Figure 1.

Alterations in GSH levels in the penumbra and the ischemic core measured by two-photon microscopy. (A) Standard curve of GSH concentration (see Supplementary information for detailed method). (B) 2,3,5-Triphenyltetrazolium chloride-stained rat brain coronal section. Numbered square areas represent locations of imaging (see Supplementary information for detailed method). (C) Kinetic monitoring of MCB labeling in contralateral (AOI #2), penumbra (AOI #2^*), and core (AOI #1^*). (D) Representative images ( × 20) of MCB-GSH fluorescence at contralateral side (AOIs #1 to 3), ischemic core (AOI #1^*), penumbra (AOI #2^*), and ipsilateral normal control (AOI #3^*) after 90 mins ischemia (middle cerebral artery occlusion) and 24 h reperfusion. In the penumbra area, blue brace points to core and red brace points to normal tissue. Contralateral side AOIs (#1 to 3) and ipsilateral AOI (#3) were normal tissues and selected as normal control. (E) Averaged GSH concentrations in cell bodies from the selected regions of ischemic brains. (F) Representatives of high magnification images ( × 60) show fluorescence intensities, representing GSH levels, in neuropil: left panel, normal tissue (AOI #2); right panel, penumbra (AOI #2^*). GSH concentration in penumbral neuropil (0.45±0.07 mmol/L) was significantly higher than in contralateral tissue from the contralateral side (0.25±0.04 mmol/L), and in ischemic core it decreased to 0.13±0.01 mmol/L. Results in E are expressed in box-whiskers (n=10 animals, averaged three slices for each animal). ^**P<0.01 compared with contralateral side.