Inhibition of rat brain monoamine oxidase activity by cerebral anti-ischemic agent, ifenprodil.
Ifenprodil, which is clinically used as a cerebral vasodilator, inhibited rat brain type A (MAO-A) and type B (MAO-B) monoamine oxidase activity. It did not, however, affect rat lung semicarbazide-sensitive amine oxidase. The degree of inhibition of either form of MAO was not changed by 30 min preincubation of the enzyme preparations at 37 degrees C with ifenprodil. Modes of inhibition of MAO-A and MAO-B by ifenprodil were competitive towards oxidation of their respective substrates, 5-hydroxytryptamine and benzylamine, with Ki values of 75 microM for inhibition of MAO-A and 110 microM for inhibition of MAO-B.
Department of Pharmacology, School of Medicine, Showa University, Tokyo, Japan.
Y
Y
Arai
K
K
Nakazato
H
H
Kinemuchi
T
T
Tadano
N
N
Satoh
K
K
Oyama
K
K
Kisara
D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D008168:Lung / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014665:Vasodilator Agents / Q000494:pharmacology*
D008996:Monoamine Oxidase Inhibitors; D010880:Piperidines; D014665:Vasodilator Agents; D006631:Amine Oxidase (Copper-Containing); D008995:Monoamine Oxidase; C010739:ifenprodil