Endogenous monoamine oxidase inhibitor-like substances in monkey brain.
The extraction and partial purification of endogenous "monoamine oxidase (MAO) inhibitor-like" material from the monkey brain are described. The endogenous material (F-1 and F-2) obtained after Bio-Gel P-2 gel filtration and silica column chromatography inhibited MAO in the monkey brain mitochondria toward 5-hydroxytryptamine (5-HT), beta-phenylethylamine (beta-PEA), tyramine and dopamine as substrates. The inhibitory effects of F-1 and F-2 were non-linear concentration dependent, and F-1 non-competitively inhibited A-form MAO, while F-2 inhibited A-form MAO competitively and inhibited B-form MAO non-competitively. These substances were more potent inhibitors of A-form than of B-form MAO. F-2 was heat stable but liable to the treatment with pepsin and trypsin. F-1 was not inactivated by heat treatment and digestion with pepsin and trypsin. F-1 may be a low molecular weight (less than 1350) compound, including certain monoamines or their metabolites or other unidentified compounds, while F-2 was a low molecular weight (about 2500) peptide.
Egashira
T
T
Department of Pharmacology, Medical College of Oita, Japan.
Obata
T
T
Nagai
T
T
Kimba
Y
Y
Takano
R
R
Yamanaka
Y
Y
D000818:Animals; D001923:Brain Chemistry; D002850:Chromatography, Gel; D000882:Haplorhini; D008928:Mitochondria / Q000201:enzymology; D008970:Molecular Weight; D008996:Monoamine Oxidase Inhibitors / Q000302:isolation & purification*; D010627:Phenethylamines / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D013379:Substrate Specificity
D008996:Monoamine Oxidase Inhibitors; D010627:Phenethylamines; C029261:phenethylamine; D012701:Serotonin