Fig. 4. Mouse kidneys were subjected to ischemia for 1 h, and reperfusion for various times ((a–e) 0, 0.5, 1, 1.5, 2 h), then the mice were injected with 0.2 mL of 1.0 mM NCNO and incubated for 10 min. (f) The mice kidneys were subjected to ischemia for 1 h, and then reperfusion for 2 h and injected with 0.2 mL of 1.0 mM NCNO together with 1.0 mM carboxyl-PTIO. (g) The relative fluorescence intensity for TP images (a–f). The two-photon excitation wavelength was 830 nm, and the fluorescence emission was collected at 600–700 nm. Scale bar, 50 μm.