title: In vivo temporal EPR study using a region-selected intensity determination method to estimate cerebral reducing ability in rats treated with olanzapine.
abstract: Region-selected intensity determination (RSID) is a method for obtaining the temporal changes in electron paramagnetic resonance (EPR) signal intensity from a target region, without the use of complicated procedures employed in the conventional imaging methods. An in vivo 700-MHz radio frequency EPR spectrometer equipped with a bridged loop-gap resonator was used with the RSID method to estimate intracerebral reducing ability in the rat following acute administration of olanzapine (OZP) or haloperidol (HPD). To this end, temporal changes in EPR signal intensity of target regions (the striatum and the prefrontal cortex) of rats which had received a blood-brain-barrier-permeable nitroxide radical (3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl) via an intravenous route were observed. The half-lives of EPR signal intensity in both regions of OZP- or HPD-treated rats were significantly longer than in control animals. This indicated that reducing abilities of the striatum and cerebral cortex decreased in the rats to which either OZP or HPD had been acutely administered.
authors.affiliation: Department of Pharmaceutical Sciences, International University of Health and Welfare, Otawara 324-8501, Japan. yokohide@iuhw.ac.jp
authors.forename: Hidekatsu
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Ishida
authors.forename: Tateaki
authors.initials: T
authors.lastname: Ogata
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000378:metabolism*; D001569:Benzodiazepines / Q000378:metabolism*; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D003497:Cyclic N-Oxides / Q000008:administration & dosage; D004578:Electron Spin Resonance Spectroscopy; D006207:Half-Life; D006220:Haloperidol / Q000378:metabolism; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D023421:Models, Animal; D000077152:Olanzapine; D010084:Oxidation-Reduction; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D011759:Pyrrolidines; D051381:Rats; D017208:Rats, Wistar
chemical_list: D014150:Antipsychotic Agents; D003497:Cyclic N-Oxides; D011759:Pyrrolidines; D001569:Benzodiazepines; C050260:3-hydroxymethyl-2,2,5,5-tetramethylpyrroline-N-oxyl; D006220:Haloperidol; D000077152:Olanzapine