Membrane permeability of human oocytes in the presence of the cryoprotectant propane-1,2-diol.
OBJECTIVE
To determine the permeability of unfertilized human oocytes to water and the cryoprotectant propane-1,2-diol over a range of temperatures and to use these data to predict osmotic responses under given conditions.


METHODS
Laboratory-based study.


METHODS
Teaching hospital.


METHODS
Infertility patients donating unfertilized oocytes in excess of those required for treatment.


METHODS
None.


METHODS
Water and cryoprotectant permeability were determined from measurements of oocyte volume excursions on exposure to 1.5 M propane-1,2-diol at 30 degrees C, 24 degrees C, and 10 degrees C.


RESULTS
Permeability of human oocytes to water and cryoprotectant increased as temperature increased. The predicted response of oocytes, based on these data, closely matched the measured response of an oocyte on exposure to a widely used method for addition of cryoprotectant before freezing.


CONCLUSIONS
Commonly used cryopreservation protocols involving slow cooling in the presence of propane-1,2-diol cause potentially damaging excursions in cell volume on exposure to cryoprotectant. Modifications that can be expected to reduce cell volume excursions, based on oocyte permeability data, are suggested.
Department of Obstetrics and Gynecology, University of Wales College of Medicine, Cardiff, UK. paynter@cardiff.ac.uk
S J
SJ
Paynter
L
L
O'Neil
B J
BJ
Fuller
R W
RW
Shaw
D002463:Cell Membrane Permeability / Q000187:drug effects*; D048429:Cell Size; D003451:Cryoprotective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D009865:Oocytes / Q000648:ultrastructure*; D009994:Osmolar Concentration; D009995:Osmosis; D010477:Perfusion; D019946:Propylene Glycol / Q000008:administration & dosage / Q000494:pharmacology*; D013696:Temperature; D014867:Water
D003451:Cryoprotective Agents; D014867:Water; D019946:Propylene Glycol