ESR imaging of the rat brain with a nitroxide radical perfused by in vivo microdialysis.
We report here our investigation of the spatial distribution of free radicals using an electron spin resonance (ESR)-imaging system combined with an in vivo brain microdialysis method, which was performed in the resonator of the ESR-imaging system. A nonmagnetic cannula, newly developed in this study, was used for the perfusion of the exogenous free radicals agent. A nitroxide, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (carbamoyl PROYXL), was used as the imaging agent in saline solution at a concentration of 0.3 M, which was perfused into the right caudate putamen of the rat at 2 microliters/min by a microinfusion pump. Two-dimensional ESR projection of the Z-X plane, which was clearly distinguished (about phi 10 mm) from the nonperfused brain area, was obtained 6 h after the beginning of perfusion of carbamoyl PROXYL. The present method is considered to be a useful tool to introduce stable free radicals into a specific area of the brain.
Ueda
Y
Y
Institute for Life Support Technology, Yamagata Technopolis Foundation, Japan.
Yokoyama
H
H
Ohya-Nishiguchi
H
H
Kamada
H
H
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002404:Catheterization / Q000295:instrumentation; D003497:Cyclic N-Oxides / Q000008:administration & dosage; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005609:Free Radicals / Q000378:metabolism; D005898:Glass; D007260:Infusion Pumps; D008297:Male; D017551:Microdialysis / Q000295:instrumentation; D008872:Microwaves; D009339:Needles; D009589:Nitrogen Oxides / Q000378:metabolism*; D011699:Putamen / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013113:Spin Labels; D013238:Stereotaxic Techniques
D000975:Antioxidants; D003497:Cyclic N-Oxides; D005609:Free Radicals; D009589:Nitrogen Oxides; D013113:Spin Labels; C012517:proxyl nitroxide; C039900:nitroxyl