Oxygen inhalation enhances striatal dopamine metabolism and monoamineoxidase enzyme inhibition prevents it: A microdialysis study

Yushi U. Adachi, Kazuhiko Watanabe, Hideyuki Higuchi, Tetsuo Satoh, E. Sylvester Vizi

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

In order to explore the effect of normobaric oxygen on the extracellular level of dopamine and its metabolites, oxygen (30, 60 and 90%) was administered to freely moving rats after the animals had been pretreated with either monoamineoxidase (MAO)-A and -B inhibitors (0.1 or 1 mg kg -1 of clorgyline, 1 or 10 mg kg -1 of selegiline and 75 mg kg -1 pargyline) or control solution. The levels of dopamine and its metabolites were monitored in microdialysis samples collected every 20 min and directly applied to an on-line high-performance liquid chromatograph combined with electrochemical detection. Normobaric oxygen inhalation decreased the level of extracellular dopamine and increased that of 3,4-dihydroxyphenylacetic acid (DOPAC) in a concentration-dependent manner. These changes were partly prevented by pre-treatment with low doses of selegiline or clorgyline, i.e. by conditions in which monoamineoxidase-A or -B was inhibited. When both isoforms of monoamineoxidase were inhibited, there was a drastic increase in extracellular concentrations of dopamine and 3-methoxytyramine, and the levels of DOPAC and homovanilic acid (HVA) were very low. These results indicate that the intracellular metabolism of cytoplasmic dopamine is enhanced by normobaric hyperoxia in rat striatum.

Original languageEnglish
Pages (from-to)61-68
Number of pages8
JournalEuropean Journal of Pharmacology
Volume422
Issue number1-3
DOIs
Publication statusPublished - Jun 22 2001

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Keywords

  • (Rat)
  • Dopamine
  • Monoamineoxidase inhibition
  • Normobaric oxygen
  • Striatum

ASJC Scopus subject areas

  • Pharmacology

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