Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
INHIBITION OF TYPE-A MONOAMINE-OXIDASE BY 2(N)-METHYL-6,7-DIHYDROXYISOQUINOLINIUM IONS
Autore:
NAOI M; MARUYAMA W; SASUGA S; DENG YL; DOSTERT P; OHTA S; TAKAHASHI T;
Indirizzi:
NAGOYA INST TECHNOL,DEPT BIOSCI NAGOYA AICHI 466 JAPAN NAGOYA INST TECHNOL,DEPT APPL CHEM NAGOYA AICHI 466 JAPAN NAGOYA UNIV,SCH MED,DEPT NEUROL NAGOYA AICHI 466 JAPAN FARMITALIA CARLO ERBA SPA,RES & DEV I-20159 MILAN ITALY UNIV TOKYO,FAC MED,DEPT BIOCHEM & NUTR TOKYO 113 JAPAN KONAN WOMENS COLL,DEPT FOOD & NUTR KONAN JAPAN
Titolo Testata:
Neurochemistry international
fascicolo: 5, volume: 25, anno: 1994,
pagine: 475 - 481
SICI:
0197-0186(1994)25:5<475:IOTMB2>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
N-METHYLISOQUINOLINIUM ION; STRUCTURALLY RELATED-COMPOUNDS; NORMAL HUMAN BRAINS; INVIVO MICRODIALYSIS; TYROSINE-HYDROXYLASE; TETRAHYDROISOQUINOLINE; ALKALOIDS; N-METHYL-1,2,3,4-TETRAHYDROISOQUINOLINE; PARKINSONISM; METHYLATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
35
Recensione:
Indirizzi per estratti:
Citazione:
M. Naoi et al., "INHIBITION OF TYPE-A MONOAMINE-OXIDASE BY 2(N)-METHYL-6,7-DIHYDROXYISOQUINOLINIUM IONS", Neurochemistry international, 25(5), 1994, pp. 475-481

Abstract

In the human brain, monoamine-derived 6,7-dihydroxy-1,2,3,4-tetrahydroisoquinolines and 1,2,3,4-tetrahydroisoquinolines have been identified and their enzymatic methylation into N(2)-methylisoquinolines has been also confirmed. N-methylated 6,7-dihydroxyisoquinolines were found to be oxidized into 6,7-dihydroxy-N-methylisoquinolinium ions. The effects of the isoquinolinium ions on type A and B monoamine oxidase wereexamined, using enzyme samples isolated from human brain synaptosomalmitochondria. 1,2-Dimethyl-6,7-dihydroxyisoquinolinium ion (N-methylsalsolinium ion) and 2-methyl-6,7-dihydroxyisoquinolinium ion (N-methylnorsalsolinium ion), were found to be potent inhibitors of type A monoamine oxidase. The inhibition was competitive to the substrate, while the isoquinolinium ions were much weaker inhibitors of type B and the inhibition was non-competitive to the substrate. Isoquinolinium ions without catechol structure. N(2)-methylisoquinolinium ion and 1,2-dimethylisoquinolinium ion also inhibited both type A and B monoamine oxidase. 1,2-Dimethylisoquinolinium was the most potent inhibitor among examined isoquinolines, followed by the N-methylsalsolinium ion. The activity-structure relationship of the isoquinolines with and without catechol structure was examined in terms of potency and selectivity of theinhibition to type A and B monoamine oxidase. Catechol structure was found to increase the selectivity of inhibition to type A, as shown bycomparison of N-methylsalsolinium ion with 1,2-dimethylisoquinoliniumion. N-Methylsalsolinium ion inhibited type A MAO more selectively than 1,2-dimethylisoquinolinium ion, which inhibited type A and type B with almost the same values of the inhibitor constant. The selective inhibition of type A monoamine oxidase by catechol isoquinolinium ions may have an important role in the brain function, since the substrates of type A monoamine oxidase are major neurotransmitters in the brain, such as serotonin and norepinephrine. The inhibition of monoamine oxidase by isoquinolinium ions may perturb the levels and function of the monoamines in the brain under physiological and pathological conditions.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 31/03/20 alle ore 21:40:56