title: N-methyl-4-phenylpyridine (MMP+) together with 6-hydroxydopamine or dopamine stimulates Ca2+ release from mitochondria.
abstract: The nigrostriatal neurotoxin N-methyl-1,2,3,6-tetrahydropyridine (MPTP) causes Parkinsonism in humans and laboratory animals. MPTP neurotoxicity is dependent on its oxidation to N-methyl-4-phenylpyridine (MPP+). The mechanism by which MPP+ causes destruction of dopamine-containing nigrostriatal cells is unknown. Here we show that MPP+ but not MPTP is taken up by energized mitochondria. MPP+ in the presence of dopamine and particularly of 6-hydroxydopamine stimulates Ca2+ release from mitochondria. Ca2+ release is accompanied by hydrolysis of intramitochondrial pyridine nucleotides. Our findings suggest that the MPTP-induced model of Parkinson's disease may be due to a disturbed Ca2+ homeostasis in dopamine neurons.
authors.forename: B
authors.initials: B
authors.lastname: Frei
authors.forename: C
authors.initials: C
authors.lastname: Richter
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D015655:1-Methyl-4-phenylpyridinium; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D004298:Dopamine / Q000494:pharmacology*; D004533:Egtazic Acid / Q000494:pharmacology; D005260:Female; D006892:Hydroxydopamines / Q000494:pharmacology*; D066298:In Vitro Techniques; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D016627:Oxidopamine; D010302:Parkinson Disease, Secondary / Q000139:chemically induced; D011725:Pyridines / Q000378:metabolism / Q000633:toxicity; D011726:Pyridinium Compounds / Q000378:metabolism / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D006892:Hydroxydopamines; D011725:Pyridines; D011726:Pyridinium Compounds; D009243:NAD; D004533:Egtazic Acid; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D016627:Oxidopamine; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D015655:1-Methyl-4-phenylpyridinium; D002118:Calcium; D004298:Dopamine