Measurement of pO₂ in cultured mouse oocytes using electron paramagnetic resonance oximetry

抄録

We investigated the feasibility of measuring the partial pressure of oxygen (pO₂) in cultured mouse oocytes by electron paramagnetic resonance (EPR) oximetry. Approximately 15 pL (0.015 μL) of Ox063, an oxygen-sensing paramagnetic material, at a concentration of 500 mM was injected into the ooplasm of mouse oocytes. When one, five and 20 oocytes were used, the sample of 20 oocytes was sufficient to yield an effective EPR spectrum for determining the pO₂. The mean pO₂ levels in oocytes cultured under tensions of 5 and 20% O₂ were 60.2 and 153.1 mmHg, respectively. The present study indicates that it is possible to utilize EPR oximetry with Ox063 for the measurement of pO₂ in cultured oocytes.