title: Protective effect of the radical scavenger edaravone against methamphetamine-induced dopaminergic neurotoxicity in mouse striatum.
abstract: The administration of high doses of methamphetamine causes the degeneration of striatal dopaminergic fibers in the brains of rodents, and oxidative stress appears to be one of the main factors of neurotoxicity. This study examined whether edaravone, a radical scavenger, protects against methamphetamine-induced neurotoxicity in mice. Methamphetamine treatment (4 mg/kg, s.c. x 4 with 2 h intervals) showed striatal dopaminergic degeneration as observed by decreases in dopamine levels and tyrosine hydroxylase immunoreactivity in the striatum. The neurotoxicity was reduced by edaravone (3 mg/kg, i.p.), when it was administered four times 30 min before methamphetamine at 2 h intervals and additionally four times after methamphetamine at 12 h intervals. An immunohistochemical study showed that methamphetamine increased 3-nitrotyrosine immunoreactivity, an in vivo marker of peroxynitrite production, and activated microglia and astrocytes in the striatum. Edaravone blocked the increase in 3-nitrotyrosine immunoreactivity and the activation of astrocytes, but it did not affect the activation of microglia. Edaravone did not affect methamphetamine-induced hyperthermia and striatal dopamine release. These results suggest that edaravone protects against methamphetamine-induced neurotoxicity in the striatum by blocking peroxynitrite production. This study also suggests that methamphetamine activates microglia in a radical-independent mechanism.
authors.affiliation: Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Kotaro
authors.initials: K
authors.lastname: Ishihara
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ago
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nakamura
authors.forename: Soichi
authors.initials: S
authors.lastname: Itoh
authors.forename: Akemichi
authors.initials: A
authors.lastname: Baba
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D000818:Animals; D000983:Antipyrine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D001831:Body Temperature / Q000187:drug effects; D002452:Cell Count; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000077553:Edaravone; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D008297:Male; D008694:Methamphetamine / Q000633:toxicity*; D051379:Mice; D017628:Microglia / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009638:Norepinephrine / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000378:metabolism; D012007:Rectum / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D005904:Glial Fibrillary Acidic Protein; D030421:Peroxynitrous Acid; D012701:Serotonin; D008694:Methamphetamine; D000077553:Edaravone; D000983:Antipyrine; D004298:Dopamine; D009638:Norepinephrine