Figure 1.

Internal levels of H₂O₂ and intracellular intake of H₂O₂ in ρ⁰ cells. A, Temporal change of H₂O₂ after treatment with H₂O₂ in ρ⁰ and parental cells using HYDROP™. In ρ⁰ cells, the relative H₂O₂ intensity was increased after treatment with H₂O₂ for 1 h. B, The intracellular intake of H₂O₂ was detected using a stable isotope_. Cells were subjected to 50 μmol/L of H₂O₂ ¹⁸O₂ solution, and the content of ¹⁸O₂ was measured using stable isotope‐ratio mass spectrometry. In ρ⁰ cells, the intake of H₂O₂ was significantly higher than that observed in parental cells after treatment. The results are expressed as the mean ± SEM. **P < .01 using Student's t test