title: A spatiotemporal study on the distribution of intraperitoneally injected nitroxide radical in the rat head using an in vivo ESR imaging system.
abstract: 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.
authors.affiliation: Institute for Life Support Technology, Yamagata Technopolis Foundation, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yokoyama
authors.forename: T
authors.initials: T
authors.lastname: Ogata
authors.forename: N
authors.initials: N
authors.lastname: Tsuchihashi
authors.forename: M
authors.initials: M
authors.lastname: Hiramatsu
authors.forename: N
authors.initials: N
authors.lastname: Mori
mesh_terms: 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
chemical_list: D005609:Free Radicals; D009589:Nitrogen Oxides; C039900:nitroxyl