Modulation of dihydroxyphenylacetaldehyde extracellular levels in vivo in the rat striatum after different kinds of pharmacological treatment

Francesco Fornai, Filippo S. Giorgi, Lucia Bassi, Michela Ferrucci, Maria G. Alessandrì, Giovanni U. Corsini

Research output: Contribution to journalArticle

Abstract

We recently identified the direct product of dopamine (DA) by monoamine- oxidase (MAO) activity, dihydroxyphenylacetaldehyde (DOPALD) in the trans- striatal dialysate. Based on these findings, in this work, we directly measured the variations in DOPALD levels after various kinds of pharmacological treatment in rat striatal extracellular fluid. Using both reversible and irreversible MAO inhibitors, we found that MAO-A inhibition suppressed, whereas MAO-B inhibition did not modify DOPALD levels in the dialysate. The vesicular DA uptake blocker Ro 4-1284 led to an increase in extracellular DA and DOPALD, whereas the increase in extracellular DA obtained after administration of the plasma membrane DA uptake blocker GBR- 12909 occurred without concomitant changes in DOPALD extracellular levels. Microinfusions of DA through the dialysis probe or systemic administration of L-DOPA increased striatal DOPALD to a greater extent compared with other DA metabolites, both in intact and in 6-hydroxydopamine (6-OHDA)-lesioned striatum. This study indicates that the direct product of MAO activity within the rat striatum derives from the activity of the isoenzyme MAO-A. The assay of DOPALD, together with DOPAC, represents a reliable tool to measure directly, in freely moving animals, DA oxidative metabolism. As recent studies have shown that microinfusions of exogenous DOPALD might induce cell death, pharmacological modulation of DOPALD levels might also be relevant for an understanding of the mechanisms involved in DA neurotoxicity. (C) 2000 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)126-134
Number of pages9
JournalBrain Research
Volume861
Issue number1
DOIs
Publication statusPublished - Apr 7 2000

Keywords

  • Dihydroxyphenylacetaldehyde
  • DOPALD
  • Dopamine
  • Dopamine metabolism
  • L- DOPA
  • Monoamine oxidase

ASJC Scopus subject areas

  • Neuroscience(all)

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