TY - JOUR
T1 - Metabolism of the Nigrostriatal Toxin 1-Methyl-4-phenyl-l, 2, 3, 6-tetrahydropyridine by Liver Homogenate Fractions
AU - Weissman, Jeff
AU - Trevor, Anthony
AU - Chiba, Kan
AU - Peterson, Lisa A.
AU - Caldera, Patricia
AU - Castagnoli, Neal
AU - Baillie, Thomas
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1985/8
Y1 - 1985/8
N2 - The metabolic fate of the nigrostriatal toxin 1-methyl-4-phenyl-l, 2, 3, 6-tetrahydropyridine (MPTP) has been examined in rat and rabbit liver mitochondrial and rabbit liver microsomal preparations. The mitochondrial preparations rapidly oxidized MPTP, in a pargyline-sensitive reaction, to a polar material that was shown to contain the 1-methyl-4-phenylpyridinium species as the principal product. NADPH-supplemented microsomal preparations converted MPTP to two principal products: 4-phenyl-l, 2, 3, 6-tetrahydropyridine and 1-methyl-4-phenyl-l, 2, 3, 6-tetrahydropyridine N-oxide. Carbon monoxide and SKF 525A selectively inhibited the oxidation of MPTP to the nor compound, indicating that this N-demethylation reaction is cytochrome P-450 catalyzed. Attempts to trap possible unstable iminium metabolites of MPTP in microsomal incubation mixtures with sodium cyanide led to the isolation of a monocyano adduct that proved to be the N-cyanomethyl derivative. Thus, hepatic mitochondrial and microsomal enzyme systems catalyze the oxidation of MPTP by different pathways, the former leading to the generation of species that may possess neurotoxic properties.
AB - The metabolic fate of the nigrostriatal toxin 1-methyl-4-phenyl-l, 2, 3, 6-tetrahydropyridine (MPTP) has been examined in rat and rabbit liver mitochondrial and rabbit liver microsomal preparations. The mitochondrial preparations rapidly oxidized MPTP, in a pargyline-sensitive reaction, to a polar material that was shown to contain the 1-methyl-4-phenylpyridinium species as the principal product. NADPH-supplemented microsomal preparations converted MPTP to two principal products: 4-phenyl-l, 2, 3, 6-tetrahydropyridine and 1-methyl-4-phenyl-l, 2, 3, 6-tetrahydropyridine N-oxide. Carbon monoxide and SKF 525A selectively inhibited the oxidation of MPTP to the nor compound, indicating that this N-demethylation reaction is cytochrome P-450 catalyzed. Attempts to trap possible unstable iminium metabolites of MPTP in microsomal incubation mixtures with sodium cyanide led to the isolation of a monocyano adduct that proved to be the N-cyanomethyl derivative. Thus, hepatic mitochondrial and microsomal enzyme systems catalyze the oxidation of MPTP by different pathways, the former leading to the generation of species that may possess neurotoxic properties.
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U2 - 10.1021/jm00146a005
DO - 10.1021/jm00146a005
M3 - Article
C2 - 3874963
AN - SCOPUS:0021819789
SN - 0022-2623
VL - 28
SP - 997
EP - 1001
JO - Journal of medicinal chemistry
JF - Journal of medicinal chemistry
IS - 8
ER -