Neurochemical and neuroprotective effects of some aliphatic propargylamines: new selective nonamphetamine-like monoamine oxidase B inhibitors.
Aliphatic N-propargylamines have recently been discovered to be highly potent, selective, and irreversible monoamine oxidase B (MAO-B) inhibitors. N-Methyl-N-(2-pentyl)propargylamine (M-2-PP) and N-methyl-N-(2-hexyl) propargylamine (2-HxMP), for example, are approximately fivefold more potent that l-deprenyl at inhibiting mouse brain MAO-B activity following oral administration. These inhibitors are nonaromatic compounds and are chemically quite different from other known MAO-B inhibitors. Some of their neurochemical and neuroprotective properties have been evaluated and compared with those of l-deprenyl. We have confirmed that these new inhibitors selectively inhibit MAO-B activity both in vitro and in vivo. 2-Phenylethylamine levels were substantially increased following administration of M-2-PP, but the levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid were not affected except at high, nonselective doses. Chronic oral administration of l-deprenyl and M-2-PP causes selective inhibition of MAO-B activity and increases dopamine levels in mouse caudate. M-2-PP, like l-deprenyl, has been shown to be potent in protecting against MPTP-induced damage in the mouse. N-(2-Chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), a noradrenaline neurotoxin, is not an MAO substrate. Its noradrenaline-depleting effects were substantially mitigated by l-deprenyl as well as by M-2-PP and 2-HxMP in the mouse hippocampus. Administration of 2-phenylethylamine, however, failed to reverse the effect of DSP-4. The neuroprotective effect of M-2-PP and 2-HxMP is apparently unrelated to the uptake of DSP-4.
Yu
P H
PH
Department of Psychiatry, University of Saskatchewan, Saskatoon, Canada.
Davis
B A
BA
Durden
D A
DA
Barber
A
A
Terleckyj
I
I
Nicklas
W G
WG
Boulton
A A
AA
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology; D000588:Amines / Q000378:metabolism; D000662:Amphetamines / Q000494:pharmacology; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism; D002421:Caudate Nucleus / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008995:Monoamine Oxidase / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D009498:Neurotoxins / Q000494:pharmacology; D010293:Pargyline / Q000031:analogs & derivatives* / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism
D000588:Amines; D000662:Amphetamines; D001596:Benzylamines; D002395:Catecholamines; D008996:Monoamine Oxidase Inhibitors; D009498:Neurotoxins; C082737:N-methyl-N-(2-pentyl)propargylamine; D012701:Serotonin; D010293:Pargyline; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D008995:Monoamine Oxidase; C012102:DSP 4