Details

Autor(en) / Beteiligte

• Paynter, S.J.
• Cooper, A.
• Gregory, L.
• Fuller, B.J.
• Shaw, R.W.

Titel

Permeability characteristics of human oocytes in the presence of the cryoprotectant dimethylsulphoxide

Ist Teil von

• Human reproduction (Oxford), 1999-09, Vol.14 (9), p.2338-2342

Ort / Verlag

Oxford: Oxford University Press

Erscheinungsjahr

1999

Link zum Volltext

Quelle

Oxford Journals 2020 Medicine

Beschreibungen/Notizen

• Equilibration of oocytes with cryoprotectants is a prerequisite of low temperature storage. However, cryoprotectant exposure may induce damage via osmotic stress. Knowledge of cell membrane permeability characteristics and their temperature dependence would facilitate the design of cryopreservation protocols in which osmotic stress is minimized and the incidence of intracellular freezing is reduced. To obtain such data, the volume change of donated human oocytes following exposure to cryoprotectant was measured at a variety of temperatures. After removal of cumulus cells, each oocyte was placed in a 5 μl droplet of phosphate-buffered medium. The oocyte was held in position by suction generated using a fine pipette and perfused with 1 ml 1.5 mol/l dimethylsulphoxide (DMSO) at 30, 24 or 10°C. The volume of the oocyte before, during and after perfusion was recorded by videomicroscopy. Oocyte volume was calculated from radius measurements and the Kedem–Katchalsky (K–K) passive coupled transport coefficients, namely Lp (hydraulic permeability), PDMSO (permeability to DMSO) and σ (reflection coefficient) were derived. The resulting coefficients were Lp = 1.65 ± 0.15, 0.70 ± 0.06 and 0.28 ± 0.04 μm/min.atm; PDMSO = 0.79 ± 0.10, 0.25 ± 0.04 and 0.06 ± 0.01 μm/s and σ = 0.97 ± 0.01, 0.94 ± 0.03 and 0.96 ± 0.01 at 30, 24 and 10°C respectively. The activation energy for Lp was 14.70 and for PDMSO was 20.82 kcal/mol. The permeability parameters of human oocytes are higher than those of murine oocytes, suggesting that they require a shorter period of exposure to DMSO with concomitantly reduced toxic effects.