Effect of cryopreservation on sperm apoptotic deoxyribonucleic acid fragmentation in patients with oligozoospermia.
OBJECTIVE
To verify if the increase in sperm apoptotic DNA fragmentation during cryopreservation is greater in oligozoospermic patients than in normozoospermic controls.


METHODS
Controlled prospective study.


METHODS
Patients in an academic research environment.


METHODS
Forty-seven patients with oligozoospermia (concentration <10 x 10(6) sperm/mL) and 30 normozoospermic men.


METHODS
Sperm cryopreservation using a standard protocol with a test-yolk buffer, glycerol as the cryoprotectant.


METHODS
Rate of apoptotic sperm DNA fragmentation as assessed by the terminal deoxynucleotidyl-mediated deoxyuridine triphosphate nickend labeling (TUNEL) assay, graded in apoptotic or nonapoptotic, before and after cryopreservation.


RESULTS
An increase in apoptotic DNA fragmentation was observed in all the groups, regardless of sperm concentration. Normozoospermic men presented a smaller rate of apoptotic DNA fragmentation than oligozoospermic patients, both in pre- and postcryopreservation samples. The increase in DNA fragmentation was similar in both groups.


CONCLUSIONS
Cryopreservation induces apoptotic sperm DNA fragmentation in men, regardless of sperm concentration. Men with oligozoospermia present with higher precryopreservation and postcryopreservation apoptotic sperm DNA fragmentation. The increase in DNA fragmentation is similar in both groups.
de Paula
Thais Serzedello
TS
Department of Surgery, Division of Urology, São Paulo Federal University, São Paulo, Brazil.
Bertolla
Ricardo Pimenta
RP
Spaine
Deborah Montagnini
DM
Cunha
Maria Adelaide
MA
Schor
Nestor
N
Cedenho
Agnaldo Pereira
AP
D000328:Adult; D017209:Apoptosis / Q000235:genetics; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D053938:DNA Fragmentation; D006801:Humans; D008297:Male; D009845:Oligospermia / Q000235:genetics* / Q000473:pathology*; D013076:Sperm Count; D013094:Spermatozoa / Q000473:pathology*