Enhanced selectivity of pargyline as an inhibitor of type B monoamine oxidase in harmaline-treated rats
1978; Elsevier BV; Volume: 22; Issue: 12 Linguagem: Inglês
10.1016/0024-3205(78)90278-3
ISSN1879-0631
AutoresRay W. Fuller, Susan K. Hemrick,
Tópico(s)Parkinson's Disease Mechanisms and Treatments
ResumoAbstract Pargyline, a slightly selective inhibitor of type B monoamine oxidase (MAO), inhibited phenylethylamine oxidation by 88 ± 1% and 81 ± 1% in rat brain and liver, respectively, at 24 hrs after injection of a 30 mg/kg i.p. dose. Serotonin oxidation was inhibited to a lesser extent, 68 ± 4% and 68 ± 2%, respectively, in brain and liver. In rats treated with harmaline, a short-lasting reversible MAO inhibitor selective for type A MAO, the inhibition of phenylethylamine oxidation after pargyline injection still occurred but the inhibition of serotonin oxidation was prevented. These results illustrate that a selective MAO inhibitor can be used to enhance the selectivity of an irreversible inhibitor, presumably by occupying active sites on a certain form of MAO temporarily and thereby preventing its inactivation. In heart, inhibition of both phenylethylamine and serotonin oxidation by pargyline was prevented by harmaline; this finding supports other evidence that phenylethylamine is metabolized by type A MAO in rat heart.
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