A spatiotemporal study on the distribution of intraperitoneally injected nitroxide radical in the rat head using an in vivo ESR imaging system.
We have developed a rapid-scan in vivo electron spin resonance (ESR) imaging system operating at 700 MHz based on an air-cored two-coil Helmholtz designed resistive magnet. Using this system, we performed ESR-CT for the intraperitoneally injected nitroxide radical, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl, in the rat head. The imaging data were collected over the time course range from 5 to 47 min after injection at an interval of 3 min and a series of ESR-CT images were reconstructed at the same slice plane (1 cm anterior to interaural line). The series of ESR-CT images thus obtained by rapid scans provided detailed spatiotemporal information on the distribution of the injected nitroxide radical in the rat head. The brain was imaged as a nitroxide-deficient area while the blood vessels and/or extracranium tissues as a nitroxide-rich area. During periods when high intensities of ESR signals were maintained, spots of nitroxide-accumulation were imaged at the central part of the brain. The spots were assigned to the middle sized blood vessels in the brain.
Yokoyama
H
H
Institute for Life Support Technology, Yamagata Technopolis Foundation, Japan.
Ogata
T
T
Tsuchihashi
N
N
Hiramatsu
M
M
Mori
N
N
D000818:Animals; D001921:Brain / Q000378:metabolism*; D055590:Electromagnetic Phenomena; D004583:Electrons; D005609:Free Radicals / Q000008:administration & dosage / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009589:Nitrogen Oxides / Q000008:administration & dosage / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014057:Tomography, X-Ray Computed
D005609:Free Radicals; D009589:Nitrogen Oxides; C039900:nitroxyl