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Cryopreservation of metaphase II human o ... ns for developmental competence
Cryopreservation of metaphase II human oocytes effects mitochondrial membrane potential: implications for developmental competence.
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BACKGROUND: Current outcome results with embryos derived from thawed MII human oocyes are significantly lower than with embryos cryopreserved at the pronuclear stage. Here, we investigated whether freezing-thawing was associated with changes in oocyte mitochondrial polarity (DeltaPsim) that could influence competence by altering ATP levels or the ability of the cytoplasm to regulate intracellular Ca2+. METHODS: Fresh and thawed uninseminated and unfertilized MII oocytes were stained with the DeltaPsim-specific probe JC-1 to detect clusters of high-polarized mitochondria (J-aggregate positive) and with the Ca2+- specific probe Fluo-4 to measure changes in intracellular levels of this cation. ATP content per oocyte was measured directly and cortical granules were visualized with a cortical granule-specific probe. RESULTS: A significant difference between fresh and thawed MII oocytes existed for pericortical J-aggregate fluorescence and for the ability of the cytoplasm to increase free Ca2+ in response to ionophore exposure. No significant difference in ATP contents was measured and cryopreservation was not associated with an apparent release of cortical granules. CONCLUSION: Irreversible loss of high DeltaPsim in thawed oocytes may be associated with defects in Ca2+ signalling after insemination and could have downstream consequences for normal embryogenesis.
Jones A, Van Blerkom J, Davis P, Toledo AA
Human reproduction (Oxford, England)
2004-08-01 00:00
19
8
1861-6
Adenosine Triphosphate,Benzimidazoles,Calcium,Carbocyanines,Cell Nucleus,Cryopreservation,Cytoplasmic Granules,Female,Fluorescent Dyes,Humans,Membrane Potentials,Metaphase,Mitochondria,Oocytes,Benzimidazoles,Carbocyanines,Fluorescent Dyes,5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine,Adenosine Triphosphate,Calcium
Reproductive Biology Associates, 1150 Lake Hearn Dr, Suite 600, Atlanta, GA 30342, USA hesikaijaolcom
Hum. Reprod.
0268-1161
10.1093/humrep/deh313
deh313
1178
True
15229209
