Effect of vitrification on mitochondrial membrane potential in human metaphase II oocytes.
OBJECTIVE
The aim of this study was to evaluate the impact of vitrification on mitochondrial membrane potential (ΔΨm) in human metaphase II (MII) oocytes, and the changes of ΔΨm on thawed MII oocytes.


METHODS
MII oocytes were obtained from clinical IVF cycles when the oocytes were failed to fertilization within 24 h after insemination. All oocytes were randomly divided into 4 groups: non-frozen (fresh group), cultured for 0 h (0 h group), 2 h (2 h group) and 4 h (4 h group) after vitrification/thawing. All oocytes were stained with the ΔΨm-specific probe JC-1 and detected by laser scanning confocal microscope (LSCM) for mitochondrial analysis.


RESULTS
The ΔΨm of oocytes was significantly decreased in 0 h and 2 h groups when compared with fresh group (0.93, 1.09 vs 1.34, P < 0.05), but similar between 4 h group and fresh group (1.30 vs 1.34, P > 0.05).


CONCLUSIONS
In the vitrification/thawing process, the ΔΨm of MII oocytes could have temporally dynamic changes within 2 h after thawing but would be fully recovered after 4 h culture.
Chongqing Medical University, 1 Yi Xue Yuan ST, Yu Zhong Dis, Chongqing 400016, China.
Cui
C
Chen
Shubiao
S
Han
Weiwei
W
Liu
Yaping
Y
Wang
Guoning
G
Huang
D000328:Adult; D001562:Benzimidazoles / Q000032:analysis; D002232:Carbocyanines / Q000032:analysis; D015925:Cryopreservation / Q000379:methods; D005260:Female; D005456:Fluorescent Dyes / Q000032:analysis; D006801:Humans; D053078:Membrane Potential, Mitochondrial; D008677:Metaphase; D018613:Microscopy, Confocal; D009865:Oocytes / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D058989:Vitrification; D055815:Young Adult
D001562:Benzimidazoles; D002232:Carbocyanines; D005456:Fluorescent Dyes; C068624:5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine