Resistance of human spermatozoa to cryoinjury in repeated cycles of thaw-refreezing.
نویسندگان
چکیده
OBJECTIVE To study the resistance of human spermatozoa to cryoinjury in repeated cycles of thaw-refreezing by using the fast liquid nitrogen vapor method. MATERIALS AND METHODS Semen specimens were obtained from sixteen normal and oligozoospermic individuals who required disposal at the sperm bank. Five of them had testicular cancer. Specimens were thawed and an aliquot was removed for analysis. The remaining specimens were refrozen without removing the cryomedia. Repeated freeze-thaw cycles were performed until no motile sperm were observed. Sperm motility, number of motile spermatozoa and viability were determined after thawing. Resistance to cryoinjury was compared between groups and also after each refreezing cycle within groups. RESULTS Motile spermatozoa were recovered after five and two refreeze-thawing cycles in normozoospermic and oligozoospermic specimens, respectively. There were no significant differences in the recovery of motile spermatozoa between thaws within each group of normal and oligozoospermic specimens, but percentage motility and total number of motile spermatozoa were significantly lower in the oligozoospermic one. Specimens from men with cancer were exposed to six refreeze-thawing cycles. Although recovery of motile spermatozoa was significantly impaired after each thawing, there were no significant differences in the recovery of motile sperm between thaws in cancer and non-cancer groups. CONCLUSIONS Human spermatozoa resist repeated cryopreservation using the fast liquid nitrogen vapor method. Normozoospermic specimens withstand refreezing for an average two cycles longer than oligozoospermic ones. Specimens from cancer patients seem to resist repeated cryoinjury similarly to non-cancer counterparts. Resistance to repeated cryoinjury was related to the initial semen quality.
منابع مشابه
O-12: Evaluation of Human Spermatozoa Resistance to Cryoinjury after Repeated Cycles of Thaw-Refreezing Using of Cryovial and Straw
Background: Sperm storage via freezing has been useful for men who have difficulty masturbating during assisted reproductive technology (ART) programs and before impotency caused by chemotherapy, vasectomy, and other procedures. Studies were undertaken to evaluate the extent of cryoinjury to both semen and sperm after repeated freezing and thawing in oligozoospermic and normozoospermic samples ...
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متن کاملEvaluation of Serial Thawing-Refreezing on Human Spermatozoa Resistance Using Cryovials and Straws
متن کامل
Evaluation of Serial Thawing-Refreezing on Human Spermatozoa Resistance Using Cryovials and Straws
BACKGROUND We designed this study to detect the cryoinjury rate on human sperm after serial freezing and thawing, taking into consideration the effects of using cryovials and straws. MATERIALS AND METHODS In this experimental study, semen specimens obtained from 15 subjects were divided into normozoospermic and oligozoospermic groups. Each of the normozoospermic and oligozoo spermic semen spe...
متن کاملEvaluation of human sperm function after repeated freezing and thawing.
Sperm storage via freezing has been useful for men who have difficulty masturbating during assisted reproductive technology (ART) programs and before impotency caused by chemotherapy, vasectomy, and other procedures. Studies were undertaken to evaluate the extent of cryoinjury to sperm after repeated freezing and thawing. The results showed that normozoospermic and oligozoospermic sperm survive...
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ورودعنوان ژورنال:
- International braz j urol : official journal of the Brazilian Society of Urology
دوره 35 5 شماره
صفحات -
تاریخ انتشار 2009