title: Biological spin trapping. II. Toxicity of nitrone spin traps: dose-ranging in the rat.
abstract: To obtain the strongest possible free radical spin adduct signal using the electron paramagnetic resonance spectroscopy-spin trapping technique, it is desirable to load an animal with the highest dose of spin trap possible. One hundred and twenty six male Sprague-Dawley rats were used to establish the toxic dose range for PBN (alpha-phenyl N-tert butyl nitrone) and 18 other similar spin traps. The lethal dose of PBN was found to be approximately 100 mg/100 g BW (0.564 mmol/100 g. The 18 other compounds were then tested, and their toxicities were gauged in terms of molar equivalents to PBN. Of these spin traps, DMPO (5,5-dimethyl-1-pyrroline-N-oxide) was found to be the least toxic (no toxic signs at twice the lethal dose for PBN) while 2,6-difluoro-PBN and M4PO (3,3,5,5-tetramethyl-1-pyrroline-N-oxide) were the most toxic, both causing death at one eighth the PBN-equivalent lethal dose. Nine of the 18 nitrones appeared non-toxic at the 0.25 PBN-equivalent lethal dose level.
authors.affiliation: National Biomedical Center for Spin Trapping and Free Radicals, Oklahoma Medical Research Foundation, Oklahoma City 73104, USA.
authors.forename: E G
authors.initials: EG
authors.lastname: Janzen
authors.forename: J L
authors.initials: JL
authors.lastname: Poyer
authors.forename: C F
authors.initials: CF
authors.lastname: Schaefer
authors.forename: P E
authors.initials: PE
authors.lastname: Downs
authors.forename: C M
authors.initials: CM
authors.lastname: DuBose
mesh_terms: D000818:Animals; D003497:Cyclic N-Oxides / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009589:Nitrogen Oxides / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013113:Spin Labels
chemical_list: D003497:Cyclic N-Oxides; D009589:Nitrogen Oxides; D013113:Spin Labels; C051831:3,3,5,5-tetramethyl-1-pyrroline N-oxide; C029217:phenyl-N-tert-butylnitrone; C017245:5,5-dimethyl-1-pyrroline-1-oxide