Antifreeze Protein III, An Ice Blocker, and Its Effect on Sperm Freezing/Thawing

Background: Sperm cryopreservation is one of the most criticalstrategies to preserve men reproductive potency. Designingan appropriate sperm freezing medium that be non-toxic andallow successful freezing is a big challenge. Antifreeze proteins(AFPs) have been used in different scientific researches suchas; cryopreservation of cells, tissues and organs. AFPs depressthe freezing point, modify the ice crystal formation process,prevent recrystallization and interact with plasma membrane atlow temperatures. Our aim was to evaluate the effect of AFPIII on post thaw plasma membrane integrity (PMI), ReactiveOxygen Species (ROS) and Total Antioxidant Capacity (TAC)of cryopreserved human sperm.Materials and Methods: Ejaculated semen was collected from۲۰ normospermic male and each sample was then divided intothree groups:۱. fresh control that analyzed immediately afterliquefaction time, ۲. cryopreservation without AFP III thatcryopreserved with Glycerol-egg-yolk-citrate (GEYC) mediumand, ۳. cryopreservation with AFPIII that cryopreserved withGEYC medium contained ۱μg/ml of synthetic peptid AFPIII.Samples were packed in to straws exposed to liquid nitrogen(LN۲) vapor for ۱۰ min and then plunged into the LN۲. After aweek, straws were thawed at ۳۷ºC for ۳۰s and then PMI, ROSand TAC were assessed.Results: The results showed that the level of ROS was increaseddramatically following freezing and thawing. However,the level of ROS in cryopreservation AFPIII+ group was significantlyless than cryopreservation AFPIII - group. A significantdecrease in TAC was observed in both cryopreservation groups.TAC was higher in cryopreservation AFPIII+ group than AFPIII - group. Also, with the supplementation of AFPIII, significantimprovement in PMI was recorded compared to AFPIII -group and decrease in PMI was seen compared to fresh control.Conclusion: The effects of cryoinjuries were determined onmitochondrial function, motility, morphology and viability ofejaculated human sperm. This study emphasized on the beneficialeffects of ۱ μg/ml AFPIII in the extender on post - thawquality of human sperm.

کلیدواژه ها:

Cryopreservation ، Antifreeze Protrin III ، Spermatozoa