Cryopreservation-thawing of fractionated human spermatozoa and plasma membrane translocation of phosphatidylserine.
OBJECTIVE
[1] To evaluate sperm membrane damage during cryopreservation-thawing by the assessment of phosphatidylserine (PS) translocation and [2] to examine the relationship between reactive oxygen species (ROS) and cryopreservation-related alterations.


METHODS
Prospective cohort study.


METHODS
University-based center.


METHODS
Men consulting for infertility and fertile donors (controls).


METHODS
Semen processing was performed by density gradient separation followed by cryopreservation and thawing.


METHODS
Membrane PS translocation was evaluated with annexin V binding, generation of ROS was detected by chemiluminescence, and motion parameters were assessed by computer analysis.


RESULTS
Annexin V binding was detected in the prefreeze fractions with high and low sperm motility. In the patient group, there were significantly higher postthaw levels of annexin V binding in both fractions when compared with prefreezing values. However, such induction of PS translocation was significantly higher in the fractions with high sperm motility. Significantly higher ROS levels were detected in prefreeze samples of the fractions with low sperm motility.


CONCLUSIONS
In the population of men studied, [1] cryopreservation-thawing was associated with induction of membrane PS translocation; [2] postthaw ROS levels were lower than before freezing; and [3] neither annexin V binding results nor the generation of ROS were able to accurately predict sperm cryosurvival rates.
Duru
N K
NK
Department of Obstetrics and Gynecology, The Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, 601 Colley Avenue, Norfolk, Virginia 23507, USA.
Morshedi
M
M
Schuffner
A
A
Oehninger
S
S
D017304:Annexin A5 / Q000378:metabolism; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D015331:Cohort Studies; D015925:Cryopreservation; D006358:Hot Temperature; D006801:Humans; D008297:Male; D010718:Phosphatidylserines / Q000378:metabolism*; D011446:Prospective Studies; D017382:Reactive Oxygen Species / Q000378:metabolism; D013081:Sperm Motility; D013094:Spermatozoa / Q000502:physiology* / Q000648:ultrastructure*
D017304:Annexin A5; D010718:Phosphatidylserines; D017382:Reactive Oxygen Species