surface of the plasma membrane. There is little information about the effects of vitrification on apoptosis.
Objective: The aim of the present study was to evaluate the effect of vitrification on apoptosis of subfertile and fertile men.
Materials and Methods: In this study, semen samples were collected from subfertile (n=20) and fertile men (n=10) after 48h abstinence of intercourse. After semen analysis according to WHO criterias, each semen sample was divided into two portions. First portion was assessed by Annexin V-flous staining kit for showing apoptosis in subfertile and fertile men and second portion was assessed after vitrification-thawing. Results were analyzed by Paired t-test and Independent t-test.
Results: After vitrification-thawing, mean percentage of apoptotic spermatozoa has increased 6 and 3 times in subfertile and fertile men respectively. This difference is significant.
Conclusion: Vitrification-thawing could disrupted membrane asymmetry and caused apoptosis. Therefore, it will cause reduction of functional spermatozoa in access of Assisted Reproduction Technologies (ART).

Keywords
Apoptosis, Vitrification, Thawing, Human spermatozoa, Fertile men, Subfertile men.