Miho C. Emoto1, Hideo Sato-Akaba2, Hiroshi Hirata3, Hirotada G. Fujii1
1Center for Medical Education, Sapporo Medical University, Sapporo, Hokkaido, Japan; 2Graduate School of Engineering Science, Osaka University; 3Graduate School of Information Science and Technology, Hokkaido University
EPR imaging using nitroxides is a powerful non-invasive method for visualizing the quantification of redox status caused by free radicals in vivo. 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (HMP) and 3-methoxycarbonyl-2,2,5,5-tetramethyl-pirrolidine-1-yloxy (MCP) are widely used as blood-brain barrier-permeable nitroxide probes. In this study, their distributions in a mouse brain and their time courses to enter the brain were compared using our newly developed EPR imaging system and by MRI. The EPR imaging results revealed that MCP was more concentrated in the brain than HMP and that MCP entered the brain more rapidly than HMP after their administration to mice.