Hyperpolarized 13C-MRI of DMPO and NAC for evaluating oxidative stress in living animal

5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) is used to detect reactive oxygen species in vitro, and N-acetyl-L-cysteine (NAC) is an antioxidant. We synthesized ¹³C-labeled DMPO and NAC, and investigated feasibility of hyperpolarized ¹³C-DMPO and ¹³C-NAC for evaluating oxidative stress in mice. Hyperpolarized ¹³C-DMPO and ¹³C-NAC provided a single peak at 76 ppm and 174 ppm, respectively, and the T₁ relaxation time was sufficiently long to apply them for mouse imaging. The signals ¹³C-DMPO and ¹³C-NAC were also detected in a mouse body after intravenous injection. The results showed ¹³C-DMPO and ¹³C-NAC can be applied to some disease models to evaluate oxidative stress in vivo.