The effects of cryopreservation on sperm morphology, motility and mitochondrial function.
BACKGROUND
The effects of cryoinjury were determined simultaneously on the mitochondrial function, motility, morphology and viability of ejaculated human sperm.


METHODS
Rhodamine 123 (R123) uptake (% of sperm) and stain intensity were used to determine sperm mitochondrial activity before and after cryopreservation from the semen of 50 men attending for infertility investigation. Morphology was assessed using Tygerberg's strict criteria and viability was assessed by eosin Y. Sperm motility was measured using computer-assisted semen analysis (CASA).


RESULTS
Freeze-thawing caused a 37% (P = 0.001) reduction in normal morphological forms of sperm. All CASA sperm motility parameters except amplitude of lateral head displacement were similarly reduced. R123 uptake and intensity within sperm mitochondria decreased by 36 and 47% respectively (both P = 0.001). In addition, there was a similar significant decrease (31%, P = 0.001) in the viability of the sperm.


CONCLUSIONS
Sperm morphology, motility, mitochondrial activities and viability are equally susceptible to cryopreservation-induced damage. R123 intensity is a novel and robust indicator of mitochondrial function before and after such trauma.
O'Connell
M
M
Department of Obstetrics and Gynaecology, The Queen's University of Belfast, Institute of Clinical Science, Grosvenor Road, Belfast BT12 6BJ, Northern Ireland.
McClure
N
N
Lewis
S E M
SE
D002470:Cell Survival; D015925:Cryopreservation; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008928:Mitochondria / Q000502:physiology*; D011309:Preservation, Biological / Q000009:adverse effects*; D020112:Rhodamine 123 / Q000493:pharmacokinetics; D013081:Sperm Motility; D013094:Spermatozoa / Q000166:cytology* / Q000502:physiology*; D013194:Staining and Labeling
D005456:Fluorescent Dyes; D020112:Rhodamine 123