scholarly journals The mechanism of the irreversible inhibition of rat liver monoamine oxidase by iproniazid (Marsilid)

1957 ◽  
Vol 67 (2) ◽  
pp. 316-322 ◽  
Author(s):  
A. N. Davison
Keyword(s):  
Monoamine Oxidase ◽  
Rat Liver ◽  
Irreversible Inhibition

scholarly journals Oxidation and enzyme-activated irreversible inhibition of rat liver monoamine oxidase-B by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)

1986 ◽  
Vol 240 (2) ◽  
pp. 379-383 ◽  
Author(s):  
K F Tipton ◽  
J M McCrodden ◽  
M B Youdim
Keyword(s):  
Monoamine Oxidase ◽  
Rat Liver ◽  
Maximum Velocity ◽  
Monoamine Oxidase B ◽  
Half Time ◽  
Inhibitory Process ◽  
Irreversible Inhibitor ◽  
Irreversible Inhibition ◽  
Km Value ◽  
Lower Maximum

The compound 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which produces symptoms resembling Parkinson's disease in humans, acts both as a substrate and an enzyme-activated irreversible inhibitor of the B-form of monoamine oxidase from rat liver. Analysis of the inhibitory process showed the compound to be considerably more efficient as a substrate than as an irreversible inhibitor, with about 17000 mol of product being formed per mol of enzyme inactivated. The half-time of the inhibitory process was about 22 min. With the A-form of the enzyme, the compound had a lower Km value and a considerably lower maximum velocity than the corresponding values obtained with the B-form. Under the conditions used in the present work the inhibition of the A-form of the enzyme was largely reversible.

scholarly journals Irreversible inhibition of putrescine-stimulated S-adenosyl-l-methionine decarboxylase by berenil and pentamidine

1985 ◽  
Vol 231 (1) ◽  
pp. 165-169 ◽  
Author(s):  
E Karvonen ◽  
L Kauppinen ◽  
T Partanen ◽  
H Pösö
Keyword(s):  
Rat Liver ◽  
Single Injection ◽  
Adenosylmethionine Decarboxylase ◽  
Irreversible Inhibition ◽  
Drug Concentrations ◽  
Bacterial Enzyme ◽  
Azo Group ◽  
Benzene Rings ◽  
Normal Rat

The putrescine-stimulated S-adenosyl-L-methionine decarboxylases from rat liver and yeast were strongly inhibited by Berenil and to a lesser extent by Pentamidine. Ten times greater drug concentrations were needed to achieve a similar level of inhibition of a Mg2+-stimulated bacterial enzyme. The inhibition was irreversible in that extensive dialyses or precipitation with (NH4)2SO4 did not restore enzyme activity. Putrescine did not protect the enzyme against Berenil, but adenosylmethionine either alone or with putrescine partially protected the irreversible action of Berenil. The compound 4,4′-diamidinodiphenylamine, which differs from Berenil only in lacking the azo group between benzene rings, was a weaker inhibitor than Berenil, and its inhibition was reversible. Berenil also inhibited the activity of adenosylmethionine decarboxylase in vivo, by depressing the activity of the enzyme in normal rat liver, for at least 24 h after a single injection (50 mg/kg body wt.) of the drug.

The oxidation of dopamine and epinine by the two forms of monoamine oxidase from rat liver

1998 ◽  
pp. 233-238 ◽  
Author(s):  
M. Strolin Benedetti ◽  
G. Sanson ◽  
L. Bona ◽  
M. Gallina ◽  
S. Persiani ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Rat Liver
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