The acute effect of the bioprecursor of the selective brain MAO-A inhibitor, MDL 72392, on rat pineal melatonin biosynthesis
The bioprecursor amino acid MDL 72394 is decarboxylated by aromatic L-amino acid decarboxylase (AADC) to liberate MDL 72392, an irreversible selective MAO-A inhibitor. Pretreatment with the AADC inhibitor carbidopa, which does not penetrate the brain-blood barrier, prevents the liberation of the MAO-A inhibitor outside the brain and results in exclusive inhibition of brain MAO-A. We found that systemic administration of MDL 72394 (0.5 mg/kg, i.p.) stimulated rat pineal melatonin biosynthesis. Carbidopa, in a dose-dependent manner, attenuated or completely prevanted MDL-induced stimulation of melatonin biosynthesis in the pineal gland located outside the blood-brain-barrier.
KeywordsSystemic Administration Monoamine Oxidase Pineal Gland Melatonin Level Pineal Melatonin
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- Oxenkrug GF (1991) The acute effect of monoamine oxidase inhibitors on serotonin conversion to melatonin. In: Coppen X, Sandier M, Harnett S (eds) 5-Hydroxy-tryptamine and mental illness. Oxford University Press, New York, pp 99–108.Google Scholar
- Oxenkrug GF, McCauley R, McIntyre IC, Filipowicz C (1984) Effect of clorgyline and deprenyl on rat pineal melatonin. J Pharm Pharmacol 36: 5SW.Google Scholar
- Palfreyman MG, McDonald IA, Fozard JR, Mely Y, Sleight AJ, Zreika M, Wagner J, Bey P, Lewis PJ (1985) Inhibition of monoamine oxidase selectively in brain monoamine nerves using the bioprecursor (E)-ß-fluoromethylene-m-tyrosine (MDL 72394), a substrate for aromatic L-amino acid decarboxylase. J Neurochem 45: 1850–1860.PubMedCrossRefGoogle Scholar