Is DOPA a neurotransmitter?

Trends Pharmacol Sci. 2002 Jun;23(6):262-8. doi: 10.1016/s0165-6147(02)02013-8.

Abstract

Historically, 3,4-dihydroxyphenylalanine (DOPA) has been considered to be an inert amino acid that alleviates the symptoms of Parkinson's disease by its conversion to dopamine via the enzyme aromatic L-amino acid decarboxylase. In contrast to this generally accepted idea, we propose that DOPA itself is a neurotransmitter and/or neuromodulator in addition to being a precursor of dopamine. Several criteria such as synthesis, metabolism, active transport, existence, physiological release, competitive antagonism and physiological or pharmacological responses must be satisfied before a compound is accepted as a neurotransmitter. Recent evidence suggests that DOPA fulfills these criteria in its involvement in baroreflex neurotransmission.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Baroreflex / physiology
  • Dihydroxyphenylalanine / antagonists & inhibitors
  • Dihydroxyphenylalanine / metabolism
  • Dihydroxyphenylalanine / physiology*
  • Dopamine / biosynthesis
  • Neurons / metabolism
  • Neurotransmitter Agents / antagonists & inhibitors
  • Neurotransmitter Agents / metabolism
  • Neurotransmitter Agents / physiology*
  • Solitary Nucleus / cytology
  • Solitary Nucleus / metabolism

Substances

  • Neurotransmitter Agents
  • Dihydroxyphenylalanine
  • Dopamine